Urethral Pressure Reflectometry Research Articles

Single-dose Tadalafil Reduces Opening Urethral Pressure: A Randomized, Double-blind, Placebo-controlled, Crossover Trial in Healthy Women

Introduction and HypothesisPhosphodiesterase enzymes are widely distributed in female urogenital tissues. Yet, the understanding of their physiological roles and the impact of phosphodiesterase inhibitors on lower urinary tract symptoms in women remains limited. Current hypotheses are conflicting: one suggests that vasodilation might expand the periurethral vascular plexus, leading to increased urethral pressure, whereas the other proposes a relaxation of urethral musculature, resulting in decreased pressure. To further clarify this, we investigated the effect of tadalafil on the opening urethral pressure and voiding function in healthy women.MethodsWe conducted a randomized, double-blind, placebo-controlled crossover trial involving 24 healthy women. Participants were randomly assigned to receive a single dose of tadalafil (40 mg) or placebo during their initial visit and then switched to the alternative treatment during their second visit. Opening urethral pressure was measured with urethral pressure reflectometry during both resting and squeezing conditions of the pelvic floor. Subsequently, voiding parameters were recorded.ResultsCompared with placebo, a single dose of tadalafil significantly reduced opening urethral pressure during both resting (-6.8 cmH20; 95% confidence interval [CI], -11.8 to -1.9; p = 0.009) and squeezing conditions (-8.8 cmH20; 95% CI, -14.6 to -3.1; p = 0.005). Voiding parameters did not show significant differences (average flow rate: -0.8 ml/s [95% CI, -2.0 to 0.4; p = 0.2]; maximum flow rate: -1.7 ml/s [95% CI, -4.8 to 1.5; p = 0.3]).ConclusionsA single dose of 40 mg tadalafil moderately reduced urethral pressure in healthy women, without affecting voiding parameters. The clinical implications of this are yet to be determined.

Research priorities for diagnostic instrumentation in urinary incontinence.

The International Consultation on Incontinence (ICI) captures current evidence on incontinence. The conference 'Incontinence: The Engineering Challenge XIII' in November 2021 heard an update on the most recent ICI summary on urodynamic testing. This paper summarises the ICI recommendations for future research in urodynamics, with a view to informing engineers of issues and challenges that could benefit from engineering solutions. Engineers are encouraged to contribute to the following areas of research, which will have a direct and positive effect on patients' quality of life and overall health: (a) Urine flow measurement: home- and app-based devices, machine learning analysis of flow shape, (b) Pressure measurement: normal values for and validation of new technologies, including air-filled, non-invasive and urethral pressure reflectometry, (c) Ultrasound imaging: bladder wall biomechanics, bladder shape analysis, (d) Assess normal and abnormal value ranges, and diagnostic performance and (e) Specific trials in understudied patient groups including those with symptoms resistant to treatment, children and the frail elderly.

Effect of single doses of citalopram and reboxetine on urethral pressure: A randomized, double-blind, placebo- and active-controlled three-period crossover study in healthy women.

AimsUrethral closure function is essential for urinary continence in women and decreased urethral pressure is associated with stress urinary incontinence (SUI). For decades, the effects of serotonergic drugs on central neural control of urethral closure have been investigated and discussed. Epidemiological studies suggest that the use of selective serotonin reuptake inhibitors (SSRIs), such as citalopram, is associated with SUI. However, the literature findings are conflicting. This study aimed to evaluate citalopram's effect on opening urethral pressure (OUP) in healthy women.MethodsWe conducted a randomized, double‐blind, placebo‐ and active‐controlled crossover study in 24 healthy women. On three study days, which were separated by 8 days of washout, the subjects received single doses of either 40 mg citalopram (and placeboreboxetine), 8 mg reboxetine (and placebocitalopram), or two placebos. Study drugs were administered at a 1‐h interval due to a difference in estimated time to peak plasma concentration (t max). We measured OUP with urethral pressure reflectometry under both resting and squeezing conditions of the pelvic floor at estimated t max for both study drugs (one timepoint).ResultsCompared to placebo, citalopram increased OUP by 6.6 cmH20 (95% confidence interval [CI] 0.04–13.1, p = 0.048) in resting condition. In squeezing condition, OUP increased by 7.1 cmH20 (95% CI: 1.3–12.9, p = 0.01). Reboxetine increased OUP by 30.0 cmH20 in resting condition compared to placebo (95% CI: 23.5–36.5, p < 0.001), and 27.0 cmH20 (95% CI: 21.2–32.8, p < 0.001) in squeezing condition.ConclusionCitalopram increased OUP slightly compared to placebo suggesting that SSRI treatment does not induce or aggravate SUI.

