Internal hernia in patients after duodenal switch: A multi‐centred comparative analysis

Summary Biliopancreatic diversion with duodenal switch (BPD‐DS) and single anastomosis duodeno‐ileostomy with sleeve (SADI‐S) are associated with superior and sustained weight loss outcomes. Despite their growing popularity, long‐term safety profiles, particularly the risk of internal hernia (IH), remain underexplored. This study aimed to evaluate the incidence and characteristics of IH following BPD‐DS and SADI‐S procedures, comparing their clinical presentation, diagnostic methods, and outcomes. A retrospective chart review was performed for patients who underwent BPD‐DS or SADI‐S between 2008 and 2023 in two high‐volume tertiary referral centres for bariatric surgery in the United States. Demographic data, comorbidities, operative details, and follow‐up outcomes were collected. A subgroup analysis of IH cases was conducted to compare the incidence, location of hernias, and diagnostic modalities between procedures. Out of 1160 patients (85.1% BPD‐DS; 14.9% SADI‐S), the overall incidence of IH was 1.12%, with a higher rate in BPD‐DS (0.8%) than in SADI‐S (0.57%). Most IHs occurred within the first 24 months postoperatively. The majority of IHs in BPD‐DS patients were in the pseudo‐Petersen's space. The single IH case in the SADI‐S group occurred in the same space. Most patients presented with abdominal pain and were diagnosed by CT imaging. SADI‐S showed a lower IH rate compared to BPD‐DS, but further studies are needed to confirm these findings. The variability in clinical presentation complicates the diagnosis of IH, emphasizing the need for increased clinical vigilance.