Transmastoid superior semicircular canal occlusion

Abstract

Objective: The traditional surgical repair for superior semicircular canal dehiscence (SSCD) involves either canal plugging or resurfacing via the middle cranial fossa approach. We describe a novel transmastoid occlusion technique.

Study design: Retrospective case review.

Setting: Tertiary referral center.

Patients: Three patients with symptomatic computed tomography-proven SSCD.

Intervention: Transmastoid superior semicircular canal occlusion using bone pate in 2 fenestrations, with 1 placed on either side of the dehiscence.

Main outcome measures: Hearing and vestibular symptoms.

Results: Two patients were primary cases of SSCD, and a third patient had failed a previous middle fossa occlusion using fascia at an outside institution. In all 3 cases, the 2 sides of the superior semicircular canal adjacent to the dehiscence were occluded using bone pate, formed from a mix of bone dust and fibrin sealant. This allowed for a permanent bony partition to be achieved between the dehiscence and the remainder of the labyrinth. In all cases, hearing was either preserved or improved, and the procedure was successful in controlling vestibular symptoms.

Conclusion: Transmastoid superior semicircular canal occlusion is a viable alternative to the customary middle fossa approach for superior canal dehiscence. Meticulous technique and the use of bone pate may help maximize auditory and vestibular results. Advantages of this technique include obviating a craniotomy, preclusion of temporal lobe retraction, familiarity of the approach for experienced otologists, and the ability to occlude the canal without manipulating the defect. The transmastoid approach for superior canal occlusion may not be possible when the dura is low hanging or when there is extensive cranial base dehiscence requiring reconstruction.