CT-Measured Psoas Area Predicts Urinary Incontinence Trajectories and Persistence After Robotic Prostatectomy: A...

Urinary incontinence (UI) remains an important complication after robot-assisted radical prostatectomy (RARP). While sarcopenia-related markers may help predict persistent UI, existing evidence is inconsistent and often based on subjective assessments. We aimed to evaluate the predictive value of preoperative psoas major muscle cross-sectional area (PMM-CSA) for moderate-to-severe UI 12 months after RARP and its association with longitudinal continence recovery.

This cohort study included 449 patients with prostate cancer who underwent RARP. PMM-CSA was measured on preoperative CT scans at the L3 vertebral level. UI volume, measured using a standardized 1-hour pad test (1hPT) at baseline and at 1, 3, 6, 9, and 12 months postoperatively, was classified as moderate-to-severe if it was ≥11 g. Univariable and multivariable logistic regression evaluated preoperative PMM-CSA as a predictor of moderate-to-severe UI at 12 months post-RARP. A multivariable-adjusted generalized estimating equation was used to assess the association between PMM-CSA and longitudinal changes in UI volume.

Moderate-to-severe UI was observed in 64 patients (14.3%) 12 months postoperatively and was significantly predicted by PMM-CSA (odds ratio per 1 cm² increase: 0.86 [95% confidence interval: 0.79-0.92]). Postoperatively, UI volume peaked at 1 month, declined until 9 months, and then plateaued. Reduced PMM-CSA was associated with increased UI volume from 3 to 12 months postoperatively.

Preoperative PMM-CSA is a significant predictor of moderate-to-severe UI 12 months after RARP and is associated with the longitudinal continence recovery. Preoperative PMM-CSA evaluation may aid in risk stratification, tailored counseling, and preventive strategies.