Urethral failure is not the predominant cause of female stress urinary incontinence

Bladder neck funneling in stress incontinence is mediated by posterior muscle forces, not abdominal pressure

“…The interpretation is from Dr Bergstrom: "This video demonstrates how the Pabd presses down the suburethral vaginal wall and how the lower bladder is drawn/tented." 1 The Bergstrom description does not fit the movement of structures observed in Figure 1, which is consistent with previous ultrasound descriptions of active opening. 2 Like Figure 1, the transperineal ultrasound study 2 showed normal urethrovesical anatomy at rest, backward/downward stretching of both vaginal walls and bladder based on straining, with concomitant opening out (funneling) of the bladder neck.…”

“…According to the UHT, 1 The explanation for maximal urine flow at very low, even zero detrusor pressure, arrow, red line, Figure 2, was explained by Griffiths 5 and Bush et al 6,7 If the urethral diameter can be opened out sufficiently, urine can be expelled with no recorded detrusor pressure; the detrusor's contractile energy is converted to flow. [5][6][7] The high flow and low pressure recorded in Figure 2 confirm this explanation.…”

“…To the Editor, Dr. Bergstrom's articles on the UHT are important. They have caused a re-evaluation of stress urinary incontinence (SUI) mechanisms, including UHT, 1 which is the purpose of this letter. The UHT hypothesizes that a ruptured pubourethral ligament (PUL) allows the increased intrabdominal pressure on effort to forcibly push open the posterior bladder wall during effort, so urine is lost.…”

“…The UHT hypothesizes that a ruptured pubourethral ligament (PUL) allows the increased intrabdominal pressure on effort to forcibly push open the posterior bladder wall during effort, so urine is lost. 1 For proof, Dr Bergstrom places much emphasis on a VIDEO by Sydney Pelvic Floor Health. https://www.youtube.com/watch?v=WLAQ1PLU2ao.…”

Reply to Bladder neck funneling in stress incontinence is mediated by posterior muscle forces, not abdominal pressure

“…According to UHT, during stress, the suburethral vaginal wall is pressed down by the increased Pabd to a greater extent than the vaginal wall supporting the BN, causing the proximal urethra to break against (hang on) the less mobile BN and is pulled open and funneled. The Pabd is fully (100%) "transmitted" to the proximal urethra (Pascal's law of hydrostatics), although this is counterbalanced by the pulling force (Fs) and the outflow distension force (Fd) 3,4 (Figure 1). Leakage of urine occurs when funneling engages the high pressure zone of the urethra.…”