Learning Curve for CO₂ Laser Stapedotomy: A Single-Surgeon Experience in South Korea

Mastering otosclerosis surgery is challenging, especially in low-prevalence Asian populations. This study defines the learning curve for a single surgeon's first 100 consecutive CO₂ laser-assisted stapedotomies by analyzing audiometric and complication outcomes. Despite widespread descriptions of laser-assisted stapes surgery, there is a paucity of data examining the learning process in low-incidence, low-volume regions like East Asia. We aim to characterize the unique challenges and surgical adaptations required in such an environment.

A retrospective review of 100 primary stapedotomy cases was performed. The proficiency changepoint was identified using Bayesian and cumulative sum (CUSUM) analyses based on success (postoperative air-bone gap [ABG] ≤ 10 dB and no significant bone-conduction deterioration). Audiometric outcomes-including postoperative ABG, achievement of "Negative ABGe" (postoperative air conduction superior to preoperative bone conduction), and change in high-tone bone conduction-were compared between the pre-proficiency (cases 1-30) and post-proficiency (cases 31-100) phases.

A proficiency changepoint was robustly identified at 30 cases. Subsequently, outcomes improved significantly: mean postoperative ABG decreased from 12.1 dB to 5.2 dB (p < 0.001), and the success rate (ABG ≤ 10 dB) increased from 53.3% to 91.4%. The rate of achieving a Negative ABGe surged from 3.3% to 50.0% (p < 0.001). The mean change in high-tone bone conduction also shifted from -0.3 to +6.1 dB of overclosure (p < 0.001). All major complications occurred within the initial 30 cases.

For CO₂ laser-assisted stapedotomy, proficiency significantly improves after approximately 30 cases. This study uniquely highlights how surgical mastery develops under conditions of limited disease prevalence and restricted training exposure. The findings suggest that even in low-volume environments, structured experience enables not only consistent ABG closure but also meaningful gains in patient-centered outcomes such as Negative ABGe and cochlear preservation. Our results advocate for simulation-enhanced education strategies tailored to resource-constrained surgical contexts.

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