Detrusor underactivity: Pathophysiological considerations, models and proposals for future research. ICI-RS 2013

Detrusor Overactivity After Partial Bladder Outlet Obstruction Is Associated With High Urinary Adenosine Triphosphate Levels in Female Wistar Rats

PURPOSE

Bladder outlet obstruction (BOO) commonly causes detrusor overactivity (DO). In this study, a post hoc analysis of previous obtained data, we investigate if DO occurring in initial phases of BOO is associated with changes in urinary adenosine triphosphate (ATP) levels.

METHODS

Adult female Wistar rats were submitted to partial BOO (pBOO) or to sham obstruction. Cystometry was performed at 3 or 15 days after pBOO and saline voided was collected for ATP determination. Normality was tested using Shapiro-Wilk test. The mean frequency of voiding contractions (VCs) of the sham-operated animals at 15 days after surgery, plus or minus 3 standard deviations, was used to represent the normal range. Statistical analyses were performed using the chi-square and Mann-Whitney tests.

RESULTS

DO was indicated by a VC frequency greater than or equal to 0.9 VCs/min. DO was observed in 63% of animals at 3 days and in 33% at 15 days following pBOO. ATP levels were significantly higher in rats with DO compared to those without DO.

CONCLUSION

The DO phenotype, occurring in the initial phases of BOO, is associated with comparatively high urinary ATP levels.

Detrusor underactivity is associated with metabolic syndrome in aged primates

Lower urinary tract (LUT) dysfunction is prevalent in the elderly population, and clinical manifestations include urinary retention, incontinence, and recurrent urinary tract infections. Age-associated LUT dysfunction is responsible for significant morbidity, compromised quality of life, and rising healthcare costs in older adults, but its pathophysiology is not well understood. We aimed to investigate the effects of aging on LUT function by urodynamic studies and metabolic markers in non-human primates. Adult (n = 27) and aged (n = 20) female rhesus macaques were evaluated by urodynamic and metabolic studies. Cystometry showed detrusor underactivity (DU) with increased bladder capacity and compliance in aged subjects. Metabolic syndrome indicators were present in the aged subjects, including increased weight, triglycerides, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and high sensitivity C-reactive protein (hsCRP), whereas aspartate aminotransferase (AST) was unaffected and the AST/ALT ratio reduced. Principal component analysis and paired correlations showed a strong association between DU and metabolic syndrome markers in aged primates with DU but not in aged primates without DU. The findings were unaffected by prior pregnancies, parity, and menopause. Our findings provide insights into possible mechanisms for age-associated DU and may guide new strategies to prevent and treat LUT dysfunction in older adults.

New Frontiers of Extracorporeal Shock Wave Medicine in Urology from Bench to Clinical Studies

A shock wave (SW), which carries energy and propagates through a medium, is a type of continuous transmitted sonic wave that can achieve rapid energy transformations. SWs have been applied for many fields of medical science in various treatment settings. In urology, high-energy extracorporeal SWs have been used to disintegrate urolithiasis for 30 years. However, at lower energy levels, SWs enhance the expression of vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS), proliferating cell nuclear antigen (PCNA), chemoattractant factors, and the recruitment of progenitor cells, and inhibit inflammatory molecules. Low energy extracorporeal shock wave (LESW) therapy has been used in urology for treating chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), interstitial cystitis/bladder pain syndrome (IC/BPS), overactive bladder, stress urinary incontinence, and erectile dysfunction through the mechanisms of anti-inflammation, neovascularization, and tissue regeneration. Additionally, LESW have been proven to temporarily increase tissue permeability and facilitate intravesical botulinum toxin delivery for treating overactive bladders in animal studies and in a human clinical trial. LESW assisted drug delivery was also suggested to have a synergistic effect in combination with cisplatin to improve the anti-cancer effect for treating urothelial cancer in an in vitro and in vivo study. LESW assisted drug delivery in uro-oncology is an interesting suggestion, but no comprehensive clinical trials have been conducted as of yet. Taken together, LESW is a promising method for the treatment of various diseases in urology. However, further investigation with a large scale of clinical studies is necessary to confirm the real role of LESW in clinical use. This article provides information on the basics of SW physics, mechanisms of action on biological systems, and new frontiers of SW medicine in urology.

