Application of Ultrasonic Bone Aspirator for Decompression of the Internal Auditory Canal via the Middle Cranial Fossa Approach.

OBJECTIVE

Evaluate the safety and efficacy of the ultrasonic bone aspirator (UBA) during middle cranial fossa (MCF) approach to vestibular schwannoma (VS).

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

PATIENTS

Charts of 192 consecutive VS patients over 18 years of age were reviewed to identify 65 patients who underwent MCF approach to VS resection between 2006 and 2017. A combination of UBA and high-speed drill (HSD) was used to decompress the internal auditory canal (IAC) in 25 patients and HSD alone was used in the other 40 patients.

INTERVENTION(S): Use of UBA during vestibular schwannoma surgery via MCF approach for decompression of the IAC.

MAIN OUTCOME MEASURE(S): Postoperative facial nerve outcomes assessed by the House-Brackmann (HB) facial nerve grading scale. Rates of gross total resection (GTR) and cerebrospinal fluid (CSF) leak.

RESULTS

There were no significant differences in postoperative facial nerve function, in rate of GTR of tumor, or in rate of CSF leak. In the UBA group 24/25 (96%) had postoperative HB grade I-II compared with 36/40 (90%) in the HSD group (p-value = 0.66). GTR was achieved in 25/25 (100%) in the UBA group compared with 38/40 (95%) in the HSD group (p-value = 1). In the UBA group, there were 0/25 (0%) cases of CSF leak compared with 1/40 (2.5%) in the HSD group (p-value = 1).

CONCLUSIONS

UBA use is a safe and effective alternative or adjunct to HSD during MCF approach to expose the IAC contents. This surgical tool allows for bone removal with low risk of injury to adjacent structures.