Effect of imipramine on urethral opening pressure: A randomized, double-blind, placebo-controlled crossover study in healthy women.

In two open-label trials, imipramine alleviated symptoms in patients with stress urinary incontinence and is therefore used off-label for this indication. However, it has never been confirmed that imipramine increases urethral pressure in a placebo-controlled setting. The purpose of this study was to investigate whether imipramine increases the opening urethral pressure compared to placebo in healthy women using urethral pressure reflectometry. A randomized, double-blind, placebo-controlled, crossover study in 16 healthy women. Opening urethral pressure was measured predose and 1 hour after a single dose of 50 mg imipramine or placebo. The washout period was minimum of 1 week. The study was approved by the local ethics committee, conducted according to the Good Clinical Practice guidelines, and registered on ClinicalTrials.gov and EudraCT before recruitment of subjects. Funding was provided by the clinical department. There were no dropouts and no serious adverse events. There were 13 adverse drug reactions related to imipramine in seven subjects, one adverse event related to placebo, and two adverse events related to the measurements with urethral pressure reflectometry. Imipramine compared to placebo increased opening urethral pressure in the resting condition with 6.5 cmH2 O (95% confidence interval [CI]: -0.5, 13.5), P = 0.07, and in the squeeze condition with 7.9 cmH 2 O (95% CI: -0.3, 16.1), P = 0.06. In conclusion, the increase in opening urethral pressure after imipramine treatment compared to placebo was neither statistically significant nor clinically relevant, and we do therefore not recommend the off-label use of imipramine for the treatment of stress urinary incontinence.

Pelvic floor muscle training with and without supplementary KAATSU for women with stress urinary incontinence - a randomized controlled pilot study.

To explore if adding occlusion training of a thigh (KAATSU) to low-intensity pelvic floor muscle training (PFMT) could increase effect of PFMT in women with stress urinary incontinence (SUI). Single-blinded randomized controlled pilot study. Women with SUI and an ICIQ-UI-SF (International Consultation on Incontinence Questionnaire-Short form) score of ≥12 were randomized to a low-intensity PFMT program followed by KAATSU (KAATSU + PFMT) or to a low-intensity PFMT program without KAATSU (PFMT group), both performed four times a week for 12 weeks. Change in the ICIQ-UI-SF score at a 12-week follow-up. a 3-day leakage diary, the PGI-I (Patient Global Index of Improvement scale), bother with KAATSU in a numeric rank scale and change in urethral opening pressure (UOP) measured with urethral pressure reflectometry (UPR) at rest, contraction and straining at the 12-week follow-up. Forty-one women with SUI and an ICIQ-UI-SF of 13 (range 12-16) were included. Fourteen in the KAATSU + PFMT and 17 in the PFMT group completed the study. Both groups had a significant and clinically relevant improvement of the ICIQ-UI-SF score and decrease in number of incontinence episodes with no significant between group differences. UOP did not increase significantly in either group. Bother with KAATSU was low but seven of 14 women expressed dislike with KAATSU. The added KAATSU protocol did not increase the effect of low-intensity PFMT and it was not well tolerated. While subjective effect was significant in both intervention groups this was not reflected in the UPR measures.

Prolapse reduction deteriorates the urethral closure mechanism.

