From the Department of Neurosurgery Helsinki University Central Hospital University of Helsinki Helsinki, Finland
Lateral Supraorbital Approach - Simple, Clean, and Preserving Normal Anatomy
Rossana Romani
Academic Dissertation
To be presented with the permission of the Faculty of Medicine of the University of Helsinki For Public Discussion in the Lecture Hall 1 of Töölö Hospital, Helsinki On November 11th, 2011 at 12.00 o’clock noon
Helsinki 2011
1 Supervised by:
Juha Hernesniemi, M.D., Ph.D., Professor and Chairman Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland
Aki Laakso, M.D., Ph.D., Associate Professor Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland
Marko Kangasniemi, M.D., Ph.D., Associate Professor Helsinki Medical Imaging Center, Helsinki University Central Hospital, Helsinki, Finland
Reviewed by:
Esa Heikkinen, M.D., Ph.D., Associate Professor Department of Neurosurgery, Oulu University Hospital, Oulu, Finland
Esa Kotilainen, M.D., Ph.D., Associate Professor Department of Neurosurgery, Turku University Central Hospital, Turku, Finland
To be discussed with:
Roberto Delfini, M.D., Ph.D., Professor and Chairman of Neurosurgery Department of Neurology and Psychiatry, University of Rome, “Sapienza”, Rome, Italy
1st Edition 2011 © Rossana Romani 2011 Cover Drawings: Front © Rossana Romani 2011, Back © Roberto Crosa 2011 ISBN 978-952-10-7253-6 (paperback) ISBN 978-952-10-7254-3 (PDF) http://ethesis.helsinki.fi/ Unigrafia Helsinki Helsinki 2011
2 To my mother
3 Author’s contact information:
Rossana Romani Department of Neurosurgery Helsinki University Central Hospital Topeliuksenkatu 5 00260 Helsinki Finland Mobile: +358 50 427 0718 Fax: +358 9 471 87560 e-mail: [email protected]
4 Table of Contents
ABSTRACT...... 9
ABBREVIATIONS ...... 12
LIST OF ORIGINAL PUBLICATIONS ...... 13
1 INTRODUCTION...... 14
2 REVIEW OF THE LITERATURE...... 15
History of Craniotomy ...... 15 Pre-Historic and Classic Eras...... 15 Neolithic Era (8000 BC) ...... 15 Classic Era...... 16 Medieval Period ...... 18 Renaissance and the 18th Century...... 18 19th Century and the Osteoplastic Craniotomy...... 18 Fedor Krause and the Unilateral Frontal Osteoplastic Craniotomy...... 19 Sir Victor Horsley: From the Transfrontal Route to the Subtemporal Approach...... 20 Francesco Durante: The First Olfactory Groove Meningioma Surgery through Unilateral Frontal Osteoplastic Craniotomy...... 20 20th Century and the Macrosurgical Period...... 21 Cushing and “The Special Field of Neurological Surgery”...... 21 Ludvig Puusepp and the First School of Surgical Neurology...... 22 Otto George Theobald Kiliani and the Bifrontal Osteoplastic Craniotomy...... 23 Louis Linn McArthur and Charles Frazier and the First Fronto-Orbital Osteoplastic Craniotomy...... 23 Walter Dandy and the Frontotemporal Craniotomy...... 24 The Leadership of Herbert Olivecrona...... 26 Aarno Snellman and the Craniotomy in Finland...... 29 20th Century and the Microsurgical Leadership of Ya2argil...... 34
Microsurgical Anatomy of Anterior Skull Base ...... 36 Bone Structures...... 36 Anterior Cranial Fossa ...... 36 Lamina Cribrosa of the Ethmoid Bone...... 36 Olfactory Fossa...... 37 Sphenoid Bone ...... 37 Superior Orbital Fissure...... 38 Anterior Clinoid Process ...... 38 Vascular and Dural Structures...... 39 Ophthalmic Segment of the ICA and Dural Rings...... 39 Arterial Supply to the Dura Mater of the Anterior Cranial Fossa ...... 40 Arterial Supply to the Dura of the Anterior Clinoid Process...... 41 Classical Approaches to Anterior Skull Base...... 42 Pterional Approach ...... 42 Fronto-Orbital and Fronto-Orbitozygomatic Approaches ...... 43 Bifrontal Approach ...... 45 Frontolateral Approach ...... 46 Meningiomas: General Concepts ...... 47 General Principles of Meningioma Surgery...... 47 Clinical Characteristics of Olfactory Groove, Anterior Clinoidal, and Tuberculum Sellae Meningiomas ...... 48 Microsurgical Treatment of OGM, ACM, and TSM through Classical Surgical Approaches ...... 50 Olfactory Groove Meningiomas...... 50
5 Anterior Clinoidal Meningiomas...... 53 Tuberculum Sellae Meningiomas ...... 56 Outcome of OGM, ACM, and TSM through Pterional, Orbitozygomatic, and Bifrontal Approaches...... 59 Olfactory Groove Meningiomas...... 59 Anterior Clinoidal Meningiomas...... 60 Tuberculum Sellae Meningiomas ...... 61 Recurrences of OGM, ACM, and TSM when Using Classical Approaches ...... 62
Anterior Clinoidectomy ...... 63 Anterior Clinoidectomy through Pterional or Orbitozygomatic Approach...... 65
Anesthesiological Procedures...... 66
3 AIMS OF THE STUDY ...... 67
4 PATIENTS AND METHODS...... 68
Treatment of OGM, ACM, TSM through LSO Approach (Publications I-IV)...... 68 Patients and Imaging ...... 68 Intraoperative Videos ...... 70 Anesthesia Records ...... 70 Follow-up ...... 71 Statistical Analysis ...... 71
Anterior Clinoidectomy through LSO Approach (Publications V and VI) ...... 72 Patients and Imaging ...... 72 Intraoperative Videos ...... 73 Follow-up ...... 73 Statistical Analysis ...... 73
Microsurgical Techniques (Publications I-VI) ...... 75 Lateral Supraorbital Approach...... 75 Patient Position...... 75 Craniotomy...... 75 LSO Approach with Minimal Temporal Exposure (Publications II and V)...... 76 Removal of OGM, ACM, TSM through LSO Approach (Publications I-III) ...... 78 Tumor Devascularization...... 78 Small and Medium-Sized OGM (< 6 cm)...... 78 Small and Medium-Sized ACM and TSM (< 4 cm)...... 79 Large OGM (> 6 cm)...... 80 Large ACM and TSM (> 4 cm)...... 80 Attachment to Surrounding Vascular Structures...... 82 Intraorbital Extension of ACM-TSM and Anterior Clinoidectomy (Publications I-III and V) ...... 83
Tailored Anterior Clinoidectomy (Publications V and VI)...... 84
5 RESULTS ...... 85
Characteristics of Meningiomas (Publications I-III)...... 85 Tumor Size ...... 85 Peritumoral Edema...... 86 Side of Approach in OGM and TSM...... 87 Hyperostosis and Infiltration of Ethmoid Sinuses in OGM ...... 87 Temporal Extension and Clinoidectomy in ACM and TSM...... 87 Infiltration of the Sellar Region (OGM and ACM) and Cavernous Sinus (OGM, ACM, and TSM) ...... 88 Intraorbital Tumor Extension and Attachment to the Optic Chiasm and Nerve...... 88 Meningioma Attachment to the Vessels ...... 88 Attachment of ICA to ACM and TSM...... 88 Attachment of ACA to ACM and TSM ...... 89
6 Attachment of AComA to TSM...... 89 Attachment of A2 to OGM and TSM...... 89 Attachment of M1 to ACM and TSM...... 89 Attachment of BA to TSM...... 90 Pituitary Stalk Involvement in TSM...... 90 Tumor Consistency...... 90 Tumor Calcifications...... 90 Operative Time ...... 91 Histological Grading of Tumors...... 91 Surgical Complications...... 91 CSF Leakage ...... 91 Postoperative Hematoma and Infection...... 92 Anosmia, Frontal Syndrome, and Visual Outcome...... 92 Outcome ...... 93 Early Outcome...... 93 Residual Tumor...... 93 Tumor Recurrence during Follow-up ...... 94 Long-term Clinical Outcome and Mortality...... 95
Method of Anesthesia for OGM, ACM, and TSM Surgery (Publication IV) ...... 95 Induction of Anesthesia...... 96 Maintenance of Anesthesia and Tumor Size...... 96 Brain Relaxation and Anesthesia...... 97 Osmotic Agents...... 97 Hemodynamics and Vasoactive and Antiepileptic Drugs...... 98 Intraoperative Bleeding and Blood Transfusion...... 99 Extubation Time...... 100
Surgical Complications and Outcome after Anterior Clinoidectomy (Publications V and VI)...... 101 Tailored Anterior Clinoidectomy ...... 101 Visual Outcome...... 101 Ophthalmoplegic Complications...... 103 CSF Leakage...... 103 Other Surgical Complications...... 103 Clinical Outcome at Discharge and at Three Months...... 105
6 DISCUSSION ...... 106
Lateral Supraorbital Approach versus Pterional, Bifrontal, and Fronto-Orbital Approaches ...... 106 LSO Approach versus Pterional Approach (Publications I-III)...... 106 LSO Approach versus Bifrontal Approach (Publications I and III)...... 107 LSO Approach versus Orbitozygomatic Approach (Publications I-III)...... 108 Neuroanesthesia in LSO Approach for a Slack Brain (Publication IV)...... 109 LSO and Anterior Clinoidectomy (Publications II-VI)...... 110 Operative Time with the LSO Approach (Publications I-III)...... 111
Surgical Complications...... 112 Olfactory Function Preservation (Publications I-III)...... 112 CSF Leakage (Publications I-VI)...... 112 Visual Outcome (Publications I-III)...... 113 Visual Outcome after Anterior Clinoidectomy (Publications V and VI) ...... 115 Surgical Mortality (Publications I-III)...... 116
Tumor Recurrence during Follow-up (Publications I-III)...... 117
Future Perspectives...... 118 Near Future...... 118 Preoperative Imaging...... 118 Skull Base Simulators...... 118 Microsurgical Techniques...... 119 Neuroanesthesia...... 119
7 Far Future ...... 120
7 CONCLUSIONS...... 121
LIST OF 15 SUPPLEMENTARY VIDEOS ON MICRONEUROSURGERY OF OGMS, ACMS, TSMS AND ANTERIOR CLINOIDECTOMY THROUGH LATERAL SUPRAORBITAL APPROACH ...... 122
ACKNOWLEDGMENTS...... 123
REFERENCES...... 126
8 “…more humanae cupidinis ignara visendi.”
Historiae, Book I, Gaius Sallustius Crispus 86-35 BC
Abstract
Objective The anterior skull base region can the LSO is presented after reviewing 82 be reached through different surgical patients who underwent surgery for vascular approaches. The most frequently used are the and neoplastic lesions between June 2007 pterional, bifrontal, and orbitozygomatic and January 2011. Altogether 273 patients of approaches. No previous reports describe the a total of 3000 LSO approaches were microsurgical technique when treating analyzed, and 15 videos were selected to olfactory groove meningiomas (OGMs), show the approach and the microsurgical anterior clinoidal meningiomas (ACMs), and techniques used. tuberculum sellae meningiomas (TSMs) Results Olfactory groove meningiomas: through the small lateral supraorbital (LSO) There was no surgical mortality. Six patients approach. The purpose here was to assess the (9%) had CSF leakage, four (6%) had wound reliability and safety of the LSO for the infections and cotton granulomas, and one treatment of vascular and neoplastic lesions (2%) had postoperative hematoma. The of the anterior skull base. The median Karnofsky score at discharge was 80 neuroanesthesia method when using this (range, 40-100). Six patients had residual small approach is also presented. When tumors: three were re-operated on after an needed, anterior clinoidectomy, intradurally average of 21 (range, 1-41) months, one was or extradurally, is also possible through the treated with radiosurgery, and two were LSO approach. followed up. During the median follow-up of Patients and Methods Between September 45 (range, 2-128) months there were four 1997 and August 2010, we analyzed the recurrences (6%) diagnosed on average 32 clinical data, radiological findings, surgical (range, 17-59) months after surgery. treatment, anesthesiological procedure, Anterior clinoidal meningiomas: At three histology, outcome, and long-term follow-up months after discharge, 60 patients (82%) of 66 OGMs, 73 ACMs, 52 TSMs had a good recovery, nine (12%) were consecutive patients treated by the senior moderately disabled, one (1%) presented author (J.H.) through the LSO approach. with severe disability, and three (4%) died Anterior clinoidectomy technique through due to surgery-related complications. Sixteen
9 patients (22%) had residual tumors, six of pressure was 95-110 mmHg during surgery. which required re-operation. Of 39 patients, The median intraoperative blood loss was pre-existing visual deficit improved in 11 200 (range, 0-2000) ml and 9% of patients (28%), worsened in four (5%), and three had red blood cell transfusion. One-hundred (4%) had de novo visual deficit. During the and fifty-seven patients (84%) were median follow-up of 36 (range, 3-146) extubated on the day of the surgery. The months tumor recurred in three patients: two median (25th/75th percentiles) time to were followed up and one was reoperated. extubation after surgery was 18 (8/105) min. Tuberculum sellae meningiomas: At three Anterior clinoidectomy: Eighty-two patients months postdischarge, 47 patients (90%) had underwent anterior clinoidectomy: 45 a good recovery, four (8%) were moderately patients (55%) were treated for aneurysms, disabled, and one (2%) died 40 days after 35 patients (43%) were treated for surgery of unexplained cardiac arrest. Of 42 intraorbital, parasellar, and suprasellar patients, pre-existing visual deficit improved tumors, and two patients (2%) presented with in 22 (42%), remained the same in 13 (25%), carotid-cavernous fistula. Intradural anterior and worsened in seven (13%), and de novo clinoidectomy was performed in 67 cases visual deficit occurred in one patient (2%). (82%); in 15 cases (18%), an extradural Seven patients (13%) had minimal residual approach was used. We performed a tailored tumors, two of which required re-operation. anterior clinoidectomy: in five patients (6%), During the median follow-up of 59 (range, 1- only the medial tip of the anterior clinoid 133) months tumor recurred in one of the process (ACP) was removed, in eight (10%) patients who had received a second the head of the ACP, in 18 (22%) the body of operation. the ACP, and in 51 (62%) the entire ACP. Anesthesia: Surgical conditions with slack Four patients (5%) had new postoperative brain were good in 154 meningioma patients. visual deficits and 12 (15%) improved their Slack brain was achieved by a head position preoperative visual deficits after intradural elevated 20 cm above cardiac level in all anterior clinoidectomy. Extradural anterior patients; administering mannitol clinoidectomy and use of ultrasonic bone preoperatively in medium or large device (Sonopet) may increase the risk of meningiomas (60 cases); propofol infusion postoperative visual deficits. There was no (46 cases) or volatile anesthetics (107 cases) mortality in the series. also in patients with large tumor (37 cases); Conclusions The LSO approach can be used and controlling intraoperative safely for OGMs, ACMs, and TSMs of all hemodynamics. The mean systolic blood sizes, with a low mortality and a relatively
10 low morbidity. Anterior clinoidectomy can achieved with more extensive, complex, and be performed through the LSO approach. time-consuming approaches. We highly However, it is required only in selected cases recommend the use of LSO for removal of and we prefer the intradural route. vascular and neoplastic lesions of the A slack brain is mandatory when performing anterior skull base. the small LSO approach and can be achieved by patient positioning, propofol or inhaled anesthetics, preoperative mannitol, and optimizing cerebral perfusion pressure. With advancements in the neurosurgical field, the skull opening should be simple and as minimally invasive as possible. Surgical results with the simple, clean, and fast LSO approach are comparable with those
11 Abbreviations
ACF: Anterior cranial fossa HH: Hunt-Hess ACA: Anterior cerebral artery ICA: Internal carotid artery AChA: Anterior choroidal artery ICP: Intracranial pressure AComA: Anterior communicating artery LSO: Lateral supraorbital ACMs: Anterior clinoidal meningiomas MCA: Middle cerebral artery ACP: Anterior clinoid process MMA: Middle meningeal artery AD: Anno domini MRA: Magnetic resonance angiography AEAs: Anterior ethmoidal arteries MRI: Magnetic resonance imaging ASB: Anterior skull base NA: No available AVM: Arterio-venous malformation OA: Ophthalmic artery BA: Basilar artery OGMs: Olfactory groove meningiomas BC: Before Christ ORs: Odds ratios CBF: Cerebral blood flow PCA: Posterior cerebral artery CIs: Confidence intervals PComA: Posterior communicating artery CPP: Cerebral perfusion pressure PEAs: Posterior ethmoidal arteries CSF: Cerebrospinal fluid SAH: Subarachnoid hemorrhage CT(A): Computed tomography SCA: Superior cerebellar artery (angiography) SOF: Superior orbital fissure DSA: Digital subtraction angiography SSS: Superior sagittal sinus ECA: External carotid artery TSMs: Tuberculum sellae meningiomas GOS: Glasgow outcome scale HES: Hydroxy ethyl starch
12 List of Original Publications
This thesis is based on the following publications, referred to in the text by their Roman numerals:
I. Romani R, Lehecka M, Gaal E, Toninelli S, Çelik Ö, Niemelä M, Porras M, Jääskeläinen J, Hernesniemi J. Lateral Supraorbital Approach Applied to Olfactory Groove Meningiomas: Experience with 66 Consecutive Patients. Neurosurgery 2009; 65 (1): 39-52. II. Romani R, Laakso A, Kangasniemi M, Lehecka M, Hernesniemi J. Lateral Supraorbital Approach Applied to Anterior Clinoidal Meningiomas: Experience with 73 Consecutive Patients. Neurosurgery 2011; 68 (6): 1632-1647. III. Romani R, Laakso A, Kangasniemi M, Niemelä M, Hernesniemi J. Lateral Supraorbital Approach Applied to Tuberculum Sellae Meningiomas: Experience with 52 Consecutive Patients. Submitted. IV. Romani R, Silvasti-Lundell M, Laakso A, Tuominen H, Hernesniemi J, Niemi T. Slack Brain in Meningioma Surgery through Lateral Supraorbital Approach. Surgical Neurology International (in press). V. Romani R, Elsharkawy A, Laakso A, Kangasniemi M, Hernesniemi J. Tailored Anterior Clinoidectomy through Lateral Supraorbital Approach: Experience with 82 Consecutive Patients. World Neurosurgery (in press). VI. Romani R, Elsharkawy A, Laakso A, Kangasniemi M, Hernesniemi J. Complications in Anterior Clinoidectomy through Lateral Supraorbital Approach: Experience with 82 Consecutive Patients. World Neurosurgery (in press).
The original publications are reproduced with permission of the copyright holders. In addition, some unpublished material is presented.
13 1 Introduction are the pterional, frontolateral, bifrontal, and 1 Introduction fronto-orbitozygomatic approaches. The aim of this study was to demonstrate the reliability and safety of the lateral The surgical opening of the skull is one of supraorbital (LSO) approach in the treatment the most fascinating practices in human of the most frequent neoplastic and vascular history. Since the first skull trepanation dates lesions of the ASB. back to the Neolithic period ca. 8000 BC, More specifically, the microsurgical enormous efforts have been made to refine technique, long-term follow-up, and this surgical procedure (247). Over the neuroanesthesia procedures were carefully centuries, especially during the last one, the examined to demonstrate the efficacy of the procedure has undergone important LSO approach for treating olfactory groove developments. This progression is due to the meningiomas (OGMs), anterior clinoidal parallel evolution of the neuroradiological meningiomas (ACMs), and tuberculum field, essential for optimal understanding of sellae meningiomas (TSMs). The results the anatomy and neurovascular relationship were then compared with those obtained of the lesion, and improvement of utilizing pterional, orbitozygomatic, bifrontal neurosurgical techniques with the approaches that are more invasive and time- introduction of the microscope and consuming approaches. Furthermore, the microsurgical techniques. skull base approach with both extradural or According to the location and anatomical intradural anterior clinoidectomy, for the features of the intracranial lesion, several treatment of vascular and neoplastic lesions, surgical approaches have been developed, was studied through the LSO approach. particularly in the last fifty years. All patients analyzed and described in this We focused our study on the surgical study were treated by a single neurosurgeon, approach to reach the anterior skull base the senior author (J.H.), at the Department of (ASB). This is the endocranial surface of the Neurosurgery, Helsinki University Central skull bordered posteriorly by the sphenoid Hospital, Finland. ridge and joined medially by the chiasmatic sulcus. This region is particularly difficult to reach because of the complex neurovascular structures present. Several surgical approaches are described to reach the ASB. Those most frequently used
14 2 Review of the Literature
2 Review of the Literature
History of Craniotomy
Pre-Historic and Classic Eras
Neolithic Era (8000 BC)
The primitive technique to open the skull anesthesia and pre-antisepsis era, patient was trephination, performed in the Neolithic survival improved if the dura mater remained era (8000-5000 BC) in different locations intact when opening the skull. While the around the world (Africa, South America, operation was performed on men, woman, and Melanesia, one of the regions of and children, the patients were most often Oceania). The first archeological findings adult males. Two-thirds of the skulls found related to perforation of the skull date back and examined reveal various degrees of to the Neolithic period and were made in healing, providing evidence of survival and France in the Neolithic site of Ensisheim in indicating great skill of the surgeon 1685 (217). considering the number of potential The word “trepanation” is derived from the complications (e.g. bleedings, infections, Greek and it means auger (hand tool for edema). boring holes). The word “trephination”, by Neolithic trepanation and trephination have contrast, refers to an opening made by a been the subject of speculation since the first circular saw of any type. Skull opening specimens were discovered in the nineteenth through trepanation was practiced in Europe, century. Archaeologists speculate that it was Asia, New Zealand, Pacific Islands, and performed to allow evil or unwanted spirits North America. to escape. More reasonable is a therapeutic Trephination or trepanation consisted of treatment of headaches, fractures, localized removing a piece of the skull (frontal, cranial deformities, mental changes, parietal, or occipital bones) from a living infections, or convulsions. Another patient to expose the dura mater. In the pre- explanation is a religious one, to acquire the
15 2 Review of the Literature rondelles (the disks of bone obtained from wound was covered with a shell, a gourd, or the cutting of circular holes in the skulls) even a piece of gold or silver. The most used as amulets or talismans. The findings of common tool used was the bow drill. The skull fracture suggested also that the bow was made of springy wood and had a procedure was performed to relieve leather thong wound around the drill several intracranial pressure. Three surgical times. To perform the procedure, the techniques were used: scraping, drilling, and operator positioned the drill tip against the cutting (Figure 1). The Neolithic Age head and bored through the bone. Drilled occurred before the introduction of holes were usually roughly circular. Holes metallurgy. The holes were made with a made by a knife were typically more square. sharp-edged flint scraper or knife, deeper and A few skulls have had up to five holes, the deeper until penetration to the dura mater longest of which measures two inches across was accomplished. In ancient Peru, people (205, 217, 247). used knives of bronze or obsidian. The
Figure 1: Schematic drawing showing the different skull trepanation techniques during the Neolithic era (8000 BC). (A) The intersecting incisions to remove a rectangular piece of skull; (B) Boring and cutting; (C) Grooving; (D) Scraping.
Classic Era
Edwin Smith was an American Egyptologist 1862 (223). Smith died in 1906 and his who bought an ancient papyrus from daughter gave the papyrus to the New York Mustapha Aga, a consular agent in Luxor in Historical Society in 1920. The papyrus was
16 2 Review of the Literature translated in 1922 by James H. Breasted, an Hippocrates was the first to demonstrate that American Egyptologist, and published in two the specific location of injury of the skull volumes in 1930. The translation of Edwin was important. Trauma at bregma was Smith's papyrus is the only medical treatise associated with a higher risk of brain injury of the Pharaonic era, and it reveals how than a lesion in the temporal region, which in advanced medical care, especially trauma turn was associated with a higher risk of surgery, was in ancient Egypt. Edwin Smith's brain injury than a lesion in the occipital papyrus describes for the first time cranial region. Simple concepts of head injury sutures, meninges, the external surface of the location and its prognosis were applied by brain, and the cerebrospinal fluid (CSF). the Hippocrates school and were valid for Forty-eight different pathological cases are many centuries. presented with details of the examination, Celsus was a counselor to the emperors diagnosis, treatment, and prognosis. Trauma Tiberius and Caligula. He was not a surgeon cases with neurological symptoms are very or physician, but a patrician intellectual who well described; for example, cervical wrote a series of books entitled: De Re vertebral dislocation was considered to be Medicina. Book VIII, Chapter 4 describes an the cause of such symptoms as quadriplegia epidural hematoma. Celsus advised operating and urinary incontinence. Trepanation is not on the patient on the side of greater pain and mentioned in the papyrus (20, 223, 247). placing the trephine where the pain is best The codification of craniotomy performed localized. This is the first observation of dura for head injury was first done by Hippocrates innervation and its sensitivity to pressure. in 5th century BC. The Corpus Celsus first described how a craniotomy is Hippocraticum is a systematic review of the performed: making a number of holes and head trauma treatment performed by ancient then connecting them with a hammer and physicians. The book describes guidelines chisel. Regarding the trephination operation, for the treatment of head trauma with Celsus considered it the “ultimum refugium”, symptoms, techniques, and complications. to be applied only when conservative The Corpus Hippocraticum remained valid methods failed. for 2000 years. Hippocrates advised Galen of Pergamon (AD 129-210) lived performing the craniotomy without delay, under the reign of Marcus Aurelius (reign within the first three days of the trauma in AD 161-180), one of the most powerful and severe contusions. In skull fractures, he important emperors of the Roman Empire. advised removal of the embedded fragments Galen was the physician of the gladiators, without lacerating the meninx (217). allowing him to treat traumatic injuries. He
17 2 Review of the Literature made important contributions to pineal and pituitary glands, cranial nerves neuroanatomical knowledge and (he identified seven), and ventricular neurosurgical techniques. He was the first to systems. Besides neuroanatomical studies, he differentiate between pia and dura mater, and provided an extensive description of how the he provided descriptions of many anatomical trephination is performed without lacerating structures, including the corpus callosum, the dura (85).
