Structural basis of geriatric voiding dysfunction. IV. Bladder outlet obstruction

Preventive Effects of Gonadotropin-Releasing Hormone Treatment on Urinary Bladder and Kidney Damage in Spinal Cord Injured Rats

INTRODUCTION

One of the main causes of a neurogenic bladder is spinal cord injury (SCI),(SCI), which induces little or no bladder reflex activity. Because of this alteration, there is an increased risk of developing urinary tract infections and kidney damage. Gonadotropin-releasing hormone (GnRH) treatment has been shown to improve micturition in a rat model of SCI.

AIM

The present study was aimed at determining whether GnRH administration is capable to reduce bladder and kidney damage in rats with SCI.

METHODS

Ovariectomized female Wistar rats were divided into three groups: sham, SCI with saline solution (SCI), and SCI treated with GnRH (SCI+GnRH) for 6 weeks. SCI was induced by compression at the T10 spinal level. At the end of the experiment, bladders and kidneys were processed for morphological and immunofluorescence analysis. For morphometric analysis, the thickness of the urothelium and the muscular layer of the bladder was measured, as well as the intensity of staining related to collagen in the kidney.

RESULTS

At the end of the experiment, all animals in the sham group showed normal urination (100%), in contrast, the percentage of untreated injured rats (SCI) that did not require manual stimulation for micturition was 19%, while the treated group (SCI+GnRH) was 68%. A significative increase in bladder weight, urothelial and muscle thickness, and collagen-related coloration in the kidney was observed in SCI when compared to sham rats.

CONCLUSION

GnRH administration decreased damage to the urinary bladder and kidneys after SCI in rats. These results suggest that this hormone could be a potential preventive treatment for SCI patients at risk of neurogenic bladder and kidney damage.

TRIAL REGISTRATION

Not applicable.

Can we predict and manage persistent storage and voiding LUTS following bladder outflow resistance reduction surgery in men? ICI-RS 2023

AIMS

Lower urinary tract symptoms (LUTS) persist in up to 50% of patients after bladder outflow resistance reduction surgery (BORRS) in men. Our think tank aims to address the predictive factors for persistent LUTS after BORRS and to propose the recommendations for future research to enable improved better patient counseling and selection by more accurate prediction of treatment outcome.

METHODS

A think tank of ICI-RS gathered in 2023, Bristol, UK, to discuss the pre and postsurgical clinical and urodynamic evaluation of men undergoing BORRS and whether it is possible to predict which men will have persistent LUTS after BORRS.

RESULTS

Our think tank agrees that due to the multifactorial, and still not fully understood, etiology of male LUTS it is not possible to precisely predict in many men who will have persistent LUTS after BORRS. However, severe storage symptoms (overactive bladder, OAB) in association with low volume and high amplitude detrusor overactivity and low bladder capacity in preoperative urodynamics, increase the likelihood of persistent OAB/storage symptoms after BORRS. Furthermore, patients who are clearly obstructed and have good bladder contractility on preoperative pressure flow studies do better postoperatively compared to their counterparts. However, the benefit of pressure flow studies is decreased in patients who do not acceptably void during the study. Poor voiding after BORRS may occur due to persistent obstruction or detrusor underactivity.

CONCLUSION

Future research is needed to increase our understanding of why male LUTS persist after surgery, and to enable better patient selection and more precise patient counseling before BORRS.

Clinical value of neutrophil to lymphocyte ratio and ultrasonic parameters in the diagnosis of bladder outlet obstruction in benign prostatic hyperplasia

AIM

This study aimed to investigate the clinical significance of neutrophil-to-lymphocyte ratio and ultrasonic parameters in diagnosing bladder outlet obstruction in patients with benign prostatic hyperplasia.

MATERIAL

Between September 2022 and January 2024, a total of 106 patients with benign prostatic hyperplasia were collected from Hongqi Hospital affiliated to Mudanjiang Medical University followed by urodynamic testing. The patients were categorized into three groups based on the International Prostate Symptom Score: mild (45 cases), moderate (36 cases), and severe (25 cases). Thirty-five healthy men were recruited at the hospital as a control group. All patients had blood tests and ultrasound scans.

RESULTS

Neutrophil-to-lymphocyte ratio, detrusor wall thickness, detrusor muscle elastic modulus, internal gland elastic modulus, intravesical prostatic protrusion, and post-voiding residual volume were significantly correlated with the bladder outlet obstruction stage and showed good diagnostic efficiency (all P<0.05. There was no statistically significant difference observed in the external gland elastic modulus between the experimental group and the control group (P>0.05).

CONCLUSIONS

The neutrophil-to-lymphocyte ratio, detrusor wall thickness, elastic modulus of the detrusor and glandular gland may hold clinical significance for diagnosing bladder outlet obstruction resulting from benign prostatic hyperplasia.

LEVEL OF EVIDENCE: 3

Comparison of early loosening vs delayed section of mid-urethral slings for postoperative voiding dysfunction

INTRODUCTION AND HYPOTHESIS

Bladder outlet obstruction (BOO) is a common occurrence after midurethral sling (MUS) insertion and can result in acute or chronic urinary retention or de novo lower urinary tract symptoms (LUTS). However, the management of BOO after MUS is not standardised. The objective of this study was to compare two therapeutic strategies for suspected BOO after MUS.

METHODS

Patients who had surgical revision for voiding dysfunction with a post-void residual (PVR) ≥100 ml after MUS in five centres between 2005 and 2020 were included in a retrospective study. Patients were divided into two groups: early sling loosening (EL) vs delayed section/excision of the sling (DS).

RESULTS

Seventy patients were included: 38 in the EL group and 32 in the DS group. The postoperative complication rate was comparable in both groups (10.5% vs 12.5%; p = 0.99). At 3 months, the rate of withdrawal from self-catheterisation was similar in the two groups (92.1% vs 100%; p = 0.25) as was the PVR (57.5 vs 63.5 ml; p = 0.09). After a median follow-up of 9 months, there were significantly more patients with resolved voiding dysfunction in the EL group (63.2% vs 31.3%; p = 0.01). The rate of persistent/recurrent stress urinary incontinence (SUI) was higher in the DS group (21% vs 43.7%; p = 0.04). In multivariate analysis, the main predictive factor of recurrent SUI was DS (OR 2.87, 95% CI 1.01-8.60, p = 0.048).

CONCLUSIONS

Early loosening of MUS in the case of postoperative voiding dysfunction offers better efficacy than DS of the sling, with a lower risk of recurrent/persistent SUI.

White Matter Integrity in Men With Benign Prostatic Hyperplasia and Bladder Outlet Obstruction and Its Contribution to Lower Urinary Tract Symptoms

Purpose

Lower urinary tract symptoms (LUTS) associated with bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) can negatively impact quality of life. We evaluated the structural connectivity of the brain in men with BPH with chronic BOO using diffusion tensor imaging (DTI).

