A comparison of periurethral blood flow resistive indices and urethral closure pressure of incontinent women

Abstract

This study correlated Doppler resistive indices (RIs) with maximum urethral closure pressures (MUCPs) in women with stress urinary incontinence. We hypothesized that urethral blood flow would be inversely correlated to urethral closure pressures. Fifty-three women underwent spectral Doppler waveform analyses of periurethral vasculature to calculate RI. Urethral morphology including pubovesicular length (PVL) with and without cough was measured. MUCPs were obtained according to International Continence Society guidelines. Physical exam and history were also obtained. Correlation coefficients were calculated for comparisons of Doppler measurements and closure pressures. Fifty patients were required to detect a difference between no correlation and a modest correlation of 0.38 with 80% power and alpha of 0.05. Significance is set at p<0.05. Measurements were reproducible between Doppler waveforms and MUCP measurements (all p=NS). RI was not correlated with age, parity, MUCP, Incontinence Impact Questionnaire-7 scores, urethral length, or urethral width (all p=NS). RI and MUCP were likewise not associated with history of diabetes, hypertension, or anterior vaginal prolapse to or beyond the hymen (all p=NS). MUCP was negatively correlated with age (r=-0.33, p=0.01) even when controlled for hormonal status (ANCOVA, p=0.003) and positively correlated with urethral/bladder neck diameter (r=27, p=0.05), PVL (r=0.30, p=0.03), and PVL with cough (r=0.36, p=0.009).

Combined estrogen and ghrelin administration restores number of blood vessels and collagen type I/III ratio in the urethral and anal canal submucosa of old ovariectomized rats

“…Hence, decreased collagen I/III ratio is associated with reduced urethral and anal canal closure function [7,[13][14][15]. Both estrogen deficiency and ageing independently and negatively influences the submucosal urethral and anal canal blood vessel counts and collagen I/III ratio in anatomical, experimental and clinical studies, similar to our findings [4,11,12,14,15]. In fact, ghrelin and its receptor are expressed in human microvascular endothelial cells and rat osteoblasts where ghrelin stimulates endothelial cell proliferation, migration, and angiogenesis as well as osteoblastic synthesis of collagen type I, as seen in this study [19,20].…”

“…We have previously reported that estrogen and ghrelin administration, separately or in combination, in middleaged ovariectomized Wistar rats significantly reversed the ovariectomy-induced decrease in submucosal urethral and anal canal vessel counts [11]. This is an important mechanism of urinary and fecal control in women [11,12]. We did not, however, compare the effect of both hormones on postovariectomy vessel number in old as opposed to young adult rats.…”

“…It is possible, therefore, that the ageing process in women accelerates the chronobiological effects of estrogen deficiency on the urinary and/or fecal continence mechanisms after menopause similar to cognitive function [22,23]. The number of submucosal vessels is an important component of, and is directly related to, intrinsic urethral and anal canal sphincteric function maintaining positive closure pressure and continence in women [4,11,12]. Changes in types I to III collagen ratio correlate with changes in the mechanical properties because type I is more rigid while type III contributes more to elastic properties [13].…”

Role of Puborectalis Muscle in the Genesis of Urethral Pressure

“…However, a Doppler blood flow study recorded the blood flow resistive index as well as MUCP in female patients and concluded that blood flow resistive index did not correlate with closure pressure or subjective complaints of incontinence. 29 The UP profile in human studies is measured using a water perfused side hole or solid-state microtip transducer that is pulled across the urethra at a constant speed. The UP profile is a bell-shaped curve with peak pressure, also called MUCP, located in the middle of the urethra.…”

Vascularity of the urethra in continent women using colour doppler high-frequency endovaginal ultrasonography

“…However, some studies performed with the use of spectral doppler in TPUS assessment of the urethral vascularity in incontinent multiparous have shown contradictory results i.e. RI was not correlated with parity (Hall et al 2006). In the study by Siracusano et al (Siracusano et al 2001) colour doppler ultrasound of the female urethra in normal fertile young women identified a significantly greater RI in the proximal urethra compared to the middle and distal urethra.…”