Cumulative Sum Analysis of Learning Curve Process for Vaginal Natural Orifice Transluminal Endoscopic Surgery Hysterectomy

Abstract

Study objective: This study aimed to evaluate the learning curve of vaginal natural orifice transuminal endoscopic surgery (vNOTES) hysterectomy in expert minimal invasive and vaginal surgery team.

Design: This is a cohort study on a retrospective analysis.

Setting: Department of Obstetrics and Gynecology of Cannizzaro Hospital in Catania Italy.

Patients: First 50 women underwent vNOTES hysterectomy between February 2021 and February 2022.

Intervention: vNOTES hysterectomy performed by a team with optimal skills in laparoscopic and vaginal surgery.

Measurement and main results: Primary outcome was surgical time. Secondary outcomes were intraoperative and postoperative complications, length of hospitalization, and first 24-hour postoperative pain. All patients underwent hysterectomy for benign indications: 27 fibromatosis, 13 metrorrhagia, and 10 precancerous. Concomitant procedures have been bilateral adnexectomy in 35 cases and bilateral salpingectomy in 15 cases. The median age was 51 years (range, 42-64). Median body mass index was 26 kg/m² (range, 21-42). The median operative time was 75 minutes (range, 40-110). The median hospital stay was 2 days (range, 1-4). There was 1 intraoperative adverse event (bladder lesion) and 1 postoperative grade 3 complication (hemoperitoneum). The median visual analog scale score for pain assessment during the first 24 hours after surgery was 3 (range, 1-6). The experience in our surgical center with the first 25 vNOTES hysterectomies showed an accumulation of initial experience in the first 5 cases with stable operating time and a gradual reduction of mean operating time in the subsequent 17 surgeries. The learning curve plotted by cumulative sum analysis shows 3 phases: phase 1 of competence (cases 1-5), phase 2 of proficiency (cases 6-26), and phase 3 of mastering the procedure (after the 31st case) with the management of more complex cases.

Conclusion: vNOTES hysterectomy is a feasible and reproducible approach for benign indications with a short learning curve and low rate of perioperative complications. For a team skilled in minimally invasive surgery, 5 cases are required to rich competence and 25 to rich proficiency in vNOTES hysterectomy. Mastering phase, with the introduction of more complex cases, should be addressed after 30 surgeries.

Keywords: CUSUM analysis; Hysterectomy; Learning curve; Natural orifice transluminal endoscopic surgery; vNOTES.