Observations on the function of the female urethra: III: An overview with special reference to the relation between urethral hypermobility and urethral incompetence

AIMS: To analyze the relation between urethral hypermobility and urethral incompetence, and to summarize the interdependence between maximum urethral closure pressure (MUCP), urethral hypermobility, and urethral incompetence. PATIENTS AND METHODS: A group of 255 patients was selected from a large bank of cases. Inclusion criteria were age 20 years or above, no neurological disease, stable bladder, and no previous incontinence surgery or hysterectomy. The degree of hypermobility (cysto-urethrocele) and the degree of urethral incompetence (abdominal leak point pressure (ALPP)) were determined. Statistical analyses between urethral hypermobility and incompetence were performed with Spearman's correlation and the Jonckherre-Terpstra test. RESULTS: The Spearman's rank correlation test showed a statistically significant relation between urethral hypermobility and the degree of urethral incompetence (P = 0.0049). CONCLUSIONS: The statistically significant relation between urethral incompetence and hypermobility suggests that urethral incompetence will increase as the degree of urethral hypermobility does. Optimal conditions for urinary continence include a high maximum urethral closure pressure, absence of hypermobility, and a low degree of urethral incompetence. This last factor is assured by a strong support underneath the urethra permitting compression of the latter during straining. Failure of the urethral closure mechanism is highly probable with a diminished maximum closure pressure accompanied by urethral hypermobility often associated with a high degree of urethral incompetence. Clinically significant urinary incontinence may appear in many intermediate circumstances between these two extreme states, but stress urinary incontinence is essentially an activity-related phenomenon.     

Observations on the function of the female urethra: I: relation between maximum urethral closure pressure at rest and urethral hypermobility

AIMS: To study the relation between maximum urethral closure pressure at rest and urethral hypermobility in female patients. PATIENTS AND METHODS: We selected 255 patients aged 20 years and older, with a stable bladder on multichannel urodynamics, without known neurological pathology, and without a history of pelvic or anti-incontinence surgery. A resting urethral pressure profile and the degree of urethral hypermobility were registered. Two-tailed analyses of variance (ANOVA) with Fisher's post-hoc tests were used to detect any statistically significant difference (P < 0.05) in urethral closure pressure between groups with varying degrees of urethral hypermobility. RESULTS: Mean age was 45.6 +/- 12.7 (range 20-77) years. Mean maximum urethral closure pressure for the entire group was 62.7 +/- 29 (range 10-150) cm of water. A statistically significant inverse relationship was found between age and maximum urethral closure pressure (r = 0.489, P < 0.0001) when both analyzed as continuous variables, and with age categorized in 10-year increments (P < 0.0001). When comparing mean urethral closure pressure in each group examined for urethral hypermobility, a statistically significant difference was noted when grades I, II, and III were compared to grade 0 hypermobility. No significant difference was observed when grades I, II, and III were compared to each other. Even if statistically non-significant, there exists an inverse relationship between the degree of urethral hypermobility and the maximum urethral closure pressure: a higher hypermobility is associated with a lesser urethral closure pressure. CONCLUSIONS: Urethral closure pressure falls significantly when urethral hypermobility is present. This decrease is not related to patient's age or parity. Our observations demonstrate an inverse relation between urethral closure pressure and the degree of cysto-urethrocele. As hypermobility increases, closure pressure decreases, even if this decrease does not reach the level of statistical significance.     

