Impact of Body Mass Index on Perioperative Outcomes in Robotic-Assisted Total Hysterectomy: A Retrospective Cohort Study.

Background/Objectives: The rising global prevalence of obesity presents an increasing challenge in gynecologic surgery. Although robotic-assisted hysterectomy is widely used, comparative data on perioperative outcomes across body mass index (BMI) categories remain limited. We evaluated whether higher BMI is associated with longer operative duration and increased perioperative complications in robotic-assisted total hysterectomy performed for benign indications. Methods: This retrospective cohort study analyzed 179 patients who underwent robotic-assisted hysterectomy at a German academic medical center between January 2018 and December 2024. Patients were stratified by World Health Organization criteria into normal weight (BMI < 25 kg/m2; n = 51), overweight (BMI 25.0-29.9 kg/m2; n = 59), and obese (BMI ≥ 30 kg/m2; n = 69) groups. The primary outcome was operative time; secondary outcomes included estimated blood loss (EBL), Clavien-Dindo complications, hospital stay, transfusion, and readmission within six weeks. Multivariable regression adjusted for uterine weight, surgeon volume, ASA class, year of surgery, and prior abdominal operations. Results: Operative time increased significantly with BMI (normal: 136.3 ± 68.7 vs. obese: 174.4 ± 74.3 min; p = 0.009). On multivariable analysis, BMI remained an independent predictor of operative time (β = 2.49 min per kg/m2, 95% CI 1.01-3.96, p = 0.001) and EBL (β = 15.0 mL per kg/m2, 95% CI 1.5-28.5, p = 0.029). Postoperative hemoglobin and transfusion rates did not differ between groups. No significant differences were detected in major complication rates (Clavien-Dindo ≥ III: 4/51 [7.8%], 1/59 [1.7%], 7/69 [10.1%]; p = 0.15), hospital stay, or readmission. High-volume surgeon status (≥30 cases) was independently associated with reduced major complications (OR = 0.16, 95% CI 0.03-0.75, p = 0.020). Conclusions: Robotic-assisted hysterectomy appears clinically feasible across all BMI categories without a detectable increase in major morbidity, although obesity was associated with moderately longer operative times and higher calculated EBL. The study was not powered to detect differences in rare events. Surgeon experience was independently associated with lower complication rates and may help offset the additional technical demands of obesity.