Impact of body mass index on outcomes after robotic transversus abdominis release in patients without obesity, with class I obesity, and with class II obesity: a multicenter study

Abstract

Background Obesity is considered as a risk factor for postoperative complications after ventral hernia repair (VHR). While promising results of robotic VHR in patients with obesity have been demonstrated, outcomes stratified across BMI categories in patients undergoing robotic transversus abdominis release (rTAR) remain limited. In this multicenter study, we compared perioperative and long-term outcomes after rTAR in patients without obesity (BMI < 30 kg/m(2)), patients with class I obesity (30-34.9 kg/m(2)), and patients with class II obesity (35-39.9 kg/m(2)). Methods We performed a retrospective cohort analysis of consecutive rTAR patients at five centers between February 2015 and July 2025. The primary outcome was overall complication rates; secondary outcomes included surgical site events (SSEs), including occurrences (SSOs), infections (SSIs), and hernia recurrences. Outcomes were analyzed using univariate tests. Multivariate logistic regression tests were run to identify independent risk factors. Results A total of 343 patients included in this study; 160 (46.6%) were patients without obesity, 117 (34.1%) patients had class I obesity, and 66 (19.2%) patients had class II obesity. Overall complication rates were comparable across groups (31.1% vs 27.6% vs 30.3%, p = 0.818). No significant differences observed in length of hospital stay, 30-day readmissions, Clavien-Dindo grades, Comprehensive Complication Index scores, or SSEs, including SSOs and SSIs. Hernia recurrence occurred in one patient per group. Multivariate analysis demonstrated that BMI category was not an independent predictor of complications. Independent risk factors for any postoperative complication included COPD (OR 3.45, 95% CI 1.58-7.11), prior wound infection (OR 2.22, 95% CI 1.19-4.11), non-use of the TEP approach (OR 1.94, 95% CI 1.10-3.43), bilateral TAR (OR 2.58, 95% CI 1.27-5.22), prolonged adhesiolysis > 30 min (OR 1.77, 95% CI 1.01-3.08), and lack of primary defect closure (OR 5.67, 95% CI 1.37-23.47). For SSEs specifically, COPD (OR 2.43, 95% CI 1.10-5.37), prior wound infection (OR 2.17, 95% CI 1.10-4.28), prolonged adhesiolysis (OR 1.96, 95% CI 1.09-3.52), and lack of primary defect closure (OR 4.78, 95% CI 1.36-16.78) were independent predictors. Conclusion Comparable short- and long-term outcomes were observed with rTAR across patients without obesity, with class I obesity, and with class II obesity. Surgeons may need to consider comorbidities, particularly COPD and prior wound infection history, alongside operative factors such as TEP access, primary defect closure, and the careful application of bilateral TAR, in order to optimize patient outcomes.