Methods

Ambulatory male patients aged ≥45 years with BPH and BOO were recruited. LUTS was defined as an International Prostate Symptom Score (IPSS) ≥12 and a maximum urinary flow rate ≤15 mL/sec. Upon recruitment, uroflowmetry and validated questionnaires regarding bladder status were collected. DTI images from each subject were aligned with the ICBM-DTI-81 atlas, defining 50 white matter tracts (WMTs). The mean values of DTI parameters—fractional anisotropy and mean diffusivity—for each WMT were extracted. These measures were then utilized to compute Pearson correlation coefficients with clinical parameters. Objective clinical parameters included uroflowmetry parameters, postvoid residual (PVR) volume, and bladder capacity. Subjective clinical parameters were assessed using validated questionnaires: the IPSS, Incontinence Symptom Index, and Sexual Health Inventory for Men.

Results

The correlation analysis revealed 15 WMTs that showed statistically significant associations (P<0.05) with objective and subjective clinical parameters. Eight tracts were associated with uroflowmetry parameters: maximum flow rate (Qmax), mean flow rate (Qmean), and PVR. Among these tracts, the middle cerebellar peduncles and left medial lemniscus were associated with Qmax; the genu of the corpus callosum, left superior corona radiata, corticospinal tract, right medial lemniscus, posterior corona radiata with Qmean; and the left posterior corona radiata with PVR. Seven tracts also demonstrated significant associations with the IPSS.

Conclusions

Our results suggest correlations between the preserved white matter integrity of specific WMTs and the severity of LUTS based on objective and subjective clinical parameters, leading us to believe that a distinct pathology of the central nervous system might exist.

Clinical Correlation of Bladder Electron Microscopic Characteristics in Patients with Detrusor Underactivity of Various Etiologies

This study aimed to investigate the ultrastructural characteristics of the bladder of patients with detrusor underactivity (DU) of various etiologies. Twenty-five patients with DU and control subjects underwent urodynamic testing and transmission electron microscopic examination of bladder specimens. The epithelium, lamina propria, and muscle layers were analyzed separately. The DU bladders exhibited total epithelial denudation (52%). In the bladders with remaining epithelium, apical cell uroplakins (44.4%) and tight junction complexes (77.8%) were also noted. The lamina propria was characterized by loose extracellular connective tissue (48%) and a lack of nerve terminals (76%). Smooth muscle shrinkage and a loss of their regular spindle shape (91.6%) were also noted in the detrusor layer. Patients with DU with intact epithelial cell layers had significantly larger void volumes and maximal flow rates than those with mild or severe epithelial denudation. Patients with remaining nerve terminals in lamina propria had a stronger first sensation of filling and smaller residual urine volume than those without nerve terminals. The proportion of ultrastructural defects of the bladder was not significantly different among patients with DU of various etiologies and treatment outcomes. DU bladders were characterized by ultrastructural defects in the entire bladder, and the defects were correlated to clinical parameters.

Human amniotic fluid stem cells can alleviate detrusor dysfunction caused by bladder outlet obstruction in rats

The present study examined whether bladder detrusor dysfunction due to partial bladder outlet obstruction (pBOO) could be improved after the treatment of human amniotic fluid stem cells (hAFSCs). 72 female rats were grouped into sham operation, pBOO, and pBOO with hAFSCs treatment (pBOO + hAFSCs) for in vitro and in vivo studies. Bladder weight, bladder wall thickness, the ratio of collagen to smooth muscle and the levels of positive CD11b/c and HIS48 cells was significantly increased after pBOO but improved after hAFSCs treatment. Cystometries showed impaired bladder function after pBOO. Protein and mRNA levels of hypoxia inducible factor-1α, CCL2, interleukin-1β, transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), α-smooth muscle actin, collagen I and collagen III were increased at 2 and/or 6 weeks, but proteins and mRNA expressions of protein gene product 9.5 were decreased at 2 and 6 weeks after pBOO. These abnormalities were improved after hAFSCs treatment. The expressions of TGF-β1 and CTGF in cultured detrusor cells of pBOO rats were increased but were improved after hAFSCs treatment. The present results showed hAFSCs treatment could improve bladder detrusor dysfunction in pBOO rats, which may be related to the reduction of inflammatory and pro-fibrotic markers in detrusor muscle cells.

Shedding light on polypragmasy of pain after transurethral prostate surgery procedures: a systematic review and meta-analysis

PURPOSE AND OBJECTIVE

To evaluate and compare the incidences of post-operative pelvic pain (PPP) in patients undergoing ablation, enucleation and conventional transurethral resection of the prostate (TURP).

METHODS

A systematic review and meta-analysis was conducted according to the PRISMA guidelines. Using MEDLINE via PubMed and Cochrane CENTRAL, randomised control trials (RCTs) and observational studies reporting PPP rates post-ablation, enucleation or TURP were identified. The risk of biases (RoB) in RCTs and observation studies were assessed using the Cochrane RoB1.0 tool and the Newcastle-Ottawa Scale, respectively.

RESULTS

62 studies were included for qualitative analysis, while 51 of them reported number of patients with PPP post-intervention. Three observational studies and 13 RCTs compared the rates of PPP in patients undergoing ablation, enucleation or TURP. The most reported types of PPP are dysuria, abdominal pain and irritative symptoms. The pooled incidence of PPP at 1-month follow-up in patients undergoing ablation, enucleation and TURP were 0.15 (95% CI 0.10-0.22), 0.09 (95% CI 0.04-0.19 and 0.10 (95% CI 0.06-0.15), respectively. PPP is no longer prevalent at 3-months and onwards post-operatively. Ablation is associated with a higher risk of PPP than enucleation (RR 2.19, 95% CI 1.04-4.62) and TURP (RR 2.40, 95% CI 1.03-5.62) in observational studies but not RCTs; and there were no significant differences in the rates of PPP upon comparison of other modalities.

CONCLUSION

PPP is common after transurethral benign prostatic hyperplasia surgery. Patients undergoing ablation had a higher rate of post-intervention PPP than those undergoing enucleation and TURP in observational studies.

The Role of Apoptosis in Detrusor Contractility

Apoptosis has been found in bladder affected by various types of voiding dysfunction. In animal studies, higher levels of apoptosis were observed in conditions of both detrusor overactivity and underactivity than in normal bladders. However, it has been difficult to establish the exact underlying mechanism of apoptosis in these conditions and to find new therapeutic targets because the causes of voiding dysfunction are diverse and the coexistence of various types of voiding problems is common. Furthermore, the lack of studies of the human detrusor contributes to our incomplete understanding of these issues. Therefore, this revies discuss the role of apoptosis in detrusor contractility based on previous studies.

Ultrastructural changes in the underactive bladder

Underactive bladder (UAB) is a symptom complex suggestive of detrusor underactivity (DU). Although it implies a primary dysfunction of the detrusor muscle, many other conditions such as advanced age, neurogenic factors, and bladder outlet obstruction also lead to UAB. The current understanding of the pathophysiology directly leading to UAB is limited. We believe that by identifying the morphological changes associated with UAB might shed light on this. Therefore, we searched literature with keywords of electron microscopy, ultrastructure, UAB, and DU to review current ultrastructural evidence concerning UAB.

