Mortality after bariatric surgery. Analysis of 13.871 morbidly obese patients from a National Registry

OBJECTIVE: To define mortality rates and risk factors of different bariatric procedures and to identify strategies to reduce the surgical risk in patients undergoing bariatric surgery. SUMMARY BACKGROUND DATA: Postoperative mortality is a rare event after bariatric surgery. Therefore, comprehensive data on mortality are lacking in the literature. METHODS: A retrospective analysis of a large prospective database was carried out. The Italian Society of Obesity Surgery runs a National Registry on bariatric surgery where all procedures performed by members of the Society should be included prospectively. This Registry represents at present the largest database on bariatric surgery worldwide. RESULTS: Between January 1996 and January 2006, 13,871 bariatric surgical procedures were included: 6122 adjustable silicone gastric bandings (ASGB), 4215 vertical banded gastroplasties (VBG), 1106 gastric bypasses, 1988 biliopancreatic diversions (BPD), 303 biliointestinal bypasses, and 137 various procedures. Sixty day mortality was 0.25%. The type of surgical procedure significantly influenced (P < 0.001) mortality risk: 0.1% ASGB, 0.15% VBG, 0.54% gastric bypasses, 0.8% BPD. Pulmonary embolism represented the most common cause of death (38.2%) and was significantly higher in the BPD group (0.4% vs. 0.07% VBG and 0.03% ASGB). Other causes of mortality were the following: cardiac failure 17.6%, intestinal leak 17.6%, respiratory failure 11.8%, and 1 case each of acute pancreatitis, cerebral ischemia, bleeding gastric ulcer, intestinal ischemia, and internal hernia. Therefore, 29.4% of patients died as a result of a direct technical complication of the procedure. Additional significant risk factors included open surgery (P < 0.001), prolonged operative time (P < 0.05), preoperative hypertension (P < 0.01) or diabetes (P < 0.05), and case load per Center (P < 0.01). CONCLUSIONS: Mortality after bariatric surgery is a rare event. It is influenced by different risk factors including type of surgery, open surgery, prolonged operative time, comorbidities, and volume of activity. In defining the best bariatric procedure for each patient the different mortality risks should be taken into account. Choice of the procedure, prevention, early diagnosis, and therapy for cardiovascular complications may reduce postoperative mortality.