# Arcuate eminence distance to temporal bone outer table in the middle fossa repair of superior canal dehiscence

## TL;DR

This study examines how the distance from the arcuate eminence to the temporal bone outer table affects surgical outcomes in superior canal dehiscence repairs.

## Contribution

The study identifies AE-OT as a novel predictor of surgical outcomes in middle fossa repairs for superior canal dehiscence.

## Key findings

- Longer AE-OT is independently associated with reduced odds of overall symptom improvement.
- AE-OT is not associated with operative duration or audiometric improvement.
- Every mm increase in AE-OT correlates with a 4-point decrease in Symptom Resolution Score.

## Abstract

To investigate the influence of arcuate eminence’s distance to temporal bone outer table (AE-OT) on surgical outcomes following the middle fossa repair of superior canal dehiscence (SCD).

We conducted a cohort study of consecutive repairs at a center between 2011 and 2022. AE-OT was measured on temporal bone CT imaging. Surgical outcomes were assessed with established metrics including Symptom Resolution Score (SRS), rate of Overall Symptom Improvement (OSI), and change in low-frequency air–bone gap (ΔLF-ABG) from pre- to post-surgery. Multivariable regression models assessing surgical outcomes were constructed with AE-OT as the primary predictor. Models adjusted for patient demographics, medical and surgical history, and follow-up duration.

A total of 402 repairs were included. Mean AE-OT was 27.1 mm (SD 2.1, range 20.8–33.9). Every mm increase in AE-OT was independently associated with a 14% reduction in odds of OSI (aOR 0.86, 95% C.I. [0.75, 0.98]) and a 4-point decrease in SRS (adj. β − 4.0 [− 6.9, − 1.1]) among frank dehiscences. AE-OT was also not associated with operative duration and ΔLF-ABG among both frank dehiscences and near dehiscences.

Longer AE-OT predicted poorer symptomatic response but similar operative duration and audiometric improvement among frank SCD cases.