A prototype non-invasive urodynamic test to estimate voiding reserve in normal adult males

Objective: To propose a prototype non-invasive test to estimate voiding reserve in normal adult men; identifying its feasibility, limitations, and initial results.

Subjects and methods: In all, 30 adult healthy male volunteers aged <40 years were included in the study. Initial free uroflowmetry was done with post-void residual urine volume (PVR) assessment using ultrasonography. The men were later asked to void into a uroflowmeter through a condom catheter attached to the glans penis and connected to an outflow tube with specific vertical heights (10, 20, 30, 40, 50 and 60 cm) on different days. The mean maximum urinary flow rate (Q_max) and PVR at each height were compared with the Q_max and PVR at the initial free uroflowmetry. The maximum height at which the Q_max and PVR remained normal was considered the normal voiding reserve for that age group.

Results: All the men completed the study without any complications. At zero level, the mean Q_max was 27.6 mL/s, which then dropped gradually to reach 17.8 mL/s at 60 cm, where still 83% of the men had a normal Q_max. The PVR was nil at zero level and started to exceed the normal range at 50 and 60 cm height (58 and 65.7 mL, respectively). So, the maximum height resistance at which the men could have a normal Q_max and normal PVR was 40 cm.

Conclusions: The use of the tube height-resistance test to assess voiding reserve is feasible, non-invasive and has no complications. A 40-cm height resistance can be considered a reference level that a young adult male should be tested against to estimate his voiding reserve.

Abbreviations: NPV: negative predictive value; P_detQ_max: maximum detrusor pressure at maximum urinary flow; PPV: positive predictive value; PVR: post-void residual urine volume; ROC: receiver operating characteristic

Non-invasive evaluation of bladder outlet obstruction in benign prostatic hyperplasia: a clinical correlation study

Objectives: To determine the utility of ultrasonography (US)-derived parameters (e.g. prostate volume [PV], bladder wall thickness [BWT], post-void residual urine volume [PVR], and intravesical prostatic protrusion [IPP]) and uroflowmetry for identifying bladder outlet obstruction (BOO) by correlating them with the results of pressure–flow urodynamic studies (UDS).

Patients and methods: In all, 164 patients presenting with lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH), from May 2016 to December 2018, were included in this study. All had International Prostate Symptoms Score (IPSS), Quality-of-Life (QOL) index, uroflowmetry (including maximum urinary flow rate [Q_max]) and PVR measured by transabdominal US. Pressure–flow UDS were performed on all men and BOO was defined by a BOO Index (BOOI) >40. Men with a Q_max of ≥12.0 mL/s were considered to have ‘good’ flow.

Results: Amongst the 164 men, the mean (SD) age, PV, BWT and Q_max were 66.72 (9.88) years, 51.91 (13.24) mm, 5.07 (0.91) mm, and 8.46 (3.59) mL/s, respectively. In all, 91 (55.49%) patients had BOO with a BOOI >40 and nine (5.49%) had equivocal BOO with a BOOI of 20–40. The IPP was a statistically significant predictor (P < 0.001) of BOO compared with other variables in the initial evaluation. In patients with BOO confirmed by the pressure–flow UDS, IPP Grade III was associated with a higher BOOI than was Grade I and II (P < 0.001).

Conclusion: BWT, PV and PVR in conjunction with IPP are good predictors of clinically significant BOO due to BPH.

Abbreviations: AUC: area under the curve; BOOI: BOO Index; BPO, benign prostatic obstruction; BWT, bladder wall thickness; IPP: intravesical prostatic protrusion; P_det: detrusor pressure; PV: prostate volume; PVR: post-void residual urine volume; Q_max: maximum urinary flow rate; QOL: quality of life; ROC: receiver operating characteristic; (TA)US: (transabdominal) ultrasonography; UDS: urodynamic studies

Value of Real-Time Shear Wave Elastography Versus Acoustic Radiation Force Impulse Imaging in the Diagnosis of Female Bladder Neck Obstruction

OBJECTIVE

To investigate the application value of shear wave elastography (SWE) and acoustic radiation force impulse imaging (ARFI) in the diagnosis of female bladder neck obstruction (FBNO), we compared the advantages of these 2 methods to provide a more accurate reference for clinical work.

METHODS

From April 2016 to February 2018, 27 patients who were diagnosed with FBNO by cystoscopy and/or urine dynamics testing were selected for the study, together with 24 healthy adults in a case-control study at Liaoning Province People's Hospital. We collected general information from 27 patients with FBNO, and using transperineal 2-dimensional ultrasound detection, shear wave elastography (SWE) and ARFI were used, respectively, to detect the Young's modulus and shear wave velocity (SWV) of the bladder necks. Cystoscopy results were considered to be the gold standard, and receiver operating characteristic (ROC) curves were drawn for ARFI, SWE, and the combined diagnosis of the two. The efficacy of the diagnosis was determined by comparing the areas under the ROC curves and calculating the sensitivity, specificity, and accuracy.

RESULTS

The areas under the ROC curve for the Q-box mean and max value detected by SWE for FBNO patients were 88.4% and 89.9%, respectively, and the sensitivity, specificity, and accuracy were 81.5%, 79.2%, and 80.4%, respectively. The area under the ROC curve detected by ARFI for FBNO patients was 93.7%, and the sensitivity, specificity, and accuracy were 88.9%, 79.2%, and 84.3%, respectively. The sensitivity, specificity, and accuracy of the combined detection of ARFI and SWE were 92.5%, 87.5%, and 90.2%, respectively. The best diagnostic cutoff point of the SWV or the Q-box mean and max value of SWE in FBNO obtained with the ROC curve was SWV = 2.38 m/s (sensitivity, 71.4%; specificity, 82.5%), Q-box mean = 20.2 kPa, Q-box max = 39.8 kPa (sensitivity, 67.5%; specificity, 76.2%). The average shear wave velocity of ARFI, Q-box mean, and Q-box max value of SWE in the control group were 1.89 ± 0.35 m/s, 15.3 ± 3.6 kPa, and 29.2 ± 8.7 kPa, respectively. In the FBNO group, these values were 2.81 ± 0.63) m/s, 27.2 ± 8.6 kPa, and 51.2 ± 12.3 kPa, respectively. The differences were statistically significant (P < .05).

CONCLUSION

The value of the ARFI in the diagnosis of FBNO is a little greater than that of SWE in terms of sensitivity and accuracy, and the combined detection of ARFI and SWE performs better than ARFI or SWE employed separately.

Persistent storage symptoms after TURP can be predicted with a nomogram derived from the ice water test

PURPOSE

To predict the persistence of storage symptoms after transurethral resection of the prostate (TURP) using a nomogram derived from the ice water test (IWT).

METHODS

The IWTs of 73 men with lower urinary tract symptoms and prostatic bladder outlet obstruction were retrospectively analyzed. The strength of the detrusor contraction was approximated by using the detrusor gradient of Δp_det /Δt at maximum detrusor pressure and the area under the curve. The parameters were utilized in a nomogram, which facilitated a severity categorization from 1 to 10. Patients with a positive IWT in the categories 1 to 2 were assigned to group A, categories 3 to 4 to group B and categories 5 and higher to group C. After TURP, patients with persisting storage symptoms were offered a botulinum toxin injection.

