Maximum urethral closure pressure and sphincter volume in women with urinary retention

PURPOSE: In 1988 a syndrome of isolated urinary retention in young women that is associated with electromyographic abnormality of the striated urethral sphincter was described. It was hypothesised that urinary retention resulted from a failure of sphincter relaxation. The electromyographic abnormality causes overactivity of the muscle and may induce changes of work hypertrophy. If the hypothesis that the electromyographic abnormality is the cause of urinary retention is correct, we would expect the urethral sphincter to be enlarged and the urethral pressure profile to be increased in these women. We evaluated the role of static urethral pressure profilometry and transvaginal ultrasound in women in urinary retention. MATERIALS AND METHODS: A total of 66 women in complete or partial urinary retention underwent electromyography of the striated urethral sphincter using a concentric needle electrode, followed by urethral pressure profile and/or urethral sphincter volume measurement by transvaginal ultrasound. RESULTS: Maximum urethral closure pressure plus or minus standard deviation was significantly increased in patients with versus without the electromyographic abnormality (103 +/- 26.4 versus 76.7 +/- 18.4 cm. water, p <0.001). Maximum urethral sphincter volume was also increased in women with versus without the abnormality (2.29 +/- 0.64 versus 1.62 +/- 0.32 cm.3, p <0.001). CONCLUSIONS: The results of this study are consistent with the hypothesis that a local sphincter abnormality is the cause of urinary retention in a subgroup of women. Urethral pressure profilometry and sphincter volume measurement are useful for assessing these cases, especially when sphincter electromyography is not readily available.     

The tension-free vaginal tape in women with a non-hypermobile urethra and low maximum urethral closure pressure

The objective of this study was to estimate the cure rate and to identify risk factors that predict failure of the tension-free vaginal tape (TVT) in women with stress urinary incontinence (SUI), a non-hypermobile urethra, and low maximum urethral closure pressure. Thirty-six women with SUI, a non-hypermobile urethra (straining urethral angle ≤35°), and low maximum urethral closure pressure (MUCP ≤25 cm H₂O) underwent a TVT. Cure was defined as resolution of subjective SUI symptoms and a negative cough stress test, which were measured after 4, 12, 18, and 24 months. Patient characteristics were compared and receiver–operator curves were used to identify risk factors for failure. The mean age was 71 years, and mean follow-up was 20.9 months. The overall cure rate was 78%. Risk factors for failure of the TVT were a straining urethral angle ≤20° (cure rate 50%, odds ratio 7.7, p = 0.02) and a MUCP ≤15 cm H₂O (cure rate 60%, odds ratio 6.3, p = 0.03). For women with both risk factors, the cure rate was only 17% (p < 0.001). No other risk factors were identified. The TVT has moderate success (50-60%) for women with SUI and one risk factor (a straining urethral angle </=20 degrees or a MVCP </=15 cm H₂O), but has poor success (17%) when both risk factors are present. Presented at the annual meeting of the Society for Gynecologic Surgeons, Dallas, TX, March 5–7, 2002. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.     

Correlation between valsalva leak point pressure and maximal urethral closure pressure in women with stress urinary incontinence

This study analyzed the relationship between valsalva leak point pressure (VLPP) and maximal urethral closure pressure (MUCP) in women with stress urinary incontinence. One hundred sixty-one patients were selected with diagnosis of mixed or stress urinary incontinence. During urodynamics we measured VLPP and MUCP. Patients were gathered according to VLPP and analysis of variance (ANOVA) was performed. Pearsons correlation coefficient and linear regression were also utilized. The group with VLPP under 60 cm H₂O had mean MUCP of 44.5 cm H₂0; the group with VLPP between 60 and 90 cm H₂O had mean MUCP of 54.3 cm H₂O; and the group with VLPP over 90 cm H₂O had mean MUCP of 60.1 cm H₂O. We observed correlation between MUCP and VLPP when we used Pearsons correlation coefficient (r=0.22) and linear regression (p<0.05). There was weak correlation between MUCP and VLPP, and MUCP was significantly lower in patients with leak point pressure inferior to 60 cm H₂O. Editorial Comment: This is a retrospective study of 161 female patients with stress urinary incontinence in which the authors analyze the relationship between urodynamic valsalva leak point pressure (VLPP) and maximal urethral closure pressure (MUCP). In analyzing their data with Pearsons correlation coefficient and linear regression, the authors found a weak correlation between VLPP and MUCP. In addition, they found a significantly lower MUCP in patients with VLPP less than 60. The authors conclude that MUCP values less than 45 cm H₂O are not sensitive in diagnosing intrinsic sphincter deficiency. Although this study supports the known correlation between VLPP and MUCP, it adds little new information to the literature. This subject has previously been studied and evaluated and numerous published articles have already confirmed this correlation. It is already generally accepted that the diagnosis of intrinsic sphincter deficiency should be based on a compilation of factors including patient history, urodynamic, anatomic, and clinical severity criteria     

