To determine the effect of bladder contractility on the outcomes of high-power (80 W) potassium-titanyl-phosphate laser vaporization of the prostate in men with lower urinary tract symptoms.

A total of 68 men with a median age of 68.5 years (range 53 to 86) were included in the study. The median follow-up was 9 months (range 6 to 21).

The median International Prostate Symptom Score and quality-of-life index decreased from 18 to 8.5 (P <0.001) and from 4 to 2 (P <0.001), respectively. The median maximal flow rate increased from 10 to 16.1 mL/s (P <0.001) and the median postvoid residual urine volume decreased from 28 to 10 mL (P <0.001). No differences were found in the change in the International Prostate Symptom Score or maximal flow rate according to age, prostate volume, or bladder outlet obstruction index. The weak bladder contractility index (BCI) group (BCI less than 100) had a smaller decrease in the median International Prostate Symptom Score and a smaller increase in the maximal flow rate than did those in the higher BCI group (BCI of 100 or more; P = 0.047 and P = 0.035, respectively). The baseline clinical parameters, including age, prostate volume, serum prostate-specific antigen, and bladder outlet obstruction index, were not significantly different between the low and greater BCI groups.

The results of the present study have shown that after high-power potassium-titanyl-phosphate laser vaporization, patients with weak bladder contractility had less subjective and objective improvement than did those patients with normal or strong bladder contractility.