Resection of Vestibular Schwannoma in a Highly Pneumatized Temporal Bone with Fat Graft-Assisted Cerebrospinal Fluid Leak Prevention: A Case-Based Technical Video Report.

This case-based technical video report demonstrates microsurgical resection of a vestibular schwannoma in a high-risk pneumatized temporal bone anatomy. A 38-year-old woman with nonserviceable hearing and preserved facial nerve function underwent surgery for a 20- × 13-mm Koos grade III vestibular schwannoma. Preoperative magnetic resonance imaging confirmed the intra- and extrameatal tumor, and postoperative magnetic resonance imaging showed gross total resection (Figure 1). Thin-slice bone-window computed tomography demonstrated extensive mastoid, petrous apex, and perilabyrinthine/petrous air-cell pneumatization adjacent to the internal auditory canal (Figure 2). Preoperative computed tomography planning estimated a maximal posterior internal auditory canal drilling range of approximately 11 mm (Figure 3); however, this value was used only as an upper-limit reference, and drilling was performed intraoperatively in a stepwise, need-based manner. A fine diamond burr was used whenever possible during posterior canal wall drilling to allow safer, more controlled bone removal. After intrameatal tumor removal and endoscopic inspection of the fundus, opened air-cell tracts and the drilled canal region were obliterated with autologous abdominal fat graft and reinforced with fibrin glue before multilayer watertight dural closure (Figure 4; Video 1). No wound leakage, pseudomeningocele, otorrhea, rhinorrhea, meningitis, or intracranial infection occurred. At 2-year follow-up, the patient remained free of recurrence and cerebrospinal fluid-related complications.