Predictive value of maximum urethral closure pressure, urethral hypermobility and urethral incompetence in the diagnosis of clinically significant female genuine stress incontinence

PURPOSE: We determined the value of urethral hypermobility, maximum urethral closure pressure (MUCP) and urethral incompetence in the diagnosis of stress urinary incontinence (SUI). MATERIALS AND METHODS: In this study 369 women with clinical symptoms suggestive of SUI without symptoms of bladder overactivity were evaluated in regard to urethral incompetence, urethral hypermobility and mean MUCP. The cohort was divided into 2 groups according to continence/incontinence status. ROC curves were used to test the performance of the various predicting factors. These factors were combined in forward stepwise logistic regression to find the cutoff point that simultaneously optimized sensitivity and specificity. RESULTS: Continent and incontinent patients differed with regards to urethral incompetence and hypermobility (each p <0.0001). Incontinent patients had a greater probability of a higher grade of each factor. Even after adjusting for the older age of incontinent patients by ANCOVA. MUCP was significantly lower in the incontinent group (p <0.001). The best univariate optimized cutoff point for discriminating continence from incontinence was obtained with urethral incompetence greater than grade I. CONCLUSIONS: The best single predictor of clinically significant SUI is urethral incompetence, followed by urethral hypermobility and MUCP. When combining several factors, namely grade II urethral incompetence with grade III hypermobility, grade III urethral incompetence with grades I to III hypermobility and grade IV urethral incompetence with or without urethral hypermobility, all indicated more than a 90% probability of clinically significant SUI.     

Relationship of urethral retro-resistance pressure to urodynamic measurements and incontinence severity

AIMS: The urethral retro-resistance pressure (URP) is a retrograde urethral pressure profile measured by a new urodynamic measurement system.1GYNECARE MoniTorr Urodynamic Measurement System (ETHICON, Inc., Somerville, NJ). URP is the pressure required to achieve and maintain an open sphincter. This clinical investigation focused on a comparison of URP to standard urodynamic measurements and an examination of their relationship to incontinence severity. METHODS: Twenty-two centers enrolled 258 stress incontinent women in a randomized, crossover study of two groups: (1) test procedure followed by multichannel urodynamics, (2) multichannel urodynamics followed by test procedure. We defined incontinence severity categories using 24 hr urine loss and assessed these categories using incontinence quality of life (I-QOL), urinary incontinence severity score (UISS), incontinence visual analogue score (VAS), URP, maximum urethral closure pressure (MUCP), and leak point pressure (LPP). RESULTS: The mean age was 56.2 (+/-12) years. No order effect was present. The correlation coefficient between URP and MUCP was 0.31 (95% CI 0.19-1, P < 0.0001); between URP and LPP was 0.28 (95% CI 0.12-1, P = 0.003); and between MUCP and LPP was 0.14 (95% CI-0.04-1, P = 0.101). The mean values for URP across symptom severity categories were significantly different (P = 0.028) and decreased with increasing severity. The mean values for MUCP and LPP did not decrease with increasing severity. CONCLUSIONS: The study demonstrated that URP had a consistent relationship with incontinence severity. The data suggested that URP is a physiological measure of urethral function and may have clinical utility as a diagnostic tool. Future outcomes-based research is necessary to establish the predictive value of URP, MUCP, and LPP measurements in terms of incontinence cure rates and diagnosis of sphincter dysfunction.     

Effect of voluntary attention on urethral pressure

We have systematically and simultaneously recorded vesical pressure and maximum urethral closure pressure (MUCP) in 109 women consulting for urinary incontinence over an extended period of time. During the recording, we asked them to peform a mental calculation (MC) test and other tests designed to induce an effort of voluntary attention. We found a significant increase in MUCP during the MC. At rest, 57 women displayed urethral pressure variations (UPV) higher than 15 cm H₂O. MC inhibited UPV in 80% of these cases. Such variations have never yet been reported. The effect of MC can be compared to an orienting reaction, which normally increases the sympathetic tonus. The role of the smooth and striated muscle fibers of the urethra, in the observed changes in urethral pressure, is discussed in light of the literature data.     