Six-microtransducer catheter connected to computer in evaluation of urethral closure function of women

A new instrument consisting of a six-transducer catheter, one transducer for the bladder and five transducers for urethral pressure recordings, and a computer with specific software was developed for urodynamic investigation of women. Twenty-six patients with stress urinary incontinence (SUI) and 10 continent female patients were evaluated during the single cough, the first and the fourth ones of the forced coughings in supine and standing positions. The results were compared with those obtained with the conventional two-transducer method. Negative urethral closure pressure (UCP) at stress, indicative of SUI, was present in 88 percent of the cases with the six-transducer method, and in 77 percent with the two-transducer method. The fourth cough in the standing position with the six-transducer method was most diagnostic. In SUI, the six-transducer method indicated exactly, e.g., the minimum bladder pressure needed for negative UCP and the duration of negative UCP. Patients with SUI had significantly lower UCP at rest, UCP at stress, and pressure transmission ratio (PTR) than continent women. Findings, that UCP at stress decreased and duration of negative UCP at stress increased but PTR did not change when the fourth cough was compared with the first one in SUI, suggest that factors which are responsible for the altered urodynamics during prolonged stress are anatomic rather than functional.     

Effect of fesoterodine on urethral closure function in women with stress urinary incontinence assessed by urethral pressure reflectometry

Introduction and hypothesis

The aim was to evaluate, using urethral pressure reflectometry (UPR), the effect of fesoterodine on urethral function in women with stress urinary incontinence (SUI).

Methods

Women aged 18 to 65 years were eligible for this randomised, double-blind, placebo-controlled, crossover study if they had had clinically significant SUI or SUI-predominant mixed urinary incontinence for >3 months. Each participant received fesoterodine 4 mg, fesoterodine 8 mg, and placebo once daily for 7 days, with a 7- to 10-day washout between treatments. UPR was performed at baseline and 4 to 8 h after the last dose in each treatment period. Participants completed a 3-day bladder diary before randomisation and during the last 3 days of each treatment period.

Results

Of the 22 women randomly assigned and treated, 17 met the criteria for the primary efficacy analyses. No statistically significant differences were seen between fesoterodine 4 mg or fesoterodine 8 mg and placebo in opening urethral pressure (primary endpoint) or other UPR endpoints. No statistically significant differences were seen between either fesoterodine dose and placebo in the change from baseline in the bladder diary variables (total urinary incontinence, SUI, or urgency urinary incontinence episodes per 24 h). Adverse events were reported by 8 participants taking fesoterodine 4 mg, 17 taking fesoterodine 8 mg, and 8 taking placebo.

Conclusions

Fesoterodine did not affect urethral pressure or significantly decrease the number of incontinence episodes in women with SUI. The UPR parameters showed no placebo effect, while there was a placebo effect of 60 % based on the bladder diary.     

The effect of changes of posture on the urethral closure pressure in healthy women

The effect of changes of posture on hydrodynamic parameters considered important for the maintenance of urinary continence was investigated in 14 healthy women. The subjects were investigated in the supine and erect positions using a previously described technique for simultaneous urethrocystometry, including recording of the urethral pressure profile. It was found that a change from the supine to the standing position increased the maximum intravesical pressure from a mean value of 13 mmHg to 22 mmHg. There was a simultaneous increase in the maximum intra-urethral pressure from a mean of 66 mmHg to 82 mmHg. As a consequence, the urethral closure pressure increased from a mean of 53 mmHg to 60 mmHg. The functional length of the urethra increased from 25 mm to 28 mm, and the absolute length from 28 mm to 36 mm. It is concluded that in healthy women, a change from the supine to the standing position causes a rise in the maximum intra-urethral pressure and an increase in the absolute and functional lengths of the urethra. These effects counteract the simultaneous increase in bladder pressure, and can be regarded as compensatory mechanisms for the maintenance of continence.     

Primary urethral tuberculosis masquerading as a urethral caruncle: A diagnostic curiosity!

Primary urethral tuberculosis associated with a caruncle is an extremely rare entity and ours is the second such case to be reported. A middle-aged woman presented with symptoms of frequency dysuria syndrome for the last 2 years. Local examination and cystoscopy revealed localized parurethral induration, tenderness and a urethral caruncle with chronic obliterative urethritis. Transvaginal ultrasound revealed a solid lesion arising from the posterior urethral wall. Excision of the caruncle andtransurethral resection of the paraurethral mass lesion revealed chronicgranulomatous inflammation with chronic urethritis and fibrocollagenous tissue. The literature regarding the genesis of urethral caruncle, the underlying conditions, its differential diagnosis and management has been reviewed.     

