The Impact of Obesity on Minimally Invasive Colorectal Surgery: A Report from the Surgical Care Outcomes Assessment Program Collaborative

Background: Operating on obese patients can increase case complexity and result in worse outcomes. We described the incremental impact of BMI on morbidity and outcomes of colorectal operations and whether laparoscopic and robotic(MIS) approaches mitigate this morbidity differently.

Methods: A retrospective cohort of patients undergoing elective colorectal operations in SCOAP was created to examine the association of increasing BMI on surgical outcomes. Additionally, multivariable logistic regression models were constructed.

Results: From 2011 to 2019, 22,863 elective colorectal operations (mean age 62, 55% female) were performed at 42 hospitals. Patients had BMI≥30 in 7576(33%) and BMI≥40 in 1180(5%) of operations. After risk adjustment, BMI≥40 was associated with increased conversions(OR1.57,95%CI1.26-1.96), increased combined adverse events(CAE)(OR1.32,95%CI1.15-1.52), and death(OR2.24, 95%CI1.41-3.55)(all p < 0.01). MIS approaches were each associated with lower CAE(lap OR0.49,95%CI0.46-0.53; robot OR0.42,95%CI0.37-0.47), and death(lap OR0.24,95%CI0.18-0.33; robot OR0.18,95%CI0.10-0.35)(all p < 0.01).

Conclusions: Severe obesity is associated with increased conversion rates and worse short-term outcomes after colorectal surgery, though this trend is partially mitigated with a minimally invasive approach. These findings support the broad application of MIS for colorectal operations in obese patients.