Simple bladder filling with a cough stress test compared with subtracted cystometry for the diagnosis of urinary incontinence

Location- and layer-dependent biomechanical and microstructural characterisation of the porcine urinary bladder wall

The knowledge of the mechanical properties of the urinary bladder wall helps to explain its storage and micturition functions in health and disease studies; however, these properties largely remain unknown, especially with regard to its layer-specific characteristics and microstructure. Consequently, this study entails the assessment of the layer-specific differences in the mechanical properties and microstructure of the bladder wall, especially during loading. Accordingly, ninety-two (n=92) samples of porcine urinary bladder walls were mechanically and histologically analysed. Generally, the bladder wall and different tissue layers exhibit a non-linear stress-stretch relationship. In this study, the load transfer mechanisms were not only associated with the wavy structure of muscular and mucosal layers, but also with the entire bladder wall microstructure. Contextually, an interplay between the mucosal and muscular layers could be identified. Therefore, depending on the region and direction, the mucosal layer exhibited a stiffer mechanical response to equi-biaxial loading than that offered by the muscular layer when deformed to stretch levels higher than λ=1.6 to λ=2.2. For smaller stretches, the mucosal layer evinces no significant mechanical reaction, while the muscular layer bears the load. Owing to the orientation of its muscle fibres, the muscular layer shows an increased degree of anisotropy compared to the mucosal layer. Furthermore, the general incompressibility assumption is analysed for different layers by measuring the change in thickness during loading, which indicated a small volume loss.

The retropubic tension-free vaginal tape procedure-Efficacy, risk factors for recurrence and long-term safety

INTRODUCTION

The retropubic tension-free vaginal tape has been the preferred method for primary surgical treatment of stress urinary incontinence and stress-dominated mixed urinary incontinence in women for more than 20 years. This study presents long-term safety and efficacy data and assesses risk factors for long-term recurrence.

MATERIAL AND METHODS

In a case-series design we assessed a historical cohort of primary surgeries performed with the tension-free vaginal tape procedure in 596 women from 1998 to 2012 with follow up through 2015. Information from the medical records was transferred to a case report form comprising data on early and late complications and recurrence of urinary incontinence defined as bothersome stress urinary incontinence symptoms. All analyses were performed with SPSS using Pearson chi-square, survival and Cox regression analyses.

RESULTS

After a 10-year follow up, mixed urinary incontinent women (hazard ratio 2.1, 95% confidence interval [CI] 1.4-3.0) had a significantly increased risk of recurrence of stress urinary incontinence symptoms compared with women with pure stress urinary incontinence as the indication for surgery. Overall cumulative cure rates after 1, 5 and 10 years were 92% (95% CI; 90%-94%), 79% (95% CI; 75%-83%) and 69% (95% CI; 63%-75%), respectively. Recurrent surgery (0.3%) and serious tape complications needing major surgical treatment (0.3%) were rare. Six patients (1.0%) had the tape cut due to urinary retention, and nine patients (1.5%) reported urinary retention more than 3 months after surgery.

CONCLUSIONS

The tension-free vaginal tape procedure has a high long-term durability. Mixed urinary incontinence as an indication for surgery predicted long-term recurrence. Long-term complications were rare.

Location-dependent correlation between tissue structure and the mechanical behaviour of the urinary bladder

The mechanical properties of the urinary bladder wall are important to understand its filling-voiding cycle in health and disease. However, much remains unknown about its mechanical properties, especially regarding regional heterogeneities and wall microstructure. The present study aimed to assess the regional differences in the mechanical properties and microstructure of the urinary bladder wall. Ninety (n=90) samples of porcine urinary bladder wall (ten samples from nine different locations) were mechanically and histologically analysed. Half of the samples (n=45) were equibiaxially tested within physiological conditions, and the other half, matching the sample location of the mechanical tests, was frozen, cryosectioned, and stained with Picro-Sirius red to differentiate smooth muscle cells, extracellular matrix, and fat. The bladder wall shows a non-linear stress-stretch relationship with hysteresis and softening effects. Regional differences were found in the mechanical response and in the microstructure. The trigone region presents higher peak stresses and thinner muscularis layer compared to the rest of the bladder. Furthermore, the ventral side of the bladder presents anisotropic characteristics, whereas the dorsal side features perfect isotropic behaviour. This response matches the smooth muscle fibre bundle orientation within the tunica muscularis. This layer, comprising approximately 78% of the wall thickness, is composed of two fibre bundle arrangements that are cross-oriented, one with respect to the other, varying the angle between them across the organ. That is, the ventral side presents a 60°/120° cross-orientation structure, while the muscle bundles were oriented perpendicular in the dorsal side.

STATEMENT OF SIGNIFICANCE

In the present study, we demonstrate that the mechanical properties and the microstructure of the urinary bladder wall are heterogeneous across the organ. The mechanical properties and the microstructure of the urinary bladder wall within nine specific locations matching explicitly the mechanical and structural variations have been examined. On the one hand, the results of this study contribute to the understanding of bladder mechanics and thus to their functional understanding of bladder filling and voiding. On the other hand, they are relevant to the fields of constitutive formulation of bladder tissue, whole bladder mechanics, and bladder-derived scaffolds i.e., tissue-engineering grafts.

