Persistent lower urinary symptoms following surgery for benign prostatic hyperplasia: who is to blame?

BACKGROUND: Lower urinary tract symptoms (LUTS) in men have been traditionally related to bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH). After surgery for BPH though, up to 30% of patients keeps experiencing bothersome LUTS. This retrospective study analyses the urodynamic findings of those patients and aims to assess the impact of detrusor underactivity (DU) on post-surgical LUTS and its correlation with high post-void residual volume (PVR).METHODS: Data of urodynamic exams (UDM) of male patients reporting persisting LUTS after BPH surgery were analyzed. Exclusion criteria were neurogenic disease, prostate cancer, UDM performed <6 months after BPH surgery, age >80 years. Urodynamic exams were performed in referral centers according to ICS good practice and guidelines. Epidemiological data of the cohort were also collected. ICS standardized terminology was used to classify LUTS and UDM findings. In absence of a consensus on significant PVR, the cut-off of 100 mL was used.RESULTS: Seventy-nine UDM were included in this study: 56% UDM showed detrusor overactivity (DO), 49% demonstrated signs of detrusor underactivity (DU); residual bladder outlet obstruction (BOO) was present in 16% of our cohort; in nine (11%) cases UDMs were normal. A significant PVR was found in 1/3 of the patients, and in 81% cases was associated with detrusor underactivity. Age >70 years had a strong association with DO. The group of patients taking alpha-blockers did not behave differently. None of those results were statistically significant, possibly for the small sample size.CONCLUSIONS: According to this study, LUTS after surgery for BPH have a strong association to bladder dysfunction whilst BOO is present only in a minority of cases. A significant PVR was also associated with signs of DU. This should be taken into consideration when counselling patients for surgery, in order to select patients that might benefit from UDM assessment before surgery and manage patient's expectations regarding symptoms after surgery.