Unstable urethral pressure: Toward a more relevant definition

There is confusion in the literature over the use of the terms unstable urethra and unstable urethral pressure, which are often held inappropriately to be synonymous. The importance of the former condition, as a cause of incontinence, is beyond doubt, although it appears to be an uncommon condition; the finding of unstable urethral pressure is reported much more frequently, although its clinical significance remains in debate. An analysis of urethral pressure recordings in a group of 131 women with urodynamically proven genuine stress incontinence, and 14 urodynamically normal women entirely free from urinary symptoms has been carried out in an attempt to define the differences between the two and thus to establish a more clinically relevant definition for the phenomenon of “unstable urethral pressure.” The variation in urethral pressure was calculated first in absolute terms, as the variation in cm H₂O above and below the mean maximum urethral closure pressure (MUCP), and second in relative terms, as a percentage of the mean MUCP itself; these two parameters are described as “delta-MUCP (absolute)” and “delta-MUCP (relative),” respectively. The mean delta-MUCP (absolute) values were 9.5 and 13.4 cm H₂O for the symptomatic and control groups, respectively (not significant); the mean delta-MUCP (relative) values were 27.0% and 17.1% of the MUCP (p < 0.001). Examination of various potential points of discrimination for the diagnosis of “unstable urethral pressure” showed a delta-MUCP (relative) of 30% to be the best discriminator, allowing the identification of a subgroup of stress incontinent women whose urethral pressure variation was likely to be of relevance in the determination of symptoms.     

Continuous recording of urethral activity in healthy female volunteers

The pressure variations at the maximal urethral closure pressure (MUCP) were continuously recorded in healthy female volunteers by means of a two-point microtip transducer catheter for one hour. Before the investigation a normal voiding was assured objectively and bladder instability was excluded. All women showed pressure variations both at the MUCP and more distally. The pressure variations, from 3 to 66 cm H₂O, showed rhythmicity and three frequency ranges could be identified. Slow pressure waves with a frequency of one in eight to 19 minutes were observed. Relatively fast-pressure waves were observed (one every one to four minutes) and relatively fast-frequency pressure waves were observed (rate: one to eight per minute). The pressure variations of the urethra seem to be an aspect of normal urethral physiology possibly contributing to continence and urinary tract infection prevention.     

Is HCl duloxetine effective in the management of urinary stress incontinence after radical prostatectomy?

INTRODUCTION: Up to 70% of patients who undergo radical prostatectomy complain about urine leakage, but persistent stress incontinence 1 year after surgery affects <5% of them. HCl duloxetine is a dual serotonin and norepinephrine reuptake inhibitor that relieves the symptoms of stress urinary incontinence. The purpose of this study was to evaluate the efficacy of HCl duloxetine in the management of urinary incontinence after radical prostatectomy and its impact in urodynamic parameters such as maximal urethral closure pressure (MUCP), abdominal leak point pressure (ALPP) and retrograde leak point pressure (RLPP). MATERIAL AND METHODS: The study included 18 men with stress urinary incontinence 12 months after radical prostatectomy. All underwent a pad test to quantify the degree of urine loss and a urodynamic evaluation before and after a three month treatment with HCl duloxetine. The intrinsic sphincter was evaluated by ALPP and RLPP and the striated sphincter by MUCP. RESULTS: At the pretreatment evaluation the mean ALPP was 52.1 cm H(2)O, the mean MUCP was 52.5 cm H(2)O and the mean RLPP was 43.1 cm H(2)O. After 3 months of HCl duloxetine treatment the mean ALPP was 59.1 cm H(2)O, the mean MUCP was 67.3 cm H(2)O and the mean RLPP was 45.1 cm H(2)O. There was a statistically significant correlation among RLPP, MUCP and ALPP before treatment. After HCl duloxetine treatment there was significant correlation between RLPP and ALPP. CONCLUSION: The use of HCl duloxetine results in mild increase of MUCP and in significant reduction of urine loss. Its action on the extrinsic sphincter does not provide a complete treatment option for postprostatectomy incontinence.     