DU Is Induced by Low Levels of Urinary ATP in a Rat Model of Partial Bladder Outlet Obstruction: The Incidence of Both Events Decreases after Deobstruction

Objectives. To investigate, in initial phases of bladder outlet obstruction (BOO), the urinary ATP levels, the incidence of detrusor underactivity (DU), and if they change after deobstruction. Methods. Adult female Wistar rats submitted to partial BOO (pBOO) and sham-obstruction were used. Cystometry was performed 3 or 15 days after pBOO and fluid was collected from the urethra for ATP determination. Bladders were harvested for morphological evaluation of the urothelium. DU was defined as the average of voiding contractions (VC) of sham-operated animals, with 3 SD at 15 days after the sham surgery. In another group of animals in which pBOO was relieved at 15 days and bladders were let to recover for 15 days, the incidence of DU and ATP levels were also accessed. The Kruskal–Wallis test was followed by Dunn’s multiple comparisons test, and Spearman’s correlation test was used. Results. DU was present in 13% and 67% of the bladders at 3 and 15 days after pBOO, respectively, and in 20% of the bladders at 15 days after deobstruction. ATP levels were significantly lower in DU/pBOO versus sham and non-DU/pBOO rats. A strong positive correlation between ATP levels and VC/min was obtained (r = 0.63). DU bladders had extensive areas in which umbrella cells appeared stretched, the width exceeding that presented by sham animals. Conclusions. Low urothelial ATP parallels with a high incidence of DU early after pBOO.

Comprehensive Review of Effective Application of Questionnaires for Clinical Research on Lower Urinary Tract Symptoms With Translation and Cultural Adaptation to the Korean Language

Lower urinary tract symptoms are highly prevalent and closely related to patients' quality of life. Clinical research on urologic disease is essential for accumulating evidence on patient management; however, the major obstacle is converting patients' subjective symptoms to objective parameters. The optimal application of well-developed and validated questionnaires is vital in achieving objectivity and minimizing bias in clinical research. Numerous questionnaires for measuring symptoms and quality of life in urologic diseases have been developed worldwide; however, they cannot be directly used in clinical studies without validation processes. This review aimed to explain the common procedures for translation, linguistic, and psychometric validation of developed questionnaires from other languages. Furthermore, we comprehensively reviewed currently available questionnaires for evaluating lower urinary tract symptoms in the Korean population.

Expandable and implantable bioelectronic complex for analyzing and regulating real-time activity of the urinary bladder

Underactive bladder or detrusor underactivity (DUA), that is, not being able to micturate, has received less attention with little research and remains unknown or limited on pathological causes and treatments as opposed to overactive bladder, although the syndrome may pose a risk of urinary infections or life-threatening kidney damage. Here, we present an integrated expandable electronic and optoelectronic complex that behaves as a single body with the elastic, time-dynamic urinary bladder with substantial volume changes up to ~300%. The system configuration of the electronics validated by the theoretical model allows conformal, seamless integration onto the urinary bladder without a glue or suture, enabling precise monitoring with various electrical components for real-time status and efficient optogenetic manipulation for urination at the desired time. In vivo experiments using diabetic DUA models demonstrate the possibility for practical uses of high-fidelity electronics in clinical trials associated with the bladder and other elastic organs.

Understanding underactive bladder: a review of the contemporary literature

Underactive bladder (UAB) is characterized by prolonged voiding, hesitancy, and slow and/or intermittent stream with or without a sensation of incomplete bladder emptying. The overlap of UAB lower urinary tract symptoms with those of overactive bladder or bladder outlet obstruction, as well as its multifactorial etiology, make UAB study, as well as its diagnosis and management, a very arduous and challenging task. Therefore, despite its incidence and significant impact in the quality of life of both men and women, UAB remains a poorly understood urologic condition with insufficient and ineffective treatment options available. In this review, we will focus on the etiology theories that have been proposed and the animal models available to test those theories.

