[Bariatric surgery: an update]

The indication of bariatric surgery as therapeutic procedure for morbid obese patients requires the application of selection criteria which deal with the degree of obesity, associated complications and previous failure of conventional therapy. Alcohol or drug addiction and concomitant serious disease are contraindications for bariatric surgery. Before operation, a full assessment is needed to identify possible eating behaviour disturbances and associated comorbidity such as cardiovascular disease, sleep apnoea, metabolic and psychiatric alterations which might induce intra and postoperative complications. Surgical techniques can be classified as restrictive, malabsortive and mixed procedures. Gastroplasty and adjustable gastric banding are restrictive techniques, which are indicated in obese patients with body mass index less than 45 kg/m2. Mixed techniques are the most used procedures. They include gastric by-pass which causes a reduction of 60-70% of weight excess, biliopancreatic diversion and duodenal switch which can eliminate a 75% of body weight excess. Following bariatric surgery a dramatic improvement in associated comorbidity can be demonstrated, specially in what refers to diabetes, hypertension, dislipidaemia and apnoea. Postoperative mortality is around 1-2%. Peritonitis and venous thromboembolism are the most serious complications. Postoperative follow-up should be lifelong and requires a progressive nutrition planning and vitamin supplementation.