Hiroki Watanabe

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 ultrasonic estimation of bladder weight as a measure of bladder hypertrophy using transabdominal ultrasonography in men with infravesical obstruction. Ultrasonically estimated bladder weight (UEBW) was calculated from the thickness of the bladder wall measured ultrasonically and the intravesical volume at the ultrasonic measurement, assuming a spheric bladder. There was a statistically significant correlation (r = 0.970, P <0.001) between the actual bladder weight of cadaver bladders and the UEBW. The UEBW did not change with bladder filling. The UEBW in the obstructed group (group O, 49.7 +/- 19.5 g, mean +/- SD) was significantly greater than that in the normal control group (group NC, 25.6 +/- 5.7 g; P <0.001) or the nonobstructed group (group NO, 28.4 +/- 4.2 g; P <0.001). The greatest UEBW was 34.8 g in group NC and 35.2 g in 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 of BPH. This new noninvasive method may be useful in investigation of bladder hypertrophy.

Noninvasive Quantitative Estimation of Infravesical Obstruction Using Ultrasonic Measurement of Bladder Weight

PURPOSE Ultrasound estimated bladder weight was compared to pressure-flow studies to test the ability of ultrasound estimated bladder weight to predict infravesical obstruction. MATERIALS AND METHODS A total of 65 men with urinary symptoms underwent ultrasonic measurement of bladder weight and pressure-flow studies. Assuming the bladder is a sphere, ultrasound estimated bladder weight was calculated from bladder wall thickness measured ultrasonically and intravesical volume. RESULTS Ultrasound estimated bladder weight correlated significantly (p < 0.0001) with the Abrams-Griffiths number, urethral resistance factor and the Schäfer grade of obstruction. A cutoff value of 35 gm. for ultrasound estimated bladder weight revealed a diagnostic accuracy of 86.2% (56 of 65 cases) for infravesical obstruction with 12.1 (4 of 33) and 15.6% (5 of 32) false-positive and false-negative rates, respectively. CONCLUSIONS Ultrasound estimated bladder weight can be measured noninvasively at the bedside and it is promising as a reliable predictor of infravesical obstruction.

Preoperative Evaluation of Localized Prostatic Carcinoma by Transrectal Ultrasonography

We evaluated 31 patients with clinically localized prostatic carcinoma by transrectal ultrasonography before radical prostatectomy. Results of ultrasonography were reviewed without previous knowledge of the extent of the disease and were compared to the pathological staging obtained by step section of the prostate. Preoperative transrectal ultrasonography was sensitive in detecting capsular and seminal vesicle involvement (89 and 100 per cent, respectively). However, the specificity of the method was low for capsular involvement (50 per cent), probably owing to the inability of this method to detect microscopic disease. This method is a valuable tool in the preoperative evaluation of patients with clinically localized prostatic carcinoma.

Reversible Change of Bladder Hypertrophy Due to Benign Prostatic Hyperplasia After Surgical Relief of Obstruction

PURPOSE Ultrasound estimated bladder weight was compared before and after surgery for benign prostatic hyperplasia (BPH) to reveal a possible reversible change in bladder hypertrophy. MATERIALS AND METHODS Ultrasound estimated bladder weight was measured before and after subcapsular (17) or transurethral (16) prostatectomy in 33 male patients with BPH. Sequential changes in the American Urological Association symptom score and urinary flow rate were also examined. RESULTS Along with a significant improvement in the American Urological Association symptom scores and maximum flow rate, ultrasound estimated bladder weight decreased from 52.9 +/- 22.6 to 31.6 +/- 15.8 gm. in 12 weeks after treatment. In all but 4 patients (29 of 33, or 87.9%) ultrasound estimated bladder weight decreased to less than 35.0 gm. in 12 weeks after treatment. Interestingly, in all patients with an initial ultrasound estimated bladder weight of greater than 80 gm. the bladder weight still remained at an abnormally high level 12 weeks after treatment. CONCLUSIONS Bladder hypertrophy was completely reversible after the surgical treatment of the obstruction in the majority of patients with BPH. The measurement of ultrasound estimated bladder weight was of value in monitoring therapeutic effects in BPH patients. An extraordinarily high ultrasound estimated bladder weight of 80 gm. or more might suggest degenerative and irreversible pathological changes in the bladder detrusor.

Preliminary results of power Doppler imaging in benign prostatic hyperplasia

Power Doppler imaging was performed in 77 patients with lower urinary tract symptoms to characterize Doppler blood-flow signals in benign prostatic hyperplasia (BPH). Pulsatile blood flows were detected in all patients, demonstrating a significant increase of the resistive index (RI) in BPH cases (n = 40, 0.72 +/- 0.05, p < 0.0001), compared to those with a healthy prostate (n = 37, 0.64 +/- 0.04). Of 40 patients with BPH, 28 (70%) had an RI of 0.70 or higher; all but 1 patient with a healthy prostate (1 of 37, 3%) had an RI lower than 0.70 (p < 0.0001). In all 10 patients with BPH, the elevated RI decreased significantly to a normal control level after surgical treatment (0.72 +/- 0.02 vs. 0.64 +/- 0.05, p < 0.001). In conclusion, Doppler RI might be useful as a new urodynamic parameter in BPH.

Absorption of anticancer drugs through bladder epithelium.