The role of clean intermittent catheterization in the treatment for detrusor underactivity

OBJECTIVE

To study the influence of clean intermittent catheterization (CIC) on the lower urinary tract function in patients with urinary retention (UR) due to detrusor underactivity (DU).

MATERIAL AND METHODS

A longitudinal study was carried out on 49 patients (28 men, 21 women) of mean age 55years, who underwent CIC for UR secondary to DU. The mean CIC frequency was 3.15 times/day. Patients' clinical data were collected, and they underwent urodynamic study before and after CIC, with a mean interval of 4years. Fisher's exact test was used for the analysis of categorical variables and Student's t test for parametric variables. The level of significance was set at 0.05 for a two-tailed test.

RESULTS

The second urodynamic study showed a significantly increased bladder compliance, the Bladder Outlet Obstruction Index (BOOI) and the Bladder Contractility Index (BCI) also increased but without reaching statistical significance. There was a significantly higher percentage of benign prostatic hyperplasia (BPH) and acontractile detrusor cases among the group of patients whose BCI improved after CIC, with significantly lower CIC time.

CONCLUSIONS

CIC improved bladder compliance in the patients of our series. The BCI improved in BPH patients and in patients with acontractile detrusor.

Do the definitions of the underactive bladder and detrusor underactivity help in managing patients: International Consultation on Incontinence Research Society (ICI-RS) Think Tank 2017?

AIMS

The Think Tank aimed to discuss the pitfalls and advantages of current definitions in terms of research and management of underactive bladder (UAB). UAB broadly defines a symptom complex of bladder emptying problems and does not indicate a specific pathology. Detrusor underactivity (DU) is a urodynamic diagnosis from pressure-flow studies. The correlation of UAB with DU remains to be precisely determined.

METHODS

The presentations and subsequent discussion, leading to research recommendations during the Think Tank of the International Consultation on Incontinence Research Society in Bristol, 2017, are summarized.

RESULTS

To develop more specific individualized management strategies, the Think Tank panel proposed (i) that, since defining a single type of index patient to represent all UAB will not fulfill all clinical research needs, several index patients should be defined by phenotyping of patients with UAB, including, children, young men and women, elderly male and female patients with co-existing DU and detrusor overactivity, and neurological patients with UAB; (ii) prospective longitudinal studies to assess the natural history of UAB, in the different target populations, based on different UAB phenotypes, should be initiated; (iii) DU should be precisely defined by urodynamic parameters; and (iv) work to develop validated specific questionnaires combined with non-invasive tests for screening, diagnosis and follow up, needs to be continued.

CONCLUSIONS

The precise relationship of UAB to DU remains to be defined. Phenotyping patients with UAB/DU, performing prospective trials of natural history, and developing symptom questionnaires and diagnostic investigations will improve our ability to identify and treat UAB/DU.

Low-intensity extracorporeal shockwave therapy ameliorates diabetic underactive bladder in streptozotocin-induced diabetic rats

OBJECTIVES

To evaluate the therapeutic effect of once-weekly low-intensity extracorporeal shock wave therapy (Li-ESWT) on underactive bladder (UAB) in the streptozotocin (STZ)-induced diabetic rat model.

MATERIALS AND METHODS

In all, 36 female Sprague-Dawley rats were divided into three groups: normal control (NC), diabetes mellitus control (DMC), and DM with Li-ESWT (DM Li-ESWT). The two DM groups received an intraperitoneal 60 mg/kg STZ injection to induce DM. The Li-ESWT was applied toward the pelvis of the rats starting 4 weeks after STZ administration and lasting for 4 weeks. The Li-ESWT was given once weekly, with an energy flux density of 0.02 mJ/mm² at 3 Hz for 400 pulses. All rats underwent conscious cystometry, leak-point pressure (LPP) assessment, ex vivo organ-bath study, histology, immunofluorescence, and Western Blot analysis.

