Prospective urodynamic model for prediction of urinary incontinence after robot-assisted radical prostatectomy.

OBJECTIVES: To assess the preoperative urodynamic predictors of urinary incontinence (UI) 1 year after robot-assisted radical prostatectomy (RARP) and to design a nomogram capable of predicting its occurrence. MATERIALS AND METHODS: Our prospective study included 58 previously continent patients who underwent RARP, in most cases, bilateral nerve-sparing and bladder neck preservation. A urodynamic examination including a urethral pressure profile was performed preoperatively. Multivariate analysis was used to assess the predictors for the need to use 1 or more pads/day and a nomogram was constructed. RESULTS: There was a 20.6% incidence of UI at 1 year after RARP. Bladder compliance, maximum urethral closure pressure and the development of bladder outlet obstruction, correlated well with the incidence of UI on the multivariate analysis (p = 0.043, 0.001, and 0.05, respectively). CONCLUSION: Bladder compliance <27.8 ml/cm H2O, maximum urethral closure pressure <50.3 cm H2O and the bladder outlet obstruction are independent urodynamic factors correlating with UI after RARP. The new nomogram can objectively predict a patient likelihood of requiring 1 or more pads/day 1 year after RARP with a good accuracy.

Comprehensive prediction model of urinary incontinence one year following robot-assisted radical prostatectomy.

OBJECTIVES: Urinary incontinence (UI) still remains one of the major functional complications after robot-assisted radical prostatectomy (RARP). As the cause for UI is multifactorial, it is quite difficult to make a prediction preoperatively. Considering intraoperative and postoperative risk factors, besides the preoperative ones, we designed an incontinence prediction model, administered 1 month after the surgery, in order to identify incontinent patients at 1 year. PATIENTS AND METHODS: We retrospectively reviewed 244 patients who underwent RARP at our institution. Only 209 patients had sufficient data, a 1-year follow-up and were continent preoperatively. The association of UI with the risk factors was assessed by univariable and multivariable regression models. RESULTS: There was a 17.2% global UI rate at 1 year after RARP. Only age-adjusted Charlson comorbidity index, erectile function assessed by International Index of Erectile Function-5, prostate volume, nerve-sparing status and 24-hour urine loss at 1 month correlated with UI (p = 0.032, 0.009, 0.031, 0.018 and <0.001, respectively). The accuracy of the prediction model of UI was 92.8% (c-index), with an area under the curve of 91.9%. CONCLUSION: Age-adjusted Charlson comorbidity index, International Index of Erectile Function-5, prostate volume, nerve-sparing status and 24-hour urine loss at 1 month after RARP can predict an individual's risk of UI at 1 year after RARP with good accuracy. Further external validation is required in order to generalize the use of this model.