Average Detrusor Research Articles

A pilot study assessing average detrusor pressure garnered from area under a urodynamic curve: Evaluation of clinical outcomes

The management of neurogenic bladder mostly relies on urodynamic studies; however, several studies have shown low interobserver reproducibility. The aim of this study was to evaluate if a new objective cystometric parameter was superior to other cystometric measures. A new parameter (pressure adjusted area under curve ratio, PAUC) was formulated from the ratio of area under the cystometry curve to a DLPP-adjusted total area (AT). AT was figured from a rectangle designed on the cystometrogram curve with a fixed height of 200 cmH2O and a width defined by the filling phase (figure). Two different estimated pressure measures derived from this (upper mean static pressure, UMSP and theoretical end filling pressure TEFP) were then calculated. Medical records of myelomeningocele patients with ultrasonography and renal scintigraphy performed at the time of urodynamics (with an interval of >5 years) were reviewed. Hydronephrosis and new scars in scintigraphy were used as the outcome measures. The study group consisted of 115 subjects with a median age of 4 (0-23) years at the time of the first urodynamic study. The median follow-up was 6 (5-14) years. PAUC and its derivatives (UMSP and TEFP) had the best discriminative power in predicting high grade hydronephrosis (0.830, 95% CI:0.732-0.927, p<0.001), worsening in hydronephrosis (0.827, 95% CI:0.723-0.931, p<0.001), and new scar formation (0.704, 95% CI: 0.576-0.832, p=0.002). PAUC>0.1 significantly correlated with urinary tract dilatation (p<0.001) and new scar formation (p=0.002). In the multivariate analysis, our three parameters and having scars at admission were the only independent risk factors for new scars (p=0.001 and p=0.002, respectively) and worsening in hydronephrosis (p<0.001 and p=0.001, respectively). Our results show that our three parameters derived from area under the urodynamic curve are more reliable than other urodynamic measures. Their major theoretical advantage is to incorporate all the pressure during filling phase giving a more accurate picture of what the intravesical pressure milleu is. Using these measures, we demonstrated their superiority in predicting clinical outcomes. Major limitations of this study are the retrospectively collected data and lack of longitudinal follow-up starting from infancy in each patient. Our new parameters (PAUC, UMSP and TEFP) which incorporate the impact of entire filling phase pressure changes in the analysis, may be useful tools to identify those patients who are under the risk of kidney damage with neurogenic lower urinary tract dysfunction.

Post-Irradiation Bladder Syndrome After Radiotherapy of Malignant Neoplasm of Small Pelvis Organs: An Observational, Non-Interventional Clinical Study Assessing VESIcare®/Solifenacin Treatment Results

BackgroundRadiotherapy is explicitly indicated as one of the excluding factors in diagnosing overactive bladder syndrome (OAB). Nevertheless, symptoms of OAB such as urgent episodes, incontinence, pollakiuria, and nocturia, which are consequences of irradiation, led us to test the effectiveness of VESIcare®/Solifenacin in patients demonstrating these symptoms after radiation therapy of small pelvis organs due to malignant neoplasm.Material/MethodsWe conducted an observatory clinical study including 300 consecutive patients with symptoms of post-irradiation bladder; 271 of those patients completed the study. The observation time was 6 months and consisted of 3 consecutive visits taking place at 12-week intervals. We used VESIcare® at a dose of 5 mg a day. Every sixth patient was examined urodynamically at the beginning and at the end of the observation period, with an inflow speed of 50 ml/s.ResultsWe noticed improvement and decline in the average number of episodes a day in the following parameters: number of micturitions a day (−36%, P<0.01), nocturia (−50%, P<0.01), urgent episodes (−41%, P<0.03), and episodes of incontinence (−43%, P<0.01). The patients’ quality of life improved. The average maximal cystometric volume increased by 34 ml (21%, p<0.01), average bladder volume of “first desire” increased by 42 ml (49%, P<0.01), and average detrusor muscle pressure at maximal cystometric volume diminished by 9 cmH2O (−36%, P<0.03).ConclusionsThe substance is well-tolerated. Solifenacin administered long-term to patients with symptoms of OAB after radiotherapy of a malignant neoplasm of the small pelvis organs has a daily impact in decreasing number of urgent episodes, incontinence, pollakiuria, and nocturia.

