Transmastoid superior semicircular canal dehiscence plugging: VHIT findings

Superior canal dehiscence syndrome (Minor's syndrome) is a condition characterized by a bony defect in the superior semicircular canal (SSCC), with treatment primarily being surgical, notably through plugging of SSCC.

To examine the clinical outcome and postoperative VHIT findings after transmastoid plugging of the SSCC.

Patients having a superior semicircular canal dehiscence (SSCCD) syndrome with debilitating symptoms who underwent a plugging of the SSCC via a transmastoid approach were included. Through a retrospective chart review and literature review, postop video head impulse test (VHIT) findings, pre and post-operative audiological/vestibular symptoms and audiograms were analyzed in a tertiary care university hospital.

All patients operated by plugging of the SSCC through a transmastoid approach had a significative post-operative VHIT deficit in the function of the SSCC (range 0.34-0.70, median gain function 0.41, mean gain function 0.46, standard deviation of 0.15, p = 0.0391) Almost all patients had improvement of their preoperative symptoms. No surgical complication was noted. The literature review also highlighted safety and effectiveness of this surgical technique.

Post-operative VHIT findings showed an elective deficit of the SSCC function thus confirming the surgical SSCC plugging through a trans mastoid approach.