Correlation of Prostatic Urethral Angle with the Severity of Urinary Symptom and Peak Flow Rate in Men with Small Prostate Volume

Purpose: To evaluate the effects of prostatic anatomical factors on male lower urinary tract symptoms (LUTS) and the peak flow rate (Qmax) in patients with small prostate volume (PV). Materials and Methods: Records were obtained from a prospectively maintained database of first-visit men with LUTS. Patients whose total PV (TPV) was greater than 30 mL were excluded; 444 patients were enrolled in the study. The TPV, transitional zone volume (TZV), transitional zone index (TZI), intravesical prostatic protrusion (IPP), and prostatic urethral angle (PUA) were measured by transrectal ultrasonography. LUTS were evaluated using the International Prostate Symptom Score (IPSS) and the Overactive Bladder Symptom Score (OABSS) questionnaires. Uroflowmetric measurements were also made. Results: PUA (r = 0.269, P < 0.001), TZV (r = 0.160, P < 0.001), and TZI (r = 0.109, P = 0.022) significantly correlated with the IPSS. Qmax (r = -0.334, P < 0.001) and OABSS (r = 0.211, P < 0.001) correlated only with PUA. In a multivariate regression analysis, PUA and age were independently associated with IPSS, OABSS, and Qmax. For IPSS of 20 or greater, the area under the ROC curve (AUC) of PUA was 0.667 and the cut-off value was 43.7 degrees. When Qmax was 10 mL/s or less, the AUC of PUA was 0.664 and the cut-off value was 43.5 degrees. Conclusions: PUA has a significant association with symptom severity and Qmax among prostatic anatomical factors analyzed in men with LUTS and small PV. PUA should be considered as an important clinical factor in male LUTS management. Furthermore, the impact of PUA on response to medical treatment and disease progression needs to be investigated.