KISEP J Korean Neurosurg Soc 36 : 107-113, 2004 Clinical Article Neurosurgical Approaches to and through the Frontal Sinus using Osteoplastic Frontal Sinusotomy Dong-Hun Kang, M.D.,1 Seong-Hyun Park, M.D.,1 Jae Chan Park, M.D.,1 Yeun-Mook Park, M.D.,1 Murali Guthikonda, M.D.,2 In-Suk Hamm, M.D.1 Department of Neurosurgery,1 Kyungpook National University Hospital, Daegu, Korea Department of Neurosurgery,2 Wayne State University, Detroit, Michigan Objective : The frontal sinus is frequently a troublesome anatomical obstacle to gain access to the medial anterior cranial base. Surgical approaches to and through the frontal sinus using osteoplastic frontal sinusotomy provide significant advantages to the treatment of lesions of the medial anterior cranial base in addition to the frontal sinus itself. However, appropriate management is necessary to avoid postoperative complications such as cerebrospinal fluid leakage, infection, mucocele formation, and deformity of the forehead. Methods : The advantages and shortcomings of the approach along with the surgical technique are reported based on our clinical experience with pertinent literature review. The approach using the osteoplastic frontal sinusotomy was applied to two cases of osteoma in the frontal sinus, seven cases of craniofacial tumors, a case of chordoma in the sphenoid and clivus, and two cases of intradural lesions in the anterior cranial fossa. The frontal sinus was managed in such a way as to prevent the postoperative complications. Results : All patients underwent gross total resection of the tumors. With a mean follow-up of 26 months, there were no postoperative complications related to frontal sinus violation. Conclusion : The neurosurgical approaches via the frontal sinus using osteoplastic frontal sinusotomy are versatile for various lesions of the anterior cranial base in patients with large frontal sinuses. In situations that the frontal sinus have to be violated to approach medial anterior cranial base, the osteoplastic frontal sinusotomy provides such advantages as optimal frontal sinus control to prevent postoperative complications; increases viewing angle with superior trajectory from nasofrontal suture; lower incidence of pnemocephalus due to minimal dural exposure; and excellent cosmesis without frontal burr holes. KEY WORDS : Anterior skull base·Combined craniofacial surgery·Frontal sinus· Osteoplastic frontal sinusotomy·Postoperative complication. Introduction originating in the nasal cavity and paranasal sinuses. Intrad- ural neoplasms such as olfactory groove or tuberculum sellae he frontal sinuses are paired pyramidal cavities with a meningiomas also occupy the medial anterior cranial fossa. T centrally positioned intersinus septum although several For the patients with large frontal sinuses, osteoplastic frontal septa can be observed in many patients. The sinuses are sinusotomy can provide an appropriate window to gain access located within the squamous portion of the frontal bone above to the medial frontal fossa in addition to the frontal sinus the nasal root and medial orbits, and therefore are in the way itself. of transcranial approaches to the medial cranial base30,46).By In this report we present our clinical experiences based on age 20, they reach adult size, measuring 28mm high, 24mm four variations of the neurosurgical approaches to and wide in each side, and 20mm deep on the average with wide through the frontal sinus using osteoplastic frontal individual variation46). sinusotomy (so-called transfrontal sinus approach). The medial anterior cranial fossa is often invaded by tumors Materials and Methods Received：March 15, 2004 Accepted：May 12, 2004 Address for reprints：Jae Chan Park, M.D., Department of Neurosurgery, Kyungpook National University Hospital, 50 Samduk Patient population 2-ga, Jung-gu, Daegu 700-721, Korea During the past five years, 12 patients underwent neuro- Tel : 053) 420-5647, Fax : 053) 423-0504 surgical approaches to or through the frontal sinus using E-mail : [email protected] / [email protected] osteoplastic frontal sinusotomy (Table 1). The first nine cases VOLUME 36 August, 2004 107 Osteoplastic Frontal Sinusotomy Table 1. Review of 12 patients who underwent neurosurgical approaches to and through the frontal sinus using Surgical procedure osteoplastic frontal sinusotomy Simple osteoplastic frontal Age (yrs), Tumor Tumor Case No Procedures Sex Histology Location sinusotomy (Case 10, 11) lt ethmoid/maxillary sinus 1 43, M esthesioneuroblastoma combined craniofacial surgery A bicoronal scalp incision nasal cavity, orbital wall 2 67, F inverted papilloma bil ethmoid/maxillary sinus was made behind the hairline combined craniofacial surgery recurrent nasal cavity and carried just anterior to the lt ethmoid/maxillary sinus 3 20, F chondrosarcoma combined craniofacial surgery tragus bilaterally. The disse- nasal cavity 4 54, F adenocarcinoma lt ethmoid/maxillary sinus ction proceeded beneath the combined craniofacial surgery recurrent nasal cavity, orbital floor galea with elevation of the lt frontal sinus 5 55, M ameloblastoma lt ehmoid/maxillary