Effect of standard versus long alimentary limb distal Roux-en-Y gastric bypass on weight loss and nutritional outcomes at 10 years in patients with BMI 50–60 kg/m2—a secondary analysis of a randomized clinical trial

OBJECTIVE: Identifying the optimal metabolic bariatric surgery approach for patients with severe obesity with a BMI ≥50 kg/m2 remains challenging. The aim of this long-term follow-up of a randomized clinical trial (RCT) was to compare distal long alimentary limb Roux-en-Y gastric bypass (RYGB) with standard RYGB for 10-year weight loss and nutritional outcomes. METHOD: Secondary analysis of a 10-year follow-up of an RCT with initially 113 patients (BMI 50-60 kg/m2) randomized to either standard (n = 57, 50 cm biliopancreatic/150 cm alimentary limb) or distal long alimentary limb RYGB (n = 56, 50 cm biliopancreatic/150 cm common limb) from March 2011 to April 2013 at two Norwegian hospitals. The final data collection date was 15 August 2023. The primary focus was weight loss (BMI reduction, %total weight loss) and other secondary outcomes included cardiometabolic risk factors, nutritional status, and health-related quality of life (HRQOL). RESULTS: Of 113 patients, 79 (69.9%, mean age 50 (s.d. 8.7) years, 50 (63%) females) patients were available for 10-year follow-up (41 standard RYGB, 38 distal RYGB). The 10-year mortality rate was 3.5% (4/113) and all deaths occurred after distal RYGB. One death may have been associated with the surgery in a patient with previously undiagnosed liver cirrhosis at the time of operation. Mean BMI reduction from baseline was 12.0 kg/m2 (95% c.i., 10.8 to 13.2) after standard RYGB and 14.7 kg/m2 (95% c.i., 13.5 to 15.9) after distal RYGB with a between-group difference of 2.7 kg/m2 (95% c.i., 1.0 to 4.5, P = 0.002). The mean percentage total weight loss from baseline was 23.0% (95% c.i., 20.8 to 25.2) after standard RYGB and 28.2% (95% c.i., 26.0 to 30.5) after distal RYGB, with a between-group difference of 5.3% (95% c.i., 2.1 to 8.4, P = 0.001). The distal RYGB group had higher rates of malnutrition (1/57 standard versus 5/56 distal; P = 0.12), diarrhoea (7/57 standard versus 15/56 distal; P = 0.05), and vitamin D deficiency (24/41 standard versus 32/38 distal; P = 0.01). There were no differences between the groups in the prevalence of type 2 diabetes, hypertension, dyslipidaemia, or metabolic syndrome at 10-year follow-up. Four patients underwent revisional surgery due to malnutrition after distal RYGB. There were no statistically significant differences in HRQOL scores between the groups at 10 years (SF-36 physical 44.2 versus 44.1, mental 50.3 versus 47.3; OWLQOL 63 versus 61; all P > 0.2). CONCLUSIONS: Distal long alimentary limb RYGB resulted in greater weight loss after 10 years with a higher risk of malnutrition, diarrhoea, and vitamin D deficiency. TRIAL REGISTRATION: Clinicaltrials.gov NCT00821197.