Cerebrospinal Fluid Leak after Acoustic Neuroma Surgery via Middle Cranial Fossa Approach

Background Postoperative cerebrospinal fluid (CSF) leakage can be a serious complication following vestibular schwannoma (VS) surgery.

Objective To evaluate the CSF leak rate after middle cranial fossa (MCF) approach to VS resection.

Methods Retrospective case series of consecutive patients undergoing MCF approach to VS resection from 2007 to 2017 at a tertiary referral academic center. Lumbar drains (LD) were routinely placed preoperatively and removed at the end of surgery. After tumor resection, the internal auditory canal dural defect and middle fossa floor were sealed with a combination of temporalis muscle graft, temporalis fascia graft, and fibrin sealant. Bone wax was applied to occlude any exposed air cells.

Results A total of 161 MCF approaches were performed for a variety of indications over the study period, including 66 standard MCF approaches for VS resection. None of the cases was previously treated with radiation therapy or surgery. There were two postoperative CSF leaks (3.0%). The average age of those with a CSF leak was 51 (42 and 60) and of those without a CSF leak was 51.7 (18–74) (p = 0.95). The average body mass index (BMI) for patients with a CSF leak was 33.7 compared with 29.3 for those without CSF leak (p = 0.23). In the two cases with CSF leakage, the mean maximal tumor dimension was 4.5 mm (3 and 6 mm), both tumors were isolated to the internal auditory canal (IAC), and both underwent gross total resection. Both CSF leaks were successfully treated with LD diversion. For the 64 cases that did not have a CSF leak, the mean maximal tumor dimension was 10.2 mm (3–19 mm), 51 were isolated to the IAC, 1 was located only in the cerebellopontine angle (CPA), and 12 were located in both the IAC and CPA. Sixty-two patients underwent gross total resection and 2 underwent near total resection.

Conclusion The standard MCF approach to VS resection of the IAC and CPA is a valuable technique that allows for hearing preservation and total tumor resection. The MCF approach can be performed with a low CSF leakage rate. This rate of CSF leak compares favorably with reported rates in the literature in regard to both translabyrinthine and retrosigmoid approaches.