Influence of Preoperative Weight Loss on Outcomes of Bariatric Surgery for Patients Under the Enhanced Recovery After Surgery Protocol.

INTRODUCTION: The enhanced recovery after surgery (ERAS) protocol, which emphasizes preoperative interventions, is safely implemented in patients undergoing bariatric surgery. Patients are additionally encouraged to achieve weight loss preoperatively. We aimed to identify factors contributing to preoperative weight loss and assess their influence on outcomes of bariatric surgery among patients under the ERAS protocol.

MATERIALS AND METHODS: We reviewed a prospectively created database in two bariatric centers with 909 bariatric patients treated in accordance with ERAS principles. The database included demographic characteristics, factors related to the surgery or perioperative period, and short-term outcomes. Our endpoints included analyses of (1) factors potentially contributing to preoperative weight loss and (2) the influence of preoperative weight loss on short-term outcomes of bariatric treatment.

RESULTS: Diabetes mellitus (p = 0.007), obstructive sleep apnea (p < 0.001), and previous surgery (p = 0.012) were identified as predictors of preoperative weight loss. Steatohepatitis (p < 0.001) and respiratory disorder (p = 0.004) decreased the chance of achieving satisfactory preoperative body mass reduction. Except for operative time, early outcomes of bariatric surgery were not influenced by preoperative weight loss. Patients who achieved preoperative weight loss were less likely to be lost to follow-up (p = 0.023). Postoperative weight loss was better in patients who could lose ≥ 5% total weight preoperatively (p = 0.009).

CONCLUSION: Unsatisfactory preoperative weight loss among patients treated under ERAS principles is not associated with increased risk of complications. Satisfactory preoperative weight loss predicts superior postoperative weight loss and follow-up participation.