A new modified catheter for voiding cystourethrography.

We made a new modified catheter for voiding cystourethrography to evaluate the function of the external urethral sphincter. Using this catheter, we can evaluate it precisely, excluding the influences of the posterior urethra. The findings of voiding cystourethrography observed by using this catheter were equal to the findings of the simultaneous recording of cystourethrogram and external urethral sphincter electromyogram, and permitted us to assess the function of each portion of the urethra separately, such as the sphincteric urethra (prostatic urethra) and external urethral sphincter (membranous urethra). In addition, this urodynamic procedure can be performed safely and easily.