Intravesical Prostatic Protrusion in Men in Olmsted County, Minnesota

Purpose: Ultrasonically measured intravesical prostatic protrusion may be a promising noninvasive method of assessing bladder outlet obstruction. Previous investigations of this technique focused on patients with acute urinary retention and symptomatic men identified in urology clinics, which may not reflect the distribution of intravesical prostatic protrusion in community dwelling men. Materials and Methods: In 2006 a total of 322 white men residing in Olmsted County, Minnesota underwent transrectal ultrasound examination which permitted direct measurement of intravesical prostatic protrusion. Cross-sectional associations between lower urinary tract symptoms/benign prostatic enlargement and intravesical prostatic protrusion were measured. Rapid increases in lower urinary tract symptoms/benign prostatic enlargement measures as predictors of severe intravesical prostatic protrusion were also assessed. Results: Overall 10% of these men had an intravesical prostatic protrusion of 10 mm or greater. Greater intravesical prostatic protrusion was weakly correlated with greater prostate volume (r_s = 0.28), higher obstructive symptoms (r_s = 0.18) and lower peak urinary flow rate (r_s = -0.18). Men with the most rapidly growing prostate before intravesical prostatic protrusion measurement were 3 times more likely to have an intravesical prostatic protrusion of 10 mm or greater. Men with an intravesical prostatic protrusion of 10 mm or greater were more likely to use medications for lower urinary tract symptoms/benign prostatic enlargement compared to those with an intravesical prostatic protrusion less than 10 mm (adjusted OR 2.95, 95% CI 1.23-7.06). Conclusions: These population based data provide reference ranges for future studies of intravesical prostatic protrusion as a predictor of adverse urological outcomes. Intravesical prostatic protrusion is significantly correlated with greater prostate volume, higher obstructive symptoms and lower peak urinary flow rate, suggesting that it may have clinical usefulness in predicting the need for treatment.