Expanded transcanal transpromontorial approach to the internal auditory canal: Pilot clinical experience

Abstract

Objectives/hypothesis: The aim of this study was to describe and evaluate the feasibility of an expanded transcanal transpromontorial approach, developed from the exclusive endoscopic transcanal transpromontorial approach.

Study design: Retrospective case series.

Methods: Retrospective chart review of 10 patients operated by an expanded transcanal transpromontorial approach in two tertiary referral centers (University Hospital of Modena, Italy and University Hospital of Verona, Italy). Data from charts and video documentation were collected and analyzed.

Results: Between April 2015 and January 2016, 10 patients underwent an expanded transcanal transpromontorial approach for vestibular schwannoma Koos stage I or II and were enrolled in the study. The size of the tumors ranged from 7 to 19 mm in maximum diameter. A gross total resection was achieved in all cases. One subject experienced postoperative cerebrospinal fluid otorhinorrhea and three subjects experienced temporary postoperative facial weakness, all of which completely resolved. The mean follow-up was 5 months.

Conclusions: The expanded transcanal transpromontorial approach allowed bimanual dissection using a microscopic technique for the treatment of pathologies of the internal auditory canal and cerebellopontine angle. This novel approach resulted in minimal morbidity and comparable facial nerve preservation rates to the traditional approaches to the internal auditory canal. The expanded transpromontorial approach to the internal auditory canal holds promise for addressing pathology in this region of the temporal bone from the external auditory canal.

Level of evidence: 4. Laryngoscope, 127:2608-2614, 2017.

Keywords: Inner ear; cerebellopontine angle; endoscopic ear surgery; internal auditory canal; transcanal approach.