Effect of Preoperative Weight Loss and Baseline Comorbidity on Short-Term Complications and Reoperations After Laparoscopic Roux-en-Y Gastric Bypass in 2,067 Patients

Purpose Decreasing popularity of Roux-en-Y gastric bypass (RYGB) in bariatric-metabolic surgery may be due to higher perceived peri-operative complications. There are few studies on whether preoperative weight loss can reduce complications or reoperations following RYGB. We investigated this using a standardised operative technique. Materials and Methods Retrospective single-centre study of RYGB from 2004 to 2019 using a prospective database. Preoperative behavioural management included intentional weight loss. Maximum preoperative weight, weight on the day of operation, and Obesity-Surgery Mortality Risk Score (OS-MRS) class were recorded. Short-term outcomes (post-operative stay, 30-day complication and reoperation rates) were analysed. Results In 2,067 RYGB patients (1,901 primary and 166 revisional), median preoperative total body weight loss (TWL) was 6.2% (IQR: 2.5-10.7%). The median age was 46 (interquartile range (IQR) 38-54) and 80.4% were female (n=1,661). For primary surgery, the median body mass index (BMI) was 47.6 kg/m(2) (IQR: 43.1-53.3). Excluding the 100-procedure learning curve, the complication rate for primary cases was 4.4% and reoperation rate of 2.8% and one peri-operative mortality (0.06%). OS-MRS >= 2 (class B or C) predicted higher risk of complications (6.1%) compared to those with a score <2 (class A) (3.8%, p=0.021), but not reoperations. Five percent preoperative TWL did not decrease complications compared to <5% TWL. Patients with >= 10% TWL had greater baseline risk and had an increased risk of complications (6.6% vs 3.7%, p=0.017) and reoperations (4.5% vs 2.7%, p<0.001). Conclusions RYGB performed using a standardised technique has low overall risk. The influence of preoperative weight loss on outcomes was inconsistent.