Impact of Obesity on Cholecystectomy Surgery

Christopher J Neylan, BA, Daniel T Dempsey, MD, MBA, Kenneth Lee, MD, PhD, Rachel R Kelz, MD, Noel N Williams, MD, Kristoffel R Dumon, MD. Hospital of the University of Pennsylvania

Objective: Laparoscopic cholecystectomy is the gold standard treatment for most gallbladder disease. However, little is known about the impact of obesity on cholecystectomy for acute cholecystitis. Few have compared laparoscopic converted to open (LCO) and open cholecystectomies in the obese. This study intended to provide a comprehensive analysis of the impact of BMI on cholecystectomy for acute cholecystitis.

Methods: Patients who underwent a cholecystectomy (laparoscopic, open, or converted) for acute cholecystitis from 2007-2013 were identified from the American College of Surgeons NSQIP database. Patients were classified into normal (BMI 18.5-25), overweight (BMI 25-30), obese (BMI 30-35), severely obese (BMI 35-40), morbidly obese (BMI 40-50), and super-obese (BMI 50+) groups. The primary outcome was morbidity. Secondary outcomes were mortality, prolonged operative time (procedure-specific operative time ≥ 90th percentile), and prolonged post-operative length of stay (procedure-specific post-operative length of stay ≥ 90th percentile). Independent multivariable regressions were used to examine the association between BMI and the outcomes of interest.

Results: Of 23,284 patients included in the study, 46% were obese (BMI ≥ 30). Approximately 80% of patients underwent laparoscopic treatment, and this remained constant across the BMI groups. Among laparoscopic patients, those with BMI ≥ 30 had a significantly prolonged operative time (OR 1.24, p = 0.019), relative to the normal BMI group (BMI 18.5-25). Among open patients, those with BMI ≥ 30 had a significantly higher morbidity rate (OR 1.38, p = 0.015), relative to the normal BMI group. Severe (OR 1.47, p = 0.02), morbid (OR 1.68, p = 0.01), and super (OR 2.01, p = 0.03) obesity were significant predictors of LCO. Further, LCO operative time was significantly greater than open operative time in all BMI groups except the normal weight group. Despite this, there were no significant differences between LCO and open outcomes in any BMI group. The sole exception was a significantly increased mortality among severely obese LCO patients. However, due to the small number of severely obese patients who died (3 in LCO vs. 2 in open), this does not appear clinically significant.

Conclusions: The data suggest that standard treatment for acute cholecystitis should not be altered based on BMI, as BMI has a limited impact on outcomes after both laparoscopic and open surgery. Further, laparoscopic surgery should be attempted, even for very high (morbid and super-obese) BMI-patients. Despite an increased risk of conversion among high-BMI patients, LCO outcomes are not worse than open outcomes.