Fluid perfused urethral pressure profilometry and Valsalva leak point pressure: a comparative study in a biophysical model of the urethra

In patient studies the correlation between maximum urethral closure pressure (MUCP) and Valsalva leak point pressure (LPP) is meagre at best (r = 0.22–0.50). We therefore studied the relation between MUCP and LPP in a flexible and extensible model urethra. We applied differently sized pressure zones and different degrees of resistance to a biophysical model urethra by stepwise inflating three types of blood pressure cuff placed around the model. At each degree of resistance we measured detrusor LPP, an in vitro equivalent of Valsalva LPP. Subsequently, we recorded the Urethral Pressure Profile using a water-perfused 5F end-hole catheter at four withdrawal rates and five perfusion rates and calculated MUCP. We tested the dependence of LPP on pressure zone length and MUCP on perfusion rate, withdrawal rate and pressure zone length using analysis of variance. We tested the correlation between LPP and MUCP using Pearson’s correlation coefficient and Linear Regression. LPP did not significantly depend on the pressure zone length (P = 0.80) and increased linearly with increasing cuff pressure. MUCP also increased with increasing cuff pressure, however, MUCP significantly depended (P < 0.01) on perfusion rate, withdrawal rate and pressure zone length. MUCP increased with increasing perfusion rate, and decreased with increasing withdrawal rate. In our model urethra MUCP only accurately reflected urethral resistance for a very limited number of combinations of perfusion rate and withdrawal rate. LPP reflected urethral resistance independent of the type of pressure zone.     

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     

Augmentation of urethral pressure profile by voluntary pelvic floor contraction

The aim of the investigation was to study the repeatability of urethral pressure profile (UPP) and to quantify the influence of voluntary pelvic floor contraction on the UPP. Seventy-two patients underwent one UPP at rest and one UPP during a pelvic floor contraction. The functional urethral length (FUL) and the maximum urethral closure pressure (MUCP) were recorded. To establish repeatability the UPP was repeated twice in 18 patients in rest, and in 15 patients during a contraction. We used the repeatability coefficient instead of the correlation coefficient. Forty-eight patients, had no major anatomical abnormalities (group A); 24 had grade 2 or more prolapse (group B). In both groups we found a shortening of the FUL and an increase in MUCP during a contraction. The UPP was reproducible, both at rest and during a contraction. In conclusion, we found a significant and constant increase in MUCP and a shortening of the FUL during a contraction. Unlike other studies we found the UPP to have good reproducibility. However, we used the repeatability coefficient instead of the correlation coefficient.     

女性尿道中静态尿道压力分布特点的研究

目的：探讨在女性尿道不同部位和不同方向上静态尿道压力图（RUPP）压力的分布特点。方法：本研究共包括因各种原因需做尿动力学检查的成年女性患者55例,年龄（41±11）岁,其中尿流动力学检查无异常者8例,压力性尿失禁19例,其他诊断（包括OAB、膀胱收缩无力等）28例。采用恒压恒速灌注法测压,将测压孔分别朝向尿道前壁（12点）、后壁（6点）、左侧壁（3点）及右侧壁（9点）四个方向描记RUPP,采用配伍区组方差分析进行统计学分析。结果：前壁的最大尿道闭合压（MUCP）最高（P％0．01）,后壁的MUCP最低（P〈0．001）,左右两侧MUCP无明显差异（P=0．571）;前壁的功能尿道长度（FUL）最短（P〈0．01）,后壁的FUL最长（P〈0．001）,左右两侧FUL无统计学差异（P=0．717）;RuPP曲线均呈抛物线形,高压区和MUCP的最大值位于尿道中段或中远段交界处。结论：本研究结果显示,静态尿道压力图在女性尿道压力分布上,前后壁方向上具有显著的方向性变异,而左右两侧具有对称性和一致性。尿道压力图的压力分布特点与女性尿道壁的组织结构和尿道腔的形态密切相关。     

Decrease in urethral pressure following repeated cough efforts: A new concept for pathophysiology of stress urinary incontinence

AIMS: To describe the decrease in maximum urethral closure pressure (MUCP) following repeated coughs in women with stress urinary incontinence (SUI). METHODS: MUCP was recorded at rest and after seven cough efforts in 70 women under age 40 referred for urodynamic investigation (47 women with SUI and 23 women without SUI). RESULTS: The intraclass correlation coefficient for repeatability was very good at 400 mL filling volume: 0.94 (95%CI: 0.85-0.98), as compared to the mean and standard-deviations of the MUCP measurements. A decrease in MUCP >20% after seven cough efforts was observed in 18(38%) patients in the SUI group and in just 1(4%) woman in the non-SUI group (P = 0.0069). CONCLUSIONS: Many women with SUI exhibit a sharp decrease in MUCP after repeated coughs. Many hypotheses may explain this phenomenon, including increased fatigue of the periurethral muscles.     