RESULTS

There were 32 patients (44%) with negative and 41 patients (56%) with positive IWTs. Patients with negative IWTs were classified in category 1. Regarding patients with positive IWTs, 14 (34%) were correlated to group A, 14 (34%) to group B, and 13 (32%) to group C. The necessity of a subsequent botulinum toxin injection correlated significantly with a higher nomogram category (P < .001) as well as higher severity categorization (P < .001). In multivariate analysis, the nomogram category was an independent predictor for botulinum toxin injection (P = .002, OR, 6.9, CI, 2.0-23.9).

CONCLUSION

The quantification of the detrusor contraction during the IWT allowed stratification of patients in risk categories for persistent storage symptoms after TURP and the potential need for later botulinum toxin injections.

Evaluation of resistive index of the prostate and bladder sonomorphologic parameters as replacements for urodynamics to predict bladder outlet obstruction in patients with lower urinary tract symptoms suggestive of benign prostatic hyperplasia

OBJECTIVE

This study investigated whether the resistive index (RI) of prostate and bladder sonomorphologic parameters (total prostate volume [TPV], detrusor wall thickness [DWT], intraprostatic protrusion [IPP]) can be used instead of urodynamic studies (UDS) to predict bladder outlet obstruction (BOO) in benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS).

METHODS

Men aged ≥50 years with clinical BPH/LUTS were prospectively enrolled included. Basic evaluations, measurement of sonomorphologic parameters, and UDS were performed in accordance with the International Continence Society's Good Urodynamics Practices protocol.

RESULTS

Data of 240 patients were divided into two groups based on the BOO index(BOOI). Group 1 consisted of patients negative for BOO (BOOI <40), whereas Group 2 consisted of patients positive for BOO (BOOI > 40). Patient age, International Prostate Symptom Score (IPSS), quality of life score and post-void residual volume were comparable between the two groups, whereas significant differences were evident in peak flow rate, TPV, DWT, RI, and IPP (P < 0.01 for all). Pearson correlation analysis revealed a significant correlation between BOOI and DWT (r = 0.198, P = 0.002), IPP (r = 0.450, P = 0.000), and RI (r = 0.334, P = 0.000). Multiple regression analysis revealed a significant correlation between BOOI and IPP (β = 0.382, P = 0.000) and RI (β = 0.226, P = 0.000). Receiver operating characteristic analysis showed that the area under curve was 0.785 for RI (95% confidence interval [CI] 0.703-0.867, P < 0.001) and 0.905 for IPP (95% CI 0.850-0.961, P < 0.001). At a cut-off value of 7.5 mm for IPP, the sensitivity was 86.9%, specificity was 83.3% and positive predictive value was 92.41%.

CONCLUSION

IPP and RI may be the best non-invasive predictors for BOO in selected patients with LUTS/BPH.

Progressive bladder remodeling due to bladder outlet obstruction: a systematic review of morphological and molecular evidences in humans

BACKGROUND

Bladder outlet obstruction is a common urological condition. We aimed to summarize available evidences about bladder outlet obstruction-induced molecular and morphological alterations occurring in human bladder.

METHODS

We performed a literature search up to December 2017 including clinical and preclinical basic research studies on humans. The following search terms were combined: angiogenesis, apoptosis, bladder outlet obstruction, collagen, electron microscopy, extracellular matrix, fibrosis, hypoxia, histology, inflammation, innervation, ischemia, pressure, proliferation, remodeling, suburothelium, smooth muscle cells, stretch, urothelium.

RESULTS

We identified 36 relevant studies. A three-stages model of bladder wall remodeling can be hypothesized involving an initial hypertrophy phase, a subsequent compensation phase and a later decompensation. Histological and molecular alterations occur in the following compartments: urothelium, suburothelium, detrusor smooth muscle cells, detrusor extracellular matrix, nerves. Cyclic stretch, increased hydrostatic and cyclic hydrodynamic pressure and hypoxia are stimuli capable of modulating multiple signaling pathways involved in this remodeling process.

CONCLUSIONS

Bladder outlet obstruction leads to progressive bladder tissue remodeling in humans. Multiple signaling pathways are involved.

Electron microscopic changes of detrusor in benign enlargement of prostate and its clinical correlation

AIMS

To study the ultra structural changes in bladder musculature in cases of BPE and their clinical relevance.

MATERIAL AND METHODS

In this descriptive longitudinal, controlled, observational study patients were enrolled into three groups, group 1, group 2A and group 2B. Control group (group-1) consisted of age matched normal male patients, who underwent surveillance or diagnostic cystoscopy for microscopic hematuria or irritative symptoms. Case group (group-2) comprised of patients with BPE, undergoing TURP. Case group (group-2) was further classified into: Category 2A (patients not on catheter) and cat-egory 2B (patients on catheter). All relevant clinical parameters like IPSS, prostate size, Qmax, PVR were recorded. Cystoscopy and bladder biopsy were performed in all patients. Various ultrastructural parameters like myocytes, fascicular pattern, interstitial tissue, nerve hypertrophy and cell junction pattern were analyzed under electron microscope and they were clinically correlated using appropriate statistical tests.

RESULTS

Control group had significant difference as compared to case group in terms of baseline parameters like IPSS, flow rate and prostate size, both preoperatively and postoperatively, except for PVR, which was seen only preoperatively. There was statistically significant difference in ultrastructural patterns between case and control group in all five electron microscopic patterns. However, no significant difference was found between the subcategories of case groups.

CONCLUSIONS

BPE is responsible for ultra structural changes in detrusor muscle and these changes remain persistent even after TURP. Nerve hypertrophy, which was not thoroughly discussed in previous studies, is also one of the salient feature of this study.

A novel algorithm for the non-invasive detection of bladder outlet obstruction in men with lower urinary tract symptoms

Objective

To determine the ability of bladder wall thickness (BWT) in combination with non-invasive variables to distinguish patients with bladder outlet obstruction (BOO).

Patients and methods

Patients completed the International Prostate Symptom Score (IPSS) questionnaire and prostate size was measured by transrectal ultrasonography (US). Pressure-flow studies were performed to determine the urodynamic diagnosis. BWT was measured at 250-mL bladder filling using transabdominal US. Recursive partition analysis (RPA) recursively partitions data for relating independent variable(s) to a dependent variable creating a tree of partitions. It finds a set of cuts of the dependent variable(s) that best predict the independent variable, by searching all possible cuts until the desired fit is reached. RPA was used to test the ability of the combined data of BWT, maximum urinary flow rate (Q_max), post-void residual urine volume (PVR), IPSS, and prostate size to predict BOO.

Results

In all, 72 patients were included in the final analysis. The median BWT, voided volumes, PVR, mean Q_max, and IPSS were significantly higher in patients who had an Abrams/Griffiths (A/G) number of >40 (55 patients) compared to those with an A/G number of ≤40 (17 patients). RPA revealed that the combination of BWT and Q_max gave a correct classification in 61 of the 72 patients (85%), with 92% sensitivity and 65% specificity, 87% positive predictive value, and 76% negative predictive value (NPV) for BOO (area under the curve 0.85). The positive diagnostic likelihood ratio of this reclassification fit was 2.6.

