Biliopancreatic diversion for severe obesity: long-term weight maintenance and occurrence of nutritional complications are two facets of the same coin

Background: Despite the widespread clinical use of hypoabsorptive metabolic bariatric surgery, very long-term outcomes are still lacking. The aim of the study was to assess the long-term safety and efficacy of biliopancreatic diversion at 30 years in patients with class 3 obesity (BMI over 40kg/m2). Methods: This retrospective single-centre study used data from a prospectively collected database on a sample of consecutive patients submitted to biliopancreatic diversion with a minimum follow-up of 30 years. Outcomes assessed included overall survival, long-term weight loss and weight maintenance, remission of obesity-related co-morbidities, and short- and long-term surgical and/or nutritional or metabolic complications. Results: Among 199 consecutive patients (136 female, 63 male) who had surgery between November 1992 and April 1994, the mean age at operation was 38 (range 14-69) years and mean preoperative BMI was 48.7 (32.0-74.3)kg/m2. At baseline, 91 of 199 patients (45.7%) had type 2 diabetes. At 20 and 30 years, 122 (61%) and 38 (19%) of the 199 patients respectively were available for follow-up. At 30 years, the overall mortality rate was 12% (23 of 199). Surgical complications were concentrated in the short-term follow-up, whereas nutritional or metabolic complications increased progressively over time. A nutritional complication was diagnosed in 73 of 122 patients (60%) at 20 years and 28 of 38 (74%) at 30 years. Weight loss and glycaemic control were maintained throughout the follow-up; mean % total weight loss was 32.8 (range 14.1-50.0) at 1 year and 37.7 (range 16.7-64.8) at 30 years. One patient presented with recurrence of type 2 diabetes at 20 and 30 years; there were no patients with new-onset type 2 diabetes. Conclusion: Biliopancreatic diversion leads to good and sustained weight maintenance up to 30 years with low perioperative risk, but at the cost of a high long-term prevalence of nutritional complications.