A comparison of the cough and standing urethral pressure profile in the diagnosis of stress incontinence

Controversy over the accuracy of the urethral pressure profile (UPP) and its role in the diagnosis of stress urinary incontinence (SUI) is unresolved. Different UPP methods and techniques have been introduced. In this study, we examined 78 female patients with mixed symptoms of stress and urge incontinence. Each had a history, physical examination, cystoscopy, and urodynamic assessment, which consisted of a cystometrogram (CMG), UPP (supine and standing), and “cough profile” by the Brown and Wickham (BW) method and also UPP (supine) and “cough profile” with the microtip transducer (MTT). The final diagnosis in 38 patients was SUI (group I) and in 40 patients, no SUI (group II). The maximum urethral closure pressure (MUCP) supine and standing was significantly lower in group I, but there was no significant difference between the two groups in the transmission index (TI) of the “cough profile.” MUCP standing showed the least overlap between the two groups, and with a cutoff point at 40 cm H₂O, the overall diagnostic accuracy was 69%, with 39% sensitivity and 98% specificity. By combining MUCP supine and standing and using cutoff points at 40 cm H₂O and 35 cm H₂O, respectively, the overall diagnostic accuracy was 72%, with 47% sensitivity and 95% specificity. We believe that the UPP is a useful ancillary tool in the assessment of complicated cases of urinary incontinence in the female.     

Clinical and urodynamic features of intrinsic sphincter deficiency

AIMS: A prospective analysis of 92 patients with genuine stress incontinence was performed to identify the clinical and urodynamic features of intrinsic sphincter deficiency (ISD). METHODS: We divided the patients into two categories: 50 patients affected by pure ISD as they had severe stress incontinence and no urethral mobility; 42 patients suffering from stress urinary incontinence without ISD as they had mild stress incontinence and marked urethral hypermobility. Cystometry was normal in all patients. The presence/absence of ISD was considered the dependent variable and was correlated against the following independent variables: age, vaginal deliveries, menopause, previous urogynecological surgery and/or hysterectomy, supine stress test, irritative and/or obstructive symptoms, Valsalva leak point pressure (VLPP), maximum urethral closure pressure (MUCP), urethral functional length (UFL), and leakage during cystometry. RESULTS: The statistical analysis showed close correlations between ISD and age (P < 0.001), menopausal status (P < 0.001), previous surgery (P < 0.0001), supine stress test (P < 0.0001), leakage during cystometry (P < 0.001), and UFL (P < 0.01). The VLPP was below the cut-off value (相似文献   

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 pressure profile: Is it affected by position?

The aim of this study was to investigate the difference between sitting and standing passive urethral pressure measurements, and to determine the accuracy of urethral pressure profilometry in each position. Urethral pressure profilometry was performed in the sitting and standing position in 98 women. Stress incontinence due to urethral sphincter incompetence was demonstrated in 59 of whom 6 also had detrusor instability. The others were normal volunteers (7), women with a normal cystometrogram (23), and women with detrusor instability (9). MUCP tended to be higher in the standing than the sitting position but this did not reach statistical significance. Urethral lengthening appeared to occur on standing with a mean increase of FUL of 5 mm on standing. For both FUL and MUCP, there was a wide variation in the difference between sitting and standing values. There was poor reproducibility of measurements of MUCP and FUL in the standing position, limiting its clinical applicability. The difference between sitting and standing MUCP and FUL was not affected by age, parity, weight, height, BMI, or oestrogen status. In women with genuine stress incontinence, there was less difference between sitting and standing MUCP, but this explained only a small part of the variability. The increase in FUL in the standing position was unaffected by diagnosis.     

