Correlation Between Prostatic Urethral Angle and Bladder Outlet Obstruction Index in Patients With Lower Urinary Tract Symptoms

Abstract

To evaluate the association of prostatic urethral angle (PUA) with bladder outlet obstruction (BOO) index in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). A retrospective analysis was made of 260 men with LUTS and/or BPH aged>50 years (median: 65.9, range: 50-87). Patients underwent an evaluation including the International Prostatic Symptom Score, serum prostate-specific antigen levels, transrectal ultrasonography, frequency-volume chart, uroflowmetry, and measurement of postvoid residual, and multichannel video urodynamic study with a pressure-flow study. Patients with higher PUA (PUA>or=35 degrees) had higher prostate-specific antigen levels (P=.043), larger prostate volume (P<.001), higher maximal urethral closure pressure (P=.004), higher detrusor pressure at maximum flow rate (P=.008), and higher BOO index (P=.032), in comparison with those who had lower PUA (PUA<35 degrees). There was no significant difference of PUA values according to the degree of intravesical prostatic protrusion. When we compared BOO index according to PUA, patients with higher PUA had higher BOO index than those with lower PUA (30.6+/-1.8 vs 23.6+/-1.8, P=.006). The area under the curve of PUA was significant for BOO (area, 63.0%; 95% confidence interval, 55.1%-70.9%; P=.002). PUA may be one method to asses the presence of BOO in men with LUTS and/or BPH. Our findings suggest that PUA may help in the treatment of individuals by better predicting their likely classification from a pressure-flow study.