Endoscopic Endonasal Approach for Craniopharyngiomas Jörg Baldauf, MDa, Werner Hosemann, MDb, Henry W.S. Schroeder, MDa,* KEYWORDS Endoscopic endonasal approach Craniopharyngiomas Retrochiasmatic tumor KEY POINTS The endoscopic endonasal approach for the management of craniopharyngiomas has increasingly been used as an alternative to microsurgical transsphenoidal or transcranial approaches. This approach is a major step forward in the treatment of these difficult lesions because of improved resection rates and better visual outcome. Especially in retrochiasmatic tumors, the endonasal approach provides better access to the lesion and reduces the degree of manipulations of the optic apparatus. The panoramic view offered by endoscopy and the use of angulated optics allows the removal of lesions extending far into the third ventricle avoiding microsurgical brain splitting. A video of the endoscopic endonasal resection of an intraventricular craniopharyngeoma accompanies this article at http://www.neurosurgery.theclinics.com/ INTRODUCTION amplitude in childhood. However, the prognosis of these tumors in particular is a matter of growth Craniopharyngiomas (CPs) represent one of the pattern. The extent of the tumor in relation to the most challenging tumor entities in neurosurgery. optic chiasm, pituitary gland and stalk, hypothala- Because of its critical vicinity to important neuro- mus, carotid artery, and anterior cerebral artery vascular structures, the surgery is demanding complex as well as the location of the tumor with and requires a thorough understanding of the respect to the sella and diaphragm, is important anatomy of the suprasellar region. for surgical planning. In addition to the tumor CPs are benign epithelial tumors of the sellar size and the multilobulated characteristics with region originating from remnants of Rathke’s cleft. solid and cystic components, it is of significant in- They are classified by the World Health Organiza- 1 terest whether the lesion does extend into the third tion as grade I neoplasms. The papillary form is ventricle or not and its relation to it. To solve the almost exclusively found in the adult population problem of choosing the right surgical strategy and the adamantinomatous subtype mainly oc- 2,3 for individual cases, a variety of topographic curs in children. There is a bimodal age dis- and clinical classifications of CPs have been trans- tribution of the incidence of CPs with a higher ferred into surgical practice parallel to Disclosure: H.W.S. Schroeder is consultant to Karl Storz GmbH & Co KG (Tuttlingen, Germany). a Department of Neurosurgery, Ernst Moritz Arndt University, Sauerbruchstrasse, Greifswald 17475, Germany; b Department of Otorhinolaryngology, Ernst Moritz Arndt University, Walter-Rathenau-Strasse 43-45, Greifs- wald 17475, Germany * Corresponding author. E-mail address: [email protected] Neurosurg Clin N Am - (2015) -–- http://dx.doi.org/10.1016/j.nec.2015.03.013 1042-3680/15/$ – see front matter Ó 2015 Elsevier Inc. All rights reserved. neurosurgery.theclinics.com 2 Baldauf et al technological progress of instrumentation and endoscope to transsphenoidal surgery more than equipment.2,4–7 a decade earlier.18 Two decades later, Carrau Albert E. Halsted has been credited with the first and Jho reported their first series of purely endo- successful transsphenoidal resection of a CP per- scopic endonasal removal of pituitary ade- formed in 1909.8 The transsphenoidal approach nomas.19,20 The continuous advancement of the for tumors of the sellar region is strongly related endoscope, in addition to the development of spe- to Harvey Cushing and Oskar Hirsch.9 In 1909, cific instruments and sophisticated endoscopic Cushing described his first surgery through the studies of the parasellar and anterior skull base transsphenoidal route for partial removal of the pi- anatomy allowed the extension of the spectrum tuitary gland in a patient with acromegaly.10 A of indications for the technique. This initial work detailed historical review concerning the endo- was spearheaded by “The original Pittsburgh nasal approach for CPs written by Gardner and group” with Carrau, Kassam and co-workers as colleagues11 mentioned that Cushing abandoned well as the Naples group with Cappabianca and the approach for CPs for safety reasons given by De Divitiis, and also the Bologna group with Frank technological and visualization limitations. In and Pasquini, who promoted the endoscopic contrast, Hirsch developed and kept to the endo- extended endonasal approach in the early years nasal transsphenoidal approach and reported his of the 21st century.21–24 Nowadays, the endo- first small series of 12 patients treated for tumors scopic approach is widely accepted and is used of