Surface functional electrical stimulation combined with electroacupuncture in treating neurogenic bladder after the spinal cord injury

Objective To observe the therapeutic effect of surface functional electrical stimulation combined with electroacupuncture on neurogenic bladder after the spinal cord injury. Methods Forty cases of neurogenic bladder after the spinal cord injury were randomly divided into a control group (n=20) and a combination group (n=20). The combination group was treated with surface functional electrical stimulation combined with electroacupuncture on the basis of internal urethral catheterization, while the control group was treated with surface functional electrical stimulation on the basis of internal urethral catheterization. The bladder urination was tested using urodynamic study before and after two months of treatment. Results There was no significant difference between the 2 groups in the average maximum bladder capacity, detrusor pressure at filling time, maximal urethral closure pressure, maximum urine flow rate and residual urine volume before the treatment. After the treatment, however, the average maximum bladder capacity, maximal urethral closure pressure and maximum urine flow rate in the combination group were significantly higher than those of the control group, while the average detrusor pressure at filling time and the residual urine volume of the combination group were significantly lower than the control group. Conclusion Surface functional electrical stimulation combined with electroacupuncture could remarkably improve bladder function of patients with the neurogenic bladder after the spinal cord injury. Key words: Surface functional electrical stimulation; Electroacupuncture; Urodynamic study; Neurogenic bladder

The significance of urodynamic analysis in evaluating neurogenic vesicoureteral reflux in patients with thoracolumbar spinal cord injury

Objective To investigate the utility of urodynamic testing in the evaluation of neurogenic vesicoureteral reflux in patients with thoracolumbar spinal cord injury at the T10 to L2 level. Methods Twenty-six patients with thoracolumbar spinal cord injury at the T10 to L2 level and who displayed vesicoureteral reflux were enrolled and divided into a detrusor hyper-reflexia group (n=21) and a detrusor a-reflexia group (n=5) according to their cystourethrograms and urodynamic test results. Their bladder volume, detrusor pressure (Pdet) and compliance were observed and analyzed at the vesicoureteral reflux point and the leak point. Results The bladder volume and compliance of the detrusor hyper-reflexia group at the vesicoureteral reflux point were (122.46±87.89) ml and (5.94±4.96) ml/H2O respectively, significantly different from the detrusor a-reflexia group (P<0.01). At the leak point, the average bladder volume of the detrusor hyper-reflexia group was (210.81±69.72)ml, while the average bladder compliance was (9.53±5.43)ml/H2O and the average detrusor pressure was (42.29±9.57)cm H2O. All were significantly different from the detrusor a-reflexia group's averages. Moreover, there was a significant difference in the Pdet between the leak point and the vesicoureteral reflux points in the detrusor hyper-reflexia group. Conclusions Patients with thoracolumbar spinal cord injuries at the T10 to L2 level with neurogenic bladder and detrusor hyper-reflexia have low bladder volumes and compliance, and vesicoureteral reflux tends to occur at an early stage after injury with a destrusor pressure lower than 40 cm H2O. For patients with detrusor a-reflexia, vesicoureteral reflux and bladder leakage may occur when detrusor pressure is low. Key words: Spinal cord injury; Neurogenic bladder dysfunction; Vesicoureteral reflux; Urodynamics

Is it possible to use the rectus abdominis neo-sphincter as a continence mechanism for urinary catheterizable channels? A histologic and histochemical evaluation in an experimental study in rabbits

ObjectiveTo evaluate in a rabbit experimental model a mechanism of continence of catheterizable urinary conduits (CUC), focusing on the behavior of intersected rectal muscle fibers in relation to the channel by histological and histochemical analysis, and secondarily to register conduit continence rates from clinical and urodynamic data. Materials and methods12 rabbits were submitted to construction of a CUC from two abdominal skin flaps and divided into two groups: 8 with a urinary neo-sphincter created according to Yachia and 4 controls. We registered clinical outcome, urodynamic studies and microscopic analysis of CUC on the surface of the conduit, which was in direct contact with the mechanism of continence. We took muscle samples from the mechanisms of continence and performed histochemical evaluation by enzymatic reactions. ResultsHistological evaluation of the CUC showed no difference between groups. Histology and immunohistochemistry of the muscle fibers showed that areas of necrosis, cell atrophy and motor neuron injury from the first eight weeks recovered by the end of 16th week. Conduit complications occurred in 4 animals (33%). The average detrusor leakage point pressure through the conduit was 90 cm H2O versus 39 cm H2O through the urethra. ConclusionThe mechanism of continence did not promote ischemic stress on the conduit, was able to promote high pressure resistance and showed good recovery of intersected muscle fibers, after an initial slight atrophy, suggesting good durability of the neo-sphincter.