Pelvic organ prolapse (POP) reduction is often performed in the preoperative assessment of women before POP surgery. Using urethral pressure reflectometry (UPR), we sought to investigate how POP reduction affects the urethral closure mechanism. Women with anterior or posterior vaginal wall prolapse stage ≥II with and without POP reduction were examined with a speculum. We performed prolapse staging according to the Pelvic Organ Prolapse Quantification system, UPR measurements at rest and during squeezing, and standardized stress tests with 300ml saline. All examinations were repeated after insertion of a speculum. We included 38 women: 22 with anterior and 16 with posterior vaginal wall prolapse POP-Q stage ≥II. During POP reduction, resting and squeezing urethral pressures decreased by 2.5 cmH2O (p = 0.007) and 5.1 cmH2O (p < 0.0001), respectively, in all women. During POP reduction, the number of positive stress tests increased from four (18%) to eight (36%) in women with anterior vaginal wall prolapse and from one (6%) to nine (56%) in women with posterior vaginal wall prolapse. POP reduction decreases urethral pressure, especially during squeezing, and consequently increases the number of positive stress tests. The test itself artificially deteriorates the urethral closure mechanism.

The urethral closure mechanism is deteriorated after anterior colporrhaphy.

Urethral pressure reflectometry (UPR) has proven highly reproducible in women with pelvic organ prolapse. We hypothesized that urethral parameters would decrease after anterior colporrhaphy. A prospective, observational study where women with anterior vaginal wall prolapse ≥stage II were assessed before and after anterior colporrhaphy. Assessments consisted of prolapse staging according to the Pelvic Organ Prolapse Quantification system, UPR measurements at rest, during squeezing and straining (at a standardized abdominal pressure of 50 cmH2O, PO-Abd 50), standardized stress tests with 300ml saline, and answering the International Consultation on Incontinence - Urinary incontinence short form. Stress urinary incontinence (SUI) was defined as a positive stress test and a questionnaire with symptoms of SUI and a bother score>1. Sample size was 30, power was 100% and the level of significance was 5%. We analyzed data with paired t-tests or non-parametric Wilcoxon signed rank tests; p-values <0.05 were considered statistically significant. Twenty-eight women who underwent anterior colporrhaphy completed the study. PO-Abd 50 decreased 12 cmH2O after surgery (p<0.0001). Five women developed postoperative SUI and one had persistent SUI; the six women's preoperative PO-Abd 50 was lower than the rest (p<0.01). If preoperative PO-Abd 50 was ≤65 cmH2O, the positive predictive value for postoperative SUI was 50%, and if PO-Abd 50 was ≥85 cmH2O, the negative predictive value was 100%. The urethral closure mechanism deteriorates after anterior colporrhaphy. Using UPR, we can calculate a woman's risk of SUI after anterior colporrhaphy.

Posterior colporrhaphy does not affect the urethral closure mechanism.

Studies have suggested that a posterior vaginal wall prolapse might compress the urethra and mask stress urinary incontinence (SUI), much like an anterior vaginal wall prolapse. A recent study with urethral pressure reflectometry (UPR) has shown that the urethral closure mechanism deteriorates after anterior colporrhaphy; this could explain the occurrence of postoperative de novo SUI. We hypothesized that urethral pressure would also decrease after posterior colporrhaphy. This was a prospective, observational study where women with posterior vaginal wall prolapse ≥stage II were examined before and after posterior colporrhaphy. We performed prolapse staging according to the Pelvic Organ Prolapse Quantification system, UPR measurements at rest, during squeezing and straining, and standardized stress tests with 300ml saline. The women filled out International Consultation on Incontinence-Urinary incontinence (ICIQ-UI) short forms. The sample size was 18, with a power of 99.9% and a level of significance of 5%. Parameters were compared using paired t tests or Fisher's exact test, where appropriate; p values <0.05 were considered statistically significant. Eighteen women with posterior vaginal wall prolapse ≥stage II were recruited. One woman did not undergo surgery. There were no changes in urethral pressure at rest (p=0.4), during squeezing (p=0.2) or straining (p=0.2), before and after surgery. The results of the stress tests and ICIQ-UI short forms were the same after surgery. The urethral closure mechanism is not affected by posterior colporrhaphy. Our study does not support the theory that the posterior vaginal wall prolapse compresses the urethra and masks SUI.

Urethral pressure reflectometry in women with pelvic organ prolapse: a study of reproducibility.

