Recent advances in bariatric/metabolic surgery: appraisal of clinical evidence

Obesity and associated type 2 diabetes mellitus (T2DM) are becoming a serious medical issue worldwide. Bariatric surgery has been shown to be the most effective and durable therapy for the treatment of morbid obese patients. Increasing data indicates bariatric surgery as metabolic surgery is an effective and novel therapy for not well controlled obese T2DM patients. The review of recent developments in bariatric/metabolic surgery covers 4 major fields. 1) Improvement of safety: recent advances in laparoscopic/metabolic surgery has made this minimal invasive surgery more than ten times safer than a decade ago. The safety profile of laparoscopic/metabolic surgery is compatible with that of laparoscopic cholecystectomy now. 2) New bariatric/metabolic surgery: laparoscopic sleeve gastrectomy (LSG) is becoming the leading bariatric surgery because of its simplicity and efficacy. Other new procedures, such as gastric plication, banded plication, single anastomosis (mini) gastric bypass and Duodeno-jejunal bypass with sleeve gastrectomy have all been accepted as treatment modalities for bariatric/metabolic surgery. 3) Mechanism of bariatric/metabolic surgery: Restriction is the most important mechanism for bariatric surgery. Weight regain after bariatric surgery is usually associated with loss of restriction. Recent studies demonstrated that gut hormone, microbiota and bile acid changes after bariatric surgery may play an important role in durable weight loss as well as in T2DM remission. However, weight loss is still the cornerstone of T2DM remission after metabolic surgery. 4) Patient selection: patients who may benefit most from bariatric surgery was found to be patients with insulin resistance. For Asian T2DM patients, the indication of metabolic surgery has been set to those with not well controlled (HbA1c > 7.5%) disease and with their BMI > 27.5 Kg/m(2). A novel diabetes surgical score, ABCD score, is a simple system for predicting the success of surgical therapy for T2DM.