Medieval Period
During this period the leading medical and classic Greek-Roman period, when the school was in Salerno, Italy. A prominent craniotomy was quite frequently performed, leader of this school was Constantinus in the Middle Ages this was an exceptional Africanus (ca. 1015-1087), known as procedure for Byzantine, Arabic, and Eastern “magister orientis et occidentis”. He was surgeons. The only procedure performed and credited for introducing Arabic medicine to only rarely was trephination (217). all of Europe. In contrast to the pre-historic
Renaissance and the 18th Century
During the Renaissance the craniotomy was Universale” by Giovanni Andrea Dalla again performed frequently, especially to Croce. Knowledge of the anatomy of the treat traumatic head injuries. In the 16th brain progressively increased, especially in century, the indications and surgical the second half of the 17th century with the techniques for craniotomy were described in studies of Malpighi and Willis (217). During the most important surgical books. These the 18th century the craniotomy procedure books included “Tractatus de fractura calvae was performed only in exceptional cases sive cranei” written by Giacomo Berengari because of the high incidence of from Carpi, Italy, “Dix Livres de la complications such as infections. Chirugie” by Ambroise Pare’, and “Cirugia
19th Century and the Osteoplastic Craniotomy
In the second half of the 19th century, with knowledge of neuroanatomy and the introduction of general anesthesia, the neurophysiology, the craniotomy was not introduction of asepsis by Lister, and greater only performed for trauma cases but also to
18 2 Review of the Literature treat intracranial expansive lesions. At the reinserted (145, 245). end of the 19th century, the first operations of The osteoplastic craniotomy was described brain tumors are described. Sir William in the Chipault volume, but it was first Macewen (1848-1924) in Glasgow pioneered applied by Wilhelm Wagner (1848-1900), a the treatment of the brain abscess and also chief general surgeon from a small hospital other lesions. On July 27, 1879, he removed in Königshütte (Germany) interested in a tumor, a meningioma, from the left cranial and spinal injuries (23, 24, 145, 246). olfactory groove. The patient had a good He was a brilliant surgeon who developed, recovery and was able to return to work in a based on cadaveric dissection, a technique of few months (7). elevating the bone flap attached to the In 1894 and 1895, Chipault A.M.J.N, a temporal muscle. Wagner met Julies Wolff, French anatomist and assistant of surgery a who created and published in 1863 an la Salpêtrière, Paris, published the experimental work where the osteoplastic Chirurgie Operatoire du Systeme Nerveux in techniques were possible. Julies Wolff two volumes. In the first volume, the history (1836-1902) was an orthopedic surgeon who of cranio-cerebral surgery from the pre- graduated from the University of Berlin and historic era was reported. The importance of investigated bone remodeling, later inspiring a small skull opening over the suspected Wagner (248). Wagner was the first to tumor area was emphasized. The osteoplastic perform the osteoplastic craniotomy on a craniotomy was described. This method was patient by cutting the bone with a chisel. At needed to expose a large area of the brain in the same time, the Gigli saw by Leonardo order to localize the neurological disease Gigli from Florence (1863-1908) was without leaving the patient with a big hole in introduced and popularized. The Gigli saw the skull. Before this, the trepanation was initially used for cutting the symphysis technique was the only one performed and pubis and later for performing the the small area of bone removed was not craniotomy (246).
Fedor Krause and the Unilateral Frontal Osteoplastic Craniotomy
Fedor Krause (1857-1937), the chairman of approaches. In 1900, he removed a revolver the surgical department of Augusta Hospital bullet from the region of the clinoid process in Berlin, was the first surgeon in Germany by performing a frontal osteoplastic to treat epilepsy. He also was known for craniotomy. Krause was the first to perform a innovative skull openings and surgical unilateral subfrontal approach without
19 2 Review of the Literature removal of the orbital rim, recommending published his surgical experiences in “Die this approach to reach pituitary adenomas. Chirurgie des Gehirns und Rückenmarks Neurosurgeons worldwide remember Krause nach eigenen Erfahrungen” (Surgery of the for his famous infratentorial supracerebellar Brain and Spine), in two volumes appearing approach in 1913, but even before this he in 1908 and 1911 and translated into English, was credited with first using the unilateral French, and Spanish (23). frontal osteoplastic craniotomy. He
Sir Victor Horsley: From the Transfrontal Route to the Subtemporal Approach
In 1889, Sir Victor Horsley (1857-1916) pituitary gland through a subtemporal route. performed in London the first pituitary Once during pituitary surgery by a adenoma operation through a transfrontal subtemporal route, Horsley was forced to route, sacrificing the frontal veins draining ligate the internal carotid artery (ICA) to into the superior sagittal sinus (SSS). The gain access to the tumor (132). Cushing patient presented with a frontal infarction spent a short time with Horsley in London documented at autopsy a few years later. and after visiting him stated that:“the Horsley subsequently abandoned the refinements of neurological surgery could transfrontal route for the temporal not be learned from Horsley” (86). craniotomy, reaching the lateral aspect of the
Francesco Durante: The First Olfactory Groove Meningioma Surgery through Unilateral Frontal Osteoplastic Craniotomy
In Rome in 1885, Durante described the first made. In the base I found the inner table to operation of meningioma removal. Durante be destroyed up to the external table. From was born in Messina (Sicily) and educated in the inner table in the frontal region I Florence, Paris (with Ranvier) and in Berlin gradually extirpated the tumor with much (with Virchow) (88). In the surgical report of care. After having removed the greater part I the operation, Durante wrote the following: found the point of attachment to the dura “With a chisel and a hammer, layer by layer mater. It was then easy to remove all of the a portion of the frontal bone, a part of the extensions of the tumor. These included the superior internal margin of the orbit was left cranial base of the anterior fossa and part removed, and an opening about 5 cm2 was of the right anterior fossa. I finally arrived at
20 2 Review of the Literature the anterior clinoid tubercle of the sella hour. The loss of blood was not great. The turcica. In the region of the lamina cribrosa patient withstood the chloroform anesthesia of the left ethmoid sinus there was a very well. Later she responded and was able prolongation of the tumor that descended to speak. On the third day after the operation into the ethmoidal cells. After excising the she had recovered” (63). tumor that was emplanted on the dura mater, Durante utilized the hypophysectomy one could observe that the orbital roof was method with a pharyngeal approach (64). He depressed, but not broken. The left frontal was also instrumental in building the lobe was replaced by a tumor the size of an Policlinico of Rome (88). The end of the 19th apple. After hemostasis was established and century is the period in which many the soft tissues were closed a drain was neurosurgeons performed brain operations inserted from the cranial cavity into the left with poor results (217). nasal cavity. The operation lasted about one
20th Century and the Macrosurgical Period
Cushing and “The Special Field of Neurological Surgery”
Harvey Cushing (1869-1939) spent one year Associate Professor of Surgery at John in Europe (July 1900- August 1901) at the Hopkins University, and in 1905 published beginning of his career. He was in Berne, in the hospital Bulletin a report entitled “The Switzerland, for five months with Special Field of Neurological Surgery”. The physiologist Hugo Kronecker researching report includes the following three sections: brainstem control of blood pressure during a The Brain and its Envelopes, The Spinal rise in intracranial pressure (Cushing Cord, and The Peripheral Nerves. In The response). He spent two months in Turin, Brain and its Envelopes, he wrote: “ For the Italy, with physiologist Angelo Mosso first time aseptic processes had permitted studying the same topic, and finally three surgeons to perform craniotomies with a months in Liverpool, England, with certain assurance... of operative safety... Not physiologist Charles S. Sherrington studying only has the localization of the more the motor cortex mapping of anthropoid apes approachable parts of the cortex –after a long (86). Returning to USA, Cushing became an series of researches culminating in Flechsig’s
21 2 Review of the Literature anatomical observations and in the subsequent perfect functional recovery, experimental researches of Sherrington and especially should a correct pathological his coworkers; -been put on a working basis diagnosis have been previously made” (41). for us, but also through the enormous strides Cushing was a leader in the development of in operative technique, particularly through neurosurgical procedures, and many Wagner’s osteoplastic method of resection, neurosurgeons from around the world we are now able to bring under observation learned from him. In 1910, he wrote another extensive portions of the cerebral surface” article “The Special Field of Neurological (43). In the same article, Cushing wrote that Surgery: five years later” where he reported a properly trained neurosurgeon must be his the following: “Neurological surgery is own clinical and experimental neuroscientist. fascinating and will long continue an Besides general surgical skills, a knowledge important and profitable field for intense of clinical neurology, neuropathology, and cultivation, partly because it has been largely experimental neurophysiology is essential unworked from an operative standpoint, not only for proper treatment of the patient partly because it deals with one of the two but also to achieve progress in the most important systems of the body - neurosurgical field (43). These statements nervous and circulatory. It is gratifying to see after almost 100 years remain true. One of that a number of young men are fitting Cushing's great contributions was to utilize themselves to specialize in it, with a the transsphenoidal approach for a pituitary preparation which makes envious one who adenoma in 1909 (86, 132). Cushing has wriggled into the subject and, like the performed the head opening to reach the proverbial squid, has left little but a trail of ASB through an osteoplastic craniotomy. ink behind him” (42). Regarding meningioma surgery, he wrote in 1922: “There is today nothing in the whole realm of surgery more gratifying than the successful removal of a meningioma with
Ludvig Puusepp and the First School of Surgical Neurology
Ludwig Puusepp (1875-1942) was born in neurologist Professor Vladimir Bechterew, Kiev, Ukraine, on December 3, 1875. He who established a special operating room for graduated in St. Petersburg, where he the surgical treatment of his patients. The undertook his neurological training with neurosurgical results were poor and
22 2 Review of the Literature Bechterew said: “If today’s neurologists Japanese war, operating on traumatic must still request the help of surgeons, then injuries. In 1907, he became an Assistant the coming generation will no longer need to Professor at the Department of Nervous and do so, for they have sized the scalpel to Mental Diseases of the St. Petersburg perform what legitimately belongs to their Military Medical Academy. In 1907 in St. realm”. These words inspired Puusepp to Petersburg, a Chair of Surgical Neurology become a neurologist and surgeon in a new was established, and Puusepp accepted this speciality. He performed his first operation post in 1910. This resulted in Puusepp being in 1899. At that time, Puusepp wrote: the first Professor of Surgical Neurology “...Today nobody is surprised at the worldwide to emerge from a neurological gynecologist performing operations in his background. After World War I and the own field, the ophthalmologist in his own: October Revolution in 1920, Puusepp moved only the neurologist is still at the sidelines... to his father’s native country (Estonia), if an operation in his field is necessary, the where he was appointed Professor of neurologist asks for the assistance of a Neurology at Tartu University. Until 1940, general surgeon... if nobody asks a surgeon Puusepp’s clinic in Tartu was the only center to remove a cataract from as small an organ specialized in neurology and neurosurgery. as the eye, how can we then insist on the Puusepp had a great influence on the Russian surgeon having detailed knowledge of so neurosurgical school. In 1917, he wrote the complicated a structure as the nervous textbook “Principles of Surgical Neurology” system?” in Russian. Puusepp is recognized worldwide During the year between 1904 and 1905, as the first neurological surgeon (192). Puusepp served as a surgeon in the Russo-
Otto George Theobald Kiliani and the Bifrontal Osteoplastic Craniotomy
In 1903 in New York, Kiliani operated on a reached through a bifrontal osteoplastic patient with pituitary apoplexy with an acute craniotomy and a subfrontal approach (132). intratumoral hemorrhage. The lesion was
Louis Linn McArthur and Charles Frazier and the First Fronto-Orbital Osteoplastic Craniotomy
In 1908, McArthur, in Chicago, performed the orbital rim. The approach to reach the the first frontal craniotomy with resection of pituitary gland was epidural, with a dura
23 2 Review of the Literature opening of 0.5 cm proximal to the chiasmatic supraorbital rim and part of the orbital roof, sulcus (155). Charles Frazier (1870-1936), in as previously described by McArthur. This Philadelphia, used a frontal extradural approach was used to remove large pituitary approach and later changed to a frontobasal adenomas (74) . intradural approach with resection of the
Walter Dandy and the Frontotemporal Craniotomy
In 1914, based on a cadaveric study, George nondominant hemisphere (86). He developed Heuer (1882-1950) of Baltimore, suggested a craniotomy techniques, performing the new approach to the pituitary region through frontotemporal approach, a large flap used to the sylvian fissure. This approach differed treat vascular and neoplastic lesions. Dandy from the approach of Krause or Frazier, and was credited with performing vascular it was first applied to a living patient by surgery with the principle of selective Walter Dandy (1886-1946), who was one of obliteration of the aneurysm, sparing the Cushing’s residents. Dandy spent his entire parent artery, and in March 1937 he was the career at the Johns Hopkins Hospital in first to apply a silver clip to the neck of a Baltimore and made important contributions posterior communicating artery (PComA) to the fields of pathophysiology and aneurysm (Figure 2) (45). Dott in 1931 used neuroradiology. The relationship between the frontotemporal approach for the surgical Cushing and Dandy was strained, the main treatment of an intracranial aneurysm by cause being Dandy’s talent. Dandy wrapping it with a piece of muscle, but this discovered ventriculography and conducted approach became popular with Dandy (73). an important study in cerebrospinal fluid The frontotemporal approach was used by physiology. He also made important findings Dandy at the beginning of his surgical career in the treatment of acustic neurinoma and to reach the pituitary region and later to treat was the first to perform hemispherectomy to vascular and tumoral lesions. eradicate an infiltrating glioma in the
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Figure 2: Schematic drawing showing the osteoplastic frontotemporal craniotomy performed by Dandy to treat a PComA aneurysm in 1937 (45).
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The Leadership of Herbert Olivecrona
Herbert Olivecrona (1891-1980) is Behandlung der Gehirntumoren: The considered the father of the European School Surgical Treatment of Brain Tumors), where of Neurosurgery and one of the founders of he thoroughly analyzed the possible causes modern neurosurgery. He started his career of surgical complications. In 1935, he at the Serafimerlasarettet in Stockholm in became a Professor of Neurosurgery at the 1918. One year later, he went to Baltimore to Karolinska Institute. In 1940 the Karolinska learn brain tumor surgery with Cushing, and Hospital was opened, later becoming the in 1922 he performed his first tumor foremost European neurosurgical school operation. A few years later, in 1927, he hospital (Figures 3 and 4). published his early experience in the treatment of brain tumors (Die Chirurgische
Figure 3: Olivecrona performing an operation at the Karolinska Institute (Courtesy of Professor Lars Kihlström from the Department of Neurosurgery of Karolinska Institute).
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Figure 4: Neuroanesthesia for posterior cranial fossa surgery (Courtesy of Professor Lars Kihlström from the Department of Neurosurgery of Karolinska Institute).
The contributions of Olivecrona to the published his early experience in AVM development of neurosurgical techniques are surgery in the Gefässmissbildungen und several. He emphasized the importance of a Gefässgeschwülste des Gehirns (Vascular precise preoperative diagnosis of intracranial Malformations and Vascular Tumors of the lesions. The surgical technique was Brain) (107). Olivecrona removed OGM performed while taking care to minimize through an unilateral frontal approach with a trauma to the surrounding normal brain, and partial lobectomy (174), and in 1946 he he considered perfect hemostasis mandatory already had a total experience of 46 cases for successful intracranial surgery. In 1930, (27). Olivecrona also performed the Olivecrona introduced use of hydrogen osteoplastic craniotomy, especially to reach peroxide solution to stop bleeding from small lesions of the temporal region (107, 148). vessels in tumor cavities. Olivecrona was a In 1951, Olivecrona wrote down his thoughts pioneer in vascular neurosurgery and was the about the development of neurosurgery. He first to perform the arterio-venous emphasized advancements in psychiatric malformation (AVM) operation (142). In neurosurgery by Egas Moniz and also in 1935, he published a book entitled functional neurosurgery. Moreover, he “Parasagittal meningiomas (Die established the basis for neurosurgical parasagittalen Meningeome)”. In 1936, he training, predicting subspecialization by
27 2 Review of the Literature subspecialists, which he referred to as collaboration with the departments of “super-neurosurgeons”. He first posed the neurology, neuroradiology, and question of whether a neurosurgeon trained neurophysiology. In his view, this was the in a specialized field, such as pediatric key to success, and it remains at the basis of neurosurgery, should be allowed to perform the organizational structure of the Karolinska vascular or spinal surgeries (176). This University Hospital. In this environment, question is today a pressing reality. Lars Leksell, a pupil of Olivecrona's, Olivecrona’s pupils became the founders of developed his stereotactic system for European neurosurgery (Figure 5). Early on, functional neurosurgery and radiosurgery, he understood the importance of the Leksell Gamma Knife (142).
Figure 5: Olivecrona and his pupils. European directors. First sitting on the right Lars Leksell (1907-1986) and first on the left Gösta Norlén (1906-1992) (Courtesy of Professor Lars Kihlström from the Department of Neurosurgery of Karolinska Institute).
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Aarno Snellman and the Craniotomy in Finland
Aarno Snellman (1893-1964) (Figure 6) is contributing to the field of neurosurgery in considered the founder of neurosurgery in Finland was F. Langenskiöld, who was a Finland. He was a general surgeon at the student of Cushing in 1929 (233-235). beginning of the career, working with Simo Neurosurgical operations were performed in A. Brofeldt (1892-1942), the head of the 1932 at the Red Cross Hospital (today Töölö Helsinki Surgical Department. Other Hospital) founded by General C.G.E. surgeons before him who were interested in Mannerheim (Figures 6-8). His sister Sophie neurosurgery included Ali Krogius, Richard Mannerheim, a head nurse, founded in Faltin, and A.J. Palmen. The Ph.D. thesis of Helsinki the school of nursing at Kirurginen the latter in 1914 was entitled “Features of Hospital. Intervertebral Tumor”. Another person
Figure 6: Aarno Snellmann (in the centre) with the head of the nurse Berrit Kihlman at the Christmas party of the Red Cross Hospital in 1942. Serious faces: there was a war on, and the previous driving chief surgeon Simo A. Brofeldt (1892-1942) had died.
Figure 7: Marshal Mannerheim cheering a patient at the Red Cross Hospital in 1942.
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Figure 8: The Red Cross Hospital (later Töölö Hospital) in 1932.
In spring 1935, Snellman went to the on February 1, 1963. He spent six months Serafimer Hospital of Karolinska Institute, with Olivecrona in 1952. After af Björkesten, Stockholm, Sweden, to study with Henry Troupp (1932- ) became the chairman Olivecrona for almost six months. When he of the Helsinki Department of Neurosurgery returned to Finland, he performed the first in 1976 (233-235). The craniotomy used by neurosurgical operation (September 18, Snellman and later by af Björkesten and 1935). Thus, the neurosurgical department Troupp for vascular or neoplastic lesions of was launched at the Red Cross Hospital, and the anterior skull base was a large it was the only neurosurgical department in frontotemporal craniotomy (Figures 9-13). Finland until 1967. After Snellman, S.G.L. af Björkesten (1912-1974), a talented and brilliant neurosurgeon, became the chairman of the Helsinki Department of Neurosurgery
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Figure 9: On the left Professor Snellman washing the head of a patient in 1953; the anesthetist was Mirja Tappura. She was the first anesthetist of Töölö Hospital and became the first head of anesthesiology of the hospital. In 1964 she moved to Tampere. On the right af Björkesten (assistant) and Snellman together performing a neurosurgical operation in 1953.
Figure 10: On the left: sister Laina (Moisio), Professors Snellman and af Björkesten performing a neurosurgical operation. Notice the basic equipment for keeping warm the saline solution for flushing the wound. On the right Professors Troupp (assistant, left), af Björkesten (surgeon, centre) and Snellman (spectator, right) during a neurosurgical operation.
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Figure 11: Left picture: Professor af Björkesten in 1960. He became Professor in 1963. Right picture: Professor Troupp, young medical student, suturing a patient wound in 1955, twenty-one years before his Professorship. In the picture sister Maire (Reuna) assisting from the outpatient clinic ward .
Figure 12: Anterior-posterior conventional angiography (left) and lateral (right) view showing a large right frontal craniotomy (arrows) for aneurysm surgery.
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Figure 13: Transcript of the operation report for an aneurysm surgery performed by Professor af Björkesten on August 12, 1957.
Present state. General condition. No heart or pulmonary problems. RR 110/70. No gastric problems. Teeth cared for. Neurologic status: 5.8.-57 (af Björkesten) Verified subarachnoidal bleeding, symptom-free, except for headache more on the right side of the head. Routine examinations. 6.8.57. Image of the skull: no obvious abnormalities. EEG: Arrhythmia not classified (labilitas functionis). Angiography (Left internal carotid) No pathology. 12.8.57. Ligatura aneurysmatis af Björkesten (1st operator) – Troupp (assistant) – Valtonen (assistant) – Kerttu (instrument nurse) Intubation + hypotension Virkkala (anesthetist) Right side Dandy modified skin incision. Bone removed in an osteoplastic flap. Intracranially, pressure reduced well when the lumbar drainage was opened. Dura was opened medially. Under the right frontal lobe are exposed the optic nerve and internal carotid. After opening the arachnoid on the lateral side of the carotid artery is exposed the base of
33 2 Review of the Literature the aneurysm, which is located in the central part of the bifurcation. Without major complications, I sutured below the central part of the aneurysm, but the suture slipped away from the aneurysm base, making the operation more difficult. Also close to the aneurysm and below but more on the medial side was a second vessel (choroid artery?), which could not be dissected from the neck. It would have been mandatory to close both vessels at the same time, hiding the carotid from everything. Thus, the suture attempt was abandoned. I prepared a small opening in the aneurysm base and at the periphery of the angle between the carotid and the opening. A different silver staple was applied on the neck of the aneurysm. This was done without bleeding; the clip was located well, and if it would be seen all the aneurysm neck bridging compressed. There was no bleeding. Dura suture with silk, suture of the periosteum with silk, and the central suture of the bone with flax. The bone was fixed with two metallic sutures. Muscles, galea, and skin suture. The patient woke up after the operation. Condition was good, no paresis.
20th Century and the Microsurgical Leadership of Ya2argil
The microsurgical era in neurosurgery microneurosurgical techniques at the started with the use of the operative University of Vermont, Burlington, microscope. In the 1950s, Theodore Kurze Vermont, where Jacobson and Donaghy (1922-2002), a neurosurgeon of the established the first microvascular training University of Southern California, Los laboratory in 1958. During his training he Angeles, recognized the surgical microscope learned how to perform microsutures on as an important instrument in acoustic animal vessels and how to use bipolar neurinoma surgery. In 1957, he performed coagulation. Upon using bipolar forceps, the first craniotomy on a human being under Ya2argil was certain that microsurgical the microscope (61). Thereafter, the use of techniques were possible (258). He returned the microscope became increasingly frequent to Zurich, where he developed his own worldwide. microneurosurgical instruments between Microneurosurgical techniques introduced by 1967 and 1993. The routine use of Ya2argil (1925- ) revolutionized the microneurosurgery began on January 18, neurosurgical field. Ya2argil worked at the 1967, and on October 30, 1967 the first University Hospital of Zurich for 40 years. extracranial-intracranial bypass was He started his training in 1953 with Hugo performed. Milestone microneurosurgical Krayenbühl (1902-1985). At the beginning principles of Ya2argil were based on of his career, between 1958 and 1965, cisternal approaches and on the knowledge Ya2argil was active in the field of cerebral of bipolar coagulation techniques (257). angiography and functional neurosurgery. Zurich became the world center for learning In 1965, he went to learn the microneurosurgical techniques; more than
34 2 Review of the Literature 3000 foreign neurosurgeons traveled here to learn these techniques, among them the present Professor and Chairman of Helsinki Neurosurgery Department, Juha Hernesniemi. Ya2argil wrote in his biography that all visiting colleagues from abroad were stimulating with their criticism, improving the microneurosurgical techniques (258). After his retirement in 1993, Ya2argil analyzed the data collected during his years in Zurich and wrote volumes IVA and IVB of Microneurosurgery, where he described the microsurgical principles for performing anterior skull base meningioma surgery through pterional craniotomy and the transsylvian approach (258); his microsurgical techniques are still used today, routinely applied worldwide.
