Detrusor underactivity after radical prostatectomy: A prospective observational study

Objective: To evaluate the impact of radical prostatectomy (RP) on bladder function with special interest in detrusor underactivity (DU) and to appraise clinical significance of DU in postprostatectomy patients.

Material and methods: This was a prospective, observational study conducted on male patients subjected to laparoscopic RP (LPR). Urodynamic studies were performed at the day before surgery (visit 1), 3-6 months postoperatively (visit 2) and more than 12 months after surgery (visit 3). Incidence of DU that occurred after LPR (de novo DU), incidence of persisting de novo DU after 12 months, clinical relevance of DU after LPR and predictive factors of de novo DU were assessed.

Results: 99 of 100 patients underwent preoperative urodynamic study (visit 1) and those were included in further analysis. 84 and 76 patients were available for follow-up at second and third visit respectively. De novo DU occurred after LPR in 25 (29.7%) patients at visit 2 (p < 0.001). Sixteen from 24 patients (66,7%) who developed de novo DU after RP (visit 2) continued to have DU 1 year after surgery (visit 3) (p = 0.04). On the multivariate analysis, urinary incontinence requiring more than 1 pad per day (odds ratio [OR] 5.11; confidence interval [CI] 1.69-17.19; p = 0.005) and preoperative IPSS storage sub-score (OR 1.25; CI 1.03-1.63; p = 0.030) were significantly associated with de novo DU. Postprostatectomy patients with DU had significantly lower Urinary Assessment of the Expanded Prostate Cancer Index Composite (EPIC) total score (819 vs. 911, p = 0.02), EPIC Function domain score (300 vs. 357, p = 0.002) and EPIC Urinary incontinence domain (137 vs. 224, p = 0.002) when compared to their counterparts without DU.

Conclusions: RP substantially influences bladder function, causing de novo DU, which persists in substantial number of patients 1 year postoperatively. Furthermore, significant correlation between DU and postprostatectomy urinary incontinence may play a role when anti-incontinence surgery is considered.