Prior Bariatric Surgery Is Linked to Improved Colorectal Cancer Surgery Outcomes and Costs: A Propensity-Matched Analysis

Background: Morbid obesity is associated with worse colorectal cancer (CRC) perioperative outcomes. The impact of bariatric surgery on these outcomes is unknown. Methods: The National Inpatient Sample Database (2006–2012) was used to identify adults with prior bariatric surgery (divided into BMI ≤35 kg/m² and BMI >35 kg/m²) or morbid obesity that underwent CRC surgery. Main outcomes were mortality, surgical complications and health care utilization. Results: There were 1813 patients with prior bariatric surgery and 22,552 morbidly obese patients that underwent CRC surgery between 2006 and 2012. Prior bariatric surgery patients were younger, with fewer comorbidities, and had less emergency CRC surgery admissions (p < 0.05). Multivariate analyses revealed no adverse association (OR 0.54, 95 % CI = 0.16 to 1.79) between prior bariatric surgery and CRC perioperative mortality. Notably, multivariate analysis revealed that bariatric surgery patients undergoing CRC surgery had fewer accidental surgical lacerations (OR 0.38, 95 % CI = 0.15 to 0.93), shorter hospitalizations (−1.85 days, 95 % CI = 2.03 to 1.67), decreased total hospital costs (US$−5374, 95 % CI = −5935 to −4813) and lower disposition to short-term rehabilitation facilities (OR 0.65, 95 % CI = −0.43 to 0.97). Propensity score matched analysis validated these reductions in surgical complications and health care utilization in bariatric surgery patients, which were further more pronounced when bariatric surgery patients were restricted to BMI ≤35 kg/m². Conclusions: Analysis of national-level data demonstrates that prior bariatric surgery is associated with fewer colorectal cancer surgical complications and improved health care resource utilization compared to morbidly obese patients. These findings emphasize and extend the therapeutic effect of bariatric surgery to the colorectal cancer perioperative setting.