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Microsurgical Anatomy of Anterior Skull Base
Bone Structures
Anterior Cranial Fossa
The skull is divided into the cranium and the cranial base has an exocranial and facial skeleton. The cranium is further endocranial surface. Both of these surfaces divided into the calvarium and the cranial are divided into three regions: anterior, base (194). The calvarium or calvaria (from middle, and posterior. latin calva: bald, plural calvariae) is the The anterior cranial fossa (ACF) is the upper part of the cranium and surrounds the endocranial surface of the skull, bordered cranial cavity containing the brain. The posteriorly by the sphenoid ridge and joined calvarium is formed by the following bones: medially by the chiasmatic sulcus. frontal, parietal, temporal, and occipital. The
Lamina Cribrosa of the Ethmoid Bone
The floor of the ACF is formed by the contains olfactory bulbs and the anterior and frontal, ethmoid, and sphenoid bones. Frontal posterior ethmoidal foramens. Through these and sphenoid bones roof the orbits. At the two foramens run the anterior and posterior midline anterior to the ethmoid, a ridge: the ethmoidal arteries and veins. Many holes are frontal crest, is formed by the frontal bones present in the cribriform plate for the (134). Located between the frontal bones, at filaments of the olfactory nerve; they are the ACF, is the ethmoid bone, including the covered by dura mater and arachnoid crista galli and the cribriform plate. The membrane. crista galli and the frontal ridge are the Between the frontal ridge and the crista galli anterior attachment of the falx cerebri (134, is a small hole: the foramen cecum, where a 194). small vein comes from the nasal cavity The ACF is not flat, and this is important for reaching the SSS. The chiasmatic sulcus and surgery. The lowest part is the cribriform the sphenoid ridge separate the anterior plate; this is part of the nasal cavity roof and
36 2 Review of the Literature cranial fossa from the middle cranial fossa. The distance from the foramen cecum to the frontosphenoidal suture is about 3 cm, and this is the area where OGMs originate (134, 209).
Olfactory Fossa
Olfactory epithelium is located at the roof of olfactory tracts run under the surface of the the nasal cavity, in the superior nasal inferior frontal lobes, extending to the conchae, and in the nasal septum. The nerve olfactory areas (26, 133, 177). Approaches to fibers pierce the cribriform plate to synapse the anterior cranial base can involve the in the olfactory bulb, which appears as an transection of the nerves to gain access to the ovoid structure located in the olfactory posterior part of the anterior skull base; an groove of the cribriform plate. The olfactory osteotomy around the cribriform plate groove is covered by dura mater and includes all of the olfactory nerves that exit averages 15 mm in length and 5 mm in the skull base (47). Nerve fibers piercing the width. The olfactory bulb averages 12 mm in cribriform plate are very fragile and often are length and 5 mm in width. The olfactory injured by the slightest manipulation. tract averages 3 cm in length (26). The posterior part of the olfactory tract has a triangular section with three crests: internal, external, and superior. Right and left
Sphenoid Bone
The central portion of the sphenoid bone is tuberculum sellae is an osseous protuberance the pituitary fossa, which is limited by the between the chiasmatic sulcus and the tuberculum sellae anteriorly, the dorsum anterosuperior limit of the pituitary fossa sellae posteriorly, and the diaphragma sellae (Figure 14). The chiasmatic sulcus is a superiorly. This is the dura covering the shallow depression between the optic pituitary gland with a small central opening foramina, bounded posteriorly by the for the pituitary stalk (195). This layer of tuberculum sellae and anteriorly by the dura extends from the posterior clinoid planum sphenoidalis. It is located anterior to processes to the tuberculum sellae. The the optic chiasm, explaining the early
37 2 Review of the Literature diagnosis of TSM due to a visual deficit. The limbus sphenoidalis, chiasmatic sulcus, limbus sphenoidalis is the small area tuberculum sellae, and diaphragma sellae are between the planum sphenoidalis and the all sphenoidal structures from which a TSM chiasmatic sulcus. The planum sphenoidalis can originate (133). Except for the dura of is the smooth surface of the medial portion of the diaphragma sellae, all other dura the lesser sphenoid wings that is in contact locations can be removed, achieving with olfactory tracts, the gyrus rectus, and Simpson grade 1. the posterior portion of the frontal lobe. The dura maters of the planum sphenoidalis,
Figure 14: The planum sphenoidalis, chiasmatic sulcus, tuberculum sellae, sella turcica, and dorsum sellae of a skull specimen.
Superior Orbital Fissure
The superior orbital fissure (SOF) is located The SOF is located laterally and inferiorly to between the less and greater sphenoid wings. the anterior clinoid process (ACP), and it is Passing through this foramen are the opened to expose the cavernous sinus oculomotor, trochlear, abducens, and structures (194). ophthalmic nerves and the ophthalmic veins.
Anterior Clinoid Process
The ACP is the medial part of the lesser the optic canal. The ACP is an important sphenoid wing and covers the lateral part of zone of dural attachment for the falciform the optic canal (194). Together with the ligament, extending from the ACP to the orbital part of the frontal bone, the ACP planum sphenoidale and covering the roof of covers the orbital roof and the lateral part of the optic canal. The orbital roof and the ACP
38 2 Review of the Literature can be pneumatized from the extension of must be borne in mind when removing the ethmoidal and sphenoid sinuses, and this ACP (209).
Vascular and Dural Structures
Ophthalmic Segment of the ICA and Dural Rings
The ICAs are located on both sides of the between the distal ring and origin of the sphenoid bone, whereas the basilar artery PComA and is also called the ophthalmic (BA) lies against the posterior surface of the segment of the ICA (52); the C1 segment sphenoid bone. Both ICAs, their perforators, arises from the origin of the PComA and and all arteries forming the circle of Willis extends to the ICA bifurcation (253). The may be encased or dislocated by a ophthalmic segment of the ICA presents meningioma originating from the ACF. several branches. The largest is the The ICA coming from the cavernous sinus ophthalmic artery (OA) arising from the makes the extradural and extracavernous dorsal or dorsomedial surface of the ICA just anterior loop (C3 segment) between the as it penetrates the intradural space. The OA proximal and distal rings inferomedial to the originates below the optic nerve and extends ACP. to the optic canal. Anterior clinoidectomy is The lateral wall of the cavernous sinus is mandatory for proper exposure of the OA formed by the superficial and inner dural and ophthalmic segment of the ICA. The layers. These two layers separate at the superior hypophyseal artery is another anterior portion of the cavernous sinus: the important perforator arising from the medial inner layer running inferior to the ACP and or inferomedial surface of the ophthalmic surrounding the C3 segment of the ICA segment of the ICA just before the origin of forms the proximal ring, which is the roof of the PComA (52). This perforator may have a the anterior cavernous sinus; the superficial horizontal direction or may ascend or layer covering the superior surface of the descend; it supplies the optic nerve and ACP envelops the ICA and forms the distal chiasm, the superior aspect of the pituitary ring. Anterior clinoidectomy is necessary to gland and stalk, and the dura around the expose this segment of the ICA. Intradural cavernous sinus (Figure 15) (52, 195). segments of the ICA begin from the distal ring: the C2 segment consists of the ICA
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Figure 15: Schematic drawing showing the internal carotid arteries, ophthalmic arteries and superior hypophyseal arteries.
Arterial Supply to the Dura Mater of the Anterior Cranial Fossa
The dura of the ACF has many invaginations dura and of the olfactory bulb and tract and and is rather thick everywhere except in the form the main supply to the OGM. region of the cribriform plates. The medial The anterior skull base receives vascular part of the dura is supplied by branches of supply from the ethmoidal arteries, and the ethmoidal arteries, and the lateral parts consequently their coagulation, necessary by frontal branches of the middle meningeal during the removal of OGM, results in artery. ischemic damage to the olfactory nerve. The Anterior and posterior ethmoidal arteries external carotid artery (ECA) and ICA (AEAs; PEAs) originate from the OA, are anastomose via the frontal branch of the the predominant vascular support of the ACF middle meningeal artery (MMA), which
40 2 Review of the Literature connects the ethmoidal branches of the OA (47, 67, 134, 194).
Arterial Supply to the Dura of the Anterior Clinoid Process
The ACP is the medial part of the lesser from the OA and from its branches, the wing of the sphenoid bone. With the orbital ethmoidal arteries (194). part of the frontal bone, the ACP covers the The optic nerve proximal to its entrance to orbital roof and the lateral part of the optic the optic canal may be covered by the canal. Important dural attachments to the falciform ligament for a length varying ACP are a) the anteromedial portion of the between 1 mm and 1 cm (195). The main tentorium with the anterior and posterior vascular supply for the optic nerve comes petroclinoid folds and the interclinoid folds from the superior hypophyseal arteries, and and b) the falciform ligament extending from care should be taken to avoid damaging the ACP to the planum sphenoidale covering them, as this may lead to ischemia of the the roof of the optic canal. These dural optic nerve (241). structures receive their main vascular supply
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“… non ragioniam di lor, ma guarda e passa”.
Dante, The Divine Comedy, Inferno Canto III: 51
Classical Approaches to Anterior Skull Base
Pterional Approach
The frontotemporal approach applied by bone 3-4 cm superior to the first burr hole Dandy and Dott was later popularized by and 1-2 cm above the orbital rim, avoiding Ya2argil. In Microneurosurgery volume I, the frontal sinus; 3) along the linea Ya2argil described the technique of the temporalis; and 4) in the squamous temporal interfascial pterional craniotomy. The head bone (Figure 16). The sphenoid ridge is of the patient is elevated slightly, rotated flattened with a drill, and the purpose of the about 30° to the contralateral side, with the approach is to have the sylvian fissure in the direction of the head around 20° vertex middle of the opening. Advantages of the down. The frontal lobe falls away from the pterional approach are to spare the SSS and orbital roof and the sphenoid ridge is frontal cortical veins, to avoid compressing directed vertically in the operating field. The the frontal lobes, and simultaneously to skin incision begins 1 cm superior to the allow the surgeon to visualize the anterior anterior aspect of the auricle extending to the circulation, the basal feeders, and the optic temporal crest in a direction perpendicular to nerve and chiasm. This approach was used the zygoma. Retraction of the temporal by Ya2argil to treat aneurysms of the anterior muscle and fascia is done through an circulation and upper basilar region and all interfascial approach. Burr holes are located tumors of the sellar and parasellar regions 1) superior to the frontal zygomatic suture (256). under the linea temporalis; 2) at the frontal
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Figure 16: 3D-CT skull reconstruction and schematic drawing showing the pterional craniotomy described by Ya2argil (256).
Fronto-Orbital and Fronto-Orbitozygomatic Approaches
Jane in 1982 (114) described a modification level of the orbital ridge, and the other just of the frontal craniotomy applied first by behind the arch of the zygomatic process McArthur in 1912 and Frazier in 1913 to (Figure 17). Both burr holes are connected reach the pituitary region (74, 155). The by using a Gigli saw, nowadays replaced by technique consisted in a bicoronal skin a high-speed drill, including the superior incision to expose the supraorbital nerve and orbital rim and part of the orbital roof. Three artery, which are often sacrificed. Two burr or four centimeters of the orbital roof can be holes are made: one at the midline, at the removed by using rongeurs. Through this
43 2 Review of the Literature approach, the brain retraction to reach the supply through the sphenoid ridge for ACM sella turcica or the anterior cerebral artery and TSM (3, 5, 6). Haddad and Al-Mefty (ACA) complex is minimal. Jane's approach recommend using spinal drainage to achieve removes the frontal and orbital rim in one a slack brain (91). Sekhar recommend a CSF bone fragment; the disadvantage of the drain or the direct opening of the basal technique with frequent opening of the cisterns to release CSF during subfrontal frontal sinus is often the sacrifice of the dissection; furosemide or mannitol can be supraorbital nerve and artery with CSF used if necessary (210). Sade and Lee leakage and disappearance of the frontal recommend a cranio-orbital approach wrinkles . associated with extradural clinoidectomy and opening of the falciform ligament before This approach is recommended by Al-Mefty ACM removal to decompress the optic nerve and Sekhar when treating OGM, ACM, and even if the meningioma is not in the optic TSM (3-6, 208, 209). Al-Mefty stresses the canal (203). Risi et al. reported a series of 34 following advantages: 1) minimal brain ACM patients with complete removal of the retraction; 2) access to the tumor via sphenoid wing, including the anterior clinoid different routes (subfrontal, subtemporal, and part of the planum sphenoidalis, with transsylvian); 3) ability to enter the early devascularization of the tumor and cavernous sinus if needed; and 4) possibility minimal brain retraction when resecting the for early interruption of the tumor blood zygomatic arch (196).
Figure 17: 3D-CT skull reconstruction and schematic drawing showing the cranio- orbitozygomatic approach (114).
44 2 Review of the Literature
Bifrontal Approach
The bifrontal craniotomy allows the access to cribriform plate is covered with a graft of the ASB through an interhemispheric pericranial tissue and Gelfoam to prevent a approach. The technique consists in a CSF leak. bicoronal skin incision, the burr holes are In the microsurgical technique of Sugita, the located behind the arch of the zygomatic bifrontal craniotomy is preferred for TSM process and frontally paramedian and surgery to avoid brain retraction. After anterior to the coronal suture (Figure 18). craniotomy, the anterior portion of the tumor The advantage of the interhemispheric route is removed, and after partial removal the is early access to the anterior cerebral attachment to the optic nerves can be arteries and the optic nerves without opening dissected. Following the arachnoidal plane, the frontal sinus, but care must be taken to the tumor is removed and a small piece can preserve the SSS and the bridging veins be left attached to the optic nerve to prevent (154). The frontal sinus is always opened visual function worsening. Sugita affirmed through this approach and can be sealed with that large TSMs can be removed also a flap of pericranial tissue. To completely through a unilateral frontal craniotomy, but remove the tumor, the dura of the skull base the bilateral approach is preferred because of should be accessed with opening of the the larger operating field and less brain ethmoid sinus, and reconstruction of the retraction (220).
45 2 Review of the Literature
Figure 18: 3D-CT skull reconstruction and schematic drawing showing the bifrontal craniotomy.
Frontolateral Approach
Al-Mefty and Babu recommended a pterional approach with the lateral unilateral frontal craniotomy with orbital supraorbital approach; the authors concluded osteotomy to prevent bifrontal retraction, that both approaches provide similar leading to possible mental changes (4, 5). A exposure to the sellar, suprasellar, and recent anatomical study compares surgical anterior communicating artery (AComA) exposure of the pterional, orbitozygomatic, areas (204). The authors further concluded and minisupraorbital approaches. The that the pterional approach gives better authors concluded that the minisupraorbital exposure of the retrosellar area. In our approach with removal of the orbital rim opinion, the LSO approach also gives good gives a similar surgical view as the pterional exposure to this region. and orbitozygomatic approaches. Inclusion Samii after extensive skull base surgery of orbital osteotomy is not necessary or experience came to the conclusion that the beneficial to reach and remove the ASB (71). frontolateral approach (without orbital A recent cadaveric study compares the
46 2 Review of the Literature inclusion) is sufficient to reach and properly treat ACF lesions (159, 161).
Meningiomas: General Concepts
Meningioma is a term first used by Cushing demarcated, round or oval, frequently in 1922 to describe a benign tumor lobulated attached to the dura. In a minority originating from the meninges of the central of meningiomas a dural attachment cannot be nervous system. Meningiomas are derived shown. The benign meningioma tend to from the neuroectoderm and arise from compress the brain but not invade it (219). arachnoidal cap cells. Meningiomas account Approximately 15 % of meningiomas have for 10-15% of all brain tumors (7). They are atypical features. Aggressive or malignant the most frequent brain tumors originating meningiomas are characterized by abundant from non-neuroepithelial progenitor cells. mitosis and invasion into brain tissue. Less Usually, they are benign and completely than 0.1% of meningiomas can metastatize to resectable. Although they can potentially extracranial sites such as the lung, liver, occur at any site in the meninges, certain pleura, and lymph nodes. Their etiology intracranial locations are more common than remains unknown and may be multifactorial, others; parasagittal, attached to the falx, over environmental (head trauma, viruses, the cerebral convexities, in the olfactory radiation) or genetic (chromosome 22 groove, on the tuberculum sellae, along the deletions, neurofibromatosis type 2) (19, sphenoid ridge, in the cerebellopontine 189). angle, along the clivus, and at the foramen magnum. Most meningiomas are well-
General Principles of Meningioma Surgery
The treatment options of meningiomas are the tumor location. Especially for ASB surgery, radiotherapy or a combination of the meningioma, a small approach can be two. The goal of surgery depends upon enough to completely remove the lesion. The meningioma location and the patient's major vascular supply of meningiomas clinical condition. Complete resection comes from the dural attachment, but in involves removal of the dura and the bone larger meningiomas there can be also feeders from which the tumor originates. The from the surrounding arteries. The first step surgical approaches are selected according to in meningioma surgery is to devascularize
47 2 Review of the Literature the tumor with high power coagulation and respectively, at 10 years. Jääskeläinen et al. after that to debulk it. A large meningioma is (111) analyzed 657 meningioma patients debulked with the help of ultrasonic aspirator over a 20-year period; the overall recurrence and after that it is gradually dissected from rate was 19%. Risk factors for recurrence the surrounding cerebrovascular structures; were simple coagulation of the tumor base, small meningioma can be removed en-block invasion of bone, and soft tumor consistency. after dura coagulation (137). Simpson in Mirimanoff et al. (156) reviewed 225 1957 (212) established four grades of patients operated on from 1962 to 1980 and meningioma resection grade I: complete found that the degree of resection is the most meningioma resection with the dura and important factor in recurrence. After subtotal underlying bone; grade II: complete resection, 37% of tumors had progressed in 5 meningioma removal with coagulation of the years, 55% in 10 years, and 91% in 15 years. dural attachment; grade III: complete Radiation therapy can arrest the growth of meningioma removal without resection or some meningiomas. The indication for their coagulation of dural attachments; grade IV: use includes: residual tumor after surgery, subtotal resection. This classification is very tumor recurrence, meningioma that could not useful in evaluating tumor recurrence. In be treated surgically and malignant lesions Simpson’s series, grades I through IV had (172). recurrence rates of 9%, 19%, 29%, and 40%,
Clinical Characteristics of Olfactory Groove, Anterior Clinoidal, and Tuberculum Sellae Meningiomas
OGMs account for 8-13% of all intracranial ACMs are frequently attached to, or even meningiomas (159). They arise at the encasing, adjacent neurovascular structures cribriform plate of the ethmoid bone and at of the anterior skull base, making the the frontosphenoidal suture at the midline of complete removal challenge (5). ACMs the ACF (37, 209, 236). They are usually account for less than 10% of supratentorial diagnosed when they reach a large size meningiomas and they were first described (173). The most frequent symptom of by Frotscher and Becker in 1910 in an patients with OGMs is mental change, autopsy of a 72-year-old man (75). In the followed by headache, visual deficit, hypo- past, they were often included in the group of anosmia, and epileptic seizures (14, 159, sphenoidal meningiomas, masking their true 173). surgical and clinical outcome (179). Medial
48 2 Review of the Literature sphenoid wing meningiomas form a different imaging and the introduction of group of meningiomas, growing mainly microsurgical techniques, the outcome is towards the temporal lobe in the medial good. TSMs form a subgroup of cranial fossa and frequently infiltrating the meningiomas often contained within the cavernous sinus. We consider ACMs to be group of suprasellar meningiomas, which meningiomas that originate from the dura of also includes anterior and posterior clinoid the inferior, superior, and lateral aspects of process, planum sphenoidalis, olfactory the ACP and grow cranially or into the optic groove, optic foramen, and diaphragma foramen. A recent report defines clinoidal sellae meningiomas (40, 112, 115, 161). meningiomas as those that have the epicenter Cushing and Eisenhardt, in their first of the tumor base on the ACP and grow classification, did not differentiate between upwards, forming a small peduncle (179). TSMs and diaphragma sellae meningiomas. However, in large meningiomas, invasion to This differentiation was introduced by Kinjo such surrounding structures as the sellar et al. in 1995 (125), when they reported 12 region, cavernous sinus, and the temporal cases of diaphragma sellae meningiomas. portion of the medial sphenoid ridge makes it However, from the microsurgical point of difficult to define origin before resection. In view, we do not consider diaphragma sellae these cases, typical tumor shape and location meningiomas to form a clearly different of ACP in the center of the lesion usually entity and include them as TSMs, defined as reveal that the tumor belongs to the ACM those meningiomas originating from the dura group. of the tuberculum sellae, prechiasmal sulcus, TSMs comprise 5-10% of intracranial diaphragma sellae, limbus sphenoidalis, and meningiomas (40, 161, 214). Their location planum sphenoidalis and growing upwards is challenging because of adjacency to with the main location over the sella (117). neurovascular structures of the anterior skull In large meningiomas, invasion to the base. Despite this, their microsurgical surrounding structures, anterior clinoid treatment today shows favorable results processes, cavernous sinus, and the temporal because visual field deficits usually lead to portion of the medial sphenoid ridge makes it diagnosis at a stage when the tumor is still difficult to define origin before resection. In small (151). Cushing and Eisenhardt (1938), these cases, typical tumor shape and main in describing their series of 28 suprasellar location over the sella reveal that the meningiomas, wrote: “... Few promise in the meningioma belongs to the TSMs. future to be easily recognized while still of Contrary to OGMs, which are diagnosed small size” (40). However, with improved when large-sized, ACMs and TSMs, because
49 2 Review of the Literature of their close relationship to the optic nerve Helsinki Neurosurgical Department and chiasm, are diagnosed when they are describes 14 anterior clinoidal meningioma small, and the most frequent symptom is cases; 11 presented with headache, eight visual impairment, followed by headache, with visual deficit, six with epilepsy, four epileptic seizures, and endocrinological with exophtalmus, and two with diplopia symptoms (16, 173). A report written in (98). 1959 by neurosurgeon Olli Heiskanen of the
Microsurgical Treatment of OGM, ACM, and TSM through Classical Surgical Approaches
Olfactory Groove Meningiomas
Italian surgeons were pioneers in treating reported in 1938 a bifrontal approach with intracranial meningiomas, and the first closure of the anterior portion of the SSS, but successful surgical removal of an intracranial preservation of the frontal lobe (232). Kempe meningioma was performed in 1835 by proposed a unilateral approach by pterional Pecchioli, a Professor of Surgery at the route, allowing dissection of the posterior University of Siena (80). The first surgical part of the lesion, thereby preserving report of an OGM comes from Francesco neurovascular structures and avoiding brain Durante in Rome (88). In 1885, he retraction and opening of the frontal sinus performed a resection of an olfactory (122). The bifrontal craniotomy with orbital meningioma through a left subfrontal removal/transbasal extension was defined by approach; the patient had a good outcome Derome in 1972 (56). In the same year, (63, 64). Harvey Cushing published in 1938 Bakay reported a personal series of 25 his lifetime experience of 29 patients with olfactory meningiomas: 12 cases were OGMs operated on via a unilateral frontal treated by using a unilateral frontal approach craniotomy (40). In the same year, Dandy and 13 cases by using bifrontal craniotomy published a bifrontal approach to treat OGMs (13). with partial bilateral lobectomy (44). In After these important initial surgical reports, 1935, Olivecrona operated on an OGM several authors have published their through a unilateral frontal craniotomy and operative experience, macro- or partial frontal lobectomy (174). Tönnis microsurgical, in the management of OGMs
50 2 Review of the Literature using unilateral (12, 57, 96, 97, 122, 159, 154, 157, 159, 162, 173, 184, 187, 200, 206, 169, 184, 206, 214, 216, 236-238, 254, 255) 211, 214, 216, 229). or bilateral approaches (12, 14, 55, 65, 79, 94, 96, 97, 99, 120, 122, 131, 146, 147, 150,
Table 1. Macro- and microsurgical series of OGM surgeries through different approaches.