RESULTS

Conscious cystometry revealed voiding dysfunction in the DMC group, whereas the DM Li-ESWT group showed significantly improved voiding function, reflected in a reduced post-void residual urine volume and increased LPP compared to the DMC group. Ex vivo organ-bath studies showed that Li-ESWT enhanced muscle contractile activity of the bladder and urethra during electrical-field stimulation and drug stimulation. Histologically, Li-ESWT significantly restored bladder morphology, reflected by a reduction in the intravesical lumen area and increased muscle proportion of the bladder wall. Western Blot analysis showed higher smooth muscle actin expression in the bladder wall in the DM Li-ESWT group compared to the DMC group. Immunofluorescence showed decreased nerve-ending distribution, and destroyed and shortened nerve fibres in the DMC group, and recovery of neuronal integrity and innervation in the DM Li-ESWT group.

CONCLUSIONS

In conclusion, Li-ESWT ameliorated UAB and urinary incontinence in the diabetic UAB rat model. The improvement appears to be the result of restoration of bladder and urethral structure and function by Li-ESWT. Li-ESWT is non-invasive and may become a better alternative therapy for UAB. Further investigations are warranted.

Intermittent Self-catheterization in Older Adults: Predictors of Success for Technique Learning

Purpose

The main goal of this retrospective study is to explore the predictors of success in learning clean intermittent self-catheterization (CISC) in patients over 65 years of age. The secondary goal is to assess whether in this population, the risk of failure to perform CISC is greater, compared with patients under 65 with similar pathologies.

Methods

All patients older than 65 consulting between January 2011 and January 2016 for learning CISC were included. A control population younger than 65 matching with sex, body mass index, and pathology was selected.

Results

One hundred sixty-nine of the 202 patients (83.7%) over 65 succeeded in learning CISC. Obesity (P<0.05), low pencil and paper test (PP test) (P<0.01) and low functional independence measure (FIM) (P<0.01) scores were risk factors of failure. No significant differences were found with sex or pathology. In multivariate analysis, low PP test perineum access (odds ratio [95% confidence interval], 2.30 [1.32–4.42]), low FIM motor (1.04 [1.01–1.08]), and FIM cognition (1.18 [1.03–1.37]) scores were independent factors of learning failure. Compared to control group, age over 65 was not predictive of failure (P=0.15).

Conclusions

Our study shows that success in learning CISC does not depend on age but on difficulties in mobility, access to perineum and probably cognitive disorders.

Characterization of voiding function and structural bladder changes in a rat model of neurogenic underactive bladder disease

OBJECTIVES

To create an animal model for neurogenic underactive bladder disease (UAB) and identify markers to describe secondary myogenic changes in the bladder wall.

MATERIALS AND METHODS

Male rats underwent either bilateral pelvic nerve injury or sham surgery. Four weeks after surgery functional evaluation was performed and tissue was harvested. Functional evaluation consisted of analysis of voiding pattern, 24-h urine collection in a metabolic cage, in vivo cystometry and in-vitro contractile function assessment. PCR and immunohistochemical localization of different smooth muscle cell and extracellular matrix markers was performed on bladder strips.

RESULTS

After pelvic nerve injury, dry bladder weight increased and voiding contractions were absent, resulting in overflow incontinence. In-vitro contractile response to carbachol was decreased. This was paired with an upregulation of synthetic smooth muscle cell (SMC) markers mRNA expression such as retinol binding protein 1 (RBP1), myosin 10 (MYH10) and osteopontin (OPN), and a downregulation of contractile SMC marker smoothelin (SMTL). The SMTL/OPN mRNA ratio was 50 times higher in sham bladders compared to PNI bladders.

CONCLUSIONS

The loss of in-vivo and in-vitro contractile function following pelvic nerve transection is characterized by a switch from a contractile to synthetic SMC phenotype, which is best characterized by the ratio SMTL/OPN mRNA expression. Modulating this phenotypical switch is a potential target for the development of UAB therapy. We suggest for the first time a set of markers that may be useful to evaluate therapeutic strategies on improvements in bladder wall structure.

