Background: The endoscopic endonasal approach is gaining popularity for the repair of anterior skull base defects. We review our experience with this procedure, including methods for repair and its overall efficacy.
Methods: Endoscopic endonasal procedures performed between 2011 and 2018 for the primary goal of anterior skull base repair were retrospectively identified and reviewed. Baseline demographics, etiology and location of the defect, presenting symptoms, method of repair, antibiotic and lumbar drain usage, need for additional procedures, and complications were noted.
Results: During the reviewed period, 74 patients underwent endonasal endoscopic procedures at our institution. Of these, 8 patients underwent 9 procedures for the primary indication of anterior skull base repair. The average follow-up was 15 ± 18 months. Three patients were men, and 5 were women with a mean age of 48 years. Six defects were spontaneous, 1 was posttraumatic, and 1 was iatrogenic. All patients with spontaneous CSF leaks were obese (mean body mass index = 35), and five of six were female. All patients presented with CSF rhinorrhea. Two additionally presented with headaches and one with meningitis. Associated encephaloceles were noted in 5 cases. Intracranial hypertension was inferred in one patient due to the presence of an empty sella on imaging. Three leaks involved the ethmoid alone, three involved the sphenoid alone, one involved both the ethmoid and the sphenoid, and one involved the sella. Intrathecal fluorescein was used in 5 cases and helped identify the leak in 4 of these cases. A nasoseptal flap was used in 1 repair. Inlay grafts were used in 7 repairs; 3 involved fat autograft and a dural substitute and 4 utilized a dural substitute alone. Overlays were used in all cases. These most commonly involved a dural sealant alone (n = 3), dural substitute and dural sealant (n = 2), and dermal matrix (n = 2). A lumbar drain was used in 6 procedures. Its use was continued postoperatively in 5 cases, for an average of 5 days. Perioperative antibiotics were used in all cases, with most patients receiving a week of treatment postoperatively. The initial procedure was successful in stopping CSF leakage in 6 (75%) of all patients, including all patients presenting with spontaneous CSF leaks. One patient who had an iatrogenic CSF leak following resection of a pituitary adenoma required a second endoscopic procedure, followed by CSF diversion with a lumbar drain. Another patient whose leak was associated with significant skull base fractures required a bifrontal craniotomy to address a persistent leak. No procedure-related complications were noted.
Conclusion: Endoscopic endonasal repair using a combination of an inlay and an overlay graft is highly effective for the repair of spontaneous anterior skull base defects. Complicated defects, such as those associated with significant trauma or previous surgical procedures may require a multifaceted approach.