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.     

Is the leak point pressure alone an accurate indicator of intrinsic sphincteric deficiency?

The aim of this study was to determine the characteristics of women who meet the criteria for intrinsic sphincteric deficiency (ISD) on maximum urethral closure pressure (MUCP) but not on leak point pressure (LPP) measurement. We performed a cross-sectional chart review of every patient who underwent multichannel, microtransducer urodynamic testing in our center between 1994 and 1996 (n=423). From this population we culled a sub-population of women who fit into one of the following two groups: women with no evidence of ISD on MUCP or LPP and women with evidence of ISD on MUCP only. Logistic regression was used to identify independent predictors of group membership. Increasing age (>60.5 years) and a positive supine empty stress test were the only independent predictors of membership in the group of women with ISD on MUCP only. Knowledge of these risk factors may help clinicians in choosing appropriate pre-operative testing.Abbreviations ISD Intrinsic sphincteric deficiency - LPP Leak point pressure - MUCP Maximum urethral closure pressure Editorial Comment: Valsalva leak point pressures and maximum urethral closure pressures are two different tests that can be used to evaluate and quantify urethral sphincteric function. The authors performed a cross-sectional study to determine the characteristics of women whose diagnosis of ISD would be missed based on an abnormal MUCP defined as <20 cm H₂0 if only a LPP was assessed. They found that of 305 patients with a normal LPP defined as >60 cm H₂0, 288 patients also had a normal MUCP (Group A) compared to 17 patients who had an abnormal MUCP (Group B). In comparing 18 patients characteristics, they found that age greater than 60 years and a positive supine empty stress test were independent risk factors for membership in Group B. It is known that both MUCP and LPP are fraught with variables making each difficult to standardize and validate. One could question whether a MUCP with a cutoff <20 cm can truly be used to define ISD. This brings up a related criticism described as a limitation by the authors—mainly that LPP were measured only at a bladder volume of 150 cc. Perhaps if the measurements were repeated at a larger bladder volume, there would have been an even greater correlation between MUCP and LPP. More needs to be done in the future to better standardize tests used to evaluate urethral function. As the authors mentioned, however, with the success of suburethal slings for all types of stress incontinence, perhaps this is a moot point.     

Weak VLPP and MUCP correlation and their relationship with objective and subjective measures of severity of urinary incontinence

The aims of the present study were to find the correlation between Valsalva leak-point pressure (VLPP) and cough leak-point pressure (CLPP) and to determine whether the water perfusion maximum urethral closure pressure (MUCP) correlates with VLPP. Seventy-nine women with previously untreated stress urinary incontinence were recruited to participate in a clinical study. Their mean age was 56.4 years, mean BMI was 27.8, and mean parity was 1.9. The mean values of VLPP and CLPP were 50.4 and 52.9 cm H₂O, respectively. We did not find statistically significant differences in the mean values of VLPP and CLPP. The mean value of MUCP at rest was 44.2 cm H₂O and the mean value of MUCP during maximal Valsalva maneuver was 37.2 cm H₂O; with 500 ml of sterile saline in the bladder the difference between them is statistically significant. In the study group (n=79), 56 patients (77%) had low VLPP (≤60 cm H₂O), 21 patients (30%) had low MUCP (≤30 cm H₂O), and 8 patients had MUCP≤20 cm H₂O (all at rest). Of the 56 patients with low VLPP, 16 also had a low MUCP (≤30 cm H₂O). This study mainly compares two parameters—the MUCP and the VLPP. Based on our results we can conclude that there is no correlation between these parameters. MUCP measures urethral resistance at rest and VLPP measures urethral resistance during increased intra-abdominal pressure (Valsalva maneuver). This work was supported by the Grant Agency of the Ministry of Health of the Czech Republic, grant NH 7378-3.