小児の排尿機構に関する研究

第1報: 超音波 Doppler 式流量計による尿流量, 尿流速の研究

抄録

Simultaneous measurements of the voiding factors: vesical pressure, urethral pressure, intraabdominal pressure, tone of anal sphincter, E. M. G. of anal sphincter including external urethral sphincter partially and flow rate or velocity were made by using a six channel polygraph. The values of measurement and patterns of voiding factors were analyzed and their correlation was studied to make clear characteristics of the voiding mechanism of normal status and obstructive diseases.
This report centers about the urinary flow rate in many voiding factors. Ultrasonic Doppler flowmeter is used for the measurement of urinary flow rate. The principle, structure of the flowmeter (Fig. 2-1, 2-2), the conditions of measuring technique (Fig. 4), the method of calibration (Fig. 6, 7, 8, 10), the limit of this method due to the error of measurement (Fig. 11) and the parameters which could be determined by this method (Fig. 12) were discussed.
It was concluded that this apparatus was probably useful to measure the urinary flow rate and velocity nonobstructively.
Fourteen parameters were taken from the relation between the urinary flow rate and vesical pressure.
Based on those, the correlation by T-test between normal boys and girls, high and low voiding voumes, normal and abnormal subjects with lower urinary tract obstructive disorder including neurogenic bladder were investigated.
The result
1) The correlation between normal boys and girls.
It was found that the effect of vesical pressure was immediately refected on urinary flow rate in girls. It was suggested that it is due to the specific anatomical and functional characters of the urethra in girls.
2) The correlation between normal and disordered subjects in lower urinary tract.
It was known that the energy, which was lost at the lower urinary tract in the latter, was extremely large. The average energy loss was in the order of neurogenic bladder, congenital bladder neck obstruction and urethral hypertonia.
When the paper speed was kept constant, the urinary flow rate curve appeared as below (Fig. 13, 14, 15, 16).
Normal subject: bell type wave
Stenosis of external urethral meatus: spike wave
Urethral hypertonia: Plateau wave or plateau and spike wave
Congenital bladder neck obstruction: plateau wave or plateau and spike wave
Neurogenic bladder:
Brain bladder: bell or plateau wave
Cord bladder:
Automatic type: hill type and spike wave
Autonomous type: intermittent serrated wave
The waves are changeable under the influence of urine output and catheters for vesical and urehtral pressure measurements. The classification according to the patterns is also only a supplementary method.