Death or morbidity/operations Author(s), year (reference) Approach (mortality or morbidity)
Macrosurgery
Durante F., 1885 (63) unilateral subfrontal 0/1 (no mortality) Dandy W., 1938 (44) bifrontal with bifrontal polar NA lobectomy Cushing H. and Eisenhardt L., 1938 unilateral frontal with partial bifrontal 8/29 (mortality) (40) lobectomy Tönnis W., 1938 (232) bifrontal without frontal 0/3 (no mortality) lobectomy Olivecrona H., 1946 (27) unilateral frontal NA/46 Bakay L. and Cares H.L., 1972 (13) unilateral frontal 1/12 (mortality) bifrontal 2/13 (mortality)
Microsurgery Ya2argil M.G., 1996 (255) pterional-transsylvian 0/14 (no mortality) Yamashita J. et al., 1980 (250) NA 6/30 (mortality) Rubin G. et al., 1995 (200) bifrontal; pterional; unilateral frontal 6/67 (mortality) Ojemann R.G., 1996 (172) bifrontal 1/19 (mortality) Gerber M. et al., 1998 (79) bifrontal 0/1 (no mortality) Paterniti S. et al., 1999 (184) pterional 2/20 (mortality) Turazzi S. et al., 1999 (238) pterional 1/37 (mortality) Tuna M. et al., 1999 (237) NA 0/15 (no mortality) D’Avella D. et al., 1999 (57) pterional 0/6 (no mortality) El Gindi S., 2000 (65) bifrontal 0/25 (no mortality) Couldwell W.T. and Weiss M.H., bifrontal NA 2000 (37) Hallacq P. et al., 2001 (94) transsinusal bifrontal osteoplastic 0/6 (no mortality) Wei C.P. et al., 2002 (243) bifrontal 0/1 (no mortality) Obeid F. and Al-Mefty O., 2003 supraorbital subfrontal (uni-bilateral) 0/15 (no mortality) (169) Dolenc V.V., 2003 (59) pterional 7/157 (morbidity)
51 2 Review of the Literature Hentschel S.J. et al., 2003 (99) bifrontal 0/13 (no mortality) Tuna H. et al., 2004 (236) bifrontal 0/19 (no mortality) pterional 0/6 (no mortality) Spektor S. et al., 2005 (216) bifrontal 1/35 (mortality) unilateral subfrontal 0/9 (no mortality) pterional 0/18 (no mortality) fronto-orbital 0/7 (no mortality) subcranial 0/12 (no mortality) Reisch R. and Perneczky A. at al., supraorbital subfrontal 0/21 (no mortality) 2005 (193) Tella Jr. O.I. et al., 2006 (229) uni-bifrontal 1/13 (mortality) Bassiouni H. et al., 2007 (14) bifrontal 3/36 (mortality) pterional 0/13 (no mortality) unilateral frontal 0/4 (no mortality) supraorbital 0/3 (no mortality) Kanno T., 2007 (120) bifrontal NA O’Brien D. et al., 2007 (168) frontal craniotomy 0/1 (no mortality) Welge-Luessen A. et al., 2007 (244) bifrontal and frontal 0/12 (no mortality) Colli B.O. et al. 2007 (34) bifrontal-uniorbital 2/17 (mortality) Nakamura M. et al., 2007 (159) bifrontal 3/46 (mortality) frontolateral 0/34 (no mortality) pterional 0/2 (no mortality) Gazzeri R. et al., 2008 (78) bifrontal 0/36 (no mortality) El-Bahy K. et al., 2009 (66) frontolateral 1/18 (mortality) Warren L.W. and Grant G.A., 2009 fronto-orbitozygomatic 0/4 (no mortality) (242)
For OGM surgery, Ya2argil recommended approach for OGMs (14, 26, 34, 57, 59, 96, understanding the relationship between the 183, 184, 216, 238). Both pterional or posterior surface of the tumor and the ACA minipterional approaches have the sylvian and optic nerves. The tumor must be fissure in the center of the craniotomy, with debulked from its lateral portion and partial exposure of the frontal and temporal devascularized from its base. The ACA can lobes (70, 254, 255). No previous report be dissected along the lamina terminalis describes the microsurgical treatment of cistern (254, 255). OGMs through a minipterional approach. Hassler and Zenter first reported in 1989 a Dolenc affirmed that complete opening of series of 11 olfactory meningiomas treated the sylvian fissure is mandatory when using the pterional approach (97). Many dealing with an OGM or TSM (59). Turazzi authors have subsequently reported this et al. reported their surgical experience of 37
52 2 Review of the Literature OGMs through the pterional approach and Colli et al. in 2007 published their series of emphasized the importance of opening the 17 OGM cases treated through a bifrontal basal cisterns for CSF release and to get approach with unilateral orbitotomy (34). more space to visualize the necessary Mayfrank and Gilsbach reported 18 cases of neurovascular structures. The author OGM treated through unilateral frontal recommend that the opening of the sylvian craniotomy and an interhemispheric route fissure be only partial. In large meningiomas, (154). debulking of the tumor enables dissection of Nakamura et al. compared the outcome and the A2 branches and the posterior part of the recurrences of OGM when treated through tumor (238). pterional, bifrontal, and frontolateral In 1996, Ojemann published 19 cases of approaches. Similar results were obtained in OGM treated through bifrontal craniotomy. the pterional and frontolateral groups. The This approach is associated with less authors recommended the use of the retraction of the frontal lobe with direct frontolateral approach instead of the bifrontal access to all sides of the tumor and allows approach (161). the debulking of the tumor and simultaneous access to the base from which its vascular support is derived (172).
Anterior Clinoidal Meningiomas
The two most frequently described surgical approaches to remove ACMs are pterional (16, 82, 135, 160, 179, 188, 201, 255) and orbitozygomatic (4, 5, 91, 196, 209, 210).
Table 2. Macro- and microsurgical series of ACM surgeries through different approaches.
Death or morbidity/operations Author(s), year (reference) Approach (mortality or morbidity)
Macrosurgery
Cushing H. and Eisenhardt L., 1938 unilateral frontal with partial 1/11 ( mortality) (39) lobectomy Uihlein A. and Weyand R.D., 1953 NA 17/52 (mortality) (240) Holub K., 1956 (106) NA 9/19 (mortality) Heiskanen O., 1959 (98) NA NA/14 Olivecrona H., 1967 (175) unilateral frontal 11/47 (mortality)
53 2 Review of the Literature Guyot J.F., 1967 (90) NA NA/13 Cook A.W., 1971 (35) pterional 2/11 (mortality) Fischer G., 1973 (72) NA 2/6 (mortality) Ugrumov V.M. et al., 1979 (239) NA 3/17 (mortality) Cophignon J. et al., 1979 (36) NA 0/6 (no mortality) Symon L. and Jakubowki J.,1979 unilateral frontal 1/30 (mortality) (225) McCarty C.S. and Taylor W.F., NA NA/47 1979 (147)
Microsurgery Ya2argil M.G., 1996 (255) pterional-transsylvian 0/9 (no mortality) Konovalov A.N. et al., 1979 (129) NA 11/92 (mortality) Bonnal J. et al., 1980 (21) pterional 3/9 (mortality) Pompili A. et al., 1981 (186) frontotemporal 1/10 (mortality) Hakuba A. et al., 1981 (93) orbitozygomatic 0/7 (no mortality) Sugita K., 1985 (220) pterional 0/7 (no mortality) Jan M. et al., 1986 (113) NA 6/19 (mortality) Jääskeläinen J., 1986 (111) NA NA/79 Al-Mefty O., 1991 (5) fronto-orbitozygomatic 2/24 (mortality) Ojemann R.G. and Swann K.W., frontotemporal 0/18 (no mortality) 1991 (173) Risi P. et al., 1994 (196) fronto-orbitozygomatic 2/34 (mortality) Rubin G. et al., 1995 (200) bifrontal; pterional; unilateral frontal 6/67 (mortality) Benjamin V. and McCormack B., pterional 0/20 1995 (18) Haddad G.F. et al., 1996 (91) orbitozygomatic NA Ojemann R. G., 1996 (172) frontotemporal 1/17 (morbidity) Puzzilli F. et al., 1999 (188) pterional 5/33 (mortality) Tuna M. et al., 1999 (237) NA 0/2 (no mortality) Tobias S. et al., 2003 (231) pterional 0/25 Chatterjee P.R. et al., 2004 (31) NA 0/1 (no mortality) Tao C.S. et al. 2005 (227) supraorbital-orbitozygomatic 1/12 (morbidity) Reisch R. and Perneczky A. at al. supraorbital subfrontal 0/18 (no mortality) 2005 (193) Cui H. et al., 2007 (38) pterional-extended pterional 0/26 (no mortality) Pamir M.N. et al., 2008 (179) pterional 0/43 (no mortality) Sade B. and Lee H.J., 2008 (203) fronto-orbital 0/52 (no mortality) Bassiouni H. et al., 2009 (16) pterional 2/104 (mortality) fronto-orbitozygomatic 0/2 (no mortality) Yang Y.M. et al., 2010 (251) pterional; frontotemporal; 1/53 (morbidity)
54 2 Review of the Literature orbitozygomatic
Ya2argil reported only nine cases of medial intradural clinoidectomy when the tumor is sphenoid wing meningioma through a inside the optic canal (173). transsylvian approach and recommended not Al-Mefty advised a fronto-orbitozygomatic removing the part infiltrating the cavernous approach to remove ACMs. After sinus in order to prevent cranial nerve palsy craniotomy, brain relaxation is achieved after surgery (255). In 2008, Pamir et al. through lumbar drainage and opening of the described a consecutive series of 43 ACMs basal cisterns. Elevation of the frontal lobe treated through a pterional approach. After should be minimal (1.5 cm) to avoid harming craniotomy, the sylvian fissure was widely the olfactory tract. The sylvian fissure is opened and the CSF removed to achieve a opened and the tumor if large can be slack brain. The MCA was followed to the debulked by an ultrasonic aspirator, after ICA and the tumor dissected following the which the MCA branches can be visualized. arachnoidal plane. The dura of the ACP was With microdissection, the tumor capsule is removed in all 43 cases (179). Bassiouni removed from the vessels. The dissection reported a multicenter series of 106 ACMs, follows all of the vessels (ICA and ACA), 104 treated using a pterional transsylvian becoming easier in the proximity of the craniotomy (in only two cases an PComA and anterior choroidal artery orbitozygomatic approach was applied). The (AChA), i.e. along the arachnoidal plane. tumor was removed via a unilateral The optic nerve also has an arachnoidal subfrontal route. Intradural clinoidectomy membrane to facilitate the dissection (5). Al- was performed in 16 cases where the tumor Mefty advised intradural removal of the was inside the orbit and in an additional anterior clinoid process if the ACM or TSM seven cases to relieve optic nerve is inside the optic canal or orbit. The compression and avoid its further damage pituitary stalk can be recognized by its color during tumor removal (16). Ojemann and vascular network. It is usually displaced reported a series of 17 ACMs through a backwards and to the opposite side and can frontotemporal craniotomy and a subfrontal be dissected following its arachnoidal plane route. After initial exposure, the medial (5, 149). portion of the sylvian fissure can be opened, followed by tumor debulking. It is important to dissect the MCA and follow it medially to the ICA. The author recommended an
55 2 Review of the Literature
Tuberculum Sellae Meningiomas
The anatomical region from which the TSM tumor removal and to preserve the originates is one of the most complex of the neurovascular structures. The most frequent brain for both transcranial and microsurgical approaches to remove TSMs transsphenoidal routes. The neural and are pterional (6, 15, 17, 68, 81, 95, 112, 124- vascular relationships with the sphenoid 126, 151, 161, 171, 178, 180, 202, 207, 214, bone are key when treating TSMs. ICA and 222, 224, 254, 255), fronto-orbital, fronto- its branches, optich chiasm and nerves, and orbitozygomatic (3, 6, 9, 10, 81, 114, 117, pituitary stalk can be attached, dislocated, 124, 125, 141, 149, 208) frontolateral (76, and encased by a TSM making challenge a 81, 124, 141, 161) and bifrontal (6, 10, 15, complete tumor removal. We consider the 76, 77, 81, 115, 125, 161, 171, 222, 224, transcranial route preferable than the 230). transsphenoidal one to achieve a complete
Table 3. Macro- and microsurgical series of TSM surgeries through different approaches.
Death or morbidity/operations Author(s), year (reference) Approach (mortality or morbidity) Macrosurgery Cushing H. and Eisenhardt L., 1938 (40) unilateral subfrontal 3/24 (mortality) Olivecrona H., 1946 (27) unilateral frontal NA/42 Hänsel G. and Seeger W., 1977 (95) pterional 0/5 (no mortality) Jefferson A. and Azzam N., 1979 (115) bifrontal 1/19 (mortality) Ugrumov V.M. et al., 1979 (239) NA 4/17 (mortality) Kadis G.N. et al., 1979 (118) bifrontal 13/105 (mortality)
Microsurgery Ya2argil M.G., 1996 (255) pterional-transsylvian 1/112 (mortality) Konovalov A.N. et al., 1979 (129) NA 5/68 (mortality) Bonnal J. et al., 1980 (21) frontotemporal NA/12 Yamashita H., 1980 (250) NA 6/39 (mortality) Solero C.L. et al.,1983 (214) unilateral frontal craniotomy with 13/55 (mortality) frontal lobectomy Chan R.C. and Thompson G.B., 1984 NA 2/12 (mortality) (28) Symon L. and Rosenstein J., 1984 (224) unilateral frontal osteoplastic 6/92 (mortality) bifrontal osteoplastic 0/4 (no mortality)
56 2 Review of the Literature Al-Mefty O. et al., 1985 (6) bifrontal (11 cases); pterional (4 3/17 (mortality) cases); subfrontal (2 cases) Sugita K., 1985 (220) bifrontal 1/9 (mortality) Jääskeläinen J., 1986 (111) NA NA/64 Grisoli F. et al., 1986 (87) pterional 0/28 (no mortality) Andrews B.T. and Wilson C.B., 1988 (9) fronto-orbital 2/38 (mortality) Al-Mefty O. and Smith R.R., 1991 (3) cranio-orbitozygomatic 0/35 (no mortality) Ojemann R.G. and Swann K.W., 1991 frontotemporal 0/20 (no mortality) (173) Benjamin V. and McCormack B., 1995 pterional 1/9 (mortality) (18) Rubin G. et al., 1995 (200) bifrontal; pterional; unilateral 6/67 (mortality) frontal Kinjo T. et al., 1995 (125) pterional (5 cases); bifrontal (3 0/11 (no mortality) cases); unifrontal (1 case); fronto- orbital (2 cases) Ojemann R.G., 1996 (172) pterional 3/21 (morbidity) Tuna M. et al., 1999 (237) NA 2/10 (mortality) Raco A. et al., 1999 (190) NA 5/69 (mortality) Arai H. et al. 2000 (10) bifrontal + orbital rim 0/21 (no mortality) Ciric I. and Rosenblatt S., 2001 (33) pterional; orbitozygomatic 0/24 (no mortality) Zevgaridis D. et al., 2001 (262) frontobasal/frontotemporal 0/34 (no mortality) Ohta K. et al., 2002 (171) pterional (15 cases); fronto- 0/33 (no mortality) orbitozygomatic/fronto-orbital (10 cases); bifrontal (6 cases); others (2 cases) Goel A. et al., 2002 (81) unifrontal 2/60 (mortality) orbitofrontal 0/3 (no mortality) bifrontal 0/4 (no mortality) orbitozygomatic 0/2 (no mortality) Fahlbusch R. and Schott W., 2002 (68) pterional 0/47 (no mortality) Jallo G.I. and Benjamin V., 2002 (112) pterional 2/23 (mortality) Dolenc V.V., 2003 (58) frontotemporal 0/49 (no mortality) Chi J.H. and McDermott M.W., 2003 (32) bifrontal (11 cases); unilateral 0/20 (no mortality) subfrontal (8 cases); pterional (1 case) Takahashi J.A. et al., 2004 (226) pterional 0/3 (no mortality) Benjamin V. and Russell S.M., 2005 (17) pterional NA Reisch R. and Perneczky A. at al. 2005 supraorbital subfrontal 0/16 (no mortality) (193) Pamir M.N. et al., 2005 (180) pterional 1/42 (mortality)
57 2 Review of the Literature Schick U. and Hassler W., 2005 (207) pterional 2/53 (mortality) Bassiouni H. et al., 2006 (15) pterional (49 cases); bifrontal (7 10/62 (morbidity) cases); unilateral subfrontal (4 cases); supraorbital (2 cases) Nakamura M. et al., 2006 (161) pterional-frontotemporal 0/21 (no mortality) bifrontal 2/21 (mortality) frontolateral 0/30 (no mortality) Park C.K. et al., 2006 (181) pterional 0/26 (no mortality) bifrontal 0/4 (no mortality) Otani N. et al., 2006 (178) pterional 0/32 (no mortality) Kitano M. et al., 2007 (126) pterional 0/12 (no mortality) Li X. et al., 2007 (140) unifrontal NA/24 pterional NA/19 Kanno T., 2007 (119) bifrontal NA de Divitiis E. et al., 2008 (54) pterional 0/36 (no mortality) unilateral subfrontal 0/4 (no mortality) bifrontal 0/4 (no mortality) Nozaki K. et al., 2008 (166) frontotemporal 0/22 (no mortality) Kim T.W. et al., 2008 (123) unilateral frontal (20 cases); 0/27 (no mortality) pterional (5 cases); fronto-orbital (2 cases) Suri A. et al., 2008 (222) pterional; bifrontal; fronto-orbito- 0/18 (no mortality) zygomatic Ganna A. et al., 2009 (77) bifrontal 0/24 (no mortality) Sade B. and Lee H.J., 2009 (202) pterional 0/31 (no mortality) Jung H.W. and Park C.K., 2009 (117) fronto-orbitozygomatic NA Warren L.W. and Grant G.A., 2009 (242) fronto-orbitozygomatic 0/10 (no mortality) Fatemi N. et al., 2009 (69) supraorbital keyhole 0/7 (no mortality) Galal A. et al., 2010 (76) frontolateral (18 cases); bifrontal 1/21 (mortality) (3 cases) Mahmoud M. et al., 2010 (149) unilateral fronto-orbital 1/58 (mortality) Xu Y.M. et al., 2010 (249) bifrontal 0/11 (no mortality) Bowers C.A. et al., 2011 (22) pterional 0/22 (no mortality) Terasaka S. et al., 2011 (230) bifrontal 3/9 (morbidity)
The largest series of TSMs, comprising 112 window should be made in the prechiasmatic cases, comes from Ya2argil (255). Ya2argil's area to devascularize the tumor. Debulking protocol involves opening the sylvian fissure, of the tumor provides space to allow as in OGM and ACM surgeries, and dissection of the optic nerves, optic chiasm, following the MCA to the ICA bifurcation. A circle of Willis, pituitary stalk, and
58 2 Review of the Literature oculomotor nerve. The tumor capsule is high magnification, the neurovascular dissected from the pituitary stalk and can be structures are dissected. The ACA and MCA removed. If the tumor extends into the optic are freed from the tumor. The arterial supply canal, this can be drilled for a few to the inferior surface of the optic apparatus millimeters, allowing mobilization of the from the superior hypophyseal artery should optic nerve and the ophthalmic artery. be preserved by following the arachnoidal Attention must be paid, however, to avoid plane during the sharp microdissection. After entering the sinuses. Ya2argil stated that tumor removal, its origin is coagulated (117). complete removal of TSMs is more often Ganna reported 24 TSMs where the possible than removal of other skull base interhemispheric approach allowed an early meningiomas (255). The surgical technique tumor devascularization, and after central described by Ya2argil was applied by other debulking of the tumor, both ICAs were authors (172, 173). identified. The optic nerves and chiasm are Jung and Parker reported a surgical not retracted because if the tumor is inside technique to remove TSMs through a fronto- the optic canal it can be unroofed. The orbitozygomatic approach and extradural tuberculum sellae hyperostosis can be clinoidectomy. Lumbar drainage is used to drilled, paying attention to reconstruct the achieve a slack brain. The sylvian fissure is skull base and avoid a CSF fistula (77). opened and the frontal lobe gently retracted. Nakamura reviewed the surgical experience The first step is to devascularize the tumor of Samii when treating TSMs through from the planum sphenoidalis to reduce pterional, frontolateral, and bifrontal intraoperative bleeding. Debulking of the approaches, and emphasized the importance tumor is done with suction and an ultrasonic of the frontolateral approach (161). aspirator or bipolar and microscissors. Under
Outcome of OGM, ACM, and TSM through Pterional, Orbitozygomatic, and Bifrontal Approaches
Olfactory Groove Meningiomas
Surgical complications in OGMs treatment Dolenc in 2003 published his personal are: CSF fistula, frontal syndrome, hypo- experience of 157 OGMs treated through the anosmia, hemiparesis, visual worsening, pterional approach. After surgery, postoperative hematoma, hydrocephalus, improvement was seen in 112 patients, no infections, seizures and mortality (159, 238). change in 38 patients, and worsened
59 2 Review of the Literature condition in seven patients. In all cases, the series of 80 OGM patients treated through tumor was completely removed. In 25 cases, different surgical approaches reported CSF reconstruction of the floor of the ACF was leakage in 10 patients (12.5%), eight required, and in all of these cases lumbar resolved with lumbar drainage and two drainage was used for one week after underwent skull base sealing. Five of their 10 reconstruction of the skull base. No mortality patients underwent bifrontal craniotomy, and occurred in the series (59). Ojemann in 1996 one patient of the bifrontal group died. No published his experience of 19 OGMs, mortality was found in the patients advising treatment through bifrontal undergoing unilateral subfrontal, pterional, craniotomy. One patient presented with CSF or fronto-orbital craniotomy (216). Tuna et leakage, requiring repair of the skull base, al. reported 25 OGMs treated through one patient had a wound infection, and one bifrontal and pterional approaches. No patient required a subdural-peritoneal shunt patient died, but four had CSF leakage, one for a subdural hygroma. Preoperative visual had epilepsy, and three developed frontal symptoms and disturbance of mental lobe edema (236). Nakamura compared the function were completely alleviated (172). treatment of OGM through bifrontal, Colli reported a series of 17 OGM patients pterional, and frontolateral approaches; four treated through bifrontal craniotomy and patients died in the bifrontal group, whereas unilateral orbitotomy. Two patients died, no mortality occurred in patients treated four had local infections, two presented with through the frontolateral or pterional route epilepsy, one had postoperative edema, and (159). one had transient ptosis (34). Spektor in a
Anterior Clinoidal Meningiomas
The close relationship of ACM with ICA, treated through pterional approach. Eight optic nerve and other neurovascular patients presented with surgical structures make their total removal challenge complications (three meningitis, and associated with postoperative postoperative hematoma, one hydrocephalus, complications (CSF leakage, visual one hemiparesis for venous infarction, one worsening, hemiparesis, aphasia, epilepsy, one pneumonia). No mortality was hydrocephalus, endocrinological symptoms, reported (179). hematoma, infections) and mortality (16, Of 24 patients treated by Sade and Lee 179). Pamir reported a series of 43 ACMs through a skull base approach with fronto-
60 2 Review of the Literature orbital craniotomy and extradural anterior Puzzilli reported a series of 33 ACMs treated clinoidectomy, preoperative visual deficit through pterional craniotomy. Four patients improved in 17 cases. No patients died (203). died after surgery. At the end of the follow- In the multicenter series of 106 ACM cases up of 19 patients for a mean of 53.7 (range reported by Bassiouni et al. through pterional 12-108) months, there were five recurrences craniotomy (104 cases) or an (188). In the Risi series treated by orbitozygomatic approach (two cases), orbitozygomatic approach, three patients had postoperative complications included aphasia CSF leakage, two patients died, and three (eight cases), transient hemiparesis (four patients had permanent morbidity. Of the 20 cases), and CSF leakage (four cases) treated patients with preoperative visual deficit, 13 by lumbar drainage. Two patients died. Of improved, one remained unchanged, and six 52 patients with preoperative visual deficits, worsened (196). Al-Mefty treated 24 21 improved and 7 worsened (16). Ojemann meningioma cases through a fronto- described one patient treated through orbitozygomatic approach and reported two frontotemporal approach; this patient had deaths. Furthermore, one patient became permanent morbidity with dysphasia and blind, one had permanent 3rd nerve palsy, hemiparesis. The author was uncertain of one had CSF leakage, and three had diabetes total tumor removal because of complicated insipidus (two transitory and one permanent) attachment to vessels (172). (5).
Tuberculum Sellae Meningiomas
Although the relation of the optic chiasm to one with undetected rhinorrhea and the sellar region frequently affects the visual meningitis who subsequently died. Forty-five outcome, other complications can occur after patients had improvement of visual function, TSM surgery. The most common 29 unchanged, and 11 impaired (255). complications are: CSF leakage, Ojemann described a series of 21 cases endocrinological disturbances, infections; operated on through a pterional approach; 18 less frequent complications are: hematoma, had good outcome, one had mild frontal lobe hemiparesis, and mortality (6, 68, 81). syndrome and worsening of visual function, Ya2argil reported through a pterional one had severe frontal lobe syndrome, and transsylvian approach 104 patients with good one had already undergone four earlier outcome, seven with moderate disability, and operations. No patients died. Visual function
61 2 Review of the Literature worsened in two cases (172). Nakamura the bifrontal group (161). compared the simple frontolateral approach Mahmoud reported 58 cases; no mortalities (very similar to our LSO approach) with the occurred and three patients presented with a bifrontal approach in microsurgery of TSMs, worsening of visual function, four had CSF and two patients in the bifrontal group died leakage with one requiring reoperation, three due to postoperative brain edema. No deaths had unilateral olfactory tract damage with occurred in the frontolateral or pterional anosmia, seven had postoperative hyposmia, groups. The authors concluded that the one had infection, and one died due to anterior third of the SSS should be preserved pulmonary embolism (149). With the during OGM surgery, and this is better bifrontal approach, the most frequent achieved with the frontolateral approach. The complication is anosmia, reported in seven visual improvement rate was significantly TSM patients by Ganna et al., only one better in patients who underwent patient had visual worsening after surgery frontolateral tumor resection compared with (77).
