Is Obesity Severity Associated With Increased Postoperative Morbidity after Minimally Invasive Appendectomy? A 2020-2024 NSQIP Propensity Score-matched Analysis

Background Obesity may increase morbidity after minimally invasive appendectomy (MIA). We evaluated 30-day outcomes by obesity status and severity. Methods Using the 2020-2024 ACS NSQIP Participant Use Files, patients with obesity (BMI ≥30 kg/m 2 ) were compared with those without obesity, and class III obesity (BMI ≥40 kg/m 2 ) with class I-II obesity. Propensity score matching (PSM) was performed. Outcomes included mortality, conversion to open surgery, surgical site infection (SSI), organ-related complications, operative time, and length of stay. Sensitivity analyses adjusted for residual comorbidity imbalance using multivariable logistic regression. Results Among 211,221 patients, 78,659 (37.2%) had obesity. PSM yielded 78,567 pairs for the main comparison and 14,203 for the subgroup comparison. Obesity was associated with higher odds of superficial SSI (OR 1.75; 95% CI 1.58-1.94), deep incisional SSI (OR 1.70; 95% CI 1.28-2.26), conversion (OR 1.33; 95% CI 1.06-1.67), and renal insufficiency (OR 1.62; 95% CI 1.32-1.98). Class III vs class I-II obesity was associated with higher odds of superficial SSI (OR 1.80; 95% CI 1.48-2.18), deep incisional SSI (OR 3.09; 95% CI 1.61-5.93), and renal insufficiency (OR 2.23; 95% CI 1.50-3.31). After additional adjustment, incisional SSI associations persisted in both comparisons, whereas conversion and renal insufficiency associations were no longer significant. Conclusions MIA showed a favorable safety profile in patients with obesity, with low absolute mortality and major complication rates. SSI associations persisted after adjustment, including class III vs class I-II obesity.