Treatment of Lateral Skull Base and Posterior Cranial Fossa Lesions Utilizing the Extended Middle Cranial Fossa Approach.

OBJECTIVE

Define the indications and outcomes for subjects undergoing treatment utilizing the extended middle cranial fossa approach (EMCF).

STUDY DESIGN

Retrospective records review.

SETTING

University-based tertiary referral center.

PATIENTS

Subjects undergoing treatment of posterior cranial fossa (PCF) lesions.

INTERVENTION(S): EMCF exposure and treatment of the indicating PCF lesion.

MAIN OUTCOME MEASURE(S): Demographic, audiometric, and cranial nerve functioning variables were assessed.

RESULTS

Thirty-five subjects who underwent an EMCF exposure were identified over a 12-year period. The most common indication was meningioma (18; 51%) followed by schwannomas (six, 17%), and vascular lesions (five, 14%). Preoperative cranial nerve complaints were common (32, 94%) as were objective cranial nerve abnormalities on physical examination (21; 60%). Preoperative audiometric data from subjects with hearing demonstrated good functioning including pure-tone average (PTA) (21.7 ± 15.6 dB HL) and word understanding scores (95.1 ± 7.4%). Most (34, 97%) subjects had intact facial nerve function. The average length of stay was 11.6 days (median = 9). Cranial neuropathies were common postoperatively with 27 (79%) subjects demonstrating some objective cranial nerve dysfunction, the most common of which was trigeminal nerve hypesthesia (21, 61.7%). Subjects with identifiable pre- and postoperative audiometric data and preoperative hearing demonstrated small declines in the four-tone average (16.2 dB) and word recognition scores (22.4%). Two subjects (6%) had new profound hearing loss postoperatively.

CONCLUSIONS

The EMCF approach can provide safe and effective exposure of the anterior PCF.