Transmastoid superior semicircular canal dehiscence plugging: VHIT findings

Background: 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.

Aims/objectives: To examine the clinical outcome and postoperative VHIT findings after transmastoid plugging of the SSCC.

Materials and methods: 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.

Results: 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.

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