Association of obesity with postoperative outcomes after proctectomy.

Background: Prior efforts evaluating obesity as a risk factor for postoperative complications following proctectomy have been limited by sample size and uniform outcome classification.

Methods: The ACS NSQIP was queried for patients with non-metastatic rectal adenocarcinoma who underwent elective proctectomy. After stratification by BMI classification, multivariable modeling was used to identify the effect of BMI class on adjusted risk of 30-day outcomes controlling for patient, procedure, and tumor factors.

Results: Of 2241 patients identified, 33.4% had a normal BMI, 33.5% were overweight, 21.1% were obese, and 12.0% were morbidly obese. Increased risk of superficial surgical site infection (SSI) was observed in obese (OR 2.42, 95%CI:[1.36-4.29]) and morbidly obese (OR 3.29, 95%CI:[1.77-6.11]) patients when compared to normal BMI. Morbid obesity was associated with increased risk of any complication (OR 1.44, 95%CI:[1.05-1.96]). BMI class was not associated with risk adjusted odds of anastomotic leak.

Conclusions: Morbid obesity is independently associated with an increased composite odds risk of short-term morbidity following elective proctectomy for cancer primarily due to increased risk of superficial SSI.