Patient Complexity and Bile Duct Injury After Robotic-Assisted vs Laparoscopic Cholecystectomy.

Importance: Recent evidence suggests higher bile duct injury rates for patients undergoing robotic-assisted cholecystectomy compared with laparoscopic cholecystectomy. Proponents of the robotic-assisted approach contend that this may be due to selection of higher-risk and more complex patients being offered robotic-assisted cholecystectomy. Objective: To evaluate the comparative safety of robotic-assisted cholecystectomy and laparoscopic cholecystectomy among patients with varying levels of risk for adverse postoperative outcomes. Design, Setting, and Participants: This retrospective cohort study assessed fee-for-service Medicare beneficiaries aged 66 to 99 years who underwent cholecystectomy between January 1, 2010, and December 31, 2021. Data analysis was performed between June and August 2024. Medicare beneficiaries were separated into model training and experimental cohorts (60% and 40%, respectively). Random forest modeling and least absolute shrinkage and selection operator techniques were then used in a risk model training cohort to stratify beneficiaries based on their risk of a composite outcome of postoperative adverse events consisting of 90-day postoperative complications, serious complications, reoperations, and rehospitalization in an independent experimental cohort. Exposures: Robotic-assisted vs laparoscopic cholecystectomy. Main Outcomes and Measures: The primary outcome of interest was bile duct injury requiring operative intervention after cholecystectomy. Secondary outcomes were composite outcomes from cholecystectomy composed of any complications, serious complications, reoperations, and readmissions. Results: A total of 737 908 individuals (mean [SD] age, 74.7 [9.9] years; 387 563 [52.5%] female) were included, with 295 807 in an experimental cohort and 442 101 in a training cohort. Bile duct injury was higher among patients undergoing robotic-assisted compared with laparoscopic cholecystectomy in each subgroup (low-risk group: relative risk [RR], 3.14; 95% CI, 2.35-3.94; medium-risk group: RR, 3.13; 95% CI, 2.35-3.92; and high-risk group: RR, 3.11; 95% CI, 2.34-3.88). Overall, composite outcomes between the 2 groups were similar for robotic-assisted cholecystectomy compared with laparoscopic cholecystectomy (RR, 1.09; 95% CI, 1.07-1.12), aside from reoperation, which was overall higher in the robotic-assisted group compared with the laparoscopic group (RR, 1.47; 95% CI, 1.35-1.59). Conclusions and Relevance: In this cohort study of Medicare beneficiaries, bile duct injury rates were higher among low-, medium-, and high-risk surgical candidates after robotic-assisted cholecystectomy. These findings suggest that patient selection may not be the cause of differences in bile duct injury rates among patients undergoing robotic-assisted vs laparoscopic cholecystectomy.