Background: Teaching in the operating room represents the cornerstone of surgical education. While residents need to perform enough basic procedures to gain independence, their impact on outcomes remains debated.

Method: We conducted a retrospective study using a Swiss national registry between 2009 and 2019. Patients who underwent laparoscopic cholecystectomy were identified. Baseline characteristics were analyzed, and a propensity score was constructed using age, gender, American Society of Anesthesiologists (ASA) classification, workday status, operation setting, and surgical indication. Patients were then matched in a 2:1 ratio (non-teaching vs. teaching), and surgical outcomes were assessed. The primary outcome was safety, defined by the incidence and severity of postoperative complications.

Results: We included 34,080 cholecystectomies in our analysis. After propensity-score matching, 7038 interventions used for surgical teaching were compared to 14,076 performed by board-certified surgeons. Mean cohort age was 53 years, and 7.7% of patients had an ASA>II. Our analysis found comparable safety outcomes in regard to frequency (1.5 vs. 1.6%, p = 0.5) and severity (Clavien-Dindo ≥IIIa: 42.0 vs. 42.7%, p = 0.8) of postoperative complications. The teaching group had a longer mean operating time (85 ± 38 vs. 73 ± 44 minutes, p < 0.001), while the mean postoperative LOS was comparable between groups (3.70 ± 5.64 days). Multivariate regression analysis identified older age, ASA ≥III, weekend days, and urgent setting as independent negative predictors of teaching.

Conclusion: Teaching residents a common surgical procedure, such as cholecystectomy appears safe, with equally low complication rates and severity, despite longer operative times.