Roux-en-Y Gastric Bypass versus a Variant of Biliopancreatic Diversion in a Non-Superobese Population: Prospective Comparison of the Efficacy and the Incidence of Metabolic Deficiencies

Background: In the non-superobese population, an agreement has not been made as to the optimal bariatric operation. The present study reports the results of a prospective comparison of Roux-en-Y gastric bypass (RYGBP) and a variant of biliopancreatic diversion (BPD) in a non-superobese population. Methods: From a cohort of 130 patients with BMI 35 to 50 kg/m², 65 patients were randomly selected to undergo RYGBP and 65 to undergo BPD. All patients underwent complete follow-up evaluation at 1, 3, 6, and 12 months postoperatively and every year thereafter. Results: Patients in both groups have completed their second postoperative year. Mean % excess weight loss (%EWL) was significantly better after BPD at all time periods (12 months, P=0.0001 and 24 months, P=0.0003), and the %EWL was >50% in all BPD patients compared to 88.7% in the RYGBP patients at 2-year follow-up. No statistically significant differences were observed between the 2 groups in early and late non-metabolic complications. Hypoalbuminemia occurred in only 1 patient (1.5%) after RYGBP and in 6 patients after BPD (9.2%). Only 1 patient from each group was hospitalized and received total parenteral nutrition. Glucose intolerance, hypercholesterolemia, hypertriglyceridemia and sleep apnea completely resolved in all patients in both groups, although mean total cholesterol level was significantly lower in BPD patients at the second year follow-up (t-test, P<0.0001). Diabetes completely resolved in all BPD patients and in 7 of the 10 diabetic RYGBP patients. Conclusion: Both RYGBP and BPD were safe and effective procedures when offered to non-superobese patients. Weight loss after BPD was consistently better than that after RYGBP, as was the resolution of diabetes and hypercholesterolemia. Because the nutritional deficiencies that occurred following this type of BPD were not severe and were not significantly different between the 2 operations, both may be offered to non-superobese patients, keeping in mind the severity and type of preoperative co-morbidities as well as the desired weight loss.