Abstract: PD18-12
Sources of Funding: none

Introduction

Robot-assisted laparoscopic radical prostatectomy (RALP) is becoming a popular treatment option for localized prostate cancer. Although the potency and stress urinary incontinence after RALP have been assessed in detail, few studies have described the storage dysfunctions such as overactive bladder (OAB) that occur after RALP. In the present study, we investigated the storage function following RALP, with a focus on de novo OAB, and evaluated the factors related to the occurrence of de novo OAB after RALP._x000D_

Methods

We prospectively examined 150 patients without OAB who underwent RALP for localized prostate cancer, and the pre- and postoperative (3 months) urodynamic studies.The evaluated urodynamic parameters were maximum urethral closing pressure (MUCP) and functional profile length (FPL). At the evaluation after 3 months of RALP, we divided the patients into two groups: patients with de novo OAB (de novo OAB group) and patients without OAB after surgery (OAB-free group). We compared the operative and urodynamic parameters between the groups and evaluated the factors related to the occurrence of de novo OAB. In the present study, OAB was defined as a score of 2 or more on the urgency component of the overactive bladder symptom score (OABSS), and a total OABSS of 3 or more. _x000D_

Results

De novo OAB after RALP was observed in 43 patients (28.7%). The International Prostate Symptom Score (IPSS) and OABSS in the de novo OAB group deteriorated significantly from 8.4 to 17 and from 2.1 to 9.3, respectively, whereas those in the OAB-free group improved significantly from 8.2 to 7.4, and from 2.8 to 2.7, respectively. Additionally, there was a significant difference in the incontinence rate, preoperative MUCP, postoperative MUCP, and postoperative FPL, as observed from the univariate comparison of operative and urodynamic parameters between the groups (Table). Multivariable logistic regression analysis performed using factors related to de novo OAB showed that postoperative MUCP was the only significant factor for predicting de novo OAB._x000D_

Conclusions

The incidence rate of de novo OAB after RALP was about 30%, which was thought to be unexpectedly high. The decrease in urethral function was related to de novo OAB after surgery, and it was attributed to the increased reflex response of the urethral afferent pathway.

Funding

none