3 The procedure
3.1 Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI‑S) for treating morbid obesity is usually done laparoscopically with the patient under general anaesthesia.
3.2 Initially, the stomach is reduced in size by a sleeve gastrectomy, which involves devascularising and excising the greater curve. This leaves a tube of stomach passing from the oesophagus to the pylorus and duodenum. The duodenum is then mobilised and divided at the level of the gastroduodenal artery using a linear stapler. This leaves a short stump of duodenum attached to the pylorus. The distal end of the duodenum is closed off permanently. A loop of small bowel, usually 200 to 300 cm from the ileocaecal valve, is anastomosed to the remnant of duodenum arising from the pylorus to restore the continuity of the gut. This anastomosis is usually sutured in 2 layers, but may be stapled. In patients at high risk because of extreme obesity, the procedure may be done in 2 stages, first sleeve gastrectomy, and then duodenal transection and duodeno-ileal anastomosis in a subsequent procedure once the patient's risks from surgery are reduced by weight loss induced by sleeve gastrectomy.
3.3 After surgery, patients are maintained on a low-calorie diet. Multivitamin, calcium and iron supplements are prescribed as needed to maintain normal blood levels.