Recurrences of OGM, ACM, and TSM when Using Classical Approaches
In the series of OGMs reported by Ojemann, the patients was treated through bifrontal no patients who underwent scans (13/19 craniotomy and for the other three the patients) had a recurrence during a mean approach was not specified. In three of these follow-up of 4.4 years (172). Snyder et al. patients, the dura was coagulated (without reported four OGM recurrences after a mean removal), and in one a subtotal tumor of 6 years (213). An extensive review of the resection was achieved. No recurrences literature on meningiomas by Black occurred in a series of 20 (total 25) OGMs unearthed a 10-year recurrence rate of 9-20% treated through bifrontal and pterional for totally resected meningiomas (19). Chan approaches during a mean follow-up of 58.4 and Thompson reviewed their experience of (range, 14-112) months (213). Nakamura 257 meningiomas, including 20 OGMs and reported OGM and TSM resection through 12 TSMs, noting recurrences in three and different surgical approaches and concluded two patients, respectively, over a mean that the rate of total tumor removal (Simpson follow-up of 9 years (range 6 months-22 grade 1 or 2) did not differ significantly years) (28). The surgical approach was not among the approaches. It was 92.7% in the specified in their series. Snyder et al. frontolateral group and 93.5% in the reported four late OGM recurrences; one of bifrontal group, and the overall recurrence
62 2 Review of the Literature was 4.9% during a mean follow-up of 5.3 proliferative index (16). Of the 17 ACM years (2.9% in the frontolateral group and cases treated by Ojemann, three had a 6.5% in the bifrontal group) (159, 161). The recurrent tumor with two requiring recurrence rate was 0 in 15 OGM patients reoperation and radiotherapy (172). Al- treated by Obeid and Al-Mefty through a Mefty reported one ACM recurrence in a supraorbital subfrontal approach (unilateral series of 24 cases followed up for 57 months or bilateral) (169). In a series of 106 ACM (5). patients treated through pterional (104 cases) None of the 112 patients operated on by and orbitozygomatic approaches (two cases), Ya2argil had a recurrence during a 10-year 10 patients experienced a recurrence during follow-up (255). In Nakamura's TSM series, the mean follow-up of 4.8 (range, 2-8) years. the recurrence rate was 2.8% (2/72 patients) Two had Simpson grade I and eight Simpson during a mean follow-up of 45.3 (range, 4- grade II removals. Three of these patients 238) months (161). In Mahmoud's series, one underwent a second surgery and three recurrence was recorded over a mean follow- fractionated radiotherapy for a high cellular up of 23 months (149).
Anterior Clinoidectomy
The medial portion of the lesser wing of the clinoidectomy in 1968 when treating carotid- sphenoid bone is the ACP (109). Its ophthalmic aneurysms, although he later anatomical location is extremely important claimed it was unnecessary (62). A few years for the relationship to the optic nerves, ICA, later, Guidetti (89), Ya2argil (259), and and other parasellar neurovascular structures. Sundt (221) described the microsurgical Anterior clinoidectomy allows the exposure technique of intradural anterior and safe mobilization of the optic nerve at its clinoidectomy for the treatment of carotid- proximal entrance to the optic canal and the ophthalmic aneurysms. ICA in its transitional segment from the cavernous to the intradural space (226); anterior clinoidectomy is a key microsurgical step for the successful and safe management of paraclinoid aneurysms and parasellar neoplastic lesions (52, 60, 261). Drake reported performing an anterior
63 2 Review of the Literature Table 4. Anterior clinoidectomy through different surgical approaches.
Intradural/Extradural Author(s), year (reference) Approach (lesions) Clinoidectomy
(number of cases) Drake C.G. et al., 1968 (62) pterional (carotid-ophthalmic intradural (14 cases) aneurysms) Guidetti B. and La Torre E., 1975 (89) frontotemporal (carotid- intradural (26 cases) ophthalmic aneurysms) Ya2argil M.G. et al., 1977 (259) pterional (carotid-ophthalmic intradural (30 cases) aneurysms) Iwabuchi T. et al., 1978 (110) unilateral frontal (carotid- intradural (6 cases) ophthalmic aneurysms) Sundt T.M. and Piepgras D.G., 1979 (221) pterional (giant aneurysms) intradural (80 cases) Heros R.C. et al., 1983 (105) pterional (paraclinoid extradural (34 cases) aneurysms) Dolenc V.V., 1985 (60) pterional (carotid-ophthalmic extradural (14 cases) aneurysms) Perneczky A. et al., 1985 (185) pterional (infraclinoid intradural (NA) aneurysms) Knosp E. et al., 1988 (127) pterional (paraclinoid intradural (NA) aneurysms) Nutik S. L., 1988 (167) NA intradural (NA) Kobayashi S. et al., 1989 (128) pterional (carotid cave intradural (32 cases) aneurysms) Ohmoto T. et al., 1991 (170) pterional (intracavernous intradural (7 cases) aneurysms) Korosue K. and Heros R.C., 1992 (130) pterional (carotid aneurysm) intradural (1 case) Day J.D. et al., 1994 (53) orbitozygomatic (upper basilar extradural (22 cases) and infrachiasmatic lesions) Yonekawa Y. et al., 1997 (261) pterional (parasellar lesions) extradural (40 cases) Tobias S. et al., 2003 (231) pterional (ACMs) extradural (23 cases) Huynh-Le P. et al., 2004 (109) NA extradural (NA) Takahashi J.A. et al., 2004 (226) pterional (ICA aneurysms, intradural en-bloc (37 TSMs) cases) Avci E. et al., 2005 (11) frontotemporal intradural (NA) extradural (NA) Benjamin V. and Russel S.M., 2005 (17) pterional (TSMs) intradural (NA) Noguchi A. et al., 2005 (165) orbitozygomatic (40 extradural (60 cases) aneurysms and 20 tumors) Chang H.S. et al., 2006 (30) frontotemporal (parasellar extradural (8 cases)
64 2 Review of the Literature tumors) Otani N. et al., 2006 (178) pterional (TSMs) extradural (32 cases) Andaluz N. et al., 2006 (8) pterional intradural (NA) Gonzalez-Darder J.M., 2007 (84) pterional (paraclinoid intradural (NA) aneurysms) Sade B. and Lee J.H., 2008 (203) pterional (ACMs) extradural (52 cases) Nozaki K. et al., 2008 (166) frontotemporal (TSMs) intradural (20 cases) Jung H.W. and Park C.K., 2009 (117) fronto-orbitozygomatic extradural (NA) (TSMs) Chang D.J. et al., 2009 (29) pterional (NA) extradural (45 cases) Sade B. and Lee J.H., 2009 (202) pterional (TSMs) extradural (28 cases) Bassiouni H. et al., 2009 (16) pterional (ACMs) intradural (23 cases) Park S.K. et al., 2009 (182) NA (PComA aneurysms) intradural (6 cases) Li-Hua C. et al., 2010 (141) fronto-orbital; frontolateral intradural (27 cases) (TSMs) Son H.E. et al., 2010 (215) pterional (paraclinoid extradural (22 cases) aneurysms) Golshani K. et al., 2010 (83) NA (PComA aneurysms) intradural (NA) Nanda A. and Javalkar V., 2011 (163) pterional (carotid-ophthalmic intradural (86 cases) aneurysms)
The milestone description of extradural pterional or orbitozygomatic approaches (52, anterior clinoidectomy by Dolenc for the 60, 89, 226, 259, 261). treatment of carotid-ophthalmic aneurysms appeared in 1985 (60). All of these reports describe the anterior clinoidectomy through
Anterior Clinoidectomy through Pterional or Orbitozygomatic Approach
A few recent reports describe surgical until the deeper side of the cortical bone is techniques to remove the ACP. Takahashi reached. With a small rongeur, the ACP is reported intradural en-bloc removal of the ruptured and removed en-bloc. ACP through a pterional approach (226). Understanding the relationship between the After dura incision and its removal ACP and the ICA or optic nerve is crucial posteriorly, a diamond drill (diameter 1 mm) (226). A similar technique and the same is used starting at the posterior edge of the pterional approach but through an extradural optic canal to 1 cm anterior of the medial route are described by Yonekawa (261). He margin of the optic canal. Drilling continues also advised en-bloc removal of the ACP;
65 2 Review of the Literature however, if en-bloc is not possible, a small wing of the sphenoid over the SOF and also piece can be removed by drilling and by the greater wing are then opened to expose microrongeur (261). Otani reported 32 cases the inferior margin of the SOF. The dura of TSM treated through pterional craniotomy over the ACP is dissected and the ACP and 20 underwent extradural clinoidectomy. removed. A 2-mm diamond drill is used The ACP was removed by using a diamond during the procedure (165). Chang described drill under microscope (178). an interesting technique to perform anterior Noguchi reported a microsurgical technique clinoidectomy extradurally and through a to extradurally remove the ACP and SOF pterional approach without the use of a high- through an orbitozygomatic craniotomy. speed drill but only microrongeurs of First the sphenoid ridge is flattened, the dura different sizes (29). dissected, and the SOF opened. The lesser
Anesthesiological Procedures
Anesthetic management can significantly affect the prognosis of a patient undergoing removal of an anterior skull base meningioma (164). No previous reports describe neuroanesthesia procedures for different ASB approaches; only general principles in dealing supratentorial procedures have been published (1, 25, 164, 191). General principles of neuroanesthesia for supratentorial procedures include: 1) optimize brain oxygenation; 2) maximize venous drainage ensuring adequate head position (15-30° tilt); 3) reduce oxygen metabolism: deepen anesthesia, bolus intravenous of anesthetic agents or lidocaine; 4) reduce extracellular fluid volume with mannitol or hypertonic saline, 5) consider hypocapnia or an anticonvulsant in some cases (25, 191).
66 3 Aims of the Study
3 Aims of the Study
I-III: To describe the microneurosurgical technique and assess the effectiveness and safety of the lateral supraorbital (LSO) approach in removing: I: Olfactory Groove Meningiomas II: Anterior Clinoidal Meningiomas III: Tuberculum Sellae Meningiomas.
IV: To assess the principles of neuroanesthesia in achieving a slack brain when removing meningiomas of the anterior cranial fossa through the LSO approach.
V and VI: To describe the microneurosurgical technique and assess the effectiveness and safety of the LSO approach when performing extradural or intradural anterior clinoidectomy for the treatment of vascular and neoplastic lesions.
67 4 Patients and Methods
4 Patients and Methods
This study is based on retrospective data and The microsurgical technique and outcome of the analysis of operative videos of 66 OGM, 82 consecutive patients undergoing an 73 ACM, and 52 TSM patients treated anterior clinoidectomy through the LSO through the LSO approach between approach between June 2007 and January September 1997 and August 2010. 2011 were retrospectively analyzed. All Anesthesiological data of these 191 patients were treated at the Department of consecutive patients were analyzed to Neurosurgery of Helsinki University Central determine the principles necessary to achieve Hospital between September 1997 and a slack brain when treating OGMs, ACMs, January 2011 by a single neurosurgeon and TSMs through an LSO approach. (J.H.).
Treatment of OGM, ACM, TSM through LSO Approach (Publications I-IV)
Patients and Imaging series of meningiomas exceeding 1200 cases. The publications I-III are based on 191 The Table 5 reports the demographics and consecutive meningioma patients (66 OGMs, clinical findings of the patients. Clinical 73 ACMs and 52 TSMs) operated on conditions, preoperative and postoperative, between September 1997 and August 2010 at were expressed by the Karnofsky the Department of Neurosurgery, Helsinki performance score (121), and Glasgow University Central Hospital, Finland, by the outcome score (GOS) was used to express senior author (J.H.), with a total personal the postoperative clinical outcome (116).
68 4 Patients and Methods Table 5. Demographic data of 191 patients. Men; 57 Woman; 134 Age (years); mean (range) 59 (range, 14-87) Karnofsky score; mean (range) 82 (range, 40-100)
Edema 86 Brain shift 79 Sellar infiltration 58
Duration of surgery; median (minutes) 115 (range, 35-442)
Computed tomography (CT) or magnetic evaluated for tumor size and lateralization, resonance imaging (MRI) of the brain was brain shift, edema, possible calcifications, performed prior to surgery. For 13 OGM, 21 signs of sellar and ethmoidal hyperostosis, ACM, and 19 TSM patients, magnetic erosion and infiltration; intraorbital, resonance angiography (MRA) was also cavernous sinus, anterior clinoid, and planum performed to evaluate the tumor's vascular sphenoidalis involvement; attachment, supply and relation to the ACAs. Possible dislocation, or encasement of ACA, MCA, tumor-related pathological changes of the ICA, and BA; involvement of optic nerves ICA, AComA, and middle (MCA) and ACA and the optic chiasm; and pituitary stalk were investigated (Figure 19). CT lateralization. An immediate postoperative angiography (CTA) was performed in three CT scan was performed on 55 OGM patients ACM and TSM cases, and digital subtraction and 37 TSM patients. An immediate angiography (DSA) was performed in four postoperative MRI scan was performed on ACM, one OGM, and one TSM case. 55 ACM patients, a CT scan only was Preoperative tumor embolization was not performed on 17 ACM and 12 TSM performed on any of the patients. When patients. One ACM patient died of a cardiac treating OGM, ACM, and TSM the main infarction before the postoperative blood supply comes from the AEAs and radiological examination. An early PEAs, which originate from the OA and they postoperative MRI with gadolinium are difficult to close endovascularly (67, 134, enhancement was done when a tumor 194). The preoperative images were remnant was suspected.
69 4 Patients and Methods
Figure 19: Large OGM as seen on preoperative MRI. A, MRA showing ACAs attached to the posterior part of the tumor (arrows). B, T2-weighted MRI showing lateral dislocation of the ACAs (arrow).
Intraoperative Videos
The videos of all operations were analyzed (Supplementary videos 6-9), and TSMs and selected to show the microsurgical (Supplementary videos 10-12) of different technique used when treating OGMs sizes and consistencies through a LSO (Supplementary videos 2-5), ACMs approach.
Anesthesia Records
The anesthesia methods of 64 OGMs, 71 blood pressure was recorded before ACMs, and 52 TSMs were analyzed. Data anesthesia. Intraoperatively invasive arterial collection included duration of anesthesia blood pressures (arterial transducer set to and surgery, anesthetic agents and their zero at the level of the foramen Monroe) doses, total amount of administered were registered at 5-min intervals for 40 min vasoactive agents (phenylephrine, ephedrine, and thereafter at 10-min intervals until the dopamine, or atropine), total amount of end of surgery. Hypertension (systolic administered crystalloids (Ringer´s acetate), arterial pressure, SAP > 160 mmHg) was colloids (hydroxyethyl starch solution, HES, scrutinized during the immediate or albumin), mannitol, red blood cell postoperative phase. The evaluation of the concentrates, fresh frozen plasma, or platelet surgical conditions during craniotomy was concentrates. Heart rate and non-invasive based on surgical charts and was classified as
70 4 Patients and Methods good, satisfactory, or poor retrospectively. such as hypertension, and the use of any Patients’ preoperative medical comorbidities, medication were registered.
Follow-up
The patients were periodically seen at the postoperative residual tumor usually had a outpatient clinic, first at three months after clinical examination and MRI follow-up discharge and then at 1- to 2-year intervals once a year. for up to seven years depending on the grade and extent of removal. Patients with a known
Statistical Analysis
Data were analyzed with the statistical preoperative symptoms of anosmia, visual software package SPSS (SPSS Inc., Chicago, deficit, size of meningiomas, peritumoral IL, USA). Categorical variables were edema, duration of preoperative visual compared with the Fisher exact two-tailed deficits, memory impairment, preoperative test or the Pearson 02 test and the Kruskall Karnofsky score, and method of anesthesia. Wallis test, and continuous variables Tumor size, consistency, attachment to between two groups with the Mann-Whitney ACAs, ICA, MCA, AComA, or the optic U-test. Univariate association of continuous nerve or chiasm, and infiltration into the variables was tested with Spearman rank paranasal sinuses were also analyzed in the correlation coefficients. Univariate and OGM group. The maximum likelihood multivariate odds ratios (ORs) with 95% stepwise forward and backward elimination confidence intervals (CIs) were estimated procedures were used with selection of using unconditional logistic regression to variables based on the magnitude of their determine factors predicting good clinical probability values (P<0.1). A two-tailed outcome (GOS=5) at the end of follow-up, probability value of less than 0.05 was good neurosurgical condition, and extubation considered significant. time. The tested variables included age,
71 4 Patients and Methods
Anterior Clinoidectomy through LSO Approach (Publications V and VI)
Patients and Imaging
Between June 2007 and January 2011, a total performance score (121) for neoplastic of 82 patients underwent anterior lesions. The Hunt-Hess (HH) scale (108) clinoidectomy through an LSO approach for was used for vascular patients. The GOS vascular and neoplastic lesions. The lesions (116) was used to reflect the postoperative and clinical data of these patients are clinical outcome of vascular and neoplastic presented in Table 6. Preoperative clinical patients. conditions were expressed on the Karnofsky
Table 6. Patients and lesions. Demographic data Men; n 21 Woman; n 61 Age [years]; median (range) 54 (range, 22-82)
Preoperative condition Karnofsky score of 35 tumor patients; 90 (range, 60-90) median (range) Hunt-Hess (n. of vascular patients) Grade 0 (3) 1 (28) 2 (5) 3 (4) 4 (3) 5 (4)
Visual impairment 27 Duration of preoperative visual deficit < 6 months 10 6-12 months 2 >12 months 15 Frontal syndrome-memory deficit 5 Oculomotor nerve deficit 10
72 4 Patients and Methods Seizures 1 Headache 17 Hemiparesis 2 Abducens paresis 1 Exophtalmus 5 Trigeminal hypoestesia 1
Location of the lesions Vascular cases 47 Carotid-ophthalmic aneurysms 21 Other carotid aneurysms 23 Basilar bifurcation aneurysm 1 Carotid cavernous fistulas 2 Tumor cases 35 Meningiomas 26 Other lesions 9
All tumor patients underwent MRI before reconstructions of CT or CTA imaging were surgery. All patients with aneurysms, analyzed to evaluate the extent of removal of ruptured or unruptured, underwent CT and the ACP in all cases. CTA before surgery. Postoperative 3D
Intraoperative Videos cases were selected to show extradural and Intraoperative videos of 82 patients were intradural clinoidectomy for vascular and analyzed for nuances of the anterior neoplastic lesions (Supplementary videos 13- clinoidectomy technique, and illustrative 15).
Follow-up
We reported early clinical outcome at outpatient clinic with special attention discharge and at three months in the focused on visual outcome.
Statistical Analysis
The statistical analysis was performed using USA). Groups were compared using Mann- SPSS 18.0 software (SPSS Inc., Chicago, IL, Whitney U-test or Pearson’s 02 test. P-values
73 4 Patients and Methods of less than 0.05 were considered significant. included in the binary logistic regression Risk factors (aneurysms, high score of HH, analysis used for multivariate comparison of opening of the superior orbital fissure, potential risk factors for postoperative visual extradural clinoidectomy, and use of deficits. P-values of less than 0.05 were ultrasonic bone device) with P-values of less considered significant. than 1.0 in the univariate analysis were
74 4 Patients and Methods
“There is nothing more difficult, more dangerous nor more least likely to succeed than to initiate a new order of things”.
Niccolo’ Machiavelli, The Prince (1469-1527)
Microsurgical Techniques (Publications I-VI)
Lateral Supraorbital Approach
Patient Position
The patient is in supine position (Figure 20 practice also to adjust the position of the A). The head fixed to the head frame is a) fixed head and body during the operation as elevated around 20 cm or more above needed, but the frequency of this maneuver cardiac level; b) rotated 20º to 30º towards could not be assessed retrospectively. No the contralateral side of the tumor or local anesthetics are infiltrated for pins of aneurysm; and c) the neck is slightly flexed Sugita frame. A bolus of remifentanil is and tilted laterally to obtain a better view of given to prevent hypertension. the anterior part of the anterior fossa, enabling optimal venous return. It is our
Craniotomy
After minimal shaving and injection of a (Figure 20 C). The upper part of the temporal vasoconstrictive agent, an 8- to 10-cm skin muscle is split and retracted towards the incision is made behind the hairline (Figure zygomatic arch. The extent of craniotomy 20 B). Following an oblique frontotemporal depends on lateralization and size of the skin incision, behind the hairline a one-layer ACM or TSM. Usually, a classic LSO skin-muscle flap is retracted frontally with craniotomy is all that is necessary. A single spring hooks, and the superior orbital rim burr hole is placed just under the temporal and the anterior zygomatic arch are exposed line of the bone, i.e. the superior insertion of
75 4 Patients and Methods the temporal muscle (Figure 20 D). A bone stitches extended over the craniotomy flap of 4 x 3 cm is detached mostly by side- dressings (Figures 20 F and 21). From this cutting drill, and the basal part can be drilled point onwards, all surgery, including skin before lifting (Figure 20 E). The dura is closure, is performed under the operating incised curvilinearly with the base microscope. sphenoidally and elevated by multiple
Figure 20: (A) Position when performing the LSO approach, (B) skin incision, (C) muscle detachment, (D) burr hole, (E) size of craniotomy, and (F) brain exposed after an LSO approach (199).
Figure 21: Exposure of the right ICA and optic nerve after performing a right LSO in a cadaveric specimen (Courtesy of Dr. Asem Salma of Columbus University, Ohio) (204).
LSO Approach with Minimal Temporal Exposure (Publications II and V)
In the classic LSO, the sylvian fissure opening, and, if needed, it can be easily remains at the inferior border of the dural opened, as our large experience on anterior
76 4 Patients and Methods and even posterior circulation aneurysms or so to the temporal side of the sylvian demonstrates (48-51, 100, 102, 138, 139, fissure (Figures 22 and 23). The head 198, 199). In 20 ACM cases and in 20 position is the same as in a classic LSO patients who underwent anterior approach, with a more caudal and posterior clinoidectomy, we performed an LSO skin-muscle cut. Size of the tumor or approach with temporal extension, i.e. the aneurysm with a significant temporal classic LSO with additional lateral extension component is the only indication for towards the middle cranial fossa for minimal temporal extension of the LSO approach. temporal exposure. This means extending the exposure for approximately one centimeter
Figure 22: (A) A CT-3D skull base reconstruction showing the classic LSO (continuous black line) and the minimal temporal extension (dotted line). (B) The origin of the OGM (dotted circle, small); ACM (continuous circle) and TSM (dotted circle, large) of the anterior skull base reached through an LSO approach.
Figure 23: The brain exposed (A) after a left LSO with minimal temporal extension and (B) after a right classic LSO.
77 4 Patients and Methods
Removal of OGM, ACM, TSM through LSO Approach (Publications I-III)
Neuroanesthesia is mandatory to achieve a sylvian fissure. If needed, it can be easily slack brain (191). The floor of the ASB is performed through the LSO approach, followed towards the ipsilateral optic nerve especially for removing larger tumors (48- and carotid artery, and CSF is released from 51, 100, 102, 138, 139, 198, 199). the basal cisterns. We seldom open the
Tumor Devascularization
The first step, after opening the basal cisterns attachment of the tumor, taking care to and achieving more space, is to reach the preserve olfactory tract function. At the dural attachments of the tumor. When beginning of OGM removal, coagulation of treating OGM the blood supply comes from the AEAs and PEAs is necessary with the the AEAs and PEAs, which originate from risk of ischemic damage to the olfactory tract the OA and they are difficult to close (47, 79). The dura of the ACP is coagulated endovascularly (67, 134, 194). We coagulate with bipolar forceps using high power (Malis the major arterial supply to the tumor before 50) to interrupt the vascular supply to the further dissection to ensure minimal tumor in order to devascularize the tumor intraoperative blood loss. With bipolar and minimize intraoperative bleeding. coagulation we devascularize the dural
Small and Medium-Sized OGM (< 6 cm)
The olfactory tract ipsilateral to the tumor is Debulking of the tumor gives more room for early identified and dissected from the tumor manipulation and allows the dissection in small and medium-sized tumors (< 6 cm) between the tumor surface and the (Figure 24 A). The olfactory tract is surrounding brain along the arachnoid plane. protected by small cottonoids and the tumor We routinely use the ‘water dissection’ is debulked with suction and high-power technique, that is very effective in dissecting bipolar forceps (Malis® CMCIII Codman, meningiomas (158). Preservation of both Synergetics™, Inc., values 50-60). olfactory tracts depends on the tumor's size,
78 4 Patients and Methods consistency, and attachments (Figure 24 B). aspect of the tumor to identify and save the Usually the ipsilateral olfactory tract is contralateral olfactory tract. Usually one identified at the beginning of the dissection olfactory tract is compromised by the tumor, and it is easier to dissect than the and a slight manipulation can abolish its contralateral one. After tumor debulking the function. dissection should be directed to the posterior
Figure 24: Intraoperative view showing involvement of the tumor with the olfactory tract. A, right olfactory tract (arrow) is preserved in a small meningioma; B, both olfactory tracts (arrows) are preserved after removal of a small OGM; C, large (> 6 cm) OGM and extremely atrophic olfactory tract (arrow) compressed by the tumor.