The mechanism of continence in women with pelvic organ prolapse (POP) before and after surgery remains unknown. Urethral pressure reflectometry (UPR) separates women with stress urinary incontinence (SUI) from continent women by measuring urethral opening pressure at an abdominal pressure of 50cmH2O (P O-Abd 50). UPR can help identify women with POP at risk of postoperative de novo SUI. The aim of this study was to investigate the reproducibility of UPR in women with POP. Women with anterior or posterior vaginal wall prolapse were recruited for this prospective, observational study from our outpatient clinic. The women were examined with UPR on two occasions. Measurements were done at rest, and during squeezing and straining. Statistical analyses were performed using SAS 9.4. A Bland-Altman analysis with limits of agreement and coefficients of variation was used to determine the level of agreement between measurements. Paired t tests were used to estimate the difference; a two-tailed P value of <0.05 was considered significant. We recruited 19 women with anterior vaginal wall prolapse and 11 women with posterior vaginal wall prolapse. There were no significant differences in the opening pressures at rest or during squeezing or in the values of P O-Abd 50. P O-Abd 50 showed limits of agreement of 15.3cmH2O and a coefficient of variation of 9.9%. UPR was found to be a highly reproducible method in women with POP. UPR may be used in future studies to help reveal urodynamic features predictive of postoperative de novo SUI in women with POP.

The promise of urethral pressure reflectometry: an update.

The urethral closure mechanism in women is incompletely understood. Measuring closure function in a collapsed urethral tube without distending the tube and changing its natural shape is impossible with conventional methods. Over the last decade, studies with urethral pressure reflectometry (UPR), a method that measures pressure and the corresponding cross-sectional area along the entire length of the urethra continuously by means of acoustic reflectometry, have been performed. The studies have mainly been performed on patients with stress urinary incontinence (SUI). Our aim was to provide an overview of the studies conducted with UPR, establishing whether the method may be used in clinical practice. We reviewed all literature published on UPR. Urethral pressure reflectometry is easily performed with limited bother for the patient. The catheter consists of a 45-cm-long PVC tube connected to a thin and highly flexible polyurethane bag, which is placed in the urethra. When inserted, the bag only occupies 0.4mm(2) of the urethra, respecting the natural shape and orientation of the urethra and, most importantly; respecting the laws of physics when measuring urethral pressure. UPR can discriminate patients with SUI from continent women and separate assessment of the sphincter function and support system is possible. Also, UPR has revealed statistically significant differences in urethral pressures after drug therapy for SUI. We conclude that UPR has a place in clinical practice. The method has shown groundbreaking potential in the understanding of urethral dysfunction in SUI patients.

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

The aim was to evaluate, using urethral pressure reflectometry (UPR), the effect of fesoterodine on urethral function in women with stress urinary incontinence (SUI). 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. 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. 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 impact of tension-free vaginal tape on the urethral closure function: mechanism of action.

To investigate if the tension-free vaginal tape (TVT) works by increasing the abdominal to urethral pressure impact ratio (APIR). Twenty one women with urodynamically proven stress urinary incontinence (SUI) were assessed by ICIQ-SF, pad-weighing test, incontinence diary and Urethral Pressure Reflectometry (UPR) before and after TVT. UPR was conducted during resting and increased intra-abdominal pressure (P(Abd)) by straining. Related values of P(Abd) and urethral opening pressure (P(o)) were plotted into an abdomino-urethral pressuregram. Linear regression of the values was conducted, and the slope of the line was found. The slope expresses the ratio of pressure increase in the urethra compared to the pressure increase in the abdomen and was called APIR. The urethral opening pressure at rest (P(o-rest)) was unchanged after TVT, while APIR increased in all women (from 0.7 to 1.4, P < 0.0001). The TVT seems to strengthen the urethral closure function by increasing the APIR while P(o-rest) is unchanged regardless of the type of pre-operative dysfunction. This confirms the theory of TVT's mechanism of action being mid-urethral support.

