Related Experiment Video
Updated: Sep 30, 2026
The Microscopic Transcanal Approach in Stapes Surgery Revisited
Published on: February 16, 2022
Preoperative air-bone gap predicts thick stapes footplate requiring microdrill fenestration in otosclerosis
Vanessa J Zhang1, Andrew W Liu1, Maimuna Ahmad2
1Department of Otolaryngology-Head & Neck Surgery, University of Massachusetts Chan Medical School, Worcester, MA, USA; Department of Otolaryngology-Head & Neck Surgery, UMass Memorial Medical Center, Worcester, MA, USA.
Objective:
To evaluate whether preoperative audiometry or computed tomography (CT) findings are associated with intraoperative microdrill conversion for a thick stapes footplate during primary stapedotomy for otosclerosis.
Methods:
Retrospective cohort study of 136 adult primary stapedotomies (2016-2025). Cases were grouped as laser-only (n = 94) versus microdrill conversion due to thick footplate (n = 30); conversions for other reasons were analyzed descriptively (n = 12). Multivariable logistic regression and receiver operating characteristic (ROC) analysis were performed.
Results:
Thick-footplate microdrill conversion cases had a larger preoperative air-bone gap (ABG) than laser-only cases (44.1 ± 9.2 vs 39.4 ± 10.7 dB; p = 0.023). ABG was independently associated with microdrill conversion (adjusted OR 1.05 per dB; AUC 0.64). In the CT subset (n = 72), fissula ante fenestram radiodensity was not predictive (p = 0.83). Operative time was longer with microdrill conversion (75.3 ± 21.5 vs 65.3 ± 15.0 min; p = 0.018).
Conclusion:
Larger preoperative ABG was statistically associated with thick-footplate microdrill conversion, but discriminative performance was modest and should not be used for individual-level prediction. Postoperative hearing outcomes remained favorable with either technique.
