Assessing the Impact of Minimally Invasive Liver Surgery in the Overweight and Obese: An International Multicenter Propensity Score Matched Analysis

Abstract

Purpose: Despite the worldwide increase of obesity prevalence and widespread expansion of minimally invasive liver surgery (MILS), the safety and efficacy of MILS in obese patients is still a matter of debate. The aim of this study is to investigate possible advantages of MILS over open liver surgery (OLS) among patients with different classes of bodyweight. Methods: A multicenter database including 14,709 patients who underwent liver surgery in 16 centers in 8 countries (2000-2019) was assessed and only patients with BMI-comprehensive data were included. Patients were stratified according to bodyweight (BMI≤24.9(n=2884), 25≥BMI≤ 29.9(n=2828), 30≥BMI≤34.9(n=926), 35≥BMI≤39.9(n=269), and BMI≥40(n=73)), and divided according to surgical approach. Outcomes were compared after propensity-score matching (PSM). Results: In the included 6,980 patients, increasing BMI was associated with higher ASA scores, increased intraoperative blood loss (IOBL), rate of wound complications and use of MILS. Furthermore, increasing BMI was associated with lower rates of previous abdominal surgery, preoperative chemotherapy, malignant disease, multiple tumors, major concurrent procedures, bile leak and length of stay (LOS) (p<0.02). 937, 833, 279, 84 and 20 patients were matched 1:1 in the respective BMI-classes. After PSM, MILS was associated with lower operative time, IOBL, rate of complications and LOS in all strata (p<.05) and a lower rate of Clavien-Dindo ≥ 3 complications in the BMI ≥ 40 stratum (p=0.008). Conclusion: The advantages of MILS over OLS persist across different BMI-classes with a trend towards increased benefits in morbidly obese patients. Whilst obesity was initially considered a relative contraindication for MILS, these results advocate for a wider adoption in this relatively frail patient population.