Urethral pressure reflectometry, a novel technique for simultaneous recording of pressure and cross-sectional area in the prostatic urethra: Testing in men without bothersome lower urinary tract symptoms

Objective. Urethral pressure reflectometry (UPR) was introduced in 2005, for simultaneous measurement of pressure and cross-sectional area in the female urethra. It has shown to be more reproducible than conventional pressure measurement. Recently, it has been tested in the anal canal and the prostatic urethra. The primary aim of this study was to describe UPR in men without bothersome lower urinary tract symptoms. Material and methods. The study investigated 18 men, median age 59 (range 50–77) with UPR and pressure–flow analyses (PQ), the International Prostate Symptom Score and the Danish version of Prostate Symptom Score, flow rate, residual urine measurements, transrectal ultrasound, urethral pressure profilometry and visual analogue scale (Discomfort). UPR parameters measured were opening and closing pressure, opening and closing elastance and hysteresis, from the bladder neck to the sphincter region. Results. All UPR parameters increased significantly from the bladder neck to the sphincter region, except for the opening pressure between the prostate and the sphincter region. Seven men were obstructed according to PQ, but with no significant differences in any other standard urodynamic parameters. The hysteresis in the sphincter region was significantly lower in the obstructed group (p = 0.005). Discomfort was significantly lower with PQ compared to UPR (p = 0.04). Nine men had slight bleeding from the urethra during measurement with UPR. Conclusions. The increase in all parameters from the bladder neck to the sphincter region is consistent with previous studies measuring the same parameters. The hysteresis may explain why seven men were obstructed according to PQ.

Urethral pressure reflectometry during intra‐abdominal pressure increase—an improved technique to characterize the urethral closure function in continent and stress urinary incontinent women

to assess the urethral closure function by urethral pressure reflectometry (UPR) during intra-abdominal pressure-increase in SUI and continent women. Twenty-five urodynamically proven SUI women and eight continent volunteer women were assessed by ICIQ-SF, pad-weighing test, incontinence diary, and UPR. UPR was conducted during resting and increased intra-abdominal pressure (P(Abd)) by straining. Related values of P(Abd) and urethral opening pressure (P(o)) were plotted into an abdomino-urethral pressuregram. Linear regression of the values was conducted, and the slope of the line ("APIR") and the intercept with the y-axis found. By the equation of the line, Po was calculated for various values of P(Abd), for example, 50 cm H2O (P(o-Abd 50)). The resting P(o) (P(o-rest)) and APIR, respectively, significantly differed in SUI and continent women but could not separate the two groups. The urethral closure equation (UCE) based on P(o-rest) and APIR provided a more detailed characterization of a woman's closure function based on the permanent closure forces (primarily generated by the urethral sphincteric unit) and the adjunctive closure forces (primarily generated by the support system). P(o-Abd 50) and UCE, respectively, which express the combined permanent and adjunctive closure forces and estimate the efficiency of the closure function, separated SUI and continent women and were highly significantly negatively correlated with ICIQ-SF, pad test, and the number of incontinence episodes. New parameters for characterization of the urethral closure function and possible dysfunctions and its efficiency were provided. P(o-Abd 50) and UCE may be used as diagnostic tests and severity measures.

A faster urethral pressure reflectometry technique for evaluating the squeezing function

Objective. Urethral pressure reflectometry (UPR) has shown to be superior in evaluating the squeeze function compared to urethral pressure profilometry. The conventional UPR measurement (step method) required up to 15 squeezes to provide one measure of the squeezing opening pressure and one measure of the squeezing elastance. The UPR technique was modified (so the examination last 7 s), requiring only one squeeze for the measurement to be made (continuous method). The aims of the study were to compare the UPR parameters measured during squeezing by the continuous method with measurements made by the step method and to measure the reproducibility of the continuous method. Material and methods. In total, 33 women were included (eight healthy and 25 with urodynamically proven stress urinary incontinence). The women were measured twice with the step method followed by five measurements with the continuous method. Results. No significant difference was seen between the mean squeezing opening pressures measured with the two methods. The squeezing elastance was significantly higher (p < 0.00001) with the continuous method (2.7 cmH2O/mm2) than with the step method (1.9 cmH2O/mm2). The coefficient of variation (CV) was 6.5% for the opening pressure measured with the continuous method and 14.8% for the squeezing elastance. Conclusions. A new method for performing UPR measurements during squeezing has been described. With the new method a UPR measurement can be conducted during only one squeeze. The squeezing opening pressure is the same while the squeezing elastance is higher with the new method compared with the conventional method.

