Analysis of the learning curve for transvaginal natural orifice transluminal endoscopic surgery in ovarian cystectomy.

Objective: This study aimed to evaluate the learning curve for transvaginal natural orifice transluminal endoscopic surgery (vNOTES) in ovarian cystectomy and to identify perioperative factors influencing operative time.

Methods: This prospective observational study included 39 patients who underwent vNOTES ovarian cystectomy at Chengdu Women's and Children's Central Hospital between June 2022 and June 2024. Patients were grouped into two surgical phases based on the operating team's self-assessed proficiency. Cumulative sum analysis of operative time (CUSUMOT) was used to model the learning curve and define distinct learning stages. Multivariate linear regression was performed to identify independent predictors of operative time.

Results: The mean patient age was 35.14 ± 9.73 years, and the mean operative time was 74.01 ± 30.09 min. Three cases (7.7%) required intraoperative conversion to transumbilical laparoscopy, and two patients (5.1%) experienced perioperative complications. CUSUMOT analysis revealed four distinct learning phases: learning (9 cases), plateau (10 cases), challenging (12 cases), and mature (8 cases). Operative time during the mature phase was significantly shorter than in earlier phases. Multivariate regression identified pelvic adhesions (β = 6.92, p = 0.027), bilateral cysts (β = 6.38, p = 0.019), cyst diameter (β = 2.85 per cm, p = 0.026), and learning curve phase (β = -17.10 for Phase II, p = 0.035) as independent predictors of operative time.

Conclusion: vNOTES is a safe and feasible approach for ovarian cystectomy with a measurable learning curve. Proficiency can be achieved after approximately 20 cases. Pelvic adhesions, cyst characteristics, and surgical experience significantly impact operative time. CUSUM analysis is a useful tool for evaluating surgical competency and guiding clinical training in vNOTES procedures.