Conclusions

It was possible to combine BWT with Q_max to create a new algorithm that could be used as a screening tool for BOO in men with lower urinary tract symptoms.

Trans-abdominal ultrasound shear wave elastographyfor quantitative assessment of female bladder neck elasticity

INTRODUCTION AND HYPOTHESIS

Disorders of micturition result from a wide variety of conditions and evaluation often involves multiple diagnostic modalities. However, the sensitivity and specificity of these techniques are highly variable and may not always yield a diagnosis. Novel imaging techniques such as ultrasound shear wave elastography may help to improve diagnostic accuracy.

METHODS

Continent women were recruited from outpatient gynecology offices from a tertiary medical system. Participants underwent ultrasound evaluation with measurement of the shear wave velocity (SWV) of the bladder neck (BN). SWV was used to determine the Young's modulus of the bladder neck. The median bladder neck stiffness was calculated and univariate and step-wise and backward multivariate logistic regression analyses were used to identify significant patient characteristics associated with bladder neck stiffness above or below the median.

RESULTS

Fifty-seven women underwent SWE of the bladder; 12 were excluded, and 45 were included in the analysis. The median bladder neck stiffness of the study population was 22 (17.1-28.2) kPa. Age greater than 45 years was associated with a bladder neck stiffness above the median, OR 8.39, p < 0.001. Having no vaginal deliveries was also associated with a bladder neck stiffness greater than 22 kPa, unadjusted OR 4.76 (95 % CI 1.41-20.0, p = 0.012). Bladder volume and bladder neck thickness were not significantly associated with bladder neck stiffness above or below the median.

CONCLUSION

Trans-abdominal shear wave elastography can be used to quantitatively assess bladder neck stiffness. This technique may potentially be useful for evaluating chronic urinary retention.

Application of Acoustic Radiation Force Impulse Imaging for Diagnosis of Female Bladder Neck Obstruction

OBJECTIVES

To determine the application value of combined transperineal sonography and Virtual Touch tissue quantification (Siemens Medical Solutions, Mountain View, CA) on acoustic radiation force impulse imaging as a scanning method for diagnosis of female bladder neck obstruction.

METHODS

Transperineal sonography and Virtual Touch tissue quantification were combined to depict the bladder neck and observe its sonographic characteristics in 36 patients with female bladder neck obstruction and 30 healthy adults in a case-control study. We measured the thickness and shear wave velocity (SWV) of the bladder neck's anterior and posterior lips.

RESULTS

There was a statistically significant difference in the thickness and SWV of the bladder neck between the healthy women and those with bladder neck obstruction, whose SWV was higher (P< .05). For the anterior lip, an SWV of 2.11 m/s was the best cutoff point for differentiating bladder neck obstruction from a normal bladder neck; for the posterior lip, an SWV of 2.06 m/s was the best cutoff point. The mean thicknesses of the anterior and posterior lips ± SD were 0.66 ± 0.05 and 0.68 ± 0.05 cm in the group with bladder neck obstruction versus 0.45 ± 0.07 and 0.52 ± 0.09 cm in the normal group. There was a significant difference between them (P < .05).

CONCLUSIONS

The bladder neck's anatomic structure can be observed visually by perineal sonography. Virtual Touch tissue quantification on acoustic radiation force impulse imaging can quantitatively reflect the bladder neck stiffness and change in texture. It could provide a quantitative indicator for clinical diagnosis of female bladder neck obstruction and etiology research and display important clinical values.

The underactive bladder: detection and diagnosis

The inability to generate a voiding contraction sufficient to allow efficient bladder emptying within a reasonable time frame is a common problem seen in urological practice. Typically, the symptoms that arise are voiding symptoms, such as weak and slow urinary flow. These symptoms can cause considerable bother to patients and impact upon quality of life. The urodynamic finding of inadequate detrusor contraction has been termed detrusor underactivity (DUA). Although a definition is available for this entity, there are no widely accepted diagnostic criteria. Drawing parallels to detrusor overactivity and the overactive bladder, the symptoms arising from DUA have been referred to as the “underactive bladder” (UAB), while attempts to crystallize the definition of UAB are now ongoing. In this article, we review the contemporary literature pertaining to the epidemiology and etiopathogenesis of DUA as well as discuss the definitional aspects that are currently under consideration.

Imaging assessments of lower urinary tract dysfunctions: Future steps

Urodynamic tests are the standard diagnostic method for lower urinary tract dysfunctions (LUTD). However, these tests are invasive. The current review describes the noninvasive imaging techniques that have been used to monitor LUTD. The main imaging technologies that have been applied in diagnosing LUTD were 2D ultrasonography, Doppler ultrasonography, and near-infrared spectroscopy (NIRS). Ultrasonographic parameters, such as bladder wall thickness (BWT), detrusor wall thickness (DWT), and ultrasound-estimated bladder weight (UEBW), have been proposed as surrogates for bladder outlet obstruction (BOO) or detrusor overactivity (DO). Few studies have reported diagnostic cut-offs in diagnosing BOO or DO; thus, there is still a need to standardize the measurement method. NIRS can detect the hemodynamic changes related to DO and BOO in real-time, which could be advantageous in clinical practice, but the liability of NIRS to motion artefacts is a limitation. Bladder strain imaging in real-time using 2D ultrasound enables noninvasive estimation of the dynamic changes in the bladder wall during voiding. Many imaging techniques have been used to monitor the urinary bladder during the storage and voiding phases of the micturition cycle. These techniques were either static [i.e., measuring fixed parameters, such as BWT, DWT, UEBW, and intravesical prostatic protrusion (IVPP)] or dynamic (monitoring the structural and hemodynamic changes in the bladder wall in real-time). These techniques are currently being developed and standardized for potential use in diagnosing LUTD in clinical practice.

Quantitative elasticity measurement of urinary bladder wall using laser-induced surface acoustic waves

The maintenance of urinary bladder elasticity is essential to its functions, including the storage and voiding phases of the micturition cycle. The bladder stiffness can be changed by various pathophysiological conditions. Quantitative measurement of bladder elasticity is an essential step toward understanding various urinary bladder disease processes and improving patient care. As a nondestructive, and noncontact method, laser-induced surface acoustic waves (SAWs) can accurately characterize the elastic properties of different layers of organs such as the urinary bladder. This initial investigation evaluates the feasibility of a noncontact, all-optical method of generating and measuring the elasticity of the urinary bladder. Quantitative elasticity measurements of ex vivo porcine urinary bladder were made using the laser-induced SAW technique. A pulsed laser was used to excite SAWs that propagated on the bladder wall surface. A dedicated phase-sensitive optical coherence tomography (PhS-OCT) system remotely recorded the SAWs, from which the elasticity properties of different layers of the bladder were estimated. During the experiments, series of measurements were performed under five precisely controlled bladder volumes using water to estimate changes in the elasticity in relation to various urinary bladder contents. The results, validated by optical coherence elastography, show that the laser-induced SAW technique combined with PhS-OCT can be a feasible method of quantitative estimation of biomechanical properties.

