Observations with electrocystography

Urinary flow in healthy schoolchildren

The urinary free flow in 180 healthy schoolchildren aged 7-16 years was examined with a new kind of uroflowmeter. The examinations were performed at ordinary school toilets and each child presented at least two registrations. Besides the shape of the flow curve, the urinary flow was evaluated by the parameters voided volume, maximum flow rate, average flow rate, flow at 1 second and at 0.5 seconds, time to maximum flow, and voiding time. All parameters were related to sex, age, and body parameters. Two recorded micturitions are considered a minimum to obtain a reliable assessment of the urinary flow curve of a child and the shape of the curve is the most important factor to analyse. The normal flow curve is "bell-shaped" regardless of sex, age, and voided volume, and the urine is emptied in one portion. At the first micturition, more curves are irregular and flow rates are significantly lower than at the second one. Voided volume, maximum flow rate, average flow rate, time to maximum flow, and voiding time increase weakly but significantly with age and body parameters. Maximum flow rate, average flow rate, and the flow at 1 second are significantly higher for girls and are correlated to each other. All examined flow parameters except the flow at 0.5 seconds are significantly correlated to voided volume. The results differ from previous studies of children by larger voided volumes, shorter voiding time and time to maximum flow and by higher values for maximum flow rate, average flow rate, and flow at 1 second.

Urorectodynamic evaluation of healthy volunteers

Twelve female and 8 male healthy volunteers underwent urorectodynamic evaluation. Mean bladder capacity was 594 ml. and mean maximal vesical pressure 12.5 cm. water (H2O). Maximal bladder pressure correlated significantly with maximal mural tension (r = 0.96) but did not correlate well with bladder capacity (r = 0.20). Mean bladder volume at first desire to void was 32 per cent of mean bladder capacity. The bladder volume at the first desire did not correlate significantly with the capacity. Mean bladder pressure at 100 ml. volume was 2.9 +/- 0.4 cm. H2O (X +/- SEM). After bethanechol injection, the bladder pressure at 100 ml. volume increased by 8.8 +/- 1.2 cm. H2O (X +/- SEM) at twenty minutes. In only 1 subject did bladder pressure rise higher than 15 cm. H2O (5 per cent). Rectal pressure increased from 1.4 +/- 0.3 to 14.1 +/- 2 cm. H2O (X +/- SEM) at sixteen minutes. Electromyogram (EMG) of the external and sphincter did not follow regular pattern with vesical filling or attempt of voiding. The data obtained in these normal subjects may serve as a basis for comparison in the interpretation of data obtained in patients.

Urodynamic studies in boys with disorders of the lower urinary tract. IV. Congenital bladder neck obstruction. A pre- and postoperative study

Eighteen boys with diagnose of bladder neck obstruction, based on roentgenological criteria, underwent urodynamic investigations. In the majority of patients, urodynamics clearly deviated from the normal range, substantiating that bladder neck obstruction, although rare, really exists in male infants and children. A rather uniform radiographic appearance of the bladder neck was associated with different urodynamic patterns, suggesting that various pathophysiological mechanisms may be involved.

Urodynamic studies in boys with disorders of the lower urinary tract. I. Urethral strictures. A pre-and postoperative study

Sixteen boys with urethral strictures underwent urodynamic investigation pre- and postoperatively. The intravesical pressure preoperatively showed wide variations during micturition and was increased in only half of the patients. The urinary flow pre-operatively displayed a uniform picture with a decreased maximum flow in all the patients, plateau-formation and slow initiation of the flow curve. The maximum exit velocity of the urinary stream was decreased and the urethral energy losses were very high. After treatment, the out-flow situation was generally improved, but restored to normal only in some cases. Patients with short strictures showed the highest degree of urethral obstruction, but they also seemed to have the best prognosis, some of them even reaching supernormal flows. Flow measurement alone is recommended in the long-term follow-u, which is necessary in these patients. After-contraction was not present in any of the patients pre-operatively, blt occurred in about half of them postoperatively. This and some other findings may indicate the existence of functional changes in the bladder neck in patients with urethral stricture. On case with partial detrusor muscle insufficiency is reported.