Laparoscopic Sleeve Gastrectomy Versus Banded Roux-en-Y Gastric Bypass for Diabetes and Obesity: a Prospective Randomised Double-Blind Trial.

Background: There are very few randomised, blinded trials comparing laparoscopic sleeve gastrectomy (LSG) versus laparoscopic Roux-en-Y gastric bypass (LRYGB) in achieving remission of type 2 diabetes (T2D), particularly silastic ring (SR)-LRYGB. We compared the effectiveness of (LSG) versus SR-LRYGB among patients with T2D and morbid obesity.

Methods: Prospective, randomised, parallel, 2-arm, blinded clinical trial conducted in a single Auckland (New Zealand) centre. Eligible patients aged 20-55 years, T2D of at least 6 months duration and BMI 35-65 kg/m were randomised 1:1 to LSG (n = 58) or SR-LRYGB (n = 56) using random number codes disclosed after anaesthesia induction. Primary outcome was T2D remission defined by different HbA1c thresholds at 1 year. Secondary outcomes included weight loss, quality of life, anxiety and depressive symptoms, post-operative complications and mortality.

Results: Mean ± standard deviation (SD) pre-operative BMI was 42.5 ± 6.2 kg/m, HbA1c 63 ± 16 mmol/mol (30% insulin-treated, 28% had diabetes duration over 10 years). Proportions achieving HbA1c ≤ 38 mmol/mol, < 42 mmol/mol, < 48 mmol/mol and < 53 mmol/mol without diabetes medication at 1 year in SR-LRYGB vs LSG were 38 vs 43% (p = 0.56), 52 vs 49% (p = 0.85), 75 vs 72% (p = 0.83) and 80 vs 77% (p = 0.82), respectively. Mean ± SD % total weight loss at 1 year was greater after SR-LRYGB than LSG: 32.2 ± 7.7 vs 27.1 ± 7.5%, respectively (p < 0.001). Gastrointestinal complications were more frequent after SR-LRYGB (including 3 ulcers, 1 anastomotic leak, 1 abdominal bleeding). Quality of life and depression symptoms improved significantly in both groups.

Conclusion: Despite significantly greater weight loss after SR-LRYGB, there was similar T2D remission and psychosocial improvement after LSG and SR-LRYGB at 1 year.

Trial Registration: Prospectively registered at Australia and New Zealand Clinical Trials Register (ACTRN 12611000751976) and retrospectively registered at Clinical Trials (NCT1486680).