Minimally Invasive Middle Fossa Keyhole Craniectomy for Repair of Superior Semicircular Canal Dehiscence.

Abstract

Superior semicircular canal dehiscence (SSCD) presents with varying degrees of auditory and vestibular dysfunction. The condition is confirmed on high-resolution computed tomography (CT) imaging, and symptoms are often improved by surgical repair. Although a classic middle fossa craniotomy has been used with good results, recent advances in technique have allowed for modification of the traditional approach into a smaller skin incision and a minimally invasive middle fossa keyhole craniectomy roughly 1.7 cm in diameter. To delineate this novel approach and describe the technique for accurate localization of the dehiscence using preoperative measurements and intraoperative image guidance, thereby minimizing the need for a larger skin incision and craniotomy. Patients were independently diagnosed with SSCD by the senior authors. Once relevant imaging was acquired, the novel keyhole technique was performed. Patients' vestibular and auditory symptoms before and after the procedure were assessed. Outcomes from a series of patients treated with this keyhole approach were tabulated and reported. Twelve cases from 11 patients were included in this series. Auditory symptoms had high rates of resolution with pulsatile tinnitus, internal amplification of sounds, and autophony being resolved in a majority of cases. Only 2 cases reported hearing decline. Sound/pressure induced vertigo and disequilibrium also demonstrated high rates of resolution. No complications were reported. The minimally invasive middle fossa keyhole craniectomy is a novel approach for the repair of SSCD. This approach may contribute to resolved auditory and vestibular symptoms with low morbidity and quick recovery.