Epidemiology of underactive bladder: Common but underresearched

Detrusor underactivity (DU) or underactive bladder is a common cause of lower urinary tract symptoms (LUTS), but it is still poorly understood and underresearched. Although there has been a proposed definition by International Continence Society in 2002, no widely accepted diagnostic criteria have been established for this entity in clinical practice. Therefore, it has been rare to identify community-based researches on the epidemiology of DU until now. Only certain studies have reported the prevalence of DU in community-dwelling cohorts with significant LUTS using arbitrary urodynamic criteria for DU and these investigations have indicated that DU accounts for 25%–48% and 12%–24% of elderly men and women, respectively. However, these prevalence data based on the urodynamic definition apparently are limited in their extrapolation to the general population. Despite the clinical ambiguity of DU, its clinical effects on quality of life are quite significant, especially in the elderly population. An overall and proper comprehension of epidemiologic studies of DU may be crucial for better insight into DU, relevant decision making, and a more reasonable allocation of health resources. Therefore, researchers should find clues to the solution for the clinical diagnosis of this specific condition of LUTS from contemporary epidemiologic studies and try to develop a possible definition of ‘clinical’ DU from further studies.

Definition and symptoms of underactive bladder

Underactive bladder (UAB) is a symptom syndrome reflecting the urodynamic observation of detrusor underactivity (DU), a voiding contraction of reduced strength and/or duration, leading to prolonged or incomplete bladder emptying. An International Continence Society Working Group has described UAB as characterised by a slow urinary stream, hesitancy and straining to void, with or without a feeling of incomplete bladder emptying and dribbling, often with storage symptoms. Since DU often coexists with bladder outlet obstruction, or storage dysfunction (detrusor overactivity or incontinence), the exact contribution of the DU to the presenting complaints can be difficult to establish. The presence of voiding and post voiding lower urinary tract symptoms (LUTS) is implicitly expected in UAB, but a reduced sensation of fullness is reported by some patients, and storage LUTS are also an important factor in many affected patients. These may result from a postvoid residual, but often they do not. The storage LUTS are often the key driver in leading the patient to seek healthcare input. Nocturia is particularly common and bothersome, but what the role of DU is in all the range of influences on nocturia has not been established. Qualitative research has established a broad impact on everyday life as a result of these symptoms. In general, people appear to manage the voiding LUTS relatively well, but the storage LUTS may be problematic.

Phenotyping women with detrusor underactivity by presumed etiology: Is it plausible?

AIMS

Underactive bladder (UAB) is a symptom complex with poorly characterized causation. The aim of this study was to determine if clinical and UDS parameters differed between categories of presumed detrusor underactivity (DU) etiologies.

METHODS

A retrospective review was performed at a single institution from 2011 to 2015 to identify patients with symptoms of UAB. Patients were excluded if they were male, had anti-incontinence, or pelvic organ prolapse (POP) surgery within 1 year, or the UDS did not demonstrate DU as defined within. Subjects were stratified by etiology into four cohorts: cardiovascular disease manifestations (CV), cardiac risk factors (CVR), neurologic (N), or idiopathic (I). Patient demographics, comorbidities, symptomatology, physical exam, and UDS parameters were compared.

RESULTS

A total of 200 patients met inclusion criteria (CV: n = 53 [26.5%], CVR: n = 44 [22%] N: n = 81 [40.5%], I: n = 22 [11%]). Women in the CV cohort were significantly older and more likely to be post-menopausal (P < 0.001). There were no differences between cohorts for BMI (P = 0.48), recurrent UTI (P = 0.63), history of urinary retention (AUR) (P = 0.65), POP (0.49), American Urological Association Symptom Score (AUA-SS) (P = 0.06), presenting symptomatology [urgency, frequency, urgency urinary incontinence, AUR, incomplete emptying, hesitancy, UTI (P = 0.97)], or UDS parameters (first sensation [P = 0.25], normal desire [P = 0.80], strong desire [P = 0.58], capacity [P = 0.11], Qmax [P = 0.50], Pdet at Qmax [P = 0.22], post-void residual [P = 0.82]).

CONCLUSIONS

Though differences were observed between cohorts for age and menopausal status, clinical or urodynamic parameters did not demonstrate distinct differences across presumed categories of etiology, suggesting that the etiology of DU may be multifactorial. Neurourol. Urodynam. 36:1151-1154, 2017. © 2016 Wiley Periodicals, Inc.