Diagnostic accuracy of single channel cystometry for neurogenic bladder diagnosis following spinal cord injury: a pilot study

INTRODUCTION

This is a cross-sectional study of 1 year duration (August 2013 to August 2014). The objective of the study was to investigate the diagnostic accuracy of single channel cystometry (SCC) for confirmation of neurogenic bladder following spinal cord injury.

MATERIALS AND METHODS

The study was conducted in both out-patient and in-patient services of Department of Rehabilitation Medicine, Hospital Sungai Buloh, Malaysia. Subjects in the study include sixteen patients with a clinical diagnosis of neurogenic bladder following spinal cord injury aged between 15 and 62 years. Patients with a clinical diagnosis of neurogenic bladder were subjected to cystometric evaluation using SCC in our hospital. Confirmation of the diagnosis was made by urodynamic study (UDS) in another hospital. SCC procedure involved manual intra-vesical pressure assessment using a 12F Nelaton catheter. Cystometric parameter measurement taken in this study was detrusor pressure (cm H₂O) done at regular intervals from baseline, throughout bladder filling phase and voiding/leaking phase. The relationship between detrusor pressure to bladder volume from initial bladder filling until voiding or leaking phase was recorded, analyzed and graph plotted. Maximum detrusor pressure (cm H₂O) during bladder filling, voiding or leaking and the maximum cystometric capacity (mls) was recorded.

RESULTS

SCC was found to have 100% sensitivity, 50% specificity, 93.33% positive predictive value and 100% negative predictive value for neurogenic bladder diagnosis. Only 55.55% patients with SCC suspicion of detrusor sphincter dyssynergia (DSD) had comparable UDS findings.

DISCUSSION

The use of SCC may be considered for objective confirmation of neurogenic bladder diagnosis following spinal cord lesion in centers with limited access to UDS. However, we are not able to establish its clinical application for confirmation of DSD.

Bladder Reconstruction with Human Amniotic Membrane in a Xenograft Rat Model: A Preclinical Study

Background: Human amniotic membranes (HAMs) are assumed to have a number of unique characteristics including durability, hypoallergenic and anti-inflammatory properties. Materials and Methods: Multilayer HAMs from caesarian sections were applied to repair defined bladder defects in male Sprague-Dawley rats. The animals were sacrificed at 7, 21 and 42 days after implantation. Bladder volume capacity after grafting was measured. Histological analyses were performed to asses a number of parameters including HAM degradation, inflammatory reaction, graft rejection and smooth muscle ingrowth. Results: One rat died from sepsis in the treated group. No severe complications or signs of leakage were observed. Bladder capacity did not change over time. The initially increased inflammation in the HAM group diminished significantly over time (p<0.05). No signs of HAM degradation were observed and smooth muscle staining increased over time. Conclusions: HAMs appear to be durable and hypoallergenic grafts. The assumed suitability for the reconstruction of urinary tract justifies further research on detailed immunological process in larger grafts.

Retrospective study on tension-free vaginal tape obturator (TVT-O)

INTRODUCTION AND HYPOTHESIS

We aim to report the 3-year outcome and complications of the tension-free vaginal tape obturator (TVT-O) in treating female stress urinary incontinence (SUI).

METHODS

Retrospective analysis for complications and outcome of surgery was performed in 419 women undergoing the TVT-O from 2004 to 2006.

RESULTS

Three patients (0.8%) with an isolated TVT-O had a blood loss of more than 200 ml. Two patients (0.5%) had bladder perforation. Out of 11 readmitted patients (2.6%), 10 were due to voiding difficulty. Six patients (1.4%) required tape loosening or division. Persistent pain occurred in 3.6% and erosion in 2.4% of patients. One hundred eighty-five patients (44.2%) came for follow-up at 3 years. The actual subjective and objective success rates were 89.7% and 99.9% at 3 years follow-up, respectively. With imputation, the 3-year subjective and objective success rates were 86.9% and 97.4%, respectively.

CONCLUSIONS

The TVT-O is effective in treating female SUI with minimal complications.

Clinical approach and office evaluation of the patient with pelvic floor dysfunction

Pelvic floor disorders are common health issues for women and have a great impact on quality of life. These disorders can present with a wide spectrum of symptoms and anatomic defects. This article reviews the clinical approach and office evaluation of patients with pelvic floor disorders, including pelvic organ prolapse, urinary dysfunction, anal incontinence, sexual dysfunction, and pelvic pain. The goal of treatment is to provide as much symptom relief as possible. After education and counseling, patients may be candidates for non-surgical or surgical treatment, and expectant management.

The use of one-channel water cystometry in patients with a spinal cord lesion: practicalities, clinical value and limitations for the diagnosis of neurogenic bladder dysfunction

STUDY DESIGN

Investigational technique evaluation.

OBJECTIVE

To evaluate the clinical value and limitations of one-channel cystometry as a method for urodynamic testing in patients with spinal cord lesion (SCL).

