The impact of operative approach for obese colorectal cancer patients: analysis of the National Inpatient Sample 2015-2019

Aim: Obesity is a well-established risk factor for the development of colorectal cancer. As such, patients undergoing surgery for colorectal cancer have increasingly higher body mass indices (BMIs). The advances in minimally invasive surgical techniques in recent years have helped surgeons circumvent some of the challenges associated with operating in the setting of obesity. While previous studies suggest that laparoscopy improves outcomes compared with open surgery in obese patients, this has never been established at the population level. Therefore, we designed a retrospective database study using the National Inpatient Sample (NIS) with the aim of comparing laparoscopic with open approaches for obese patients undergoing surgery for colorectal cancer.Method: A retrospective analysis of the NIS from 2015 to 2019 was conducted including patients with a BMI of greater than 30 kg/m(2) undergoing surgery for colorectal cancer. The primary outcomes were postoperative in-hospital morbidity and mortality. Secondary outcomes included postoperative system-specific complications, total admission healthcare cost and length of stay (LOS). Multivariable logistic and linear regressions were utilized to compare the two operative approaches.Results: A total of 4742 patients underwent open surgery and 3231 underwent laparoscopic surgery. We observed a significant decrease in overall postoperative morbidity [17.5% vs. 31.4%, adjusted odds ratio (aOR) 0.56, 95% confidence interval (CI) 0.50-0.64; p < 0.001], gastrointestinal morbidity (8.1% vs. 14.5%, aOR 0.59, 95% CI 0.50-0.69; p < 0.001) and genitourinary morbidity (10.1% vs. 18.6%, aOR 0.61, 95% CI 0.52-0.70; p < 0.001) with the use of laparoscopy. Postoperative LOS was 1.7 days shorter (95% CI 1.5-2.0, p < 0.001) and cost of admission was decreased by $9106 (95% CI $4638-$13 573, p < 0.001) with laparoscopy.Conclusion: Laparoscopic surgery for obese patients with colorectal cancer is associated with significantly decreased postoperative morbidity and improved healthcare resource utilization compared with open surgery. Laparoscopic approaches should be relied upon whenever feasible for these patients.