[The role of voiding cysto-urethrography (VCU) in urological practice (author's transl)].

The role of VCU in the management of various urological conditions was discussed after retrospectively analyzing 197 voiding cysto-urethrograms performed on 167 cases. 1) The normal voiding is initiated when the base plate breaks open by virtue of its own contraction and continues smoothly while detrusor contraction follows toward the trigonal canal which is progressively transformed from the base plate. 2) In vesical neck contracure, inadequate contraction of the base plate presents a poor opening of the internal urethral orifice. 3) In benign prostatic hypertrophy, the base plate is distorted by the enlarged prostatic adenoma so that the dynamic of the internal urethral orifice is evaluated poorly from VCU. Meanwhile postoperative VCU offers an excellent diagnostic tool to obtain various informations as regards both anatomical and functional status of prostatic urethra. 4) In mechanical obstruction of both anterior and posterior urethra, i. e. either stricture or valve, it is an indispensable diagnostic method to obtain both anatomical and physiological features of the obstruction. 5) VCU is a must examination for the management of ureteral reflux. When it is used in combination with various urodynamic examinations, an improved pathophysiological understanding of the lower urinary tract and uretero-vesical junction is possible. 6) Because of the high incidence of both falsely negative and falsely positive diagnosis of distal urethral stenosis (DUS), the cysto-urethrographic diagnosis of DUS must be conjoined with careful calibration of the distal urethral segment. 7) The patients with infrequent voiding habit show atomically capaceous bladder which contracts poorly on voiding. The role will be expanded when it is performed as an adjunctive diagnostic method with other endoscopic and urodynamic examinations, frequently referring to the basic anatomy and physiology of the lower. urinary tract.