How safe is teaching of highly specialized rectal surgery? A propensity score-matched 10-year cohort study.

Abstract

This study aimed to assess the impact of an institutional teaching program of highly specialized rectal procedures on intra- and early postoperative outcomes. We performed a retrospective 10-year cohort study of consecutive patients undergoing low anterior resection (LAR) or abdominoperineal resection (APR) for rectal cancer <12 cm from the anal verge or restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) at a tertiary high-volume academic centre (2014-2023). Procedures were classified as expert (consultant-only) or teaching procedures (performed ≥75% by the trainee under direct supervision). Groups were balanced after 1:1 propensity score matching (PSM) for age, sex, BMI, ASA, Charlson index, neoadjuvant therapy and surgical approach. Primary outcomes were intraoperative surgical adverse events (iAEs, defined according to the Classintra classification) and 30-day complications. Multivariable logistic regression identified predictors of morbidity. A total of 573 surgeries were included (375 expert-led, 198 teaching procedures). After matching, 374 remained (187 per group). IAEs occurred in 16% and 17% of expert-led and teaching procedures, respectively (p = 0.9). Overall morbidity was 43% vs. 46% (p = 0.7); severe complications (Clavien-Dindo ≥ IIIb) occurred in 16% vs. 17% (p = 0.9), while 30-day mortality was 1.1% vs. 0% (p = 0.5). Median length of stay was 8 vs. 7 days (p = 0.6). Reoperation within 30 days occurred in 15.5% in both groups, and readmissions in 16% vs. 10% (p = 0.2). Multivariable analysis revealed high comorbidity indices and immunosuppression as independent risk factors. Robotic surgery was independently associated with lower postoperative morbidity, while teaching was neither associated with overall morbidity (OR 0.60, 95% CI 0.30-1.17) nor severe complications (OR 0.64, 95% CI 0.26-1.48). Closely supervised teaching of highly specialized rectal surgery can be safely implemented into clinical practice without increasing perioperative morbidity, supporting the dual mission of surgical proficiency and training of high-volume centres.