DeLancey J O
Department of Obstetrics and Gynecology, University of Michigan Medical School, Ann Arbor 48109-0718.
Ciba Found Symp. 1990;151:57-69; discussion 69-76. doi: 10.1007/978-1-84628-505-9_1.
Stress continence depends upon three factors: proximal urethral support, vesical neck closure, and urethral contractility. The position of the vesical neck is not static but mobile and under voluntary control. Its support depends upon connections of the urethrovaginal endopelvic fascia to the medial aspect of the levator ani. In addition, these fasciae are attached to the arcus tendineus fasciae pelvis which supports the urethra during levator relaxation, and probably during stress. Levator contraction supports the proximal urethra and also pulls the vesical neck anteriorly against a band of endopelvic fascia which is suspended between the arcus tendinei, compressing it closed. Relaxation of the muscles allows the vesical neck to descend, and facilitates its opening. The connective tissue and smooth muscle of the trigonal ring encircles the vesical neck's lumen, and may contribute to closure of this area. The striated urogenital sphincter muscle can contract to assist in maintaining continence in continent women whose vesical neck is not competent. It has a circular sphincteric portion from 20 to 60% of urethral length. From 60 to 80% it has a considerable bulk of muscle which forms an arch at the perineal membrane that would compress the urethra from above.
近端尿道支撑、膀胱颈闭合和尿道收缩力。膀胱颈的位置并非固定不变，而是可移动的，且受自主控制。其支撑取决于尿道阴道盆内筋膜与肛提肌内侧的连接。此外，这些筋膜附着于盆筋膜腱弓，在肛提肌松弛时，可能在压力状态下也能支撑尿道。肛提肌收缩可支撑近端尿道，并将膀胱颈向前牵拉，使其抵住悬吊于耻骨弓状韧带之间的盆内筋膜带，从而将其压缩闭合。肌肉松弛时，膀胱颈下降，便于其开放。三角环的结缔组织和平滑肌环绕膀胱颈管腔，可能有助于该区域的闭合。在膀胱颈功能不全的控尿女性中，横纹肌性尿道括约肌可收缩以协助维持尿失禁。它有一个环形括约肌部分，长度占尿道的20%至60%。在60%至80%的长度范围内，它有相当大量的肌肉，在会阴膜处形成一个弓形，可从上方压迫尿道。
