Figure 1 How the hemostat test mimics normal control of SUI.
Upper figure A firm pubourethral (PUL) attaches to the lateral part of urethra, pubococcygeus muscle (PCM) and vagina [6]. It prevents the posterior reflex closure forces LP (levator plate) and conjoint longitudinal muscle of the anus (LMA) acting on the trigone to pull open the posterior urethra during effort [5]. Likewise, in SUI women, transverse and retropubic tapes create new collagen below the midurethra to prevent elongation of a loose or weakened PUL during effort.
Normal urethral closure Three reflex directional muscles forces close urethra: pubococcygeus (PCM) contracts forwards against PUL to close distal urethra; levator plate (LP), contracts backwards to tension PUL, and to stretch bladder base and trigone backwards for LMA (conjoint longitudinal muscle of the anus), to pull the anterior tip of LP downwards https://www.youtube.com/watch?v=3vJx2OvUYe0
This downward action rotates bladder base around PUL and pubovesical insertion into the arc of Gilvernet (not shown) to close urethra at bladder neck [5].
Stress urinary incontinence If PUL is weak or loose, it cannot sustain the powerful posterior forces LP/LMA on effort; it lengthens, the anterior vaginal and trigone are pulled downwards; urethra is opened from “C” closed to “O” open; urine is lost on effort [5]. The hemostat mechanically supports PUL, prevents lengthening and controls SUI, as in the VIDEO and right ultrasound frame.
Lower figure The ultrasound figures show typical geometry of SUI caused by loose PUL [9]. Left frame : REST. Urethra closed. Structures in normal anatomical position, S=symphysis;U=urethra; B=bladder; “a”& “p” = anterior and posterior walls of vagina; red broken lines mark a whitish continuum which represents distal ligamentous support of the urethra from EUL=external urethral ligament to the yellow dots which mark another thickening, the pubourethral ligament . Middle frame : STRAINING. Pubourethral ligament (yellow dots) lengthens and cannot sustain the posterior forces acting on the anterior (“a’) and posterior (“p”) walls of the vagina are tensioned and pulled backwards/downwards. The urethra is opened along its length; urine is lost on effort. Right frame ; MID/UR ANCHOR A hemostat placed at midurethra as in the video mechanically supports PUL (yellow dots), prevents lengthening and restores continence, as in VIDEO1.