Small and Medium-Sized ACM and TSM (< 4 cm)
A classic LSO approach allows a complete sharp bipolar forceps and water dissection removal of small and medium-sized ACMs technique (158). In our experience ACMs and TSMs (< 4 cm). The dura is opened and and TSMs meningiomas smaller that 2 cm slack brain is achieved by modern can be safely removed en-bloc. Medium- neuroanesthesia (191). The first step is to sized ACMs and TSMs (2-4 cm) can be devascularize the tumor pay attention not to attached to the ICA, the optic nerve, the coagulate the dura too close to the optic oculomotor nerve, the MCA, and the ACA. canal; high power coagulation of the dura After tumor devascularization we debulk it to close to the optic canal could damage the gain adequate space to reach the basal optic nerve. For this purpose low-power cisterns and ensure safe dissection. A micro- coagulation (Malis 20-25) should be used in Doppler can be used to find the ICA and the proximity of the optic nerve. Water prevent its accidental injury when the tumor dissection technique is used to dissect the envelops the ICA. In hard meningioma tumor from the surrounding brain (158). The without an arachnoidal plane, the tumor dissection can be safely performed, in soft detachment should proceed by using sharp tumor, along the arachnoid plane by using bipolar forceps, low-power coagulation
79 4 Patients and Methods (Malis 20-25), microdissector, and and optic chiasm can be manipulate and microscissors. Based on the severity of dissected avoiding postoperative visual preoperative visual deficit, the optic nerve deficits.
Large OGM (> 6 cm)
Both olfactory tracts can be compressed or some feeders to a large OGM (Figure 25). destroyed by a large OGM (> 6 cm) (Fig. 24 Preservation of ACA’s branches is C). An attempt is made to enter the basal mandatory to avoid ischemic lesions on the cisterns and to release CSF and if this is not medial aspect of the frontal lobe. We avoid possible the tumor is partially debulked. We the use of mechanical retractors that can use high power bipolar forceps coagulation, increase edema in the frontal lobe. The tumor high-power suction and/or microscissors. We is debulked and it is carefully dissected from rarely use an ultrasonic aspirator, as the the surrounding brain and neurovascular combined repetitive movement of suction structures by using water dissection (158). and bipolar forceps gives the same result with less bleeding. ACA’s branches can give
Figure 25: Surgical view. (A) Small branches of the ACA supplying the OGM (arrows). (B) OGM attached to right optic nerve and right ICA (arrows).
Large ACM and TSM (> 4 cm)
The LSO approach can be extended 1-cm to medial sphenoid wing. The dura is opened the temporal side in large ACMs (> 4 cm) and the sylvian fissure is visualized. The first (Figures 22 and 23) and this allows a better step is to debulk a large ACMs and TSMs by visualization of the temporal portion of the using suction and high-power (Malis 50)
80 4 Patients and Methods coagulation with bipolar forceps. After this and cut. The perforators coming from the step the basal cisterns can be entered for CSF ICA and ACA (Figures 26 and 27 C) should removal. The vascular support to the tumor be preserved; they are often inside the tumor coagulated and with water dissection and they can be confused with the tumor's technique (158) the lesion is dissected from vascular supply. The ICA 3-5 mm proximal the brain. Also for large tumor ultrasonic to its bifurcation (253) gives branches to the aspirator is never used and we prefer the dura of the ACP and these can be coagulated combined use of suction and bipolar forceps. and cut. ICA, ACA, MCA, optic nerve, and In case of hard tumor without arachnoidal optic chiasm can be enveloped or dislocated plane, a micro-Doppler is used to find the from a large ACMs or TSMs and sometimes ICA and other vessels. The ICA is gently small pieces of the tumor may need to be left freed from the tumor by using sharp bipolar attached to the vessels or to the optic forceps and suction. The attachment of the nerve(s), preventing postoperative visual tumor to the ICA is coagulated (Malis 20) deficits or ischemia.
Figure 26: (A) Small branches of MCA. (B) After complete removal of a left large ACM, the dura of the ACP is coagulated (*) and all vessels are preserved.
Figure 27: Intraoperative view of a medium-sized TSM and the right optic nerve (A); atrophic optic nerve compressed by a large TSM (B); and perforators from the ACA attached to a large TSM (C).
81 4 Patients and Methods
Attachment to Surrounding Vascular Structures
The tumor vascular supply comes from the much more difficult to deal with later. ethmoidal arteries and small branches of the OGMs, ACMs, and TSMs, can be attached to ACA and ICA that can be coagulated and the supraclinoid carotid arteries and the optic cut. The recurrent artery of Heubner has to nerves or chiasm (Figure 27 A and B). We be preserved and not confused with these use high magnification, sharp bipolar forceps branches. Small perforators coming from the (Malis +20, +25), and sharp dissection to ACA, in the region of the AComA, run preserve all of the small perforators, above the optic chiasm and courses anterior including the blood supply of the optic to the ACA and they should be preserved chiasm. (102, 252). ICA in its intradural C1 and C2 The dura of the ASB is carefully coagulated segments may be attached to or encased by (Simpson grade 2) after tumor removal. We the tumor. Small veins can be attached to the remove the dura of the origin of the tumor and these also should be preserved meningioma in patients with long life whenever possible. They can be coagulated, expectancy. The hyperostotic bone (Figure if necessary. If these veins are torn 28) is drilled away (Simpson grade 1) by accidentally they tend to contract backwards using a high-speed diamond drill sometimes and unless previously coagulated, keep resulting in opening of the ethmoid sinuses; oozing, often from behind a corner, and are care should be paid to seal the sinuses with muscle, TachoSil (Human Fibrinogen, 4.8 x 4.8 cm, NYCOMED, Austria GmbH, Linz) and fibrin glue to prevent postoperative CSF leakage.
Figure 28: Sagittal MRI scan showing hyperostosis (arrows) of the ethmoidal bone in a large OGM.
82 4 Patients and Methods
Intraorbital Extension of ACM-TSM and Anterior Clinoidectomy (Publications I-III and V)
ACMs and TSMs can sometimes grow inside formed by a surface of cortical bone and the optic canal and an anterior clinoidectomy diploe of cancellous bone, which sometimes is necessary to remove the tumor. We usually communicate with the cavernous sinus (209), perform anterior clinoidectomy when there is and fibrin glue can be used to control the tumor-related hyperostosis of the ACP and bleeding coming from the cavernous sinus encasement of the ICA by the tumor (Figures through these venous channels. The 29 and 30). The policy of the senior author unroofing of the medial portion of the orbital (J.H.) is to perform an intradural anterior roof allows the exposure of the optic nerve clinoidectomy (see Discussion). The and laterally the C3 segment of the ICA. The technique consists in cutting and removing intraorbital portion of the meningiomas is the dura of the ACP 1 cm from the medial removed in small pieces, taking care not to border. High-speed diamond drill and damage the optic nerve. Extradural anterior ultrasonic bone curette (Sonopet Omni, clinoidectomy is seldom used in ACMs and Model UST-2001 Ultrasonic surgical system, TSMs surgery. After performing a LSO Synergetics™, Inc., Miwatec Co., LTD, approach the dura is gently detached from. Kawasaki, Japan) are both used to remove The orbital roof is removed 1 cm distal to the the ACP. Sometimes the senior author uses medial border of the ACP by using an a microrongeur (Mizuho Rongeurs Series 16 ultrasonic bone curette or high-speed drill, or cm curved, Japan). The bone of the ACP is a microrongeur.
Figure 29: Left large meningioma in a 58-year-old man. (A) Anterior view of DSA showing vascular support to the meningioma from the ICA (arrow). (B) Coronal 2D reformatted image from Dyna CT during left carotid arteriogram showing small branches (arrow) of the anterior clinoid process to the ACM. (C) Preoperative coronal contrast- enhanced T1-weighted MRI showing the large ACM. (D) Postoperative coronal contrast-enhanced T1-weighted MRI showing the complete removal of the tumor.
83 4 Patients and Methods
Figure 30: Coronal 2D CTA of a right large ACM in a 39- year-old woman. Vascular support comes from small vessels of the ACP (arrow), which appears hyperostotic (*).
Tailored Anterior Clinoidectomy (Publications V and VI)
We prefer to perform a tailored clinoidectomy refers to removal of the tip clinoidectomy, i.e. to remove only the and head of the ACP, i.e. approximately 1/3 necessary amount of bone for the treatment of total ACP; C) subtotal clinoidectomy of the aneurysm or the tumor. Figure 31 refers to removal of the tip, head, and body shows the classification of a tailored of the ACP, i.e. approximately 2/3 of total clinoidectomy: A) minimal clinoidectomy ACP; and D) total clinoidectomy refers to refers to resection of the tip of the ACP, removal of the tip, head, body, and base of usually less than 1/3 of total ACP; B) partial the ACP.
Figure 31: A 3D CT skull base reconstruction (left) and a schematic drawing (right) showing a right ACP and a tailored clinoidectomy through an LSO approach (grid). A) minimal clinoidectomy with removal of the tip of the ACP (less than 1/3 of total ACP); B) partial clinoidectomy with removal of the tip and head of ACP (1/3 of total ACP); C) subtotal clinoidectomy with removal of the tip, head, and body of the ACP (2/3 of total ACP); and D) total clinoidectomy with removal of the tip, head, body, and base of ACP (whole ACP).
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5 Results
Characteristics of Meningiomas (Publications I-III)
Tumor Size
The average OGM tumor size was 47 (range 45 patients (68%), extended to the right in 11 20-85) mm. Twenty-five (38%) of 66 OGMs patients (17%), and extended to the left in 10 were large (> 6 cm), 27 (41%) medium (3–6 patients (15%). cm), and 14 (21%) small (< 3 cm) (Figure 32). Tumors were located in the midline in
Figure 32: Sagittal contrast-enhanced T1-weighted MRI. Examples of (A) small (with ethmoidal infiltration), (B) medium, and (C) large OGMs, which presented also with sellar involvement (arrows).
The mean ACM tumor size was 32 (range 4- challenging. Twenty (27%) of 73 ACM 72) mm. We considered ACMs and TSMs > tumors were small (< 2 cm), 32 (44%) were 4 cm to be large and distinct from OGMs medium-sized (2-4 cm), and 21 (29%) were because the close relationship with the large (> 4 cm) (Figure 33). neurovascular structures makes the surgery
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Figure 33: Coronal contrast-enhanced T1-weighted MRI showing right small (A), medium (B) and large (C) ACMs.
The mean TSM tumor size was 31 (range 6- were associated with the presence of edema, 84) mm. Seven (13%) of 52 TSMs were brain shift, and involvement of neurovascular small (< 2 cm), 34 (66%) were medium-sized structures, but the tumor size did not predict (2-4 cm), and 11 (21%) were large (> 4 cm) tumor consistency and was not related to the (Figure 34). Both ACMs and TSMs size existence of preoperative visual deficits.
Figure 34: Axial contrast-enhanced T1-weighted MRI showing right small (< 2 cm) (A), medium (2-4 cm) (B), and large (> 4 cm) (C) TSMs.
Peritumoral Edema
Preoperative edema was present in medium Four small OGMs (< 3 cm) presented also and large-sized OGMs, ACMs, and TSMs. with peritumoral edema.
86 5 Results Side of Approach in OGM and TSM
For midline meningiomas as OGMs and posterior clinoid meningioma on the left TSMs we prefer a right (non-dominant) LSO removed together with the OGM; in one approach, more convenient for a right- there was preoperative left-sided optic nerve handed neurosurgeon. Fifty-five OGMs were dysfunction; and in one there was an removed via right side even if the tumor extensive scarring on the right due to extends more to the left side; 11 OGMs previous surgery. Preoperative visual deficit patients were approached from left because and main tumor location were the of marked tumor extension to the left; the determinant factors in the choice of the side other three patients were approached from of the craniotomy. left because: in one there was a separate
Hyperostosis and Infiltration of Ethmoid Sinuses in OGM
Thirty-two OGM patients presented OGMs infiltrated the ethmoid sinus, preoperative hyperostosis, and it was related irrespective of hyperostosis or tumor size. to the tumor size (p00.001) (Figure 28). The Four patients of 25 with OGM inside the hyperostotic bone was drilled during surgery ethmoidal sinus were deliberately left with with a high-speed diamond drill. Twenty-five extracranial tumor tissue behind.
Temporal Extension and Clinoidectomy in ACM and TSM
Twenty (27%) ACM patients (two small, intraorbital extension of the tumor; in twelve five medium-sized, and 13 large ACMs) cases the anterior clinoidectomy was underwent a LSO with temporal extension predicted by the hyperostosis of the ACP predicted by the tumor size (p<0.001). In 53 (p<0.05). Sixteen patients underwent (73%) ACM patients (eight large ACMs) a intradural clinoidectomy and five extradural. classic LSO was enough to remove the The LSO approach with temporal extension tumor. Twenty-one ACMs patients required was used to treat one TSM patient. anterior clinoidectomy, six of whom had an
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Infiltration of the Sellar Region (OGM and ACM) and Cavernous Sinus (OGM, ACM, and TSM)
Five OGM and 16 (12 large) (p<0.001) ACM small, six medium, and 10 large ACMs patients had tumors infiltrating the sellar (p<0.05) and four TSMs (two large and two region. Seven ACM patients with sellar medium-sized), presented attachment to the infiltration also had the tumor attached to the dura of the cavernous sinus. dura of the cavernous sinus (p<0.05). One
Intraorbital Tumor Extension and Attachment to the Optic Chiasm and Nerve
Thirty patients presented with OGM which large, two medium-sized, and one small was attached to the optic chiasm, 14 of ACM. In 11 ACMs (10 large and one small), whom had preoperative visual deficit. Ten sellar involvement was also observed. ACMs had an intraorbital extension and six Chiasmatic compression was associated with of which required an anterior clinoidectomy. preoperative visual deficit in 12 of 15 cases The size of ACM predicted optic nerve and (p<0.05). An intraorbital extension of TSM chiasmatic compression (p<0.001). was seen in one large TSM. Chiasmatic compression was observed in 12
Meningioma Attachment to the Vessels
Attachment of ICA to ACM and TSM
ACM and TSM size predicted tumor inside the tumor, present in 27 ACM and attachment to the ICA (p<0.05). ICA nine TSM cases, was also related to tumor attachment was found in 60 ACM and 49 size (p<0.001). In 33 TSM cases, both ICAs TSM cases. In seven ACMs (four large and were involved. The ICA was narrowed in three medium-sized), and two TSMs (one only one medium-sized TSM. In one large large and one medium-sized) the ICA was and one medium-sized ACM the ICA was dislocated by the tumor. Encasement of ICA closed.
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Attachment of ACA to ACM and TSM
ACA was attached to 41 ACM and 38 TSM In 30 TSM cases, both A1s were involved. In cases, and it was related to tumor size 14 cases, the ACA was dislocated by the (p<0.001). In 12 ACMs and four TSMs ACA TSM; this was related to tumor size was encased by the tumor (p<0.05). The (p<0.05). In 10 cases, both A1s were ACA was dislocated by the ACM in 17 dislocated; in four cases, only one. patients but remained patent in all of them.
Attachment of AComA to TSM
Forty-one meningiomas were attached to by the tumor. In no case was the vessel AComA and it was related to tumor size closed or narrowed by the tumor (Figure 35). (p<0.05). In 15 cases, the vessel was also dislocated, and in three cases only encased Figure 35: A 3D-CTA reconstruction showing a large TSM and its vascular relationship.
Attachment of A2 to OGM and TSM
In 33 OGM and 36 TSM patients the A2s were involved, and it was related to tumor size (p<0.001). Postoperative ischemic complications in OGM surgery were not predicted by the attachment to A2s. In 31 TSMs both pericallosal were involved (Figure 35). Both pericallosal arteries were dislocated by the TSM in 13 cases.
Attachment of M1 to ACM and TSM
Attachment to M1 was found in 48 ACMs, was also dislocated (p<0.001). In 14 ACMs, and tumor size again predicted this the vessel was encased by the tumor, but had (p<0.001). In 19 of these ACMs, the vessel remained patent. Seven TSMs were attached
89 5 Results to M1 predicted by tumor size (p<0.05).
Attachment of BA to TSM
Two TSMs (one medium and one large) were attached to the BA.
Pituitary Stalk Involvement in TSM
The pituitary stalk was involved in 42 TSM with pituitary stalk involvement had patients and was associated with tumor size preoperative endocrinological deficits. The (p<0.05). In 20 cases, it was encased, in four pituitary stalk was preserved in all cases. cases dislocated by the tumor and in 18 cases only attached to the tumor. Three patients
Tumor Consistency
Tumor consistency was not predicted by ACM, and 14 TSM patients had a tumor of tumor size, patient’s age, or preoperative medium consistency (some parts can be neurological deficits, nor was it related to removed with suction). postoperative clinical or surgical Fourteen OGM patients had a hard (not complications. Twenty-eight OGM, 30 suckable) tumor; 18 ACM and 14 TSM ACM, and 24 TSM patients had a soft patients also had hard tumors. (suckable) tumor. Twenty-four OGM and
Tumor Calcifications
Tumor calcifications presented in 13 ACMs and was not related to postoperative surgical (seven medium- and six-large- sized) and 11 complications, but eight ACM patients TSMs (nine medium- and two large-sized) presented with postoperative clinical did not affect the time meningioma removal complications (p<0.05).
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Operative Time
The mean OGM operative time from skin to The mean duration of all TSM operations skin was 158 (range, 60-350) min: 84 (range, from skin to skin closure was 116 (range, 43- 60-120) min for small, 142 (range, 73-255) 442) min: 62 (range, 43-75) min for small, min for medium-sized, and 217 (range, 115- 107 (range, 53-180) min for medium, and 350) min for large OGMs (p<0.001). 182 (range, 83-442) min for large tumors. The mean ACM duration of operation from Duration of surgery was affected by TSM skin to skin closure was 120 (range, 35-285) size (p<0.05). Duration of surgery also min: 87 (range, 35-235) min for small, 98 depended on attachment to the optic chiasm (range, 50-190) min for medium-sized, and (p<0.05), A1 attachment or encasement, and 186 (range, 111-285) min for large tumors. AComA and A2 attachment (p<0.05). Interestingly, the duration of surgery was Interestingly, tumor consistency did not affected by tumor size (p<0.001), attachment affect operation time in any meningioma to M1 (p<0.05), ICA (p<0.05), and ACA group. (p<0.001), and encasement of M1 (p<0.001), ICA (p<0.001), and A1 (p<0.05).
Histological Grading of Tumors
All meningiomas were grade 1, except for 10 patients with atypical grade 2 meningiomas. (two OGMs, seven ACMs, and one TSM)
Surgical Complications
CSF Leakage
Six OGM patients (9%) developed CSF Three ACM and three TSM patients had leakage from the nose; three of them had cranionasal CSF leakage. All three ACM tumor infiltration into the ethmoid sinuses. patients underwent clinoidectomy during the Four of the six patients were treated with operation. All six patients were treated using lumbar drainage for a few days. The other an external spinal drainage for a few days. two patients required a fascia lata graft.
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Postoperative Hematoma and Infection
One OGM patient had a postoperative subdural hematoma that did not require hematoma in the resection cavity requiring evacuation. Postoperative infection occurred evacuation. in four OGM and one ACM patient. Two ACM postoperative hematomas in the resection cavity were observed; only one required evacuation. One TSM patient had a one ACM patient.
Anosmia, Frontal Syndrome, and Visual Outcome
New postoperative anosmia appeared in six postoperative visual deficits. Of the 14 OGM OGM patients and was unrelated to tumor patients with a preoperative visual deficit, size. All six tumors were of either hard (three three improved after surgery and 11 cases) or medium consistency. Three of these remained unchanged. Neither tumor size nor six patients had tumor infiltration into the tumor consistency predicted occurrence of ethmoid sinuses. Olfactory function new postoperative visual deficits. improved in two patients, both of whom had Three ACM patients had new visual deficits: a medium-sized tumor extending more to the one transitory decline of visual acuity right side. ipsilateral to the tumor, one unilateral Three OGM patients had postoperative quadrantopsia, and one temporal frontal syndrome. One ACM patient had hemianopsia. anosmia and one frontal syndrome. No TSM Eleven of 39 ACM patients experienced an patients had postoperative hypo- or anosmia improvement to pre-existing visual deficits or frontal syndrome. after the operation. Improvement was Fourteen of 30 OGM patients with optic unrelated to tumor size (two large, four chiasm attachment, had preoperative visual medium, and five small) and tumor deficits. Of the 16 patients with normal consistency (three soft, five medium, and preoperative vision, five developed new three hard). deficits (two were large and soft; one was One TSM patient had a de novo visual deficit small, one was medium, and one was large; with right-sided eye blindness and left all were of medium consistency). No patients temporal quadrantopsia. Pre-existing visual with a hard tumor developed new deficits improved because of the operation in
92 5 Results 22 (52%) of 42 TSM patients. This was deficit that had lasted for less than six related to tumor size (two large, 18 medium, months improved in 13 of 20 patients, a and two small), but not tumor consistency deficit lasting between 6 and 12 months (12 soft, six medium, and four hard). improved in seven of 11 patients, and a Improvement of visual outcome was deficit lasting over 12 months improved in predicted by duration of the preoperative only two of 11 patients. visual deficit (p<0.05). A preoperative visual
Outcome
Early Outcome
Clinical outcome at discharge was good in (12%) had moderate disability. Eight OGM 43 OGM (65%), in 54 ACM (74%) and in 45 (12%), one ACM (1%) and one TSM (2%) TSM patients (87%). Fifteen OGM (23%) had severe disability. Three ACM patients and ACM (21%) and six TSM patients died for surgery.
Residual Tumor
Six OGM patients (9%) showed a residual behind a corner in the operative field, as tumor in the early postoperative MRI. Five documented by the postoperative CT scan were benign meningiomas (G1) and one was and MRI. Two of the six patients were atypical (G2). Five of the residuals were followed up only with MRI, receiving no attached to the ACAs. Four of the six tumors additional treatment. infiltrated the ethmoid sinuses on Sixteen ACM patients had residual tumor; all preoperative images and were deliberately were benign, but one was atypical (G2); this left behind, but two were unexpected patient was treated in 1997 by another findings. Three of the tumors were large, two neurosurgeon, underwent reoperation of the were medium, and one was small. Three of residual tumor in 2004 and 2006, followed the six patients underwent redo surgery for by radiosurgery (20 Gy). Two other patients the tumor remnant, and one had were previously operated on by another radiosurgery. One of these three patients was surgeon. One patient had been operated on reoperated on one month after the first twice, in 1977 and 1992, and presented again surgery because some tumor had been left with a residual tumor (benign, medium-
93 5 Results sized, medium consistency) and an intraoptic interrupted tumor removal and some tumor component with documented growth, and was left behind. Both patients had good therefore underwent a right LSO approach recovery. In the remaining 11 patients, the with subtotal removal in 2003. Since then, residual tumor was attached to the optic the residual has been stable and the patient nerve (five patients), located at the medial has had a good recovery. The second patient sphenoid wing (three patients), located at the was treated in 1994. There was a residual cavernous sinus (two patients) and one was tumor attached to the optic nerve that was intraorbital. growing and was reoperated in 2000 (the Seven TSM patients had residual tumor. Two tumor was small, medium consistency, and were reoperated on by the senior author benign). After the operation, the residual was (J.H.), one was treated by radiosurgery, and treated with radiotherapy (50.4 GY) and has four were only followed up. All tumors were been stable since (last MRI performed in benign (G1), but the one patient who January 2008). In two patients, an underwent radiosurgery presented with intraoperative laceration of the vessel multiple meningiomas.
Tumor Recurrence during Follow-up
Four OGM cases (7%) recurred during a wing and was reoperated on. One patient median follow-up of 45 (range, 2-128) presented a small recurrent tumor at the months. All of these G1 tumors infiltrated medial sphenoid wing five years after the the ethmoid sinuses and had a hard first operation for a large-sized ACM; the consistency. Their initial diameters were 61 residual was stable during a six-year follow- mm, 53 mm, 43 mm, and 20 mm (redo case). up. Tumor recurrence was observed in three Tumor recurrence affected only one TSM ACM patients during a median follow-up of during the follow-up. This patient had a 36 months (range, 3-146). One patient had a medium-sized (maximum diameter 24 mm) small, soft, benign tumor (maximum soft tumor attached to both optic nerves, the diameter 10 mm) operated on in 2001. The optic chiasm, both A1s and ACAs, the recurrence of about 4 mm, attached to the AComA, and the right ICA. After the first medial side of the optic nerve, was operation in 2001, the patient’s preoperative discovered in an MRI performed in visual deficit (bilateral visual deficit and September 2009. One patient presented with bitemporal hemianopsia) improved, but in a medium-sized ACM, which recurred two 2005 and 2009 a sudden decrease in visual years after surgery at the medial sphenoid acuity led to the discovery of a recurrent
94 5 Results tumor that was reoperated twice, in 2006 and 2009.
