Impact of Class III Obesity (Morbid Obesity) on the Perioperative, Functional, and Oncological Outcomes of Robotic-Assisted Radical Prostatectomy

Abstract

Background: The growing prevalence of obesity, particularly morbid obesity (BMI > 40 kg/m2), presents unique challenges in surgical management. In robotic-assisted radical prostatectomy (RARP) for prostate cancer, morbid obesity is associated with longer operative times, increased blood loss, and complex nerve-sparing procedures. These challenges may impact functional and oncological outcomes, making it essential to understand how high BMI affects RARP results. However, data on outcomes for patients with morbid obesity remain limited. Methods: We retrospectively reviewed 14,444 patients who underwent RARP by a single surgeon from 2008 to 2023. A total of 183 patients with morbid obesity (BMI > 40 kg/m2) were matched 1:1 with 183 normal-weight patients (BMI 18.5–24.9 kg/m2) using propensity-score matching based on age, PSA levels, clinical staging, ISUP grade, comorbidities, and baseline urinary and sexual function scores. We compared perioperative variables, complications, and oncological and functional outcomes between groups. Results: Patients with morbid obesity had longer console times (median 90 vs. 75 min, p < 0.001) and higher rates of estimated blood loss over 100 mL (39% vs. 22%, p = 0.001). Full nerve-sparing was less frequent in this group (16.9% vs. 38.8%, p < 0.001), and postoperative lymphocele formation rates were higher (12.7% vs. 6.0%, p = 0.021). While patients with morbid obesity demonstrated a higher incidence of pT3a disease (34.4% vs. 20.2%, p = 0.015), no significant differences were observed in BCR and PSM (24% vs. 18%, p = 0.25) or functional outcomes, such as potency and urinary continence, at 12 and 24 months after operation. Conclusions: RARP in patients with morbid obesity is safe and feasible, with low rates of complications and no observed differences in functional and oncological outcomes compared to normal-weight patients. Further studies are needed to assess long-term outcomes in this growing patient population.