ULTRASONIC ESTIMATION OF BLADDER WEIGHT AS A MEASURE OF BLADDER HYPERTROPHY IN MEN WITH INFRAVESICAL OBSTRUCTION - A PRELIMINARY-REPORT

The aim of the present study was to evaluate the usefulness of ultraso nic estimation oi bladder weight as a measure of bladder hypertrophy u sing transabdominal ultrasonography in men with infravesical obstructi on. Ultrasonically estimated bladder weight (UEBW) was calculated from the thickness of the bladder wall measured ultrasonically and the int ravesical volume at the ultrasonic measurement, assuming a spheric bla dder. There was a statistically significant correlation (r = 0.970, P < 0.0001) between the actual bladder weight of cadaver bladders and th e UEBW. The UEBW did not change with bladder filling. The UEBW in the obstructed group (group 0, 49.7 +/- 19.5 g, mean +/- SD) was significa ntly greater than that in the normal control group (group NC, 25.6 +/- 5.7 g; P < 0.0001) or the nonobstructed group (group NO, 28.4 +/- 4.2 g; P < 0.0001). The greatest UEBW was 34.8 g in group NC and 35.2 g i n group NO, whereas 94% (45 of 48) of group O had a UEBW greater than 35.0 g. In all 5 patients with benign prostatic hyperplasia (BPH), the increased UEBW decreased to a normal control level at 3 months after treatment for BPH. This new noninvasive method may be useful in invest igations of bladder hypertrophy.