Work Capacity of the Bladder During Voiding: A Novel Method to Evaluate Bladder Contractile Function and Bladder Outlet Obstruction

Background:

Work in voiding (WIV) of the bladder may be used to evaluate bladder status throughout urination rather than at a single time point. Few studies, however, have assessed WIV owing to the complexity of its calculations. We have developed a method of calculating work capacity of the bladder while voiding and analyzed the associations of bladder work parameters with bladder contractile function and bladder outlet obstruction (BOO).

Methods:

The study retrospectively evaluated 160 men and 23 women, aged >40 years and with a detrusor pressure at maximal flow rate (P_det Q_max) of ≥40 cmH₂O in men, who underwent urodynamic testing. The bladder power integration method was used to calculate WIV; WIV per second (WIV/t) and WIV per liter of urine voided (WIV/v) were also calculated. In men, the relationships between these work capacity parameters and P_det Q_max and Abrams-Griffiths (AG) number were determined using linear-by-linear association tests, and relationships between work capacity parameters and BOO grade were investigated using Spearman's association test.

Results:

The mean WIV was 1.15 ± 0.78 J and 1.30 ± 0.88 J, mean WIV/t was 22.95 ± 14.45 mW and 23.78 ± 17.02 mW, and mean WIV/v was 5.59 ± 2.32 J/L and 2.83 ± 1.87 J/L in men and women, respectively. In men, WIV/v showed significant positive associations with P_det Q_max (r = 0.845, P = 0.000), AG number (r = 0.814, P = 0.000), and Schafer class (r = 0.726, P = 0.000). Conversely, WIV and WIV/t showed no associations with P_det Q_max or AG number. In patients with BOO (Schafer class > II), WIV/v correlated positively with increasing BOO grade.

Conclusions:

WIV can be calculated from simple urodynamic parameters using the bladder power integration method. WIV/v may be a marker of BOO grade, and the bladder contractile function can be evaluated by WIV and WIV/t.

Underactive Bladder

Underactive bladder (UAB) is a very common condition leading to disabling lower urinary tract symptoms. There has been an increasing interest in this condition as there is no effective treatment currently available. UAB has been described in many ways, but there is no agreed upon consensus on its terminology. The prevalence of UAB may be underestimated. This review focuses on the terminology, pathophysiology, common causes, its treatment, and future areas of research.

Recent advances in the understanding of male lower urinary tract symptoms (LUTS)

In this review, we have looked at three important areas in understanding male lower urinary tract symptoms. These are improvement in terminology, detrusor underactivity, and nocturia. Benign prostatic hyperplasia leading to bladder outlet obstruction has been covered in a previous review.

Age-related changes in murine bladder structure and sensory innervation: a multiphoton microscopy quantitative analysis

Our study aimed to examine and quantify age-related structural alterations in the healthy mouse bladder using ex vivo two-photon laser scanning microscopy (TPLSM). Freshly dissected bladders from 25-, 52-, and 85-week-old C57bl/6J mice were examined, and morphological analyses and quantification of cell layers and nerves were performed. The numbers of stretched, curled, branched, and total number of nerves in volume units of the stained muscle layer were quantified. We observed differences in the bladder wall architecture and innervation with age. Especially in 85-week-old mice, age-related changes were found, including detachment of urothelial cells and an increase in connective tissue, intermingled with the smooth muscle fibers in the muscle layer (collagen-smooth muscle ratio of 1.15 ± 0.29). In 25- and 52-week-old mice, the collagen-smooth muscle ratios were 0.20 ± 0.04 and 0.31 ± 0.11, respectively, and a clear separation of collagen and muscle was observed. The overall number of nerves and the number of curled nerves were significantly higher in the 85-week-old mice (74.0 ± 13.0 and 25.9 ± 4.8, respectively), when comparing to 25-week-old mice (26.0 ± 2.7 and 6.7 ± 1.2, respectively) and 52-week-old mice (43.8 ± 4.3 and 22.1 ± 3.3, respectively). Significant age-related alterations in bladder morphology and innervation were found, when comparing freshly dissected bladder tissue from 25-, 52-, and 85-week-old mice. The higher number of curled nerves might be an indication of an increased neurotransmitter release, resulting in a higher nerve activity, with a part of the nerves being possibly mechanically impaired. This study shows that two-photon laser scanning microscopy of healthy aging male mice is a useful method to investigate and quantify the age-related changes in the bladder wall.

