Procedure-Specific Early Complications Following Bariatric Surgery: A High-Volume Single-Institution Analysis

Metabolic and bariatric surgery (MBS) is an established treatment for severe obesity and its related comorbidities. While long-term outcomes are often emphasized, early postoperative complications remain a critical metric of safety and resource utilization. Large database studies have reported national trends in MBS outcomes but are limited by lack of granularity, inconsistent definitions, and inclusion of heterogeneous surgical experience. This study aimed to provide a detailed analysis of 30-day postoperative complications following sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and duodenal switch (DS) over a 17-year period at a single high-volume quaternary academic center.

A retrospective cohort study of adult patients who underwent primary laparoscopic SG, RYGB, or DS between 2008 and 2024. All procedures were performed by fellowship-trained, minimally invasive bariatric surgeons. Complications occurring within 30 days postoperatively were identified through comprehensive chart review and classified using the Clavien-Dindo grading system. Primary outcomes included incidence, severity, and type of complications, as well as rates of readmission, reoperation, and reintervention. Multivariable logistic regression was used to identify predictors of overall and major complications.

Of 2190 patients included, 413 (18.9%) experienced at least 1 early complication, totaling 467 discrete events. DS had the highest complication rate (29.3%), followed by RYGB (18.4%) and SG (17.5%). RYGB was associated with a high burden of major complications, including anastomotic strictures, GI bleeding, and reoperations for obstruction or leak. The 30-day rates of readmission (2.0%) and reoperation (1.3%) were low across all groups. Independent predictors of major complications included venous stasis (aOR=3.22), renal insufficiency (aOR=2.65), and type 2 diabetes (aOR=1.96); both RYGB (aOR=2.25) and DS (aOR=2.77) carried higher risk than SG.

This study provides a granular, procedure-specific profile of early complications after SG, RYGB, and DS. While all 3 procedures demonstrated acceptable safety profiles, DS had the highest overall complication rate, and RYGB carried the greatest burden of major complications. These findings underscore the variability in early postoperative outcomes by procedure type and reflect the value of institutional experience in characterizing complication profiles.