Outcomes following Semicircular Canal Plugging

Abstract

Objectives: 1) Examine audiometric outcomes following semicircular canal plugging for either superior semicircular canal dehiscence syndrome or refractory positional vertigo. 2) Review symptom control rates and complication rates for canal plugging procedures. Methods: Retrospective chart review at a private neurotologic tertiary referral center. Patients undergoing semicircular canal plugging for superior semicircular canal dehiscence syndrome or refractory positional vertigo from January 1, 2007, to December 31, 2012, were included. Pre- and postoperative audiometry, operative findings, and clinical symptoms were assessed through chart review. Acoustic reflex testing, vestibular testing, and canal dehiscence size were examined in superior canal dehiscence patients. Results: A total of 28 patients underwent a canal plugging procedure during the study period: 24 superior canal dehiscence syndrome patients and 4 posterior canal occlusion patients. Postoperative air conduction pure-tone averages were 22.5 and 13.0 dB for these two groups, respectively, compared to their preoperative values of 21.1 and 11.0 dB. The average pre- and postoperative word-recognition scores for the entire cohort were 96.2% and 94.0%. Vestibular evoked myogenic potential data showed reduced thresholds in 7 canal dehiscence patients. The average size of the canal dehiscence, based on preoperative radiological measurements, was 3.4 mm. Surgical complications were limited to one temporary facial weakness (Grade 2). Complete symptom improvement was noted in 35.7% of all patients, while 16.7% of canal dehiscence patients reported no change in symptoms. Conclusions: Semicircular canal plugging procedures are associated with excellent hearing outcomes and may reduce preoperative symptoms in patients with canal dehiscence and refractory positional vertigo.