Future Perspectives in Bladder Tissue Engineering

Substantial clinical need persists for improved autologous tissues to augment or replace the urinary bladder and research has begun to address this using tissue engineering techniques. The implantation of both tissue scaffolds which allow for native bladder tissue ingrowth and autologous bladder grafts created from in vitro cellularization of such scaffolds have been tested clinically; however, successful outcomes in both scenarios have been challenged by insufficient vascularity resulting from large graft sizes, which subsequently limits tissue ingrowth and leads to central graft ischemia. Consequently, recent research has focused on developing better methods to produce scaffolds with increased tissue ingrowth and vascularity. This review provides an update on bladder tissue engineering and outlines the challenges that remain to clinical implementation.

Differentiation of lower urinary tract dysfunctions: The role of ambulatory urodynamic monitoring

OBJECTIVES

To determine the value of ambulatory urodynamic monitoring in the assessment of patients with lower urinary tract symptoms.

METHODS

This was a cross-sectional study including patients who underwent both conventional urodynamic and ambulatory urodynamic assessment at our Center between December 2002 and February 2013. The ambulatory urodynamic studies were interpreted in a standardized way by a resident experienced with urodynamic measurements, and one staff member who specialized in incontinence and urodynamics.

RESULTS

A total of 239 patients (71 male and 168 female) were included in the present study. The largest subgroup of patients, 79 (33%), underwent ambulatory urodynamic monitoring based on suspicion of an acontractile bladder. However, 66 of these patients (83.5%) still showed contractions on ambulatory urodynamics. Other groups that were analyzed were patients with suspected storage dysfunction (47 patients), inconclusive conventional urodynamic studies (68 patients) and incontinence of unclear origin (45 patients). Particularly in this last group, ambulatory urodynamics appeared to be useful for discrimination between different causes of incontinence.

CONCLUSIONS

Ambulatory urodynamic monitoring is a valuable discriminating diagnostic tool in patients with lower urinary tract symptoms who have already undergone conventional urodynamics, particularly in the case of patients with suspected bladder acontractility and incontinence of unclear origin during ambulatory urodynamics. Further study is required to determine the clinical implications of the findings and their relationship with treatment outcome.

Long-term caloric restriction in rats may prevent age related impairment of in vitro bladder function

PURPOSE

Bladder function is often impaired with aging. In other organs caloric restriction has had a prophylactic effect on the biological changes associated with aging. We tested the hypothesis that long-term caloric restriction can prevent age related impaired bladder function in the rat.

MATERIALS AND METHODS

Fisher 344 male rats were divided into 3 groups, including 16 young rats at age 6 months with free access to normal food, 15 old rats at age 25 to 28 months with free access to normal food and 16 old rats at age 25 to 28 months fed with normal food 3 days per week since age 6 weeks (caloric restriction). We performed frequency volume measurements, in vitro organ bath functional studies using full-thickness longitudinal detrusor strips, evaluation of muscarinic and purinergic receptor mRNA expression, and histological examination with Masson trichrome staining of bladder tissue.

RESULTS

Frequency volume changes did not significantly differ among the 3 groups. The old group fed normal food showed weaker contractile responses to carbachol and electrical field stimulation (especially in the cholinergic component), lower M3 receptor mRNA expression and higher collagen deposition compared to the young group. These age related bladder changes were milder in the old group with caloric restriction than in the old group fed normal food.

CONCLUSIONS

This study suggests that in the rat long-term caloric restriction has a preventive effect against age related functional and morphological bladder changes. These changes include impaired detrusor contractility that may be related to decreased expression of M3 receptors and to bladder wall fibrosis.