前立腺肥大症における排尿障害の水力学的研究

Abstract

In order to investigate vesical function and processes of voiding in normal adults and in a cases of benign prostatic hyperplasia, the following study was conducted. The measurement of the urethral resistance in uroflowmetric study is known as the "Pressure Flow Study" in our department. This research was conducted on 20 healthy adult males and 103 benign prostatic hyperplasia subjects. A) Healthy adult male subjects. 1. Maximum intravesical voiding pressures were influenced during voiding by body positions. The pressures obtained in the standing position were highest and those in the sitting position were slightly diminished while those in the prone position were found to be lowest. It was found that the volume (capacity of the bladder) had no relationship to the maximum iniravesical pressure. 2. Flow rate was not found to be significantly different in standing or sitting positions. However, the volume was found to have a marked influence on the flow rate. It was found that in normal subject the flow rates were diminished with decreased volume. 3. Urethral resistance was not found to be influenced by position on voiding. Increase of volume resulted in decrease of urethral resistance. From the above results obtained, uroflowmetric study, namely "Pressure Flow Study", was then performed only in standing position and with maximum volume. B) Benign prostatic hyperplasia subjects. 1. Results from "Pressure Flow Study" in 103 benign prostatic hyperplasia cases were statistically analyzed with regards to urethral resistance, residual rate, volume, sizes of prostates. 2. In view of the statistical findings, 6 categories of grade of benign prostatic hyperplasia were proposed and the progression of this disease was discussed. In brief, during early stages the voiding pressure remains normal but the flow rate decreases; whereas in later stages residual urine occurs. In more advanced stages voiding pressure increases and residual urine diminishes. In later stages bladder pressure increases but flow rate becomes impaired and residual urine occurs again. These conditions become more severe throughout the course of disease, and finally result in total retention of urine.