Change in Parameters before and after Alpha-1-Blocker Therapy for Men with Lower Urinary Tract Symptoms Using Color Doppler Ultrasound Urodynamics: Possible Application for Prediction of Clinical Outcome

Abstract

Introduction: We previously developed a noninvasive video urodynamic study using color Doppler ultrasonography. We sought the best flow velocity-related parameter which would allow prediction of an improvement in lower urinary tract symptoms (LUTS) after α₁-blocker treatment. Methods: Twenty-two men with benign prostatic hyperplasia who were treated with a nonselective α₁-blocker (urapidil) were included. Subjective symptoms were evaluated using the International Prostate Symptom Score (IPSS) before and after α₁-blocker treatment. We measured the flow velocities using a transperineal ultrasound technique in the distal prostatic urethra just proximal to the external urethral sphincter (V₁) and in the sphincteric urethra (V₂), and used them to obtain the velocity ratio (VR = V₁/V₂). The corresponding functional cross-sectional areas of the urethra at these two sites (A₁ and A₂) were calculated as Q_max/V. All these parameters obtained by the velocity-flow urodynamics were compared before treatment and after 4 weeks. Results: After treatment, V₁ and VR were decreased, and A₁ was increased. V₂ correlated best with the change in IPSS before and after α₁-blocker therapy, with Spearman’s rho of 0.584. All men with V₂ exceeding 50 cm/s did not show an improvement in the LUTS. Conclusions: The maximum flow velocity at the sphincteric urethra (V₂) can predict the subjective outcome of α₁-blocker treatment. The velocity-flow parameters changed after α₁-blocker treatment. We confirmed that the transperineal ultrasound urodynamic study is not only noninvasive but also informative.