Changes of lower urinary tract function after robot-assisted radical prostatectomy: An urodynamic follow-up within 1 year.

Objectives: This study investigated the changes of lower urinary tract function after robot-assisted radical prostatectomy (RaRP) with 1-year urodynamic follow-up.

Materials and methods: Clinically localized prostate cancer patients receiving RaRP were prospectively enrolled. We analyzed their clinical symptoms, stress urinary incontinence (SUI) and urge urinary incontinence (UUI) status, and videourodynamic studies (VUDSs) during the postoperative 1^st year.

Results: In total, 74 patients were enrolled with a mean age of 69.4 ± 8.1 years, a mean total prostate volume of 34.7 ± 15.9 mL, a ≥pT3 stage proportion of 37.8%, and a positive surgical margin rate of 18.9%. The International Prostate Symptom Score significantly reduced from 7.3 ± 6.0 before surgery to 4.1 ± 4.1 at postoperative 1 year. Significantly increased full sensation, reduced detrusor voiding pressure, increased maximal urinary flow rate, and decreased bladder outlet obstruction index were noted at 1-year VUDS follow-up. The changes of VUDS parameters were significantly different between the patients with and without preoperative bladder outlet obstruction. At postoperative 1 year, 8.1% and 6.8% of patients experienced SUI and UUI, respectively. In multivariate analysis, the factors of T stage ≥3, preoperative detrusor overactivity (DO), and positive surgical margin were the independent predictors of immediate SUI and SUI at 3 and 12 months, respectively.

Conclusion: During the 1^st year after RaRP, patients experienced significant changes of lower urinary tract function demonstrated in VUDS with the improvement in clinical symptoms. Factors of T stage ≥3, preoperative DO, and positive surgical margin were the predictors of postoperative SUI.