Urethral pressure reflectometry before and after tension‐free vaginal tape

Urethral pressure reflectometry (UPR) is a new method for measuring pressure and cross-sectional area in the urethra. Our aim was to investigate if the UPR parameters at rest and during squeeze were unchanged after TVT. The technique enables measurement along the entire length of the urethra simultaneously and avoids the common artefacts encountered with conventional catheters. Twenty-two stress urinary incontinent women were included. The UPR polyurethane bag was placed in the urethra and connected to a pump and an acoustic transmitter. The bag was inflated, distending it accordingly, and the CA within the bag, and thus the urethra, was measured with acoustic reflectometry. Opening and closing pressure and elastance, and hysteresis were measured. "Relaxing" and "squeezing" measurements were conducted in the supine and standing position before and after TVT. Subjective and objective cure rates were 82% and 100%, respectively. Maximum urine flow rate decreased from 31 to 18 ml/sec (P = 0.0002). Supine and standing relaxing urethral opening and closing pressures were unchanged. Supine opening elastance increased 18% (P = 0.04), which indicates an increased resistance against the opening of the urethra. Supine squeezing opening pressure decreased 10%. UPR measurements confirmed that urethral opening pressure at rest is unchanged after TVT. The TVT somewhat improves the closure function by providing increased resistance against the dilation of the urethra, which probably explains the decreased maximum urine flow rate.

Urethral pressure reflectometry; a novel technique for simultaneous recording of pressure and cross‐sectional area: a study of feasibility in the prostatic urethra

What's known on the subject? and What does the study add? In the 1980s and 1990s, a method for direct measurement of pressure and cross-sectional area in women and men was developed. It was successful in terms of obtaining meaningful results in several studies. But the technique, which was based on the field gradient principle, was never implemented in the clinical setting because of technical limitations. In 2005, urethral pressure reflectometry was introduced as a new technique in female urodynamics. The technique has been shown to be more reproducible than conventional urethral pressure profilometry, when measuring incontinence in women. In 2010 it was also introduced as a new measuring technique in the anal canal. This study, adds a new and interesting technique to the field of male urodynamics. For the first time, sound waves have been used to measure pressure and cross-sectional area simultaneously, directly in the prostatic urethra. The results from this first trial with urethral pressure reflectometry are promising, in terms of obtaining meaningful physiological parameters. Our hope is that, future trials will help us to be able to identify specific areas of obstruction or rigidity in the prostatic urethra, making treatment more direct and side effects from surgery less severe. However, further studies are needed to evaluate the technique with regards to clinical usefulness in men with benign prostatic obstruction. Urethral Pressure Reflectometry (UPR) was introduced in 2005, and it has since been used in the female urethra for simultaneous measurement of pressure (P) and cross-sectional area (CA). It has shown to be more reproducible than conventional pressure measurement and reintroduced direct measurement of pressure and elastance in the urethra as important parameters when assessing incontinent women. To test the feasibility of UPR in the prostatic urethra. We tested the technique in ten male patients, median age 73 and range 51-91. Measurements were performed in the supine position, with less than 50 ml of urine in the bladder. The UPR valuables measured were opening and closing pressure, opening and closing elastance and hysteresis. The PVC tube was easy to insert to the same degree as a normal KAD. Opening pressure and opening elastance were measured on all patients. The sphincter area was easily identified during measurements. UPR provides results compatible with previous techniques. A standardized method for measurements was developed. UPR has been shown feasible in the prostatic urethra. Further studies on healthy volunteers and patients with lower urinary tract symptoms and benign prostatic obstruction (BPO) are needed, to determine if UPR has a future role in urodynamic diagnostics of male patients with BPO.