sinus superficial layer of the tempo- combined craniofacial surgery 3rd molar ralis fascia and the fat pad to lt ethmoid/maxillary sinus 6 27, M schwannoma combined craniofacial surgery protect the frontalis branches nasal cavity sphenoid body subfrontal transbasal approach of the facial nerve. The peri- 7 60, M chordoma upper clivus with orbital osteotomy cranium was incised at the transcranial intradural approach 8 45, F meningioma olfactory groove with orbital osteotomy posterior limit of exposure transcranial intradural approach 9 38, F meningioma tuberculum sellae and along the superior tempo- with orbital osteotomy 10 30, M osteoma frontal sinus frontal sinusotomy only ral line, then elevated anteri- 11 38, F osteoma frontal sinus frontal sinusotomy only orly along the supraorbital rim 12 71, M esthesioneuroblastoma ethmoid & frontal sinuses transcranial approach and the nasofrontal suture to bil : bilateral, lt : left, M : male, F : female be used for later reconstru- in the table 1 we- ction of the cranial base15,26). The supraorbital nerves were re operated by t- released from the supraorbital notch or foramen with an wo authors (M. osteotome. G. & J. P), and t- The shape of the frontal sinus was then outlined with a he last three cas- marking pen by applying a sterilized X-ray template from 6- es were operated feet Caldwell view with a magnification factor, almost 1.0 by another author (Fig. 1). The anterior wall of the frontal sinus was cut with (Y. M. P). Seven cases were cran- Fig. 1. X-ray of 6-feet Caldwell view with a iofacial tumors. magnification factor, almost 1.0, which is Six of the seven confirmed with a coin on the glabella. The craniofacial tu- inlet shows a sterilized X-ray template cut from the Caldwell view. mors were rese- cted by combined A B anterior craniofacial surgery, and one case was removed by transcranial approach only. The tumors originated in the nasal cavity or paranasal sinuses and invaded anterior cranial base. They revealed various pathologies such as esthesioneu- roblastoma, inverted papilloma, chondrosarcoma, adenocar- cinoma, ameloblastoma, and schwannoma. One of the twelve C D cases was a chordoma involving sphenoid body and upper clivus. It was resected by the transfrontal sinus-transbasal Fig. 2. Photographs demonstrating the osteoplastic frontal approach. Intradural lesions that were resected by the bilateral sinusotomy. The anterior wall of the frontal sinus is cut with oscillating saw or high-speed drill (Midas Rex C1 drill bit). The blade or drill bit is orbitofrontal craniotomy in addition to the transfrontal sinus angled to create an oblique cut to assure an osteotomy within the approach were an olfactory groove meningioma and a confines of the sinus(A). The lower limit of cutting is the nasofrontal suture(B). A photograph after cutting the frontal sinus in another tuberculum sellae meningioma. patient is shown(C). An osteotome is used to transect the intersinus The remaining two cases were osteomas in the frontal septum and to pry the sinus open(D). sinuses. 108 J Korean Neurosurg Soc 36 DH Kang, et al. was allowed to drain freely from the dural opening to aid extradural brain retraction. The operation was then carried out with an osteotomy through the planum sphenoidale and the roof of the ethmoids on the A B C cranial side, opening the ethmoid air cells from above (Fig. 4)39). In Fig. 3. Case 2, a case of combined craniofacial surgery. A : Schematic illustration showing that craniofacial tumor is attacked from above and below. B & C : Preoperative sagittal (B) & coronal (C) the case of unilateral involvement T1-weighted magnetic resonance image after Gd-DTPA administration demonstrating of cribriform plate, olfaction was heterogeneous enhancement of the lesion occupying the maxillary sinuses, nasal cavity, and ethmoid sinuses. preserved by leaving the contrala- teral side of the cribriform plate with olfactory rootlets intact. After extirpation of the tumorous lesion, the dura was closed with a con- tinuous suture and the pedicled pericranial flap was rotated over the defect onto the floor of the A B C anterior cranial fossa. It was then Fig. 4. A & B : Illustrations showing the steps of the combined craniofacial surgery. The crista galli is secured to the basal dura and the removed with a narrow-tipped rongeur after removing the posterior wall of the frontal sinus (A). The bony skull base. After obliteration anterior and posterior ethmoidal arteries at the ethmoidal foramina are cauterized with bipolar of the dead space of the frontal cautery and the adjacent dura is cut sharply (B). C : A photograph just before entering the ethmoid sinus. sinus with abdominal fat, the anterior wall of the sinus was oscillating saw or high-speed drill (Midas Rex C1 drill bit) restored and secured with minip-lates and screws (Fig. 5). with a lower limit of cutting through the nasofrontal suture. The facial component of the craniofacial tumor was The blade or drill bit was angled to create an oblique cut to resected by maxillectomy, often combined with ethmoid- assure an osteotomy within the confines of the sinus.