Correlation of intravesical prostatic protrusion with bladder outlet obstruction

OBJECTIVES To determine the effect of intravesical protrusion of the prostate (IPP, graded I to III) on lower urinary tract function, by correlating it with the results of a pressure-flow study. PATIENTS AND METHODS In a prospective study men (aged> 50 years) with lower urinary tract symptoms were initially evaluated as recommended by the International Consultation on Benign Prostatic Hyperplasia, together with the IPP and prostate volume, as measured by transabdominal ultrasonography. These variables were then correlated with the results from a pressure-flow study. RESULTS The IPP was a statistically significant predictor (P < 0.001) of bladder outlet obstruction (BOO) compared with other variables in the initial evaluation. In all, 125 patients had significant BOO, defined as a BOO index of> 40. Of these men, 94 had grade III and 30 had grade I-II IPP. Seventy-five patients had a BOO index of < 40; 69 had grade I-II and six grade III IPP. In patients with BOO confirmed on the pressure-flow study, grade III IPP was associated with a higher BOO index than was grade I-II (P < 0.001). CONCLUSION The IPP assessed by transabdominal ultrasonography is a better and more reliable predictor of BOO than the other variables assessed.