1514 OUTCOME OF DUAL FLANGE METALLIC URETHRAL STENTS IN THE TREATMENT OF NEUROPATHIC BLADDER DYSFUNCTION AFTER SPINAL CORD INJURY

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Neurogenic Voiding Dysfunction1 Apr 20111514 OUTCOME OF DUAL FLANGE METALLIC URETHRAL STENTS IN THE TREATMENT OF NEUROPATHIC BLADDER DYSFUNCTION AFTER SPINAL CORD INJURY Andre Van der Merwe, Ed Baalbergen, Ray Shrosbree, and Chris Heyns Andre Van der MerweAndre Van der Merwe Cape Town, South Africa More articles by this author , Ed BaalbergenEd Baalbergen Cape Town, South Africa More articles by this author , Ray ShrosbreeRay Shrosbree Cape Town, South Africa More articles by this author , and Chris HeynsChris Heyns Cape Town, South Africa More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1493AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To audit the results of metallic urethral stents used in patients with spinal cord injury (SCI). The bladder management after spinal cord injury (SCI) may determine the life expectancy of these patients, because the second leading cause of death (after respiratory causes) is urinary tract complications. Renal failure may follow vesico-ureteric reflux caused by highpressure neurogenic bladder dysfunction. METHODS We performed a case note review of dual flange Memokath™ stents placed from March 2008 until April 2010. Inclusion criteria were: (1) severe autonomic dysreflexia, (2) repeated catheter blockage, bladder stones, urinary tract infection (UTI), (3) prevention of upper urinary tract damage, if signs of severe bladder hostility were seen on urodynamic study (UDS) or cystography, coupled with symptoms of autonomic dysreflexia. Patients received, under deep general anaesthesia, a thermo-sensitive expandable metallic stent which was positioned over the internal and external urethral sphincters. The stent was expanded by irrigating it with warm saline when seen in position on X-ray fluoroscopy. RESULTS In total, 21 stents were placed in 19 male patients. The most common length stent was 6 cm (range 4–7cm). SCI was cervical in 16 patients and thoracic in 3. Average age of the patients was 35 years. The most common cause of spinal cord injury (SCI) was motor vehicle accident (MVA). Average follow-up time was 15 months (5–25). The most common indication was repeated catheter blockage and -UTI (8). The median time to stenting post-SCI was 21 months (1–468). Average detrusor pressure (Pdet) on pre-operative UDS was 65 cm H2O. Severe autonomic dysreflexia was present in 13 cases. Stents failed in 6 patients (31%) and were removed. Most common reason for failure was poor drainage with UTIs (5 cases). Two patients with failed stents had flaccid bladders pre-operatively. Median time to placement of stents that subsequently failed was 72 months and median time to placement of stents that were successful was 20 months. One major complication was stent migration that caused a urethra-cutaneous fistula. CONCLUSIONS Metallic stenting in SCI related neuropathic bladder dysfunction is a minimally invasive, reversible procedure with acceptable success and complication rates. Earlier placement during SCI evolvement may be associated with better outcomes. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e607 Peer Review Report Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Andre Van der Merwe Cape Town, South Africa More articles by this author Ed Baalbergen Cape Town, South Africa More articles by this author Ray Shrosbree Cape Town, South Africa More articles by this author Chris Heyns Cape Town, South Africa More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Systemic Nitric Oxide Augmentation Leads to a Rapid Decrease of the Bladder Outlet Resistance in Healthy Men

ObjectiveWe examined the immediate effect of a systemic nitric oxide augmentation on the bladder outlet resistance in healthy men. MethodsEleven healthy male volunteers with a mean age of 25.5 yr were included in the study. They were prepared for a standard urodynamic study, and a baseline pressure-flow study was obtained. The subjects were then given 20mg isosorbide dinitrate sublingually, and after refilling their bladder a second pressure-flow study was done after 20min. The pressure-flow studies were then compared in regard to the average flow rate, the average detrusor pressure during micturition, and the detrusor pressure at maximum flow rate. ResultsOne of the subjects was unable to void and had to be excluded from the study. In the remaining 10 men, the mean average flow rate increased from 16.7ml/s before to 20.2ml/s after the intake of the NO donor (P=0.013). Concomitantly, the average detrusor pressure during micturition decreased from a mean of 57 to 52cm H2O (P=0.004) and the mean detrusor pressure at maximum flow rate decreased from 60 to 52cm H2O (P=0.013). ConclusionsSystemic NO augmentation can lower the functional bladder outlet resistance very rapidly in men. Our results support the concept that the NO-cGMP pathway may be a promising target for medical treatment of lower urinary tract symptoms.

