IBC Oxford University Oral Abstract 48 - Comparison of SADI-S and RYGB as revisional surgeries after sleeve gastrectomy: a retrospective study
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
Revision surgeries have become crucial in bariatric surgery, accounting for 7.4% of procedures in 2016. Although sleeve gastrectomy (SG) has good short-term results, many patients require revisional surgery due to insufficient weight loss or functional complications. Options for revisional surgeries after SG include Roux-en-Y gastric bypass (RYGB), repeated sleeve gastrectomy, biliopancreatic diversion, duodenal switch, duodenal-jejunal bypass, one-anastomosis gastric bypass (SADI-S), single anastomosis duodeno-ileal bypass, and transit bipartition. This study aims to evaluate the efficacy and safety of SADI-S versus RYGB as revisional surgeries after SG.

Methods
A retrospective analysis was performed on patients who had primary SG and required revisional surgery for inadequate weight loss or regain 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 91 patients (♀81; ♂10), with 64 RYGB and 27 SADI-S. Before surgery, both groups had similar rates of smoking history, diabetes prevalence, hypertension, and obstructive sleep apnoea, but the SADI-S group had a higher prevalence of dyslipidaemia (44.4% versus 21.9%, P = 0.029). Prior to SG, the SADI-S group had a higher average BMI (50.5 ± 8.1 kg/m² versus 44.6 ± 6.6 kg/m², P &lt; 0.001). There were no statistically significant differences in the time between SG and revision surgery (RYGB 75.1 ± 22.9 months versus SADI-S 64.8 ± 24.0 months, P = 0.055). At the time of surgery, the SADI-S group had a higher average weight (113.4 ± 20.8 kg versus 102.2 ± 15.5 kg, P = 0.006) and BMI (42.7 ± 6.0 kg/m² versus 36.5 ± 6.8 kg/m², P &lt; 0.001).
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 RYGB group, with 6 (9.4%) postoperative complications, 2 of which were Clavien-Dindo grade IIIb or higher. After SADI-S, 4 (14.8%) patients had three or more bowel movements per day, and 1 (3.7%) experienced steatorrhea. The reduction rates for diabetes were similar between groups and consistently high at all times. Still, the reduction in hypertension and dyslipidaemia was better in the RYGB group in the short term (6 to 12 months), which in the medium term ended up disappearing the differences (18 to 24 months).
Medium-term weight loss results were similar between groups, with no statistically significant differences in weight loss success (≥20% TWL and ≥50% EWL) at 24 months (RYGB 87.0% versus SADI-S 73.7%, P = 0.276).

Discussion
SADI-S can be an effective revision surgery after SG, with results comparable to RYGB in the medium term. Notably, the SADI-S group experienced no postoperative complications, while the RYGB group did. Both groups exhibited similar rates of resolution of diabetes, dyslipidaemia, and hypertension in the medium term (18 to 24 months). Additionally, there were no significant differences in weight loss between the two groups in the medium term (24 months). The SADI-S group reported minimal gastrointestinal side effects, challenging the perception of frequent bowel-related complications with SADI-S.
More studies are needed to evaluate long-term effects of SADI-S and improve selection criteria for post-SG surgery.