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

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).     

Urethral and bladder current perception thresholds: normative data in women

PURPOSE: Given increased evidence of sensory dysfunction in lower urinary tract pathology, we determined normative current perception threshold values in the lower urinary tract of asymptomatic women. MATERIALS AND METHODS: After receiving institutional review board approval women without lower urinary tract symptoms underwent current perception threshold testing of the urethra and bladder using a Neurometer constant current stimulator. Current perception threshold values were determined at 3 frequencies, including 2,000 Hz (corresponding to A-beta fibers), 250 Hz (corresponding to A-delta fibers) and 5 Hz (corresponding to C fibers). RESULTS: A total of 48 women with a mean age of 38 years (range 23 to 67) underwent current perception threshold testing. Normative values were established for the urethra and bladder at 2,000, 250 and 5 Hz. Median urethral current perception thresholds at 2,000, 250 and 5 Hz were 1.2 (IQR 0.76-1.5), 0.45 (IQR 0.33-0.56) and 0.11 mA (IQR 0.07-0.24), respectively. Median bladder current perception thresholds at 2,000, 250 and 5 Hz were 4.1 (IQR 2.0-6.3), 2.3 (IQR 0.87-5.5) and 1.4 mA (IQR 0.22-2.9), respectively. Urethral and bladder current perception thresholds increased significantly with subject age at all 3 frequencies (p<0.0005). Prior pelvic surgery was associated with an increased bladder current perception threshold at all 3 frequencies (p<0.005) but not with the urethral current perception threshold. CONCLUSIONS: We report urethral and bladder current perception thresholds for a large sample of asymptomatic women. These reference values may help elucidate changes in afferent nerve function in women with lower urinary tract dysfunction.     

Micturitional static urethral pressure profilometry in women

Micturitional static urethral pressure profilometry is an accurate method to identify the location and degree of bladder outlet and urethral obstruction in men. Described herein are the results of micturitional static urethral pressure profilometry in 17 women: 13 were nonobstructed, 3 were obstructed, and 1 voided by abdominal straining. The location of the static pressure drop was in the terminal urethral segment in all patients and was clearly distal to the location of the maximum urethral pressure determined on urethral closure pressure profilometry. It is concluded that the terminal urethral segment controls urinary flow, determines the voiding pressure, and that micturitional static urethral pressure profilometry can accurately identify the location of physiologic obstructions in the female urethra.     

Clinical experience with urethral retro-resistance pressure measurement: a prospective pre- and postoperative evaluation in women with stress urinary incontinence

AIMS: To identify possible correlations of urethral retro-resistance pressure (URP) with clinically and urodynamically proven stress urinary incontinence (SUI) and the outcome of anti-incontinence surgery. MATERIALS AND METHODS: URP was measured using the Monitorr system in women with clinically and urodynamically proven SUI without prolapse before and after anti-incontinence surgery (colposuspension n = 8, tension-free vaginal tape n = 6, tension-free transobturator tape n = 34). RESULTS: Forty-eight women (mean age 61.8 +/- 8.9 years) were evaluated preoperatively and on average 10 weeks postoperatively. Mean URP was 75.6 +/- 20.8 cm H(2)O preoperatively versus 75.4 +/- 17.9 cm H(2)O postoperatively (P = 0.898). The type of anti-incontinence surgery performed had no significant effect on postoperative URP. While no association was found between age and URP (P = 0.35), there was a positive correlation between URP and body mass index (BMI; r = 0.49, P = 0.0004). There was no correlation of URP with the preoperative pad test (P = 0.17) and urethral closure pressure at rest (P = 0.51). Finally, URP did not correlate significantly with the preserved length of the continence zone (0-1/3-2/3-3/3) as determined by the urethral stress profile (P = 0.37-0.72) or with the objective cure rate (negative pad test). CONCLUSIONS: Preoperative URP does not correlate with SUI in all women, has no predictive value, and does not correlate with the outcome of anti-incontinence surgery. However, there seems to be an association with biomechanical factors such as obesity, which may open up a new area of application for URP measurement in urogynecologic diagnosis.     