Measurement of Urethral Closure Function in Women With Stress Urinary Incontinence

We assessed the use of urethral pressure reflectometry in detecting pressure increases in the female urethra and compared the usefulness of urethral pressure reflectometry vs urethral pressure profilometry in a pharmacodynamic intervention study. In this randomized, double-blind, placebo controlled, crossover study 17 women with stress urinary incontinence or mixed urinary incontinence received 4 mg esreboxetine or placebo for 7 to 9 days followed by a washout period before crossing over treatments. Urethral pressure reflectometry and urethral pressure profilometry were performed before and at the end of each treatment period. The urethral opening pressure measured with urethral pressure reflectometry increased significantly compared to placebo by 13.7 cm H(2)O (p <0.0001) with an observed within subject standard deviation of 5.4. The increase in maximum urethral closure pressure was 8.4 cm H(2)O compared to placebo (p = 0.06) and for maximum urethral pressure the increase was 9.9 cm H(2)O (p = 0.04). However, the within subject SD for these parameters was higher at 11.4 and 12.2, respectively, implying lower power for these analyses. While receiving esreboxetine patients had significantly fewer incontinence episodes and reported a treatment benefit (global impression of change) compared to placebo. The opening pressure measured with urethral pressure reflectometry was less variable compared to the parameters measured with urethral pressure profilometry (maximum urethral closure pressure and maximum urethral pressure). Consequently using urethral pressure reflectometry would result in a more efficient study design when investigating pharmacological effects on the urethra in future studies. We also found that esreboxetine was well tolerated, and had a positive and clinically relevant effect on urethral closure function and symptoms of stress urinary incontinence.

Urethral injection therapy: What is the mechanism of action?

The mechanism of action of injection therapy is virtually unknown. Urethral Pressure Reflectometry (UPR) is a novel technique for measuring pressure and cross-sectional area in the urethra. UPR which provides reliable physiological meaningful parameters was used to study the mechanism of urethral injection therapy. Fifteen patients with stress urinary incontinence (nine women) and mixed incontinence (six women) were investigated with UPR before and 101 days after urethral injection therapy. The patients subjectively judged if their stress and urge symptoms were cured/improved almost unchanged or worsened. Ten women were cured/improved after the injection therapy. None became worse. Six patients had urge symptoms before injection therapy which did not change after the procedure. The patients were divided into two groups based on their subjective assessments of effect. One group with effect (10 women) and 1 group without effect (5 women). The patients had significantly higher squeezing opening pressure after the treatment. The other parameters were unchanged. The mean squeezing opening pressure increased significantly (P < 0.01) more in the group of patients with effect (10.6 cmH(2)O) than in the group without effect (-1.6 cmH(2)O). Injection therapy may work by increasing the power of the urethral sphincter. The bulking material may function as additional central filler volume which increase the length of the muscle fiber and thereby the power of the sphincter.

Urethral pressure reflectometry and pressure profilometry in healthy volunteers and stress urinary incontinent women

Urethral pressure reflectometry (UPR) is a novel reliable method for simultaneous measurement of pressure and cross-sectional area in the female urethra. The aim of this study was to report values for UPR parameters in healthy and stress urinary incontinent (SUI) women and compare UPR with urethral pressure profilometry (UPP) parameters. The study included 30 SUI women and 30 volunteers (23 "continent" and 7 "nearly continent"). The women were examined in the supine position both while relaxed and during squeezing, and upright position. The following UPR variables were measured; opening and closing pressure, opening and closing elastance, hysteresis(absolute) and hysteresis(percent). UPP with the perfusion technique was carried out with the women supine while relaxed and during squeezing. The maximum urethral pressure (MUP) and maximum urethral closure pressure (MUCP) were obtained. All parameters except the hysteresis(percent) were significantly decreased in the SUI group compared to the volunteers. The squeeze opening pressure increased in all women compared to the resting condition, while MUP and MUCP during squeeze increased in 78% and decreased in 22%. The separation between the continent and SUI women was better using the resting and squeezing opening pressure than the corresponding UPP parameters. UPR is a clinically reliable technique, which provides sound physiological parameters. The resting and squeezing opening pressures separate SUI from continent women better than the UPP parameters. The UPR parameters have the potential to provide a pathophysiologic subdivision of SUI and other dysfunctions.