Bariatric conversional surgery in younger adults ≤40: who gets converted and comparative risks of conversion to...

The incidence of bariatric surgery in younger adults, and subsequently conversional surgery, is increasing.

We aim to describe patients ≤40 requiring conversion, operative details, and complications associated with different procedures.

MBSAQIP centers (United States and Canada).

We included patients ≤40 years from 2020 to 2022 undergoing a conversion procedure to sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), single anastomosis duodeno-ileal bypass (SADI-S), or biliopancreatic diversion-duodenal switch (BPD/DS). Baseline characteristics and bivariate complication rates were compared. Multivariate models were generated for 30-day complication for all patients undergoing conversion surgery from index adjustable gastric banding (AGB) or SG.

Of 13,486 patients, 842 were converted to SG, 9812 to RYGB, 549 to SADI-S, and 2283 to BPD/DS. The most common reason for conversion to RYGB was gastroesophageal reflux disease (GERD) (48.7%) and to SADI-S and BPD/DS was insufficient weight loss/regain (89.6% and 88.1%, respectively). On multivariate analysis, conversion to RYGB (adjusted odds ratio [aOR] 2.14) and BPD/DS (aOR 2.30) were associated with increased risk compared to SG. After controlling for initial operation, conversion of AGB to RYGB had a higher likelihood of having 30-day serious complication compared to SG (aOR 2.18). For patients with an index SG, conversion to BPD/DS carried similar likelihood of 30-day complication to RYGB (aOR .78, P = .302), while conversion to SADI-S carried lower likelihood (aOR .47, P = .031).

Each conversion surgery is associated with differing rates of complications, and conversion from index AGB to SG versus RYGB and from index SG to SADI-S versus RYGB or BPD/DS may be associated with fewer complications.