Efficacy and safety of single-anastomosis duodeno-ileal bypass with sleeve gastrectomy versus Roux-en-Y gastric bypass in France (SADISLEEVE): results of a randomised, open-label, superiority trial at 2 years of follow-up

BACKGROUND Since 2007, single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) has been proposed as an alternative to Roux-en-Y gastric bypass (RYGB) in the treatment of obesity. We conducted a multicentre randomised trial, with the hypothesis that SADI-S could be more effective than RYGB at 2-year follow-up. METHODS This multicentre, open-label, individually randomised superiority trial was conducted in France; patients were recruited from 22 bariatric institutions, mostly public academic hospitals. Key inclusion criteria were patients with a BMI ≥40 kg/m2 or ≥35 kg/m2 with obesity-related comorbidities (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, or osteoarthrosis), and a candidate for SADI-S or RYGB gastric bypass as a primary surgery or after a sleeve gastrectomy. Main key exclusions included previous bariatric surgery (other than sleeve gastrectomy), inflammatory bowel disease, type 1 diabetes, and untreated Helicobacter pylori infection. Participants were randomly assigned (1:1) to SADI-S or RYGB, stratified by centre, failure of sleeve gastrectomy, and presence of type 2 diabetes. The primary endpoint was percentage excess weight loss (%EWL) at 2 years (%EWL=[(weight at 2 years - initial weight)/(initial weight - ideal weight)] × 100). The study is registered with ClinicalTrials.gov, NCT03610256 and is completed. FINDINGS Between Nov 8, 2018, and Sept 29, 2021, a total of 381 patients were randomly assigned (intention-to-treat population) and included in the primary analysis (SADI-S: 190, RYGB: 191). Mean age was 44·4 years (SD 10·64), mean BMI was 46·2 kg/m2 (6·40), 265 (70%) were female, and 79 (21%) had a primary sleeve gastrectomy. 43 (12%) of 370 participants were lost to follow-up. At 2 years, the mean %EWL was statistically significantly higher in the SADI-S group compared with the RYGB group (-76·0% [SD 26·7] vs -68·1% [28·7], confirming the superiority of SADI-S (mean difference -6·72% [95% CI -12·64 to -0·80], p=0·026). The primary outcome was missing for 78 (20%) of 381 participants, with 46 (59%) of 78 participants in the SADI-S group and 32 (41%) of 78 in the RYGB group, p=0·09. The number of serious adverse events related to the surgical technique in the safety population, including all operated patients, was 40 in the SADI-S group including three anastomotic leaks and eight severe diarrhoea compared with 35 in the RYGB group including five internal hernia and five severe abdominal pain cases of which two required diagnostic laparoscopy. INTERPRETATION SADI-S showed superior weight loss compared with RYGB at 2 years, with a similar safety profile.