Outcomes of Transzygomatic Middle Cranial Fossa Approach for Resection of Skull Base Tumors

Objectives: To evaluate surgical outcomes of transzygomatic middle cranial fossa (OZ-MCF) approach for tumor control in patients with large skull base lesions involving the middle cranial fossa and adjacent sites including petrous apex, Meckel’s cave, cavernous sinus, and anterior cerebellopontine angle (CPA).

Setting: Tertiary skull base center.

Design: Retrospective case series.

Main Outcome Measures: Tumor control (recurrence), new onset cranial neuropathies or other neurological complications, facial nerve and audiometric outcomes, cerebrospinal fluid (CSF) leak and wound complications.

Results: A total of 588 consecutive skull base cases were identified between 2010 and 2017. Of these cases, 12 patients were identified with median age of 47.5 years (range: 25–72) that underwent OZ-MCF. The mean maximum linear tumor dimension was 4.34 cm (SD: 1.3) and 8 (66.7%) tumors were left sided. Tumor pathology included meningioma (n = 5), chondrosarcoma (n = 4) and 1 case each of trigeminal schwannoma, facial schwannoma and hemangiopericytoma. Mean follow-up was 2.4 years (0.3–7.0).

The most common preoperative symptoms were facial numbness/pain (n = 6) followed by diplopia (n = 3). Cranial nerve deficits included CN V (n = 4), CN VI (n = 2) and polyneuropathy (CN IV, V, and VI) in one case. Gross-total or near-total resection was achieved in nine patients and subtotal resection was performed in the remaining three patients. Anterior petrosectomy was performed in eight patients and intracavernous sinus dissection was done in three patients for tumor resection. Six patients received adjuvant radiation therapy. Intra-op CN V and IV were sacrificed in three and two patients, respectively.

Postoperative additional new cranial nerve deficits included CN V (n = 2), CN III (n = 2), CN VI (n = 1) and CN X (n = 1). One patient had mild facial paresis (House–Brackmann 2/6). All patients except one had maintenance of serviceable hearing. Other neurologic morbidity included transient hemiplegia (n = 1), SCA (superior cerebellar artery) infarct (n = 1), dysphagia necessitating placement of feeding tube (n = 2) and tracheostomy (n = 1). There were no cases of CSF leak or any wound complications. At the last follow-up imaging, there was no evidence of tumor recurrence or growth in all patients.

Conclusion: Various skull base tumors involving middle cranial fossa with extension to adjacent sites can be successfully resected using the OZ-MCF approach in a multidisciplinary fashion. This approach yields optimal exposure with resultant excellent tumor control with acceptable cranial nerve and neurological morbidity.

No conflict of interest has been declared by the author(s).