Abstract
Urodynamics were studied in one group of boys with definite infravesical obstruction and in another group with various other disorders of the lower urinary tract. They were compared with a group of normal cases and a control group without infravesical obstruction. In the group with a priori definite infravesical obstruction, opening pressure, maximum voiding pressure and peak-flow pressure relatively often fell outside the 2 standard deviations of the control group. As regards other pressure variables, there was a high degree of overlap between normal and abnormal micturition. In individual patients combinations of normal pressure/decreased flow were observed. Bladder pressure measurement alone provides only a limited basis for evaluation. Boys with lesions of the lower urinary tract use abdominal straining to a much greater extent than normal boys, but apparently with little improvement in bladder emptying. Maximum flow in all patients with a priori definite infravesical obstruction fell outside the lower normal limit. All these cases had increased minimum urethral resistance. In a number of patients with a priori doubtful infravesical obstruction normal maximum flow was combined with slightly increased intravesical pressure. Estimation of maximum flow and evaluation of the flow curve would appear to constitute a suitable method for urodynamic screening. The various micturition patterns in different diagnostic groups are exemplified. The method employed provides valuable diagnostic information.