Fundamental and clinical evaluations of ten anticancer drugs were performed. The required qualities of an anticancer drug ideal for bladder instillation therapy are thought to be as follows: (1) a high sensitivity for bladder tumor cells; (2) a pKa which provides a high percentage of nonionized molecules in a pH 6-7 solution; (3) a log P in the range from -0.4 to -1.2 or from -7.5 to -8.0; and (4) a molecular weight over 200.

Correlation of presumed circle area ratio with infravesical obstruction in men with lower urinary tract symptoms.

OBJECTIVES To examine the predictive value of ultrasonic measurements obtained by transrectal ultrasonography for infravesical obstruction as evaluated by pressure flow studies. METHODS In 85 men with moderate to severe lower urinary tract symptoms, ultrasonic measurements including prostatic volume, transition zone volume, transition zone index (transition zone volume/prostatic volume), and presumed circle area ratio (PCAR) were compared with urodynamic parameters obtained by pressure flow studies. RESULTS There were significant interrelationships between these ultrasonic measurements, which were all significantly greater in the obstructed patients than in the unobstructed patients. A simple regression analysis demonstrated that prostatic volume (r = 0.362, P < 0.001), transition zone volume (r = 0.373, P < 0.0005), transition zone index (r = 0.331, P < 0.005), and PCAR (r = 0.487, P < 0.0001) correlated significantly with the Abrams-Griffiths number. More importantly, a multiple regression analysis demonstrated PCAR to be the only independent determinant of the Abrams-Griffiths number. A receiver operator characteristics curve analysis showed that 0.8 was the most suitable cutoff value of PCAR for the prediction of infravesical obstruction with a diagnostic accuracy of 76.5%. CONCLUSIONS PCAR is useful as a transrectal ultrasonic measurement in assessing the severity of infravesical obstruction in men with lower urinary tract symptoms.

Kinetic study of tumor blood flow in prostatic cancer using power doppler imaging

We examined the changes in tumor Doppler flow signals as well as prostatic volume in 11 cases of prostatic cancer, before and after castration, by using power Doppler imaging, and compared the changes in vascular resistance (RI) and prostatic volume (PV) in 11 cases. RI, except for one case, and PV decreased after castration in all cases without exception. In both, the manner of decrease showed an exponential curve. However, the reduction time of RI fell in an extremely narrow range compared with that of PV. Tumor vascular flow was influenced by castration, resulting in a decrease of RI. The dynamic change of vascular flow occurred earlier than that of PV. Analysis of changes in tumor blood flow signals could offer valuable information on early therapeutic effects in patients with prostatic cancer; however, it might not be a useful parameter for the prediction of prognosis.

The American Urological Association symptom index for benign prostatic hyperplasia as a function of age, volume and ultrasonic appearance of the prostate

PURPOSE Our study was conducted to reveal quantitatively the relative effects of age and ultrasonic appearance of benign prostatic hyperplasia (BPH) on urinary symptoms as evaluated by the American Urological Association (AUA) symptom index score. MATERIALS AND METHODS In 929 examinees (732 with a normal prostate and 197 with BPH) on a mass screening program for prostatic diseases using transrectal ultrasonography in Japan, the AUA symptom score was compared to age, prostatic volume and presumed circle area ratio using simple and multiple regression analyses. RESULTS Simple regression analysis demonstrated the symptom score to correlate significantly with age (R = 0.162, p < 0.0001), prostatic volume (R = 0.072, p = 0.0281) and presumed circle area ratio (R = 0.150, p < 0.0001). However, multiple regression analysis demonstrated that age and presumed circle area ratio were significant independent determinants of the total symptom score. Among 7 symptoms included in the AUA symptom index weak stream and hesitancy scores were not influenced by age, prostatic volume or presumed circle area ratio. CONCLUSIONS As a parameter representing the degree of BPH in terms of the severity of urinary symptoms, presumed circle area ratio was preferable to prostatic volume. Regression analyses confirmed again that the AUA symptom index was influenced considerably by age and was not specific to BPH.

A STATISTICAL STUDY OF THE AMERICAN UROLOGICAL ASSOCIATION SYMPTOM INDEX FOR BENIGN PROSTATIC HYPERPLASIA IN PARTICIPANTS OF MASS SCREENING PROGRAM FOR PROSTATIC DISEASES USING TRANSRECTAL SONOGRAPHY

PURPOSE A study was done on the prevalence of urinary symptoms in community based populations in Japan regarding the influences of aging and benign prostatic hyperplasia (BPH) as evaluated by transrectal sonography. MATERIALS AND METHODS In 961 Japanese men 55 to 87 years old who underwent mass screening for prostatic diseases the American Urological Association symptom index scores were compared with age and ultrasonic diagnosis of the prostate. RESULTS Moderate to severe symptoms (symptom score 8 or more) were found in 265 of our 961 samples (27.6%), while BPH was also recognized ultrasonically in 197 (20.5%). Frequencies of urinary symptoms and BPH increased significantly with age. BPH related increase in total symptom scores occurred only in select men when adjusted by age. CONCLUSIONS The ability of the American Urological Association symptom index to characterize BPH in an individual was limited because of the lack of specificity to the disease along with the considerable influence of aging on the symptom score. Currently, transrectal sonography is the most reliable method for the definitive diagnosis of BPH.