Thüroff J W, Casper F, Heidler H
Urol Int. 1987;42(3):185-9. doi: 10.1159/000281892.
There is still controversy regarding the active role of striated intramural and periurethral muscles and their relative share of function for urinary continence under stress conditions. To evaluate the function of the periurethral muscles, we subjected a dog model to the physiologic stress condition created by sneezing. Simultaneous measurements of intravesical and three urethral pressures were obtained in the intact urinary tract and in a noncontractile substitute urethra, which was pulled through the pelvic floor and studied with and without additional pelvic floor suspension. The data clearly confirm the active role of striated sphincteric muscles for continence under stress conditions. The reflex contraction of the striated sphincteric muscles constitutes the majority of the distal urethral closure mechanism under stress conditions and generates intraurethral pressures, which exceed those of passive transmission of intra-abdominal pressure. The intramural striated sphincter contributes a share of less than 10% to this stress response, while the vast majority of the pressure rise is generated by the periurethral striated muscles. Surgical suspension of the pelvic floor can enhance effectivity of this stress mechanism, and thus seems to be a sound physiological concept in surgical treatment of incontinence.
关于横纹肌壁内肌和尿道周围肌在应激状态下对尿失禁控制的积极作用及其相对功能份额仍存在争议。为了评估尿道周围肌的功能，我们使犬模型处于由打喷嚏产生的生理应激状态。在完整尿路和非收缩性替代尿道中同时测量膀胱内压和三个尿道压力，该替代尿道穿过盆底，并在有无额外盆底悬吊的情况下进行研究。数据清楚地证实了横纹括约肌在应激状态下对控尿的积极作用。横纹括约肌的反射性收缩构成了应激状态下尿道远端闭合机制的主要部分，并产生超过腹内压被动传导的尿道内压。壁内横纹括约肌对这种应激反应的贡献不到10%，而绝大多数压力升高是由尿道周围横纹肌产生的。盆底手术悬吊可增强这种应激机制的有效性，因此似乎是尿失禁手术治疗中一个合理的生理概念。
