Clinical Report: Postoperative Outcomes of 350 Superior Semicircular Canal Dehiscence Surgeries

Overview

This study analyzes 350 surgical interventions for superior semicircular canal dehiscence (SSCD) performed via the middle cranial fossa (MCF) approach. It provides comprehensive data on symptom resolution, surgical techniques, and demographic factors influencing postoperative outcomes.

Background

Superior semicircular canal dehiscence (SSCD) is a rare vestibular disorder caused by thinning or absence of bone overlying the superior semicircular canal, creating a pathological third mobile window. Patients present with auditory and vestibular symptoms such as tinnitus, hearing loss, vertigo, and disequilibrium. Diagnosis relies on high-resolution CT imaging and vestibular evoked myogenic potentials. Surgical repair, primarily via the MCF approach, aims to resurface or plug the dehiscence to alleviate symptoms.

Data Highlights

Key Findings

• All surgeries were performed via the MCF approach using a minimally invasive keyhole craniectomy (~1.7 cm diameter).
• Symptom resolution was assessed postoperatively with specific attention to auditory and vestibular complaints.
• True dehiscence was defined as bone thickness <= 0.5 mm on HRCT; thin bone (>0.5 mm) was differentiated and also considered clinically relevant.
• Both resurfacing and plugging techniques were utilized with no standardized consensus on superiority.
• Demographic factors such as age and gender were not predictive of postoperative symptom outcomes.
• Bilateral SSCD was common, and some patients underwent staged bilateral repairs.

Clinical Implications

The MCF approach with minimally invasive keyhole craniectomy provides direct access for effective SSCD repair with symptom improvement. Differentiating true dehiscence from thin bone on imaging is important for surgical planning. Given the lack of standardized materials and techniques, individualized surgical strategies remain necessary. Age and gender should not be considered limiting factors when selecting surgical candidates.

Conclusion

This large series confirms that MCF approach surgery for SSCD is effective in symptom resolution across diverse patient demographics. Continued refinement of surgical techniques and materials is warranted to optimize outcomes.

References

1. Minor et al., 1998 -- Initial description of SSCD syndrome
2. Bárány Society Recommendations, 2021 -- Diagnostic criteria for SSCD
3. Current Study, 2021 -- Postoperative Results of Superior Semicircular Canal Dehiscence