SETTING

Spinal Cord Injury Centers Asia.

METHODS

Protocol, equipment and practical performance of the one-channel cystometry as used in Ho Chi Minh City and Chiang Mai were studied.

RESULTS

One-channel cystometry permits to accurately evaluate bladder pressure development at constant filling speed. It shows detrusor muscle behaviour as detrusor overactivity and allows evaluating sensation of bladder filling. It can strongly suggest detrusor external sphincter dyssynergia. The need of bladder-relaxant drugs and their effectiveness can be evaluated. The major limitation is that the one pressure line will show changes of intravesical pressure independent of their cause, which makes a continuous thorough observation mandatory throughout the test. Other limitations are a filling rate higher than physiological and a filling solution at room temperature. As in more elaborate urodynamic testing, the observations do therefore not necessarily reflect the function of the lower urinary tract in daily life.

CONCLUSION

One-channel cystometry is easy to perform, cheap and clinically valid. The results need to be integrated in the overall knowledge of the patient's neurological situation. The method permits one to gather a lot of information on bladder function in persons with SCL. With proper interpretation and a clear understanding of the shortcomings, it is a good guide for bladder management. It is applicable everywhere.

A critical review of diagnostic criteria for evaluating patients with symptomatic stress urinary incontinence

The first paper in this section is a review by several highly respected authors of diagnostic criteria for evaluating patients with symptomatic stress urinary incontinence, and is followed by a review of the role of urgency and its measurement in the overactive bladder symptom syndrome, with emphasis on current concepts and future prospects. These are two important papers, which point the reader in the direction of a greater understanding of these conditions. The concept of alpha-blockade before a trial without catheter after acute urinary retention is revisited by authors from the UK, who used tamsulosin in a randomized controlled trial. They found that it is appropriate to recommend tamsulosin for such use in this condition.

Further characterization of the supine empty stress test for predicting low valsalva leak point pressures

The aim of this study is to determine if the diagnostic accuracy of the supine empty stress test (SEST) differs depending on the volume of residual urine. We performed a review of all patients who were diagnosed with stress urinary incontinence (SUI) via multi-channel urodynamics including valsalva leak point determinations (VLPP). A SEST was performed and the residual urine recorded via catheterization. The test-specific indices of the SEST for the prediction of low VLPP (defined as <60 cm H(2)0) were determined for varying residual volumes. Ninety-nine patients were included. Regardless of residual volume, low sensitivities, specificities and positive predictive values were demonstrated. Sensitivity and positive predictive values were further reduced and negative predictive values were improved slightly with higher residual volume. The highest negative predictive value was 89% at a residual volume of greater than 10 mL. Residual urine volume has minimal impact on the utility of the SEST.

Good practice in continence care: development of nurse-led service

The implementation of evidence-based interventions in clinical practice is often alluded to in the literature; however, the development of these interventions is rarely documented. Within continence care, there is a larger body of relevant literature on which primary clinical interventions can be based. The Leicestershire Medical Research Council (MRC) Incontinence Study is a series of inter-related studies exploring the epidemiology of urinary symptoms, including incontinence, and evaluating service provision and treatment options for these symptoms. This article describes one aspect of the Leicestershire study, namely the development of evidence-based intervention protocols for use in a new nurse-led continence service. This service is currently being evaluated in a randomised controlled trial.

The supine stress test: a simple method to detect intrinsic urethral sphincter dysfunction

PURPOSE

A new clinical test for intrinsic urethral sphincter dysfunction is proposed and compared to abdominal leak point pressure determination by video urodynamics.

MATERIALS AND METHODS

Patients were prospectively included in the study if they had stress urinary incontinence symptoms and were to undergo video urodynamic testing. Patients with urinary tract infection, cystocele, rectocele and vaginal vault prolapse were excluded from study. A supine stress test using cough and Valsalva's maneuvers was performed after bladder filling to 200 ml. with sterile normal saline solution by gravity. Efflux of the bladder solution from the meatus coinciding with the cough or Valsalva maneuver indicated a positive clinical test. A video urodynamic study, including abdominal leak point pressure, was performed. Intrinsic urethral sphincter dysfunction was diagnosed if abdominal leak point pressure was less than 100 cm. water. Test indexes were calculated based on the results of the supine stress test and the abdominal leak point pressure measurements.

RESULTS

Results were positive in 30 of 41 consecutive patients and negative in 11. Using abdominal leak point pressure measurement, the supine stress test had 93.5% sensitivity, 90.0% specificity, 96.7% positive predictive value and 81.8% negative predictive value for detecting intrinsic urethral sphincter dysfunction.

CONCLUSIONS

The supine stress test is easy, quick and inexpensive, and a positive test is a reliable predictor of intrinsic urethral sphincter dysfunction. A negative test is highly correlated with the absence of intrinsic urethral sphincter dysfunction during video urodynamic testing. This test is more reliable in diagnosing intrinsic urethral sphincter dysfunction than other nonurodynamic tests reported in the literature. The supine stress test can be a useful supplement to cotton swab testing for urethral hypermobility in determining the appropriate management for stress urinary incontinence.