Intravesical prostatic protrusion can predict therapeutic response to silodosin in male patients with lower urinary tract symptoms.

OBJECTIVES

To investigate the predicting factors of therapeutic response to α1-blockers in patients with lower urinary tract symptoms associated with benign prostate enlargement based on a urodynamic study.

METHODS

This was a prospective study involving 125 outpatients with lower urinary tract symptoms associated with benign prostate enlargement. They received 8 mg of silodosin for 12 months. International Prostate Symptom Score, Overactive Bladder Symptom Score, International Prostate Symptom Score quality of life assessment, and urodynamic study were used to assess subjective and objective symptoms. Patient age, prostate-specific antigen level, prostate volume, International Prostate Symptom Score, Overactive Bladder Symptom Score, maximum flow rate and post-void residual urine volume, and intravesical prostatic protrusion were investigated as potential parameters to predict the therapeutic response. Baseline parameters that influenced the improvement of International Prostate Symptom Score and bladder outlet obstruction were statistically analyzed.

RESULTS

A total of 103 patients with mean age of 69.2 years and mean prostate volume of 46.8 mL were included in the analysis. A total of 39 patients (37.9%) showed insignificant improvement in International Prostate Symptom Score (<25%), whereas 36 patients (35.0%) showed insufficient improvement in bladder outlet obstruction index (less than 25%). Prostate volume, maximum flow rate and intravesical prostatic protrusion were independent predictors of ineffective treatment. On multivariate logistic regression analysis, intravesical prostatic protrusion was found to be the only factor related to improvement of both the International Prostate Symptom Score and bladder outlet obstruction. Additionally, multiple linear regression analysis showed that intravesical prostatic protrusion was the only significant factor for predicting improvement of the International Prostate Symptom Score (r = -0.56, P < 0.001) and bladder outlet obstruction (r = -0.59, P < 0.001).

CONCLUSIONS

Intravesical prostatic protrusion can be considered a useful predictor of therapeutic response to silodosin for subjective symptoms and bladder outlet obstruction in male patients with lower urinary tract symptoms associated with benign prostate enlargement.