Transurethral water vapor ablation of the prostate with the Rezum system: Urodynamic findings

Aims The efficacy of the transurethral convective interstitial radiofrequency water vapor thermal ablation of the prostate with the Rezum system for the treatment of male lower urinary tract symptom due to benign prostatic hyperplasia is well proven. The improvement of urodynamic parameters obtained from a simple uroflowmetry cannot measure the effect of water vapor injection on the bladder outlet obstruction. Methods This monocentric retrospective pilot study analyzes the data of pressure-flow studies performed before and after 17 Rezum procedures to answer the question whether thus obtained ablation of prostate tissue has a disobstructive effect on the bladder outlet. Results All the functional outcomes were consistently improved after the procedure, with a median flowrate increase of 5.1 ml/s (p = 0.0022) and a median postvoid residual urine (PVR) reduction of 100 ml (p = 0.0042). The prostate volume was reduced by 40% (p < 0.0001) and the median Bladder Outlet Obstruction Index (BOOI) reduction was 53.8 (p < 0.0001). Conclusions These data show that the possibility to significantly reduce the obstruction grade with even a single Rezum procedure is concrete and seems to be independent from the degree of the obstruction grade.