Contemporary concepts in the aetiopathogenesis of detrusor underactivity

Detrusor underactivity (DUA) is a poorly understood, yet common, bladder dysfunction, referred to as underactive bladder, which is observed in both men and women undergoing urodynamic studies. Despite its prevalence, no effective therapeutic approaches exist for DUA. Exactly how the contractile function of the detrusor muscle changes with ageing is unclear. Data from physiological studies in animal and human bladders are contradictory, as are the results of the limited number of clinical studies assessing changes in urodynamic parameters with ageing. The prevalence of DUA in different patient groups suggests that multiple aetiologies are involved in DUA pathogenesis. Traditional concepts focused on either efferent innervation or myogenic dysfunction. By contrast, contemporary views emphasize the importance of the neural control mechanisms, particularly the afferent system, which can fail to potentiate detrusor contraction, leading to premature termination of the voiding reflex. In conclusion, the contemporary understanding of the aetiology and pathophysiology of DUA is limited. Further elucidation of the underlying mechanisms is needed to enable the development of new and effective treatment approaches.

Detrusor Underactivity: The Current Concept of the Pathophysiology

Based on evidence from available literature, we review the pathophysiology of detrusor underactivity (DU). DU is likely to be multifactorial. Aging reduces detrusor activity, but other concomitant causes may aggravate this condition, resulting in decrease of detrusor contractility. Impaired detrusor contractility has been regarded as a major etiologic factor of DU. However, a more complex pathology has been proposed. As contributing factors to DU, we discuss disturbances of the sensory afferent side of the micturition reflex, the central nervous system (CNS) and the efferent side of the reflex, including nerves and the detrusor muscle. Particularly, dysfunction of afferent nerves in the bladder and urethra may play a crucial role in the pathogenesis of DU. In addition, recent studies suggest that chronic bladder ischemia and resultant oxidative stress cause detrusor overactivity progressing to DU and inability to empty the bladder.

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

AIMS

Detrusor underactivity, resulting in either prolonged or inefficient voiding, is a common clinical problem for which treatment options are currently limited. The aim of this report is to summarize current understanding of the clinical observation and its underlying pathophysiological entities.

METHODS

This report results from presentations and subsequent discussion at the International Consultation on Incontinence Research Society (ICI-RS) in Bristol, 2013.

RESULTS AND CONCLUSIONS

The recommendations made by the ICI-RS panel include: Development of study tools based on a system's pathophysiological approach, correlation of in vitro and in vivo data in experimental animals and humans, and development of more comprehensive translational animal models. In addition, there is a need for longitudinal patient data to define risk groups and for the development of screening tools. In the near-future these recommendations should lead to a better understanding of detrusor underactivity and its pathophysiological background. Neurourol. Urodynam. 33:591-596, 2014. © 2014 Wiley Periodicals, Inc.

Factors determining the amount of residual urine in men with bladder outlet obstruction: Could it be a predictor for bladder contractility?

Objective

To determine from urodynamic data what causes an increased postvoid residual urine volume (PVR) in men with bladder outlet obstruction (BOO), urethral resistance or bladder failure, and to determine how to predict bladder contractility from the PVR.

Patients and methods

We analysed retrospectively the pressure-flow studies (PFS) of 90 men with BOO. Nine patients could not void and the remaining 81 were divided into three groups, i.e. A (30 men, PVR < 100 mL), B (30 men, PVR 100–450 mL) and C (21 men, PVR > 450 mL). The division was made according to a receiver operating characteristic curve, showing that using a threshold PVR of 450 mL had the best sensitivity and specificity for detecting the start of bladder failure.

Results

The filling phase showed an increase in bladder capacity with the increase in PVR and a significantly lower incidence of detrusor overactivity in group C. The voiding phase showed a significant decrease in voided volume and maximum urinary flow rate (Q_max) as the PVR increased, while the urethral resistance factor (URF) increased from group A to B to C. The detrusor pressure at Q_max (PdetQ_max) and opening pressure were significantly higher in group B, which had the highest bladder contractility index (BCI) and longest duration of contraction. Group C had the lowest BCI and the lowest PdetQ_max.

Conclusions

In men with BOO, PVR results from increasing outlet resistance at the start and up to a PVR of 450 mL, where the bladder reaches its maximum compensation. At volumes of >450 mL, both the outlet resistance and bladder failure are working together, leading to detrusor decompensation.

Assessment of BPH/BOO

The assessment of men with bladder outflow obstruction relies on an adequate history and examination. Uroflowmetry and post-void residue estimation are very revealing and may be sufficient in the majority of men. The prostate-specific antigen test may be used to select men who are at a high risk of progression. In specific situations, cystometry may be required. We discuss the use of cystometry and the newer less-invasive methods of assessment that have emerged over the last few years, including ultrasound estimation of intravesical prostatic protrusion, prostatic urethra angle, detrusor wall thickness, ultrasound-estimated bladder weight, near-infrared spectroscopy and the condom catheter and penile cuff tests. Although these techniques show promise, they still require further modifications, standardization and testing in larger populations. In addition, they should be used in men where only specific questions need to be answered.

Treatment of bladder dysfunction using stem cell or tissue engineering technique

Tissue engineering and stem cell transplantation are two important options that may help overcome limitations in the current treatment strategy for bladder dysfunction. Stem cell therapy holds great promise for treating pathophysiology, as well as for urological tissue engineering and regeneration. To date, stem cell therapy in urology has mainly focused on oncology and erectile dysfunction. The therapeutic potency of stem cells (SCs) was originally thought to derive from their ability to differentiate into various cell types including smooth muscle. The main mechanisms of SCs in reconstituting or restoring bladder function are migration, differentiation, and paracrine effects. Nowadays, paracrine effects of stem cells are thought to be more prominent because of their stimulating effects on stem cells and adjacent cells. Studies of stem cell therapy for bladder dysfunction have been limited to experimental models and have been less focused on tissue engineering for bladder regeneration. Bladder outlet obstruction is a representative model. Adipose-derived stem cells, bone marrow stem cells (BMSCs), and skeletal muscle-derived stem cells or muscle precursor cells are used for transplantation to treat bladder dysfunction. The aim of this study is to review stem cell therapy and updated tissue regeneration as treatments for bladder dysfunction and to provide the current status of stem cell therapy and tissue engineering for bladder dysfunction including its mechanisms and limitations.

Association between the bladder wall thickness and urodynamic findings in patients with spinal cord injury

PURPOSE

To investigate whether ultrasonographic bladder wall thickness (BWT) correlates with urodynamic parameters in patients with spinal cord injury (SCI).

METHODS

Two hundred and seventy-two patients with SCI were enrolled in the study. All of the patients underwent bladder ultrasonography and urodynamic study. The anterior bladder wall was measured and compared to urodynamic data.