Urodynamic evaluation of the human bladder response to an increase in outlet resistance.

We prospectively evaluated the response of the human bladder to a chronic increase in urethral resistance according to the indices of pressure, volume flow rate, total (external) bladder work, and maximum and average detrusor power. Six men with incontinence after radical prostatectomy were evaluated urodynamically before and 3-6 months after undergoing a bulbourethral sling procedure. None of the men suffered from significant obstructive or irritative voiding symptoms preoperatively. Urodynamic evaluation showed postoperative increases in both average detrusor pressure and pressure at maximum flow, but there were no significant changes in voided volume, void time, or postvoid residual urine volume. Maximum detrusor power, average detrusor power, and total (external) bladder work were all significantly increased. These data confirm that the human bladder possesses a functional reserve, which is elicited by an increase in urethral resistance.

PRESSURE FLOW ANALYSIS MAY AID IN IDENTIFYING WOMEN WITH OUTFLOW OBSTRUCTION

We refined recently developed pressure flow cutoff values for female bladder outlet obstruction and applied these values in a consecutive group of women undergoing urodynamic testing for various lower urinary tract symptoms. A total of 87 women with clinical obstruction determined by history and presenting complaint were enrolled in our prospective evaluation of pressure flow studies. We identified 3 groups of participants according to the suspected cause of obstruction, including prolapse in 33, previous incontinence surgery in 25, and no likely source of obstruction identified from history and physical examination only in 29. An additional 124 patients presenting for evaluation of stress urinary incontinence served as controls. Optimal cutoff values for determining obstruction were developed using receiver operating characteristic curves. To determine the prevalence of bladder outlet obstruction these values were prospectively applied to 106 women undergoing urodynamics for various voiding complaints. In controls the average maximum flow rate was 23 cc per second and average detrusor pressure was 21.9 cm. water, whereas the corresponding values in those with clinical obstruction were 10.7 cc per second and 40.8 cm. water (p <0.001). No differences were noted in the various obstruction groups. Receiver operating characteristics analysis revealed that cutoff values of 11 cc per second or less and 21 cm. water or more optimized the selection of patients with bladder outlet obstruction. Using these values we noted a bladder outlet obstruction prevalence of 20% in a consecutive cohort of women undergoing urodynamic studies at our center. We propose cutoff pressure flow values for identifying women with bladder outlet obstruction although they should be used only in conjunction with the overall clinical situation. Neither pressure flow data only nor clinical symptoms alone may be sufficient for diagnosing obstruction in women.

Quantification of urethral resistance and bladder function during voiding, with special reference to the effects of prostate size reduction on urethral obstruction due to benign prostatic hyperplasia

AbstractIn pressure/flow studies of adult voiding the behaviour of the urethra can be distinguished from that of the bladder, and quantified separately, as follows. Different degrees of urethral obstruction can be quantified and ranked using a group‐specific resistance factor (URA) that is based empirically on the pressure/flow plots obtained in a large number of voidings of adult patients. Different detrusor contractions can be similarly quantified using a physiologically based measure (WF, abbreviated from power [W] factor) of the contraction strength. Both URA and WF can be calculated by computer from measurements of detrusor pressure, voiding flow rate, and the residual volume in the bladder after voiding. For other groups of patients, e.g., children, different group‐specific resistance factors are appropriate.In men with obstructed voiding due to benign prostatic hyperplasia (BPH), “chemical castration” with cyproterone acetate or buserelin caused a substantial, reversible reduction in the size of the prostate. The effect on the degree of urethral obstruction and the voiding bladder contraction has been studied using the above‐mentioned methods. There was an increase in peak urinary flow rate, a reduction in residual urine, and a decrease in daytime voiding frequency. Surprisingly, however, there was on average no decrease in urethral resistance but only an increase in the average detrusor contraction strength. In individual patients large increases and decreases of urethral resistance and detrusor contraction strength occurred, which largely cancelled each other out. These large changes masked the relatively modest urethral resistance decrease caused directly by prostate size reduction.