. Posted in Mediotol 2012

Surgery of the superior semicircular canal dehiscence syndrome (SSCD) by middle fossa approach (VIDEOS). Technique, indications and results in 13 patients.

Department of Otolaryngology and Skull Base Surgery
University Hospital of Bordeaux

Aim: To report vestibular and audiological functional results after superior semicircular canal plugging through a middle fossa approach (MFA) in SSCD.

Material: Eleven patients were surgically handled among 33 patients diagnosed of a SSCD. Two patients were operated on both sides. Only patients suffering from very severe and disabling vestibular symptoms associated with abnormal Vestibular Evoked Myogenic Potentials (VEMPS) threshold and a typical CT scan were considered for surgery. The lumen of the superior canal was obscured with bone wax and bone pâté through MFA. Were analyzed and compared symptoms, audiological and vestibular data (clinical status and quality of life, VEMPS, Vibratory testing, videonystagmography) in the pre and post operative courses

Results: No neurosurgical complications were observed.  Of the 13 patients, 8 suffered from a mixt hearing loss. Eight had a Tullio’s phenomenon. All, except one who was retired, were so disabled that they had stopped their occupation. In the postoperative course, 2 patients had immediate severe vertigo and nystagmus associated with a sensorineural hearing loss treated with steroid and bed rest. After 5 days, they returned to normal on the audiological point of view. Clinically, all the patients were improved. All came back to their occupation. Two patients had 4-months duration vestibular rehabilitation to help them to compensate (they had bilateral SCCD). No patient had hearing sequels. In seven of the 8 preoperatively deaf patients we observed an ABG closure and a postoperative normal or subnormal hearing. In 9 cases, VEMPS returned to normal. In 5 cases VEMPS could not be obtained.

Conclusion: plugging of the superior canal by  MFA is a very efficient procedure. It necessitates a great expertise to avoid neurosurgical complications and above all sensorineural complications. Indication of this surgery must be limited to very disabling SSCD, associated to severe vestibular symptoms.