RESULTS

The mean age of the patients was 37.4 years. The mean BWT was 3.9 mm. BWT was significantly higher in the patients with neurogenic detrusor overactivity associated with detrusor sphincter dyssynergia (NDO/DSD) compared to those without sphincter dyssynergia (4.2 vs. 3.6 mm, respectively, p < 0.001) and in those with compliance <20 ml/cm H2O. Nevertheless, ROC curve analysis [ROC = 0.624, 95 % CI (0.530, 0.718), p = 0.011] showed that no meaningful BWT measurement cutoff could be made to predict an elevated detrusor pressure in the storage phase.

CONCLUSIONS

Increased BWT was present in patients with low bladder compliance and NDO/DSD. No BWT cutoff value to predict an elevated detrusor pressure was found. Therefore, the measurement of BWT has no clinical role in patients with SCI and cannot replace urodynamic evaluation.

How antepartum and postpartum acute urinary retention affects the function and structure of the rat bladder

INTRODUCTION AND HYPOTHESIS

To examine the effect of acute urinary retention (AUR) on the urodynamic function and molecular structure of rat bladders in pregnancy and after parturition.

METHODS

Forty-eight nulliparous rats were distributed into AUR and non-AUR groups. AUR was induced by clamping the distal urethra of each rat after infusing 3 ml of saline for 60 min. Plasma progesterone levels and cystometric data were evaluated on the 14th day of gestation, 3 and 10 days postpartum, and in virgin rats. The immunoreactivity of caveolins and nerve growth factor (NGF) was analyzed. The number of caveolae in bladder muscle cells was evaluated by electron microscopy.

RESULTS

Progesterone levels significantly increased during pregnancy and 3 days postpartum. In cystometric results, the AUR group has significantly shorter intercontraction interval, lower void volume and greater residual volume compared with the non-AUR. AUR rats exhibited higher NGF immunoreactivity, lower caveolin-1 immunoreactivity, and less caveolae in the bladder compared with the non-AUR. The caveolin-1 and NGF immunoreactivity and the number of caveolae in the bladder decreased during pregnancy and 3 days postpartum compared with virgin rats. By using Pearson correlations, we found significant correlations between urodynamic variables (residual volumes and intercontraction intervals) and the expressions of caveolin-1, caveolae and NGF in the AUR rats on the 14th day of gestation and 3 days postpartum.

CONCLUSIONS

Bladder dysfunction in pregnancy and immediately postpartum in a rat model caused by AUR is associated with the plasma progesterone level change and the expressions of caveolin, caveolae, and NGF in bladder muscle cells.

Detrusor underactivity and the underactive bladder: a new clinical entity? A review of current terminology, definitions, epidemiology, aetiology, and diagnosis

CONTEXT

Detrusor underactivity (DU) is a common cause of lower urinary tract symptoms (LUTS) in both men and women, yet is poorly understood and underresearched.

OBJECTIVE

To review the current terminology, definitions, and diagnostic criteria in use, along with the epidemiology and aetiology of DU, as a basis for building a consensus on the standardisation of current concepts.

EVIDENCE ACQUISITION

The Medline and Embase databases were searched for original articles and reviews in the English language pertaining to DU. Search terms included underactive bladder, detrusor underactivity, impaired detrusor contractility, acontractile detrusor, detrusor failure, detrusor areflexia, raised PVR [postvoid residual], and urinary retention. Selected studies were assessed for content relating to DU.

EVIDENCE SYNTHESIS

A wide range of terminology is applied in contemporary usage. The only term defined by the standardisation document of the International Continence Society (ICS) in 2002 was the urodynamic term detrusor underactivity along with detrusor acontractility. The ICS definition provides a framework, considering the urodynamic abnormality of contraction and how this affects voiding; however, this is necessarily limited. DU is present in 9-48% of men and 12-45% of older women undergoing urodynamic evaluation for non-neurogenic LUTS. Multiple aetiologies are implicated, affecting myogenic function and neural control mechanisms, as well as the efferent and afferent innervations. Diagnostic criteria are based on urodynamic approximations relating to bladder contractility such as maximum flow rate and detrusor pressure at maximum flow. Other estimates rely on mathematical formulas to calculate isovolumetric contractility indexes or urodynamic "stop tests." Most methods have major disadvantages or are as yet poorly validated. Contraction strength is only one aspect of bladder voiding function. The others are the speed and persistence of the contraction.

CONCLUSIONS

The term detrusor underactivity and its associated symptoms and signs remain surrounded by ambiguity and confusion with a lack of accepted terminology, definition, and diagnostic methods and criteria. There is a need to reach a consensus on these aspects to allow standardisation of the literature and the development of optimal management approaches.

Adhesion molecules of detrusor muscle cells are influenced by a hypercholesterolemic diet or bladder outlet obstruction in a Wistar rat model

Background

Cell adhesion molecules (CAMs) are essential for maintaining tissue integrity by regulating intercellular and cell to extracellular matrix interactions. Cadherins and catenins are CAMs that are located on the cell membrane and are important for adherens junction (AJ) function. This study aims to verify if hypercholesterolemic diet (HCD) or bladder outlet obstruction (BOO) promotes structural bladder wall modifications specific to alterations in the expression of cadherins and catenins in detrusor muscle cells.

Methods

Forty-five 4-week-old female Wistar rats were divided into the following three groups: group 1 was a control group that was fed a normal diet (ND); group 2 was the BOO model and was fed a ND; and group 3 was a control group that was fed a HCD (1.25% cholesterol). Initially, serum cholesterol, LDL cholesterol and body weight were determined. Four weeks later, groups 1 and 3 underwent a sham operation; whereas group 2 underwent a partial BOO procedure that included a suture tied around the urethra. Six weeks later, all rats had their bladders removed, and previous exams were repeated. The expression levels of N-, P-, and E-cadherin, cadherin-11 and alpha-, beta- and gamma-catenins were evaluated by immunohistochemistry with a semiquantitative analysis.

Results

Wistar rats fed a HCD (group 3) exhibited a significant increase in LDL cholesterol levels (p=0.041) and body weight (p=0.017) when compared to both groups that were fed a normal diet in a ten-week period. We found higher β- and γ-catenin expression in groups 2 and 3 when compared to group 1 (p = 0.042 and p = 0.044, respectively). We also observed Cadherin-11 overexpression in group 3 when compared to groups 1 and 2 (p = 0.002).

Conclusions

A HCD in Wistar rats promoted, in addition to higher body weight gain and increased serum LDL cholesterol levels, overexpression of β- and γ-catenin in the detrusor muscle cells. Similar finding was observed in the BOO group. Higher Cadherin-11 expression was observed only in the HCD-treated rats. These findings may be associated with bladder dysfunctions that occur under such situations.

Stem cell therapy in bladder dysfunction: where are we? And where do we have to go?

