IBC Oxford University Oral Abstract 40 - Efficacy and safety of single anastomosis duodeno-ileal bypass with sleeve gastrectomy: a comparative analysis from a centre of excellence
Authors: de Sousa J P Vieira , Santos-Sousa H , Nogueiro J , Amorim-Cruz F , Vaz S , Peleteiro B , Lemos J , Resende F , Costa-Pinho A , Preto J , Freitas P , Carneiro S , da-Costa E Lima 
Published: February 2025

Abstract

Introduction
Single Anastomosis Duodena-Ileal Bypass with Sleeve Gastrectomy (SADI-S) has emerged as a simpliﬁed and effective alternative to the traditional duodenal switch. SADI-S eliminates the alimentary limb, and the common channel is lengthened from 200 to 300 cm. This modification results in a single ileo-duodenal anastomosis, reducing the complexity and potential complications associated with multiple anastomoses, such as internal hernias. SADI-S can be done as 1-stage surgery or as 2-stage surgery. However, more studies are needed to prove its safety and effectiveness. This study aims to evaluate the efficacy and safety of SADI-S as 1-stage or 2-stage surgery.

Methods
A retrospective analysis was performed on patients who underwent 1-stage SADI-S or 2-stage SADI after sleeve gastrectomy (SG) between 2019 and 2023. Patient demographics, length of hospital stay, preoperative and postoperative weight, complications, and comorbidities were obtained from medical records. Outcomes measured were weight loss, resolution of obesity-related comorbidities, and postoperative complications. Statistical analysis was conducted using Stata®.

Results
The study included 40 patients (♀38; ♂2), with 13 1-stage SADI-S and 27 2-stage SADI-S. Before surgery, both groups had similar rates of dyslipidaemia, diabetes hypertension, and obstructive sleep apnea prevalence. BMI before surgery was comparable between 1-stage or 2-stage SADI-S, 53.5 ± 4.3 kg/m² versus 50.5 ± 8.1 kg/m², respectively (P = 0.217). The average time between surgeries in the 2-stage SADI-S was 64.8 ± 24.0 months.
There were no conversions to laparotomy in either group. The average length of hospital stay was not significantly different between the groups. Complications occurred only in the 1-stage group, with 1 (7.7%) postoperative complication (hyperinsulinaemic hypoglycemia). After surgery, there were no differences in the number of patients experiencing three or more bowel movements per day (1-stage 23.1% versus 2-stage 14.8%, P = 0.519). The reduction rates for diabetes and hypertension were similar between groups and consistently high at all times. Still, the reduction in dyslipidemia was better in the 1-stage SADI-S in the short term (6 to 18 months), which in the medium term ended up disappearing the differences (24 months).
Postoperatively, excess weight lost (%EWL) and total weight lost (%TWL) are statistically higher in 1-stage SADI-S compared to that performed in 2-stage (at 24 months %TWL 1-stage 43.4% versus 2-stage 20.1%, P = 0.003). However, regarding weight loss success (≥20% TWL and ≥50% EWL), there were no statistically significant differences between the two groups (1-stage SADI-S 100% versus 2-stage SADI-S 73.7%, P = 0.160).

Discussion
The results demonstrate that 1-stage SADI-S yields significantly higher %TWL and %EWL at 24 months postoperatively compared to the 2-stage SADI-S, although both achieve similar success rates in terms of weight loss benchmarks. While the 1-stage group experienced some postoperative complications, the overall complication rates were low, and the reduction in obesity-related comorbidities such as diabetes and hypertension was comparable between both groups. These findings suggest that 1-stage SADI-S may offer a more favourable weight loss outcome without compromising safety. Further research with larger sample and longer follow-up is recommended to evaluate efficacy and safety considering other outcomes like postoperative gastroesophageal reflux, diarrhoea and nutritional changes.