Hearing Outcomes after Transmastoid Plugging of Superior Canal Dehiscence

Abstract

Background: Patients with a superior canal dehiscence syndrome display symptoms of the vestibular disorder except that of hearing loss. Therefore, any type of surgery should treat those symptoms without affecting the hearing threshold. The aim of this study was to evaluate the extent to which the hearing threshold has been affected; the evaluation process was carried out by a transmastoid plugging of the superior canal. Another aim was to estimate the risk in loss of hearing due to this surgery. Material and Methods: In a retrospective study, 31 patients with dehiscence of the superior canal, who underwent a transmastoid plugging, were included. Additionally, 8 of them with the clinical symptoms of the Menière’s disease received an endolymphatic sac surgery. A b-c threshold at 0.25, 0.5, 1, 2, and 4 kHz was observed in all patients pre and postoperatively as well as in the long-term follow-up. Results: After a mean interval of 149 days, a change in the b-c threshold of 5.9 dB was detected. After 149 days, in the patient group comprising those who underwent an additional endolymphatic sac surgery, a b-c threshold change of 17.18 dB was detected. Conclusion: The transmastoid plugging of the superior semicircular canal can be performed with an acceptable risk of hearing affection. If the surgery was combined with other techniques, (e.g. endolymphatic sac surgery) then the risk increases.

Gauging the effectiveness of canal occlusion surgery: how I do it

“…Multiple subsequent studies, however, have confirmed that transmastoid canal occlusion in the context of BPPV or superior semicircular canal dehiscence is effective in providing vertigo relief while preserving hearing. 9,10 There remains a paucity of quantifiable vestibular data in human subjects to support the subjective improvements reported. 11,12…”

Spontaneous Tegmen Tympani Dehiscence: Causes and Treatment of Conductive Hearing Loss

“…Patients with synchronous SSCCD are an even more complex subset of CHL. BC increased (deteriorated) in the low frequencies postoperatively in all ears with SSCCD in this series-a common finding after SSCCD repair owing to normalization of the suprathreshold BC (29,30). Although an accompanying improvement in low-frequency AC is often said to result in a decrease in, or even closure of the ABG, substantial interpatient variability has been documented.…”

Triple Semi-Circular Canal Occlusion and Cochlear Implantation: A Treatment Option for Single-Sided Menière’s Disease with Functional Deafness—A Case Series

“…Transmastoid plugging of the semi-circular canals is one surgical option in patients with vestibular symptoms caused by the canal dehiscence syndrome or benign paroxysmal vertigo, as conservative medical treatment is limited. Results from human studies show that vertigo control can be achieved via semi-circular canal plugging, and hearing is not affected [15]. Several studies showed that in 10% to 35% of patients with single-sided Menière's disease, so-called silent contralateral endolymphatic hydrops can be detected [18][19][20][21].…”

“…The area of each canal was covered afterward with a muscle patch and bone pate. Finally, the sealing patch was secured with fibrin glue (Figure 4) [5,15]. The subjective and objective vestibular findings were assessed preoperatively, directly postoperatively, as well as 6-8 weeks and 6 months after surgery.…”