the pituitary gland in 1911 at the third interna- regularly. However, there is a long learning curve tional laryngo-rhinological congress in Berlin.12 and cadaver studies are recommended. Addition- Ten of the patients improved in clinical outcome ally, close cooperation between an ENT-head and 2 died. The latter were subjected to autopsy. and neck surgeon and neurosurgeon is necessary. In one, a large tumor of the pituitary gland was Based on their extraordinary experience, Kassam found that mainly extended into the intracranial and colleagues24 specified a V-level scale of space and third ventricle. Hirsch made 2 important complexity of endoscopic endonasal skull base statements about his experience regarding the procedures that provides a useful guide. Accord- transsphenoidal approach. First, an improvement ing to their scale, the endoscopic endonasal of clinical symptoms can be expected if the tumor approach to CPs is a level IV category referring to is located exclusively inside the sella and reveals the fact that intradural surgery is usually required. cystic components. Second, if a tumor is mainly Several studies have demonstrated already excel- growing intracranially, the endonasal approach lent results for CP patients.25–30 Compared with the and all other extracranial methods will not suc- transcranial microscopic approach, the endo- ceed. Fortunately, the introduction of the oper- scopic approach promises a higher rate of gross ating microscope opened a new door to total resection (GTR) and improved visual outcome neurosurgery in general, as well as to the trans- because there is less manipulation of the optic sphenoidal endonasal route particularly. Hardy apparatus, especially in retrochiasmatic lesions.31 stressed the importance of the microsurgical approach for pituitary adenomas and CPs in INDICATIONS AND LIMITATIONS FOR 1971 and mentioned that “the intrasellar subdiag- ENDOSCOPIC EXTENDED ENDONASAL phragmatic type of CP can be totally removed APPROACH transphenoidally.”13 Laws improved the microsur- gical technique for CPs and expressly underlined Patients with CPs can present with a great variety that if “the sella turcica is enlarged, transsphenoi- of symptoms including headache, visual symp- dal microsurgery can be the procedure of choice, toms, hormonal disorders such diabetes insipidus even when significant intracranial extension is and hypopituitarism, mental and memory dis- present.”14,15 turbances, gait difficulties, and hypothalamic The stepwise technological progress extended disturbances such as the Fro¨ hlich’s syndrome the transsphenoidal access, initially described by (adiposogenital dystrophy). The typical symptoms Weiss,16 to reach the suprasellar/supradiaphrag- of increased intracranial pressure are commonly matic space. However, transcranial approaches related to an associated hydrocephalus owing to to CPs with intraventricular growth have also tumor extension into the third ventricle. been used via pterional, transcortical, interhemi- All symptomatic CPs are an indication for sur- spheric, transcallosal, and transforaminal routes.2 gery. Asymptomatic lesions can be followed with The microsurgical–endonasal resection of sellar MRI. However, growing lesions should be treated tumors was successfully complemented by the before they become symptomatic.32 If the patient use of an endoscope by Apuzzo and colleagues17 presents with acute hydrocephalus owing to in 1977 after Guiot had already introduced the obstruction of the foramina of Monro by a cystic Endonasal Approach for Craniopharyngiomas 3 component of the tumor, an initial transcranial Box 1 transventricular endoscopic cyst fenestration can Limitations and unfavorable factors of the be performed before the endonasal tumor resec- endoscopic extended endonasal approach tion to release the increased intracranial pressure. The goal of surgery for CPs is GTR or near total 1. Hypoplastic sphenoid sinus resection, if feasible. However, tumor removal has 2. Narrow sellar floor/reduced intercarotid ar- to be restricted to subtotal resection or even par- tery distance tial resection when the risk of neurovascular dam- 3. Combined prechiasmatic and retrochias- age is expected to be high to avoid unacceptable matic tumor extension postoperative morbidity. The surgical approach 4. Significant lateral tumor extension depends on the individual growth pattern of the tu- mor. Important essentials for the endoscopic 5. Predominantly solid component in large extended endonasal approach are listed in Table 1 tumors and limitations are presented in Box 1 with respect 6. Type IV lesions according to Kassam6 to the recent literature.6,25,27,30 Categories A through G try to display an increase of the neces- sary surgical expertise according