To evaluate continence status and mechanism of urinary incontinence immediately after robot-assisted radical prostatectomy (RARP) by performing urodynamic evaluation.

A total of 87 patients with localized prostate cancer who underwent RARP were included. Filling cystometry, urethral pressure profilometry, and abdominal leak point pressure (ALPP) tests were performed before and immediately after RARP.

The mean urine loss ratio (ULR), calculated by dividing the total urine volume by the weight of urine loss after RARP, was 17.8%. Nerve-sparing (NS) surgery significantly affected ULR compared with non-NS surgery. In the comparison between preoperative and postoperative results, the mean maximal cystometric capacity (MCC) and maximal closure urethral pressure (MUCP) decreased from 341 mL and 84.6 cm H₂O to 250 mL and 35.6 cm H₂O, respectively. No urine leakage was observed in ALPP test preoperatively; however, urine leakage was observed postoperatively in 75 patients (86%), with a mean ALPP of 47.7 cm H₂O. Multivariate analysis revealed that MCC, MUCP, and ALPP after RARP were predictive factors for ULR. Linear correlations were found between ULR and MUCP and between ULR and ALPP after RARP. NS status and MUCP after RARP (r = 0.247; P = .021) and the ALPP (r = 0.254; P = .018) were significantly correlated.

In urodynamic evaluation immediately after RARP, MCC, MUCP, and ALPP were found to predictive factors for urinary incontinence. The NS procedure contributed to continence status after RARP.