Long-term Clinical Outcome and Mortality
The median follow-up of OGM patients was medium-sized hard tumor attached to the 45 (range, 2-128) months. During the follow- ICA, MCA, and ACA developed a severe up 53 patients (80%) had a good recovery, vasospasm with hemispheric infarction and five patients (8%) moderate disability and died 19 days after surgery. One patient died eight patients severe disability (12%); the on the second postoperative day because of median Karnofsky score was 90. Of the 13 acute myocardial infarction after a good patients with moderate or severe disability, initial recovery from the operation. One all but one had a medium (seven patients) or patient with a large, medium consistency large (five patients) tumor. Multivariate tumor attached to the ACA and MCA and analysis showed that only the preoperative encasing the ICA developed hemiparesis and Karnofsky score significantly (p<0.001) died because of severe lung infection one predicted good outcome (OR 2.8, 95% CI month after the operation. 1.6–5.0, per 10 points of Karnofsky score). The median follow-up of TSM patients was Age, tumor size, and tumor consistency were 59 (range, 1-133) months. At the outpatient not independent risk factors. clinic 47 patients (90%) with good recovery The median follow-up of ACM patients was and four patients (8%) with moderate 36 (range, 3-146) months. The median disability. One patient (2%), already in poor Karnofsky score was 90. At the three-month condition preoperatively, died 40 days after outpatient visit, 60 patients (82%) had good surgery due to cardiac arrest. The median recovery, nine patients (12%) had moderate Karnofsky score was 80. disability and three patients (4%) died for surgery-related reasons. One patient with a
Method of Anesthesia for OGM, ACM, and TSM Surgery (Publication IV) not available for two OGM patients and two Data analysis includes surgical data for 191 ACM patients. patients and anesthesiological records for The surgical conditions were classified as 187 patients. Anesthesiological charts were good (slack brain achieved) for 154 patients
95 5 Results (82%), as satisfactory for 18 patients (10%), and as poor for 15 patients (8%).
Induction of Anesthesia
Diazepam (5-15 mg) was given orally to all disease and a medium-sized TSM. The mean patients one hour before surgery. Tiopenthal (range) total intraoperative amount of (median dose 377 mg, range 300-500 mg) fentanyl was 0.56 (0.150-3) mg, mainly was used in 186 (99%) patients to induce given as a single bolus at the induction of anesthesia. Etomidate (14 mg) was used in anesthesia. an 80-year-old patient with congestive heart
Table 7. Method of anesthesia. Method Number of patients Intravenous anesthesia Propofol infusion 46 (25%)
Volatile agents Sevoflurane 74 (40%) Isoflurane 33 (17%)
Combined anesthesia Sevoflurane/Isoflurane + 34 (18%) propofol infusion
Maintenance of Anesthesia and Tumor Size
Propofol infusion (46 patients/25%), infusion and sevoflurane/isoflurane (34/18%) sevoflurane (74/40%), or isoflurane were used for anesthesia (Table 7). (33/17%), or a combination of propofol Anesthesia was maintained with Nitrous
96 5 Results oxide (N2O) in 140 patients (75%). N2O was correlation between tumor size and method most often combined with sevoflurane or of anesthesia. isoflurane (95/51%) (p<0.05). One-hundred sixty-six patients (89%) Twenty-one medium and 21 large received remifentanil infusion. A meningioma received propofol anesthesia. combination of remifentanil with sevoflurane Only four patients anesthetized with propofol (71 cases) or isoflurane (20 cases) was used had a small meningioma. Twenty-four in 91 patients (49%) or with propofol in 41 patients anesthetized with propofol presented patients (22%). with peritumoral edema. Neuromuscular block was achieved by non- Sevoflurane or isoflurane anesthesia was depolarizing muscle relaxants (rocuronium given to 37 large-, 45 medium-, and 25 or vecuronium) in all study patients. In 33 small-sized meningioma patients received, patients neostigmine was necessary to and 40 of them (10 medium and 30 large reverse the neuromuscular block at the end meningiomas) presented with peritumoral of surgery. edema. Univariate analysis disclosed no
Brain Relaxation and Anesthesia
Brain relaxation was good in 154 patients Nine patients with brain swelling had either (82%). In 18 patients, brain relaxation was sevoflurane (six cases) or isoflurane (three classified as satisfactory (10%) and optimal cases) anesthesia. In multivariate analysis, slack brain was achieved by opening the swelling of brain was associated with basal cisterns during surgery. medium- to large-sized meningiomas, In 15 patients (8%), the brain swelled peritumoral edema, volatile or combined intraoperatively. Thirteen of these patients anesthesia, and poor preoperative clinical had large tumors (p<0.001). The median condition (Karnofsky score <70) (p<0.01). Karnofsky score was 80 (range 50-90), and 14 of the 15 patients had peritumoral edema.
Osmotic Agents
The administration of 15% mannitol meningioma size and preoperative cerebral according to meningioma size is presented in edema (p<0.05). However, in two small- Table 8. The use and amount of mannitol meningioma patients without peritumoral were significantly associated with edema, 500 ml of mannitol was administered
97 5 Results before surgery because they had been The median cumulative amount of urine operated on before the year 2000, when during surgery was 350 (range 0-348) ml for mannitol began to be given routinely. 177 patients (95%); for 25 of these patients, Hypertonic saline was not administered to it was recorded as 0 ml. any patient.
Table 8. Size of tumor and amount of mannitol used (p=0.01). Small Medium Large Total of patients < 2cm 2-4 cm >4cm Mannitol ML
100 0 1 3 4 200 0 1 1 2 250 0 0 1 1 270 0 0 1 1 350 00 11 400 0 2 2 4 500 2 12 35 49
Total of Patients 2 16 44 62
Hemodynamics and Vasoactive and Antiepileptic Drugs
Systolic and diastolic arterial pressures and patients (157/84%) had a systolic blood heart rate are shown in Figure 36. The mean pressure of less than 160 mmHg for the first systolic blood pressures ranged between 95 six hours after the operation. Intraoperative and 110 mmHg during surgery. Heart rate phenylephrine infusion was given to 60 remained stable. Extreme hemodynamic (32%) patients and dopamine to four (2%) changes were not observed. Hemodynamic patients. Sixty-nine patients were also data on the size and type of tumor were administered a bolus of phenylephrine. A similar. The mean preoperative systolic and bolus of ephedrine (mean 3.9; range, 5-75 diastolic blood pressure was 125 and 70 mg) was given to 52 (28%) patients. mmHg, respectively. The majority of the Labetalol (mean 14 mg; range, 9-120 mg)
98 5 Results was given to 68 (36%) patients. Other (three cases), and atropine (two cases). vasoactive agents used in 29 (16%) patients Droperidol was administered to three (2%) were dihydralazine sulfate (15 cases), patients. The use of any vasoactive agent was clonidine (six cases), metoprolol succinate unrelated to type or size of tumor.
Figure 36: A graphic illustration showing the mean pre-, intra-, and post-operative arterial pressure.
One-hundred-four (56%) patients received antiepileptic drugs perioperatively. These drugs comprised fosfenytoin (95 cases), carbamazepine (six cases), fenytoin (two cases), and lorazepam (one case). The administration of antiepileptic drugs was not related to tumor location, but was related to tumor size (p<0.05).
Intraoperative Bleeding and Blood Transfusion
Blood loss was related to tumor size had a very large vascularized (maximum (p<0.001). The median cumulative diameter > 8 cm) OGM meningioma. Red intraoperative blood loss was 200 (0-2000) blood cell transfusions were administered to ml. In 44 patients (23%), the estimated 17 patients (9%) (Table 9). Interestingly, 170 intraoperative blood loss was less than 50 ml. patients (91%) did not require a red blood Two patients had blood loss above 1500 ml. cell transfusion. Fresh frozen plasma and In one patient (blood loss of 1800 ml) the platelet concentrates were given to two internal carotid artery lacerated accidentally patients each. during the removal of a small ACM; and the laceration was repaired with microsuture. The other patient (blood loss of 2000 ml),
99 5 Results Table 9. Size of tumor and red blood cell transfusion (p<0.05). Small Medium Large Total of patients < 2cm 2-4 cm >4cm Red blood cells unit (ml) 0 298061170 1001102 2001012 250 0 1 0 1 400 0 0 1 1 500 0 0 6 6 6001001 7500022 8000011 1000 0 0 1 1
Extubation Time
One-hundred and fifty-seven patients (84%) Twenty-nine patients (16%) were extubated were extubated on the day of the surgery. during the following days after surgery: 21 The median (25th/75th percentiles) time to patients on the first postoperative day, three extubation after surgery was 18 (8/105) min. patients on the second postoperative day, one Fifty-three patients (28%) were extubated patient on the third postoperative day, two within 10 min of completion of surgery (14 patients on the fourth postoperative day, and small, 33 medium, and six large one patient on the fifth or sixth postoperative meningiomas). Forty-five patients (24%) day (one case each). In univariate and were extubated within 30 min of surgery (13 multivariate analyses, preoperative clinical small, 24 medium, and eight large status (Karnofsky score < 70) (p<0.001), meningiomas). Fifty-nine patients (32%) tumor size and location (OGM) (p<0.001), were extubated within 1 h (10 cases), 5 h (36 peritumoral edema (p<0.001), and brain cases), or more than 5 h postsurgically, but swelling at surgery (p<0.05) were predicting nevertheless on the same day of the surgery factors for prolonged extubation time after (13 cases). surgery (days after surgery).
100 5 Results
Surgical Complications and Outcome after Anterior Clinoidectomy (Publications V and VI)
Tailored Anterior Clinoidectomy
We performed a tailored clinoidectomy in 82 the head of the ACP (around 1/3 of ACP); 3) patients (Table 10). We removed only the the tip, the head and the body of the ACP necessary amount of bone for the treatment (around 2/3 of ACP); 4) the whole ACP. In of the aneurysm or the tumor. We classify eight patients (three vascular and five tumor this removal as follows 1) the tip of ACP cases) the anterior clinoidectomy was (less than 1/3 of all clinoid); 2) the tip and extended laterally to open the SOF.
Table 10. Site of the lesions and tailored anterior clinoidectomy. Tailored clinoidectomy Minimal Partial Subtotal Total Total number of Clinoidectomy cases
Vascular cases Carotid-ophthalmic aneurysm 1 0 8 12 21 Other carotid aneurysms 1 3 3 16 23 Basilar bifurcation aneurysm 1 0 0 0 1 Carotid-cavernous fistula 0 0 1 1 2
Tumor cases Meningioma 2 4 5 15# 26 Other lesions 0 1 1 7 9
Total 5 8 18 51 82 (vascular + tumor cases) # In one case orbital roof was also removed.
Visual Outcome
Preoperative visual deficits were present in endovascular treatment and radiosurgery. 27 patients (33%) and worsened after surgery After these the patient had right oculomotor in three patients (4%). One patient with palsy, chemosis and bilateral decrease of bilateral carotid-cavernous fistula had visual acuity. Extradural anterior previously undergone two sessions of clinoidectomy was performed with Sonopet
101 5 Results and drill and the fistula was successfully cases that experienced postoperative visual closed. The visual deficit improved in the left complications. The whole ACP was removed eye but worsened in the right. One patient in five cases. However, univariate or had preoperative bilateral visual acuity multivariate statistical analyses did not deficit due to anterior clinoidal meningioma reveal any factors that would statistically and developed a unilateral blindness after significantly associate with the occurrence of surgery. One patient presented with postoperative visual deficits. intraorbital fibrous dysplasia and both visual Twelve patients (15%) with preoperatively acuity and visual field deficit, which existing visual deficits improved after worsened after surgery. surgery (the patient with bilateral carotid- Four patients (5%) with preoperatively intact cavernous fistula and an improvement of the vision had new visual deficits left but worsening of the right eye visual postoperatively. One patient with a small acuity not included). Again, statistical unruptured carotid-ophthalmic aneurysm analysis did not reveal factors associating developed unilateral blindness. One patient with improvement of visual deficits. with a medium-sized unruptured carotid- Interestingly, however, intradural ophthalmic aneurysm developed temporal clinoidectomy was performed in all patients hemianopsia. One patient with a ruptured with improvement in visual deficits. blister-like ICA aneurysm and HH Grade 5 subarachnoid hemorrhage had a unilateral decrease of the visual acuity. One patient with intraorbital cavernoma developed unilateral blindness after surgery (Table 11). Sonopet was used in five out of these seven
CSF leakage 5 Table 11. Wound infection 1 Postoperative complications ICA rupture 1 in 82 patients who underwent Meningitis 1 tailored anterior clinoidectomy. Oculomotor palsy 16 (transient) Oculomotor palsy 1 (permanent) Visual deficits 7
102 5 Results Ophthalmoplegic Complications
Seventeen patients (21%; ten aneurysm and oculomotor palsy was not related to the seven tumor cases) developed oculomotor anterior clinoidectomy itself (only the medial palsy after surgery and they were not related tip of the ACP was removed). In only one of to anterior clinoidectomy. Thirteen of them these patients was the SOF opened; this had recovered completely at three months, patient had an anterior clinoid–cavernous three had improved significantly, and sinus meningioma, and the whole ACP was symptoms persisted in only one patient. This removed extradurally. This patient also patient was operated on for an unruptured developed a transient abducent nerve palsy. giant basilar bifurcation aneurysm, and the
CSF Leakage
Five patients (6%; three aneurysm and two occlude the cranionasal fistula, and in two an tumor cases) had postoperative CSF external lumbar drainage for a few days was rhinorrhea (Table 11). Three of them sufficient. required a reoperation and duraplasty to
Other Surgical Complications
One patient presented with unruptured vessel. The rupture site was repaired with carotid-ophthalmic and intracavernous AnastoClip (AnastoClip Vessel Closure carotid aneurysms, and the operation was System 1.4 mm; LeMaitre Vascular, planned to treat only the ophthalmic Burlington, MA, USA) (Figures 37 and 38). aneurysm. During the extradural removal of This case has previously been published as a the ACP with microrongeur, the technical case report (197). One patient had intracavernous aneurysm attached to the meningitis and one patient severe wound ACP ruptured together with the parent infection (Table 11).
103 5 Results
Figure 37: Sagittal view of a 2D reconstruction CT showing the relationship between the anterior clinoid process (arrows) and the intracavernous aneurysm.
Figure 38: 3D-DSA, intraoperative view and schematic drawing of left ICA aneurysms showing the tear of the ICA repaired by using AnastoClips.
104 5 Results
Clinical Outcome at Discharge and at Three Months
At discharge, 66 patients (80%) had good recovery, seven patients (9%) had moderate disability, seven patients (9%) had severe disability, and two patients (2%) were unconscious. These two patients were admitted because of Hunt-Hess grade 5 subarachnoid hemorrhage. Disability was not related to the anterior clinoidectomy itself in any of the patients. At three months, 71 patients (87%) had good recovery, six patients (7%) had moderate disability, four patients (5%) had severe disability, and one patient (1%) remained in a vegetative state. Three patients experienced a worsening of neurological condition that did not improve in three months: one patient with a giant unruptured basilar bifurcation aneurysm had hemiparesis and severe disability; one patient with kidney failure who underwent clipping for giant carotid-ophthalmic aneurysm had a slow recovery and severe disability still at three months; one patient with a spheno- orbital meningioma suffered from severe wound infection at one week from surgery and had moderate disability at three months. There was no surgical mortality in the series.
105 6 Discussion
6 Discussion
This series of 273 patients treated through results in terms of safety and extent of tumor the LSO approach and by a single-surgeon is removal. The LSO approach can be the largest series published to date. The LSO performed in 10 minutes, allows the approach is simpler, faster, and less neurosurgeon to remove the tumor with extensive than the previously advocated minimal blood loss, and avoids brain damage pterional, bifrontal and orbitozygomatic or contusion with most of the patients approaches, while producing comparable extubated the same day of surgery.
Lateral Supraorbital Approach versus Pterional, Bifrontal, and Fronto-Orbital Approaches
LSO Approach versus Pterional Approach (Publications I-III)
Both pterional or minipterional approach and can easily be opened if necessary, as our were used by the senior author (J.H.) to treat experience with MCA and other anterior 39 OGM patients since 1979. The pterional circulation and even posterior circulation or minipterional approaches have the sylvian aneurysms shows (48-51, 100, 102, 138, 139, fissure in the center of the craniotomy, with 198, 199). partial exposure of the frontal and temporal The most widely described approach for lobes (70, 254). During the years, with OGM, ACM, and TSM surgery in the experience the senior author noted that the literature has been the pterional one (14, 59, middle fossa extension was unnecessary and 68, 188, 238, 255, 260, 261). This approach, only the frontolateral part of the approach described by Dandy in 1942 (46) and later was needed during the surgery. This perfected and popularized by Ya2argil (254), subsequently led to the development and use is commonly used for vascular and of the LSO approach for vascular and neoplastic lesions of the anterior and medial neoplastic lesions (101). The sylvian fissure cranial fossa. When treating OGMs, ACMs, remains at the border after a LSO approach and TSMs the pterional approach allows to
106 6 Discussion visualize the anterior circulation, the basal be performed in 10 minutes, allows the feeders, and the optic nerve and chiasm. neurosurgeon to remove the tumor with In larger tumors with more temporal minimal blood loss (median cumulative extension, the LSO may be modified with a blood loss in meningioma patients was 200 1-cm temporal extension to fully visualize ml), and avoids brain damage or contusion the temporal portion of the sylvian fissure. with most of the patients extubated the same This modified approach was applied in 20 day of surgery (157 meningioma patients). ACM patients. However, for small or Modern neuroanesthesia (191) and CSF medium-sized meningiomas, the classic LSO release after opening the basal cisterns give approach is generally sufficient to safely and space to visualize the necessary completely remove the tumor. The LSO neurovascular structures. A recent cadaveric approach gives the same advantages as the study demonstrates that the LSO approach classic pterional approach, but is less gives the same advantages than the pterional traumatic and faster. The LSO approach can one (204).
LSO Approach versus Bifrontal Approach (Publications I and III)
OGMs and TSMs can be treated by using a is seldom opened during the LSO approach. bifrontal transbasal interhemispheric In a recent study comparing a simple approach. This approach provides an easier frontolateral approach (very similar to our anatomical orientation to both optic nerves, LSO approach) with the bifrontal approach the optic chiasm, and vascular structures, and in microsurgery of OGMs, three patients in allows the surgeon to devascularize the the bifrontal group died due to postoperative tumor. LSO approach gives less exposure of brain edema. No deaths occurred in the the frontal lobes than the bifrontal approach, frontolateral group. The authors concluded with minimal surgical manipulation. that the anterior third of the SSS should be Bilateral retraction of the frontal lobe and the preserved during OGM surgery, and this is sacrifice of the anterior third of the SSS and better achieved with the frontolateral of the frontal draining veins are not needed approach (159). These authors also compared when using the LSO approach with minimal the frontolateral and the bifrontal approach risk of postoperative infarction or increased for TSM surgery, the incidence of edema. The frontal sinus is always opened postoperative brain edema and venous when performing the bifrontal approach with infarction being higher in patients the risk of postoperative CSF leakage and undergoing bifrontal craniotomy. The infections. In our experience the frontal sinus authors concluded that the anterior third of
107 6 Discussion the SSS should be preserved because its complications or death (161). closure is not safe, often resulting in
LSO Approach versus Orbitozygomatic Approach (Publications I-III)
Frazier in 1913 first described the brain can be achieved by modern orbitozygomatic approach to reach the neuroanesthesia (191) without spinal pituitary gland (74). This approach was later drainage. In small and medium-sized refined by Jane (114) and it is recommended meningiomas additional space and brain by many authors to remove OGMs, ACMs, relaxation is achieved by opening the basal and TSMs (3, 5, 149, 209, 216). cisterns. In large tumor debulking with high For OGM surgery, Al-Mefty and Babu power bipolar and suction is one of the first recommended a unilateral frontal craniotomy steps of the operation, followed by the with orbital osteotomy to prevent bifrontal opening of the basal cisterns. When using the retraction, leading to possible mental LSO approach, the tumor can be reached changes (3, 5, 149, 209, 216). The subfrontally, but the sylvian fissure can also orbitozygomatic approach is recommended be easily opened. The subtemporal route is by Al-Mefty and Sekhar when treating not needed when treating ACMs or TSMs ACMs and TSMs (3, 5, 209). When because the main vascular support comes performing the orbitozygomatic approach from the dura of the anterior clinoid, planum there is a minimal brain retraction; there is sphenoidale, and orbital roof via the AEA possibility to access to the tumor via and PEA. different routes (subfrontal, subtemporal, Pterional, orbitozygomatic, and transsylvian); the cavernous sinus can be minisupraorbital approaches were compared entered if needed; the vascular support to the in a recent cadaveric study (71). The tumor can be easily reached (4, 5). Haddad minisupraorbital approach with removal of and Al-Mefty recommend using a spinal the orbital rim gives a similar surgical view drainage to achieve a slack brain (91). The as the pterional and orbitozygomatic LSO approach provides the same advantages approaches. In our experience, inclusion of as the orbitozygomatic approach, especially orbital osteotomy is not necessary or if the operator enters from the side of the beneficial when the LSO approach is used to head to have a better angle, but is by far remove OGMs, ACMs, and TSMs. simpler, less traumatic, and faster. A slack
108 6 Discussion Neuroanesthesia in LSO Approach for a Slack Brain (Publication IV)
Based on our review on 187 neuroanesthesia according to the systemic blood pressure procedures in patients who underwent LSO measurement . The safe lower limit of CPP approach, we found that patient position, was determined individually by assessing the method of anesthesia, osmotherapy, and overall hemodynamic profile. The systolic adequate cerebral perfusion pressure, all blood pressure varied on average between 95 together gives a slack brain. One-hundred and 110 mmHg, providing a CPP of above and fifty-four patients (82%) had slack brain, 60 mmHg. The targeted CPP was achieved 17 (10%) had a satisfactory neurosurgical by use of relatively small doses of vasoactive conditions and 15 (8%) had brain swelling drugs, i.e. phenylephrine or ephedrine, after craniotomy. Volatile anesthesia was without excessive intravenous fluid given to nine (5%) patients with brain administration. During removal of a brain swelling. The LSO approach with a bone flap tumor it is also essential to avoid peak about 3-4 cm in diameter is not traumatic increases in systolic arterial blood pressure to (100, 101, 103, 104) and intraoperative minimize bleeding. Clinical assessment of bleeding was high in only two patients due to CPP was optimal in all patients since none of accidental ICA lesion or a well-vascularized the patients had ischemic brain lesions tumor. postoperatively and blood loss was minimal The head of the patient should be elevated intraoperatively. 30° and should be as neutral as possible to Adequate depth of anesthesia and analgesia facilitate the venous return (153). The senior gave hemodynamic stability. A bolus of author (J.H.) used in all patients a round firm fentanyl (5-7 microg/kg) following infusion pillow under the shoulders of the patient and of remifentanil blunts sympathetic activity the position of teh head is adjusted so that during craniotomy. Inhaled anesthetics were the operating table was usually 20 cm over used in patients with all tumor sizes. Our the cardiac level. observations confirm the results of previous Brain relaxation can be achieved during studies showing that inhaled anesthetics are craniotomy by regulating cerebral blood flow suitable in patients undergoing resection of a (CBF) and cerebral perfusion pressure brain tumor (25, 37). (CPP). Physiological pressure-flow In patients with high intracranial pressure autoregulation, ventilation (CO2 reactivity), (ICP) (large tumor) inhaled anesthetics are method of anesthesia regulate CBF. contraindicated. To counteract the An arterial transducer set at zero at the level vasodilatory effect of inhaled anesthetics on of the foramen of Monroe optimized the CPP cerebral arteries, the patient must be slightly
109 6 Discussion hyperventilated. Propofol anesthesia was all minimize blood loss during brain tumor given to 43% of study patients, most often surgery. Furthermore, the duration of surgery patients with medium or large tumors, was short, even in patients with a large supporting the capacity of propofol to tumor. Indeed, the intraoperative blood loss decrease ICP. Mannitol before opening of was on average only 200 ml, and very few the dura increases brain relaxation especially patients received red blood cell transfusion. in large tumor or in presence of brain edema. No previous report has described The use of Mannitol should be reserved in intraoperative bleeding after OGM, ACM, selected cases because it may induce and TSM. The uneventful intraoperative unfavorable side-effects such as disturbances phase is also reflected in the immediate in electrolyte concentrations, renal postoperative period. Most of the patients dysfunction, or coagulation disorder (143, were extubated on the day of surgery, and 144). the median early Karnofsky score was 80. Careful microsurgical technique, optimal brain relaxation, and cerebral hemodynamics
LSO and Anterior Clinoidectomy (Publications II-VI)
The choice of intradural or extradural Intradural anterior clinoidectomy is choosen anterior clinoidectomy and the extent of ACP when needed in ACM or TSM surgery which removal are related to the size and location conforms to the opinion and technique of of the lesion. The policy of the senior author many other authors (68, 81, 149). The ACP (J.H.) for all surgeries is to minimize the is removed after the tumor resection unless procedure and its risks, and when performing the tumor is completely intraorbital or inside skull base approaches to remove just enough the optic canal. bone to treat the lesion. In aneurysm surgery, Extradural anterior clinoidectomy is the goal of anterior clinoidectomy is to preferred by other author (165) who achieve proximal control of the ICA. emphasized the role of the opening of the Sometimes the ACP is not at all removed, SOF through the orbitozygomatic approach but merely coagulate the dura over the ACP for the treatment of both aneurysms and to gain a few millimeters of space, sufficient tumors. Opening of the SOF allows a better for the proximal control of the ICA. Based exposure of the cavernous sinus and on the senior author’s (J.H.'s) experience, we mobilization of the cranial nerves inside perform anterior clinoidectomy in all (165). We have also performed extradural vascular cases intradurally. anterior clinoidectomies and we nowadays
110 6 Discussion use the intradural-extradural approach for Many authors (29, 52, 105, 151, 261) neoplastic lesions, i.e. after orienting consider the extradural route safer because ourselves carefully with the anatomy using the dura protects the neurovascular the intradural approach, we switch to the structures, whereas other authors (68, 141, extradural route for actual ACP removal. 149, 170) prefer the intradural route. Similarly, Dolenc in 1985 advised opening Intradural visualization of the ICA and the the dura before complete unroofing of the optic nerve is mandatory for exact optic canal in giant carotid-ophthalmic anatomical orientation and safe anterior aneurysms or aneurysms extending over the clinoidectomy. We recommend intradural ACP or into the cavernous sinus (60). anterior clinoidectomy for all vascular and most neoplastic lesions.
