Auditory function in patients with surgically treated superior semicircular canal dehiscence.
OBJECTIVE
To characterize preoperative and postoperative audiologic findings in patients with superior semicircular canal dehiscence syndrome.


METHODS
Retrospective case review.


METHODS
Tertiary referral center.


METHODS
Patients with documented superior semicircular canal dehiscence syndrome (according to history, vestibular testing, and high-resolution computed tomography imaging) who underwent surgical repair of their dehiscence.


METHODS
Middle fossa craniotomy for superior semicircular canal plugging and/or resurfacing.


METHODS
Audiologic testing both before and after surgery with pure-tone threshold measurements of air and bone conduction.


RESULTS
Twenty-nine subjects underwent surgical repair of superior semicircular canal dehiscence. Overall, there were no statistically significant differences by paired t test in hearing before or after surgery, in either air-conduction or bone-conduction thresholds, for 19 patients that had no previous surgical history. At least partial closure of air-bone gap was achieved in five patients. One patient with previous stapes surgery had significantly worse hearing both before and after canal repair compared with those without previous surgery. Two patients who had undergone previous middle fossa surgery with incomplete resolution of symptoms developed sensorineural hearing loss after revision surgery. Previous middle-ear exploration and tympanostomy tube placement did not seem to affect audiologic outcomes. Surgical hearing results did not differ according to method of canal repair (plugging versus resurfacing).


CONCLUSIONS
Primary middle fossa repair of superior semicircular canal dehiscence is not associated with sensorineural hearing loss and, in some cases, can lead to normalization of conductive hearing loss. Revision middle fossa repair or previous stapes surgery may be associated with postoperative sensorineural hearing loss.
Limb
Charles J
CJ
Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, MD 21287, USA. climb@jhmi.edu
Carey
John P
JP
Srireddy
Sharmila
S
Minor
Lloyd B
LB
D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D005260:Female; D006314:Hearing Loss, Conductive / Q000209:etiology* / Q000503:physiopathology; D006319:Hearing Loss, Sensorineural / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008876:Middle Ear Ventilation; D013506:Otologic Surgical Procedures / Q000009:adverse effects*; D012086:Reoperation / Q000009:adverse effects; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000473:pathology*; D013199:Stapes; D013529:Surgical Wound Dehiscence / Q000503:physiopathology*; D013577:Syndrome; D014057:Tomography, X-Ray Computed