Urethral pressure reflectometry vs urethral pressure profilometry in women: a comparative study of reproducibility and accuracy

OBJECTIVE: To compare urethral pressure reflectometry (UPR), a new and simple technique for simultaneous measurements of cross-sectional area (CA) and pressure in the female urethra, with urethral pressure profilometry (UPP). PATIENTS, SUBJECTS AND METHODS: The study included 143 women (105 patients and 38 healthy volunteers); the UPR was measured using a very thin polyurethane bag in the urethra; a pump applied pre-selected pressures stepwise to the bag and for each step the CA was measured by acoustic reflectometry. Measurements were made during both inflation and deflation. The women were examined supine both while relaxed and during 'squeeze', and while upright and relaxed. The following variables were measured; the opening and closing pressure, the opening and closing elastance and the hysteresis. For UPP we used the perfusion technique with the patient supine and relaxed. All the women were assessed twice with both UPR and UPP at the same setting (short-term reproducibility) and 17 patients were assessed with both methods on two different days (long-term reproducibility). RESULTS: The mean pressures were 51.7 and 52.9 cmH(2)O for the UPR and UPP, respectively (not significant) at a CA of 5.1 mm(2); the limit of agreement between the methods was -19.4 to +17.0 cmH(2)O (mean and 2 SD). The Pearson coefficient was - 0.16 (not significant). The variability (2 sd) of two consecutive measurements was significantly less with UPR (9.5 cmH(2)O) than UPP (13.8 cmH(2)O; P < 0.001). For the opening and closing pressures the coefficient of variation (CV) was 5.9-11.6%; for the elastances the CV was 14.3-31.2% and for the hysteresis the CV was 12.9-49.1%. In test-retest measurements, the variability of the UPR values (2 sd, 8.7 cmH(2)O) was significantly less than for UPP (15.4 cmH(2)O; P < 0.05). The discomfort of UPR was statistically less than for UPP or than a standard gynaecological examination. CONCLUSION: Compared at the same CA, UPR measured the same pressure as UPP but the UPR was more reproducible. With the patient relaxed the opening and closing pressure, opening and closing elastance and the hysteresis can be measured while supine and upright; while squeezing, the opening pressure and elastance can be measured.     

Levator function and voluntary augmentation of maximum urethral closure pressure

Introduction and hypothesis

The aim of the study was to test whether women with symptoms of pelvic floor dysfunction can augment maximum urethral closure pressure (MUCP) with a pelvic floor muscle contraction (PFMC) and whether augmentation is associated with structure and function of the levator ani muscle.

Methods

Between January and December 2009, 300 women attended a tertiary referral service for multichannel urodynamic testing and 4D pelvic floor ultrasound. The MUCP was obtained with a perfused fluid-filled catheter. Augmented MUCPs were obtained during directed PFMC. Levator contraction strength was assessed digitally, using the Modified Oxford Grading (MOS). Levator integrity was determined using tomographic ultrasound, and we also measured dimensions of the levator hiatus at rest and on PFMC, blinded against all clinical data.

Results

The MUCP was measured at a mean of 36?cm H₂O (range 2–111). Augmented MUCP was 42?cm H₂O on average (4–125). Of those who attempted augmentation (n?=?275), 80 produced a reduction in MUCP and were excluded, leaving 195. There was a significant correlation between MOS and augmentation (r?=?0.24, P?=?0.001). Women with an intact levator muscle were able to augment more effectively (P?=?0.038).

Conclusions

Urethral closure pressure can be augmented voluntarily by symptomatic patients, on average by about 20?%. The degree of augmentation is positively associated with levator contractility as measured by digital palpation and negatively with levator avulsion.     

Rotational differences in urethral pressure in incontinent women

Urethral pressure profile measurements are made by means of microtransducers at four different positions in the urethra (anterior, posterior, left and right side). The maximum urethral closure pressure (MUCP) is always highest in the anterior position in stress as well as in urge incontinent women. The functional urethral length shows no differences in the four positions. In all positions the recorded pressures and urethral length are higher in the urge incontinent group than in the stress incontinent group. A decrease of MUCP with age is observed in both groups.     

The urethral pressure profiles in continent and stress-incontinent women

Simultaneous urethrocystometry, including recording of the urethral pressure profile, was performed in 127 women aged 30 to 69 years; 42 of the women were free from urologic disorders and 85 had stress incontinence of urine. Both groups were subgrouped according to age. The results in the continent and the incontinent women were analyzed separately, in order to disclose any age-related changes. The data within each decade of age were also comparatively analyzed. In the bladder pressure at rest no age-related changes were found, and the readings were similar in the continent and the incontinent women. The maximum urethral pressure fell significantly with rising age in both groups and was significantly reduced in stress incontinence. The urethral closure pressure showed variations similar to those in the maximum urethral pressure. No lower limit of urethral closure pressure that definitely predisposed to stress incontinence could be established. The functional length of the urethra diminished significantly with rising age in the continent, but not in the incontinent women. The absolute length of the urethra did not show such diminution. Both the functional and the absolute urethral length were significantly less in the incontinent than in the continent women in the age groups between 30 and 49 years.