0022-5347/98/1604-1459$03.00/0 zyxwvutsrqp THE zyxwvutsrqponm JDIJRNAL OF UROLOGY zyxwvutsrqpo Copyright zyxwvutsrqponm 0 1998 by AMERICAN UROLOGICAL ASSOCIATION, INC Vol. 160, 1459-1462, October 1998 z Printed in U.S.A. NONINVASIW EVALUATION OF BLADDER COMPLIANCE IN CHILDREN USING ULTRASOUND ESTIMATED BLADDER WEIGHT OSAMU UKIMURA,* MLJNEKADO KOJIMA, EM1 INUI, ATSUSHI OCHIAI, YOSHIO NAYA, AKIHIRO KAWAUCHI AND HIROKI WATANABE From the Department of zyxwvut Urology, Kyoto Prefectural University zyxwv of Medicine, Kyoto, Japan ABSTRACT Purpose: In healthy children as well as those with urinary disturbance we determined ultra- sound estimated bladder weight with the aim of revealing its possible usefulness as a measure of bladder compliance. Materials and Methods: We measured ultrasound estimated bladder weight in 71 healthy children with a mean age of 10.3 years, and determined a standard value. A total of 82 patients with a mean age of 9.6 years with urinary disturbance also underwent ultrasound estimated bladder weight measurement as well as conventional urological examinations, including filling cystometry. Results: In healthy children ultrasound estimated bladder weight increased with age, showing a significant linear correlation (r = 0.80, p <O.OOOl). Using the formula for linear correlation, 0.86 x patient age + 6.9 gm., we obtained an age matched estimated weight. In 82 patients the percent deviation of the estimate from age matched values was calculated using the formula, (measured ultrasound estimated bladder weight -age matched ultrasound estimated bladder weight)/age matched ultrasound estimated bladder weight x 100, and then correlated with bladder compliance. In 75 of 77 patients (97%) with compliance of 10 ml./cm. water or more the estimate was within 100% deviation. In contrast, 4 of 5 patients (80%) with a low compliant bladder (less than 10 ml./cm. water) had an ultrasound estimated bladder weight greater than 100% deviation. When the estimate was within 100% deviation, all but 1 patient (75 of 76,98.7%) had compliance of 10 ml./cm. water or more compared to 33.3% (2 of 6) of those with an estimate greater than 100% deviation. As a result, with the use of a cutoff value of 100% deviation ultrasound estimated bladder weight predicted a low compliant bladder with a diagnostic accuracy as high as 96.3% (79 of 82 cases). Conclusions: Ultrasound estimated bladder weight may be used to evaluate bladder compli- ance in children. It seems to be a suitable noninvasive urodynamic test in children with suspected urodynamic abnormalities. KEY WORDS: bladder, ultrasonography,urodynamics We recently developed measurement of ultrasound esti- mated bladder weight with the aim of evaluating bladder hypertrophy noninvasively and quantitatively.' Our studies demonstrate that this value potentially represents the de- gree of bladder hypertrophy due to infravesical obstruc- tion2-4 or neurogenic bladder dysfunction.5 In our previous study comparing ultrasound estimated bladder weight with bladder compliance in adults with neurogenic bladder dys- function the estimate proved to increase significantly with aggravated compliance.5 These results prompted us to meas- ure ultrasound estimated bladder weight in children with suspected bladder dysfunction. In this study we determined ultrasound estimated bladder weight in healthy children as well as in those with urinary disturbance with the aim of (evaluating its possible usefulness as a reliable measurement lof bladder compliance. MATERIALS AND METHODS boys and 20 girls. Urinary disturbance in the latter children consisted of a weak stream, dribbling, pollakiuria, urgency, incontinence and bed-wetting. In all 153 children body height and weight were recorded. The 82 patients underwent con- ventional urological examinations, including cystometry. Ultrasound estimated bladder weight was measured ac- cording to the method reported previously (fig. 1l.I Briefly transabdominal ultrasound was performed with the child supine using a 7.5 MHz. PLF-703ST probe.? Using sagittal t Toshiba, Tokyo, Japan. 3 BV=TV - zyx IV UEBW=BV zyx x Specific gravity (1.0) F ~ ~ , 1. Calculation of ultrasound estinated bladder weight (UEBW) using ultrasound measurement of bladder wall thickness (7') and intravesical volume (N). ID, inner diameter. OD, outer diameter. zyxwvu W, total vesical volume. BV, bladder wall volume. Between January 1995 and August 1997 ultrasound esti- mated bladder weight was measured in 71 healthy children 3 to 19 years old (mean age 10.3), including 40 boys and 31 girls. It was also determined in 82 children with urinary disturbance 1 to 19 years old (mean age 9.61, 62 Accepted for publication May 1, 1998. * Requests for reprints: Department of Urology, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602, Japan. 1459