Endoscopic Surgical Skill Qualification System: propensity-score matched cohort analysis of accredited supervisors in laparoscopic rectal cancer surgery

Background: The Endoscopic Surgical Skill Qualification System (ESSQS) in Japan evaluates the surgical skills required for laparoscopic surgery as an operator as well as a supervisor. This study aimed to demonstrate the benefits of an ESSQS-certified surgeon’s participation in laparoscopic rectal resections as a supervisor (assistant or advisor). Methods: We retrospectively reviewed laparoscopic resection results for cStage II and III rectal cancer performed at 56 Japanese hospitals between 2014 and 2016. We used propensity score matching to generate paired cohorts with or without an ESSQS-certified supervisor at a one-to-one ratio. The impact of ESSQS-certified supervisors’ participation on short-term outcomes was assessed. In the matched cohort, multivariable logistic regression analysis and multivariable regression analysis of postoperative complication rate and intraoperative blood loss were performed to further mitigate the impact of pathological factors. Results: Two groups (n = 399 each) with or without an ESSQS-certified supervisor were well matched by clinical factors. The group with an ESSQS-certified supervisor had lower blood loss (68 mL vs. 98 mL, P = 0.036) and a lower incidence of severe morbidities of Clavien-Dindo grade ≥IIIa (8.0% vs. 13.3%, P = 0.016). Multivariable logistic regression analysis and multivariable regression analysis confirmed that the attendance of ESSQS-certified supervisors reduced postoperative complication occurrence (adjusted odds ratio: 2.28, 95% confidence interval: 1.38 – 3.80, P = 0.001) and intraoperative blood loss (estimated difference: -15.7 mL, P = 0.016). Conclusion: This study demonstrated the educational benefits of ESSQS-certified supervisors, including assistants and advisors, evidenced by their superior short-term outcomes.