Operative Time with the LSO Approach (Publications I-III)
LSO approach can be performed in only 10 from skin to skin was 158 min, which was min from skin incision to opening of the less than a previous OGM series of 18 dura, which is far less than the time and consecutive patients operated on by using a workload needed for either the bifrontal bifrontal approach (230 min) (154). In all approach or the fronto-orbital approach, not 191 patients the operative time was related to to mention one of the more extensive skull the size of the meningiomas, but, base approaches. Skin-to-skin operative time surprisingly, unrelated to tumor consistency. includes the approach, tumor removal, From the economic viewpoint, the relatively hemostasis, and wound closure. Closing time short operating times with the LSO approach is usually three times longer than opening allow more efficient use of the operating time. Opening and closure are shorter in the room, as more surgeries can be performed in LSO approach than in the pterional, the same room over the course of a single bifrontal, or other skull base approaches. In working day and also shorter operation times our OGM series, the mean operative time are presumably beneficial for patients.
111 6 Discussion
Surgical Complications
Olfactory Function Preservation (Publications I-III)
Olfactory function preservation is one of the was less frequent, and it was often possible key factors driving the development and to preserve the function of the contralateral improvement of different surgical olfactory tract. Welge-Luessen reported approaches for OGMs. Excessive retraction potential preservation of the olfactory tract and manipulation or excessive coagulation contralateral to the tumor in OGMs of less around the base of the tumor near the than 3 cm (244). Although the function of vascular supply to the olfactory tract can the ipsilateral olfactory tract is often lost, the easily harm the olfactory function (79). surgical technique should aim at preservation Cribriform plate osteotomy through bifrontal of both olfactory tracts by delicate dissection craniotomy for extradural lesions of the ACF in all areas, as this improves the general level has been reported to preserve or even of the surgery even in large tumors. In improve olfactory function (218). Dare patients with good olfactory function, stresses the need to know the exact distance coagulation of the dura of the cribriform below the cribriform plate to transect the plate (Simpson grade II) should be limited to ethmoidal bone in order to preserve olfactory preserve blood supply to the olfactory tracts function; skull base approaches to the (79). Our considerable experience with anterior cranial base often involve the anterior circulation aneurysms indicates that transection of olfactory nerves (47). We olfactory lesions may be caused by the believe that preservation of olfactory slightest retraction and are often difficult to function is only possible in small and some avoid (102). Six OGM patients had new medium-sized OGMs. Large OGMs postoperative anosmia; only one ACM presenting with anosmia showed no patient had postoperative anosmia, and no improvement after surgery. In small and TSM patients had hypo- or anosmia. medium-sized tumors, preoperative anosmia
CSF Leakage (Publications I-VI)
Other surgical series with OGM surgery have approach (14, 65, 159, 236). This high rate of reported CSF leakage in 3-16% of patients CSF leakage in OGM surgery is due to operated on via the frontolateral or bifrontal infiltration of the tumor of the ethmoid bone
112 6 Discussion and also to its drilling to prevent recurrences; temporary lumbar drainage in all cases. leakage in OGM surgery can occur Incidence of CSF leakage after anterior irrespective of the approach used. CSF clinoidectomy has ranged between 0% and leakage was a postoperative complications in 6% (112, 178, 210, 215, 226, 261). The six OGM patients; two patients required a anatomical continuity between the ACP and reoperation and three patients had infiltration the ethmoid sinuses can lead to CSF fistula into the ethmoid sinuses. with leakage from the nose. Five patients In previous ACM reports, CSF leakage (6%) in our series experienced postoperative incidence rates have ranged between 4% and cranionasal CSF leakage; two of them were 9% (4, 196). Three ACM patients had treated with temporary lumbar drainage for a cranionasal CSF leakage, which was few days and three required new operations successfully treated with temporary lumbar for plastic repair of the skull base. All of drainage in all cases. Clinoidectomy was these patients had good recovery at performed on all three patients, probably discharge. leading to opening of the ethmoid sinus. In TSM surgery, CSF leakage ranges from 4% to 33% (10, 76, 161, 207, 224, 230). Three TSM patients in our series experienced postoperative cranionasal CSF leakage, which was successfully treated with
Visual Outcome (Publications I-III)
Especially in large OGM tumors visual Eleven of 39 ACM patients with deterioration is a known complication. The preoperative visual deficit experienced range of visual complications has ranged improvement of their pre-existing visual between 7-12% in patients operated on via a deficits. Five of these patients underwent bifrontal or unilateral/subfrontal approach anterior clinoidectomy (four intradurally and (65, 169, 214). In our series, five OGM one extradurally). In our series, 22 of 42 patients had new postoperative visual TSM patients with preoperative visual deficits; in four of these, the OGM was deficits experienced improvement in these attached to the chiasm and the ACAs. Two deficits. Improvement was related to the of these five patients improved. preoperative duration of the deficit. Vision in 10 of these TSM patients was restored
113 6 Discussion completely after the operation; the deficit (90%) of these patients, compared with 83% had lasted less than six months in six cases in patients without a clinoidectomy. The and between 6 and 12 months in four cases. authors attributed this good outcome to the Seven TSM patients experienced a extradural clinoidectomy, to opening of the worsening of the preoperative visual deficit, SOF, to sectioning of the falciform ligament, and one patient presented a new visual and to decompression of the optic nerve deficit. The visual deficit remained stable in (136, 178). Mathiesen and Kihlström 13 of 42 patients with pre-existing visual reported on a series of 23 TSM patients deficits. The range of visual improvement in treated by a pterional and extradural previous TSM series has been between 19% clinoidectomy approach, hypothesizing that and 91%, and the range of visual early optic nerve release can improve visual deterioration between 3% and 39% (15, 68, outcome (151). The senior author (J.H.) 76, 151, 160, 178, 180, 181, 202, 207, 222, prefers to remove the ACP intradurally in 224, 230). ACM and TSM surgery to maintain good Pamir and colleagues recently reported a control of all neurovascular structures. We series of 43 ACMs, noting that during the also recommend use of low-power extradural clinoidectomy when the dura is coagulation on the dura in the proximity of retracted the tumor is also retracted, leading the optic nerve to avoid nerve damage. to additional pressure to the optic nerve and All patients with new visual deficits possible damage. The authors believed that presented with an ACM where the ICA and the intradural procedure is safer in preserving its branches were attached to or encased by the optic nerve (179). Lee and coworkers the tumor. During surgery the vascular published a series of 15 patients with ACMs support to the optic nerve, mainly from the (including one patient with superior hypophyseal arteries, may be hemangiopericytoma), with improvement of damaged, with subsequent optic nerve the preoperative visual deficits in six patients ischemia and visual deficits (241). Al-Mefty and no change in two patients. Otani et al. and Smith state that direct compression of published a series of 32 patients with TSMs; the tumor on the vascular support to the optic 20 patients received a selective extradural chiasm and optic nerve is the main cause of anterior clinoidectomy (178). The visual impairment (3). preoperative visual deficit improved in 15
114 6 Discussion
Visual Outcome after Anterior Clinoidectomy (Publications V and VI)
Worsening of the visual acuity affected our series when analyzed the critical factors seven (9%) of the 82 patients and pre- affecting visual outcome, such as opening of existing visual deficits improved after the SOF, extra- or intradural route, duration surgery in almost half of cases (12/27) who of pre-existing visual deficits, and underwent anterior clinoidectomy. Intradural instruments used to perform the route was used in all patients in whom vision clinoidectomy. This is probably due to the improved. Visual worsening after anterior rather small number of patients with visual clinoidectomy has ranged from 0% to 13% complications and the subsequent lack of (29, 128, 149, 151, 178, 202, 215, 261). statistical power. However, after scrutiny of Yonekawa reported in 1997 thirty-two the operative videos, we consider that usage patients who underwent a pterional and of the ultrasonic bone dissector (Sonopet in extradural anterior clinoidectomy for supra- our case) too close to the optic nerve may and parasellar lesions and three had visual have a role in optic nerve injury. worsening after surgery (261). The “no drill” The most widely used technique to remove technique to remove ACP extradurally was the ACP is high-speed drilling. Chang reported by Chang in 2009, and two of 45 scrutinized 45 consecutive cases undergoing patients had postoperative visual deficits anterior clinoidectomy through a (29). The role of the extradural anterior frontotemporal craniotomy, and assumed that clinoidectomy, sectioning of the falciform high-speed drilling can injury the ligament and opening of the SOF to improve surrounding neurovascular structures directly postoperative visual outcome in ACM and (mechanical) or indirectly (thermal damage) TSM surgery, is emphasized by some (29). The ultrasonic bone aspirator has been authors (151, 178, 202). However, we do not introduced to avoid the risks of drilling and routinely perform anterior clinoidectomy for few reports exist regarding its use in anterior all ACM and TSM in accordance with some clinoidectomy (29, 92). Chang supposes the other authors (15, 17, 68, 81, 112, 117, 126, possibility of ultrasound-related cranial nerve 141, 207). When anterior clinoidectomy is damage. Furthermore, the ultrasonic bone required for complete tumor removal, we dissector is a very expensive piece of prefer a tailored clinoidectomy and remove instrument with additional accessory device only as much of the ACP as required. No costs. Recently has been published a report statistically significant factors were found in about the use of the ultrasonic bone dissector
115 6 Discussion in spinal surgery (123) and the authors report one patient with a carotid-cavernous fistula six cases of dural injury and one case of and another patient with intraorbital fibrosis, spinal cord injury attributable to the use of both of whom experienced postoperative the device. In our series, in the patient with visual deficits, ultrasonic bone dissector was no pre-existing visual deficits and a small used close to the optic nerve. We therefore carotid-ophthalmic aneurysm, the ultrasonic believe that ultrasonic bone dissectors are bone dissector was used close to the optic certainly not harmless and may cause optic nerve, and this may have caused the nerve injuries. postoperative blindness of the eye. Also, in
Surgical Mortality (Publications I-III)
The closure of the SSS and frontal cortical In our ACM series, three patients (4%) died. veins and compression of both frontal lobes One had severe vasospasm and died 19 days after bifrontal craniotomy had a high after the operation; one developed mortality (65). The advantage of the LSO hemiparesis and died of severe pneumonia approach is to preserve the SSS and the one month after surgery; one patient had a frontal cortical veins, avoiding bifrontal good initial recovery, but died two days after compression. No OGM patient in our series the operation of myocardial ischemia. had increased edema postoperatively and no Nakamura et al. report the surgical results of immediate deaths occurred after the surgery. 72 TSMs removed via the bifrontal, Surgical mortality in OGM surgery had pterional, and frontolateral approaches (161). ranged between 0% and 28% in previous Two patients died in the bifrontal group. No series (13, 39, 65, 94, 157, 159, 169, 228, patients died with the pterional or 236, 244). frontolateral craniotomy (161). In our series, Mortality in ACM and TSM surgery has one patient with severe disability been relatively high in published patient preoperatively and a large tumor (diameter series (4-6, 76, 81, 82, 112, 149, 161, 188, 60 mm) died 40 days after surgery due to 196, 214, 224). This is explained by the close cardiac arrest. She had slowly recovered and proximity of important neurovascular was able to walk one month after the structures. operation. Surgical mortality reported in all In previously published ACM series, the TSM series has ranged from 0% to 44% mortality has ranged between 2% and 15% when using pterional, bifrontal, supraorbital, when orbitozygomatic and pterional and orbitozygomatic approaches (6, 76, 81, approaches were applied (4, 5, 82, 188, 196). 112, 149, 161, 214, 224).
116 6 Discussion Tumor Recurrence during Follow-up (Publications I-III)
In our OGM series, with a median follow-up of 23 months (149). Nakamura et al. of 45 months, tumor recurrences was 6%. compared the incidence of recurrence in 72 The tumor recurrence rate for OGMs varies TSM patients treated using frontolateral, between 5% and 41%, depending on the bifrontal, and pterional approaches and extent of the initial resection, but more observed no differences during a mean long- importantly, on the duration of follow-up (2, term follow-up of 45 months (161). 19, 111, 152, 156, 159, 212, 214, 250). A previous series of 657 meningioma Ethmoid sinus infiltration predisposes to patients treated at our department was tumor recurrence, and a radical resection of carefully reviewed, and the overall the tumor tissue from these sinuses leads to recurrence rate over 20 years was estimated lower recurrence rates (169). In older to be close to 20% (111). Risk factors for patients, we do not advocate (overly) radical recurrence were coagulation without removal surgeries because of the associated higher of the dural insertion, invasion of bone, and risk of complications and only the soft consistency of the tumor (111). With a intracranial tumor mass should be removed. longer follow-up, the recurrence rate would In young patients with preoperative anosmia, certainly have been higher in our series, but we perform a radical resection of the tumor in general the OGM, ACM, and TSM with extensive ethmoidal bone drilling. recurrence rates do not seem to be higher Previously reported tumor recurrence of with the LSO approach than with other ACMs has varied from 9% to 15% (250). In approaches. the present report, with a mean follow-up of 36 (range, 3-146) months, three patients (4%) had a recurrence. Published tumor recurrence rates in TSMs have varied from 0% to 8% using different approaches (9, 68, 76, 81, 149, 161, 202, 207, 214). One patient (2%) of our TSM series had a recurrence five years from the first operation. Mahmoud et al. reported 58 TSMs with total resection in 88%, and a recurrence rate of 2% over a mean follow-up
117 “Il n’y a rien comme un rêve pour créer l'avenir. L'utopie d'aujourd'hui réalité de demain.”
Victor Hugo (1802-1885)
Future Perspectives
Near Future
Preoperative Imaging
Preoperative high-field magnetic resonance prevent its opening during anterior imaging may provide a better view of the clinoidectomy, thereby avoiding anatomical relationship between the lesion postoperative CSF leakage. Predicting the and the surrounding neural and vascular exact consistency of the tumor and its dural structures. The location of the optic nerve origin may also be possible. A and chiasm relative to the tumor or aneurysm neuronavigator system will be used routinely and to the anterior skull base may be to specify the tumor or aneurysm relationship visualized by novel MR diffusion tensor to the skull base. The progress in the imaging techniques in the future, whereas the endovascular field will make possible to anatomy of small perforators may be better close preoperatively all the vascular support imaged by advanced MRA techniques. A to the tumor even if coming from small careful preoperative anatomical study will arteries challenges to reach. reduce surgical complications. It may be possible to localize the ethmoid sinus and
Skull Base Simulators
Virtual reality may be used to improve structures and the tumor or aneurysm, technical skills. An operation performed in allowing a precise operative plan to be virtual reality before the real one will formulated that specifies all potential provide skull base visualization and elucidate difficulties and complications. Virtual reality the relationship between neurovascular will enable the surgeon to perform
118 increasingly more challenging procedures on approaches. the anterior skull base through small
Microsurgical Techniques
Refinement of neurosurgical instruments will and without a risk of lesions in the allow the neurosurgeon to perform simple, surrounding vascular or neural structures. elegant, and definitive procedures. Smaller Smaller and flexible endoscope will be used instruments must be designed. A higher routinely to visualize the tumor behind the magnification microscope with different corner of bone and neurovascular structures. devices for visualization of the vascular The microscope will be replaced by simple anatomy of the tumor, for instance, will glasses connected to a fiber optic devices allow devascularization of the lesion without which will allows the neurosurgeon to have intraoperative bleeding or a risk of ischemia. huge magnification avoiding the A new computerized device in the encumbrance of the microscope. microscope together with preoperative Robot-assisted surgery can physically imaging will facilitate total removal of replace the presence of the neurosurgeon in lesions, avoiding residual tumors. The the operative field as nowadays the daVinci microsurgical instrument of the future as a robot does in urology field. bone removal device will be lighter, stable,
Neuroanesthesia
Advancements in neuroanesthesia will eliminating anesthetic drug interactions. The enable a slack brain to be achieved, avoiding procedures will be shorter, as will also the diuretic osmosis, especially in large tumors. postoperative intensive care period of the An optimal surgical condition may be patient. accomplished by using only one drug,
119 Far Future
A better understanding of brain function will improve the prevention and cure of vascular and neoplastic lesions of the brain. Medical treatments may in the distant future reduce the need for invasive treatments, such as surgery or radiotherapy, but this will require accurate non-invasive diagnosis of brain diseases and considerable developments in specially targeted minimally invasive treatment methods.
120 7 Conclusions
The simple and fast LSO approach can be visual deficit. We recommend the intradural used for OGMs, ACMs, and TSMs of all approach for anterior clinoidectomy in all sizes and has a relatively low morbidity and vascular and most tumor cases. low mortality. Surgical results and tumor recurrence during The LSO approach requires good operating follow-up with this fast and simple method site conditions and a slack brain. The latter is were similar to those obtained with more achieved by correct patient positioning and extensive, time-consuming approaches. neuroanesthesia. In small or medium-sized High-power coagulation should be avoided lesions, both intravenous and volatile in the proximity of the optic nerve and anesthesia can achieved a slack brain. In chiasm, taking special care to preserve the large meningiomas, we prefer propofol vascular support coming from the ICA. anesthesia and mannitol. Early devascularization of the tumor and The anterior clinoid process can be removed intraoperative hypotension reduce through the LSO approach without mortality intraoperative bleeding. Postoperative and with low morbility. The ultrasonic bone ventilator therapy is related to tumor size and device carries the risk of a postoperative the patient's preoperative clinical condition.
121 List of 15 Supplementary Videos on Microneurosurgery of OGMs, ACMs, TSMs and Anterior Clinoidectomy through Lateral Supraorbital Approach
The supplementary CD includes 15 videos on microneurosurgery of OGMs, ACMs, TSMs, and anterior clinoidectomy through LSO approach:
1. Lateral supraorbital approach (right side) 2. Microneurosurgical treatment of a small (30 mm) OGM through a right LSO 3. Microneurosurgical treatment of a medium-sized (50 mm) OGM through a right LSO 4. Microneurosurgical treatment of a large (> 60 mm) OGM through a right LSO 5. Microneurosurgical treatment of a large (> 60 mm) OGM through a right LSO 6. Microneurosurgical treatment of a small (13 mm) ACM through a right LSO 7. Microneurosurgical treatment of a medium-sized (28 mm) ACM through a right LSO 8. Microneurosurgical treatment of a large (59 mm) ACM through a right LSO 9. Microneurosurgical treatment of a large (60 mm) ACM through a right LSO 10. Microneurosurgical treatment of a medium-sized (24 mm) TSM through a right LSO 11. Microneurosurgical treatment of a medium-sized (25 mm) TSM through a right LSO 12. Microneurosurgical treatment of a large (60 mm) TSM through a right LSO 13. Microneurosurgical treatment of intra-extradural ICA junction aneurysm through a left LSO and intradural anterior clinoidectomy 14. Microneurosurgical treatment of an ACM through a right LSO and intradural anterior clinoide ctomy 15. Microneurosurgical treatment of a spheno-orbital meningioma through a right LSO and extradural anterior clinoidectomy Eleven videos are selected reviewing all operations on microneurosurgical treatment of OGMs, ACMs, and TSMs, performed by Professor Hernesniemi at the Department of Neurosurgery, Helsinki University Hospital, between September 1997 and August 2010. Three videos are selected from all operations in which anterior clinoidectomy, through LSO approach, was performed by Professor Hernesniemi between June 2007 and January 2011.
122 “A l'alta fantasia qui mancò possa; ma già volgeva il mio disio e 'l velle, sì come rota ch'igualmente è mossa, l'amor che move il sole e l'altre stelle.”
Dante, The Divine Comedy, Paradiso, Canto XXX: vv.142-145 Acknowledgments
This study was carried out at the Department of Neurosurgery, Helsinki University Central Hospital, in 2008-2011. I wish to thank the following professors, colleagues, friends and relatives for their teaching, help, and support during the past years.
I owe my deepest gratitude to my mentor Professor Juha Hernesniemi for his invaluable guidance, daily support, and encouragement. Without his constant forward thrust, I would not have been able to finish this work. He is a genius and an innovator in the neurosurgical field. If I had to compare him to a great Italian artist I would certainly choose Michelangelo. I feel very lucky to have assisted him in close to two thousand neurosurgical operations, and my heartfelt thanks go to him for sharing his immense experience in neurosurgery with me.
I am also indebted to Docent Aki Laakso for his efficient supervision of my work. I am grateful for his teaching in the OR and in scientific writing. Beside his neurosurgical skills, he is a great experimental neuroscientist. His constructive criticism has been essential for the success of this work.
I am grateful to my third supervisor Docent Marko Kangasniemi for his patience in helping with this thesis and for his insightful ideas for improving the manuscript. He is always enthusiastic about new projects and makes pleasant the most boring work. It is a great pleasure to work with him.
I thank the official reviewers of this thesis, Docent Esa Heikkinen and Docent Esa Kotilainen, for their excellent comments and corrections.
I warmly thank Dr. Leena Kivipelto and Professor Fady Charbel, the informal reviewers of this thesis. Their corrections and comments improved the manuscript significatively.
123 I am indebted to Docent Tomi Niemi and Dr. Marja Silvasti-Lundell for their teaching and help in preparing the anesthesia paper.
I thank Docent Mika Niemelä for his support in scientific writing.
I am grateful to Professor Juha Jääskeläinen and Dr. Martin Lehe6ka for their assistance at the beginning of this work. Their teaching influenced and noticeably improved my scientific thinking.
I deeply thank my coauthors Drs. Matti Porras, Stefano Toninelli, Emilia Gaal, Özgür Çelik, and Ahmed Elsharkawy. Their contributions have been substantial.
I am grateful to Professor Henry Troupp for sharing some important old details of Finnish Neurosurgery with me.
I thank Professor Lars Kihlström for his unique contribution in the history of Olivecrona.
I am grateful to Dr. Roberto Crosa for his invaluable and beautiful drawings.
I thank Dr. Asem Salma for the cadaveric work of this thesis.
This work has been supported by an Ehrnrooth Fellowship, which I deeply appreciate.
I am indebted to my neurosurgical, neuroanesthesiological, and neuroradiological colleagues for their vast experience and invaluable teaching as well as for always being ready to help and discuss cases during my clinical work.
I thank Virpi Hakala and Eveliina Salminen for solving all technical problems and for generous help over the years.
I thank all nurses at the neurosurgical department for their expertise and patience when working with me. They have provided great support.
I thank Carol Ann Pelli for editing the English language of this manuscript.
124 I am grateful to my former chairman of the Department of Neurosurgery of the Catholic University of Sacred Heart in Rome, Professor Gianfranco Rossi, for giving me the opportunity to enter the neurosurgical world.
I warmly thank all of my friends and sisters in Rome with whom I shared the most carefree time of my life. They helped me in many different ways and have taught me that attitudes to life can be very different and colorful.
I thank Lode, Elina, Uschi, Joseph, and the entire Focolarini clan for their love and support.
I am deeply grateful to Kaija, Pekka, Anna, Kaisu, and Ulpu for being my Finnish family. Their support, advice, and affection have helped me through many difficulties and homesickness. They helped me appreciate and enjoy the Finnish culture and beautiful landscape. I thank them for putting up with me in my worst stressful moments.
A silent thanks goes out to my late father, Francesco, who greatly influenced my interest in medical art. I am sure that he protects me. My heartfelt thanks go to Vincenzo for his help, support and affection. I thank my elder sister Romina for being the most wonderful of sisters and for always being there for me. She is a cornerstone in my life. Alessio and Francesco I thank for being the light of my life, for their love, and for always waiting for me in Italy. Their genuine happiness adds energy and optimism to my life.
Finally, I dedicate this work to my mother Carolina. I appreciate all of the sacrifices that she made. She is the most hard-working and honest person I know and at the same time is the sweet and wonderful mom that anyone would wish for. My deepest gratitude for everything she did for me cannot be expressed in words.
This study was financially supported by the Helsinki University Central Hospital and an Ehrnrooth Fellowship.
In Helsinki, October 2011
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