Association of severe obesity with risk of conversion to open in laparoscopic cholecystectomy for acute cholecystitis

Background: Obesity is a known risk factor for cholecystitis and is associated with technical complications during laparoscopic procedures. The present study seeks to assess the association between obesity class and conversion to open (CTO) during laparoscopic cholecystectomy (LC). Methods: Adult acute cholecystitis patients with obesity undergoing non-elective LC were identified in the 2017-2020 Nationwide Readmissions Database. Patients were stratified by obesity class; class 1 (Body Mass Index [BMI] = 30.0-34.9), class 2 (BMI = 35.0-39.9), and class 3 (BMI >= 40.0). Multivariable regression models were developed to assess factors associated with CTO and its association with perioperative complications and resource utilization. Results: Of 89,476 patients undergoing LC, 40.6 % had BMI >= 40.0. Before adjustment, class 3 obesity was associated with increased rates of CTO compared to class 1-2 (4.6 vs 3.8 %; p < 0.001). Following adjustment, class 3 remained associated with an increased likelihood of CTO (Adjusted Odds Ratio [AOR] 1.45, 95 % Confidence Interval [CI] 1.31-1.61; ref.: class 1-2). Patients undergoing CTO had increased risk of blood transfusion (AOR 3.27, 95 % CI 2.54-4.22) and respiratory complications (AOR 1.36, 95 % CI 1.01-1.85). Finally, CTO was associated with incremental increases in hospitalization costs (beta + $719, 95 % CI 538-899) and length of stay (LOS; beta +2.20 days, 95 % CI 2.05-2.34). Conclusions: Class 3 obesity is a significant risk factor for CTO. Moreover, CTO is associated with increased hospitalization costs and LOS. As the prevalence of obesity grows, improved understanding of operative risk by approach is required to optimize clinical outcomes. Our findings are relevant to shared decision-making and informed consent.