Impact of obesity on peri-operative and functional outcomes after robotic-assisted simple prostatectomy

Obesity represents a worldwide epidemic disorder, increasing the overall morbidity and mortality rate. In this study we assessed the impact of obesity on perioperative and long-term functional outcomes of robotic-assisted simple prostatectomy (RASP).

Baseline measurements of uroflowmetry and validated questionnaire responses were prospectively recorded, which were repeated at follow-up. Composite outcomes (trifecta) were defined as combination of post-operative Q-max >15 ml/s, IPSS score <8, and absence of complications. Pentafecta included 2 additional criteria, namely post-operative ejaculation persistence (MSHQ score >0) and erectile function maintenance (ΔIEEF <6). Data analysis was stratified by BMI (<30 or ≥30).

Eighty-one patients underwent RASP in our institution. Baseline demographic and clinical features, questionnaire scores, and baseline uroflowmetry results showed no significant differences between obese and non-obese cohorts. However, during follow-up, obese patients reported less improvement in IPSS (p = 0.02) and OABQ scores (p <0.001), along with a higher incidence of stress incontinence requiring duloxetine (p <0.001). Uroflowmetry outcomes were also lower in the obesity group (p = 0.02 and p = 0.03 for Qmax [ml/s] and post-void residual [ml], respectively). However, when considering assessment of comprehensive outcomes, obese patients demonstrated similar rates of achieving trifecta (67% vs 54%, p = 0.39) and pentafecta (p = 0.76) compared to non-obese patients.

Our results show that obesity is associated with poorer functional outcomes. Specifically concerning storage LUTS and incontinence rates following RASP. However, no impact of obesity on the achievement rates of trifecta and pentafecta outcomes was observed.