下部尿路の尿流動態研究

Abstract

A silicone gel prosthesis, reported by Kaufman in 1973 for the urinary anti-incontinence operation, has been implanted in 3 patients.Case 1: An 8-year-old boy complained of continuous dribbling of urine owing to congenital malformation of the external sphincter. The postoperative distension of prosthesis following the implantation was performed in 2 occasions with 7 ml of contrast medium. The maximum urethral pressure is presently 52mmHg and the result is good.Case 2: A 27-year-old man with a traumatic urethral rupture. The silicone gel prosthesis was implanted after transurethral resection of massive fibrosis at the posterior and bulbous urethra. The postoperative infusion of 8ml contrast medium failed to increase the maximum urethral pressure above 30mmHg. A penile clamp is necessitated; poor result.Case 3: A 42-year-old man with a traumatic urethral rupture. The sling operation at the anterior urethra was previously attempted in vain using the fascia of rectus muscle. The postoperative distension of prosthesis with 10ml of contrast medium following the implantation was not sufficient to prevent the incontinence completely. The amplitude of the maximum urethral pressure remained at 28mmHg; poor result.While the immediate postoperative results were excellent in all cases, the compression effect started to deteriorate in about one week after operation. The fall of compression strength had to be compensated by the infusion of contrast medium up to 10ml. It is speculated that the dissipation of local edema and/or elongation of ischiocavernosus muscle and Dacron-velour straps are responsible for this change. The present results, 8 to 20 months later, are 1 good and 2 poor.A thorough urodynamic investigation on the lower urinary tract should be considered for all patients before and after the operation. The urethral pressure profilometry is quite of use to evaluate both the remaining urethral sphincter function preoperatively and the strength of urethral compression attained by prosthesis postoperatively. A patient who has shown the fibrotic degeneration at the site of bulbous urethra cannot be a candidate for this operation, since the scar tissue with a high elastic constant prevents the urethral lumen to be occluded completely with this prosthesis. Urinary flowmetry and urethrocystography are also of value to investigate the functional and organic alterations caused by the implantation of prosthesis.