To date, stem cell therapy for the bladder has been conducted mainly on an experimental basis in the areas of bladder dysfunction. The therapeutic efficacy of stem cells was originally thought to be derived from their ability to differentiate into various cell types. Studies about stem cell therapy for bladder dysfunction have been limited to an experimental basis and have been less focused than bladder regeneration. Bladder dysfunction was listed in MESH as "urinary bladder neck obstruction", "urinary bladder, overactive", and "urinary bladder, neurogenic". Using those keywords, several articles were searched and studied. The bladder dysfunction model includes bladder outlet obstruction, cryoinjured, diabetes, ischemia, and spinal cord injury. Adipose derived stem cells (ADSCs), bone marrow stem cells (BMSCs), and skeletal muscle derived stem cells (SkMSCs) are used for transplantation to treat bladder dysfunction. The main mechanisms of stem cells to reconstitute or restore bladder dysfunction are migration, differentiation, and paracrine effects. The aim of this study is to review the stem cell therapy for bladder dysfunction and to provide the status of stem cell therapy for bladder dysfunction.

Ultrasound bladder vibrometry method for measuring viscoelasticity of the bladder wall

Increase in bladder stiffness could be associated with various pathophysiologic conditions. Measuring bladder viscoelasticity could be an important step towards understanding various disease processes and improving patient care. Here, we introduce ultrasound bladder vibrometry (UBV), a novel method for rapid and noninvasive measurement of bladder wall viscoelasticity. UBV uses acoustic radiation force to excite mechanical waves in the bladder wall and track the motion using ultrasound pulse-echo techniques. Fourier domain analysis of the tissue motion versus time is used to calculate the phase velocity dispersion (change of phase velocity as a function of frequency). The measured phase velocity dispersion is fit with the antisymmetric Lamb wave model to estimate tissue elasticity and viscosity. We used finite element analysis of viscoelastic plate deformation to investigate the effect of curvature on Lamb wave dispersion and showed that the effects of curvature are negligible. The feasibility of the UBV technique was demonstrated in ex vivo and in vivo settings. Elasticity and viscosity of excised pig at various filling volumes (V) and pressures (p) were found to be µ1 = 9.6 kPa and µ2 = 0.2 Pa s (V = 187 ml and p = 8.6 mmHg), µ1 = 48.7 kPa and µ2 = 3.5 Pa s (V = 267 ml and p = 17.6 mmHg), and µ1 = 106.9 kPa and µ2 = 1.5 Pa s (V = 327 ml and p = 27.6 mmHg) respectively. Transabdominal measurements in an anesthetized pig found values of bladder elasticity µ1 = 26.1 kPa and viscosity µ2 = 0.9 Pa s and demonstrate the ability of UBV to perform in vivo measurements. The results presented in this paper introduce a novel technique for measuring mechanical properties of the bladder and lay the foundation for further investigation of the effects of pathology on bladder viscoelasticity.

Transurethral prostate resection in patients with hypocontractile detrusor--what is the predictive value of ultrastructural detrusor changes?

PURPOSE

Men with detrusor failure and chronic urinary retention have a lower voiding success rate and higher postoperative morbidity following transurethral prostatectomy than those with bladder outlet obstruction. Current investigations, including urodynamics, may be unable to predict the response to surgical treatment. We identified ultrastructural features on detrusor biopsy that correlated with the postoperative voiding outcome in patients with a hypocontractile detrusor undergoing transurethral prostatectomy.

MATERIALS AND METHODS

Detrusor biopsies were obtained from 17 patients with urodynamic evidence of bladder outlet obstruction or a hypocontractile detrusor undergoing transurethral prostatectomy and from 5 controls. Specimens were examined by transmission electron microscopy. Ten individual detrusor ultrastructural features were analyzed. Findings were compared with preoperative and postoperative clinical parameters.

RESULTS

Failure to void after transurethral prostatectomy was significantly associated with the ultrastructural features of variation in muscle cell size, muscle cell shape, collagenosis and abnormal fascicles. These 4 features were significantly associated with each other, defining a distinctive pattern of detrusor failure. For transurethral prostatectomy failure the sensitivity, specificity, and positive and negative predictive values of all 4 features together were 60%, 91%, 75% and 84%, respectively. Three or 4 features on detrusor biopsy predicted voiding failure.

CONCLUSIONS

Detrusor ultrastructural analysis is highly predictive of voiding outcome following transurethral prostatectomy in patients with detrusor failure. Patients with ultrastructural features previously described as part of the myohypertrophy pattern do not have a primary diagnosis of bladder outlet obstruction but rather detrusor failure secondary to bladder outlet obstruction.

Bladder Wall Thickness is Associated with Responsiveness of Storage Symptoms to Alpha-Blockers in Men with Lower Urinary Tract Symptoms

Purpose

Bladder wall thickness (BWT) is reported to be related to detrusor overactivity and bladder outlet obstruction. We investigated the relationship between BWT and the responsiveness of storage symptoms to alpha-blockers in men with lower urinary tract symptoms (LUTS).

Materials and Methods

A total of 74 patients with LUTS were enrolled. International Prostate Symptom Score, uroflowmetry with post-void residual urine volume, and transrectal ultrasonography (TRUS) were investigated. BWT was measured by performing TRUS at the midsagittal plane view, and the average value of BWT at the anterior, dome, and trigone areas was used. After 4 weeks of alpha-blocker medication, patients were reevaluated and divided into two groups. The responder group consisted of patients who reported improvement in the storage symptom subscore of 2 points or more; the non-responder group consisted of patients who reported improvement of less than 2 points. Clinical parameters including BWT were compared between the two groups.

Results

A total of 52 patients were followed. BWT was positively correlated with intravesical prostate protrusion (IPP) (9.26±4.99, standardized beta=0.393, p=0.002) and storage symptom subscore (0.35±0.43, standardized beta=0.458, p=0.002). Compared with that in the responder group, BWT was thicker in the non-responder group, and improvement in the storage symptom score was correlated with BWT (0.58±0.09 cm vs. 0.65±0.11 cm, p=0.018) and prostate volume (27.08±16.26 ml vs. 36.44±10.1 ml, p=0.018).

Conclusions

BWT was correlated with IPP, the storage symptom subscore, and the responsiveness of storage symptoms to alpha-blockers in LUTS/benign prostatic hyperplasia (BPH) patients. As BWT increased, the responsiveness of storage symptoms to alpha-blocker decreased in LUTS/BPH patients.

Vascular incontinence: incontinence in the elderly due to ischemic white matter changes

This review article introduces the new concept of vascular incontinence, a disorder of bladder control resulting from cerebral white matter disease (WMD). The concept is based on the original observation in 1999 of a correlation between the severity of leukoareosis or WMD, urinary symptoms, gait disorder and cognitive impairment. Over the last 20 years, the realization that WMD is not a benign incidental finding in the elderly has become generally accepted and several studies have pointed to an association between geriatric syndromes and this type of pathology. The main brunt of WMD is in the frontal regions, a region recognized to be crucial for bladder control. Other disorders should be excluded, both neurological and urological, such as normal-pressure hydrocephalus, progressive supranuclear palsy, etc., and prostatic hyperplasia, physical stress incontinence, nocturnal polyuria, etc. Treatment involves management of small vessel disease risk factors and anticholinergic drugs that do not easily penetrate the blood brain barrier to improve bladder control.

Does bladder wall thickness decrease when obstruction is resolved?

INTRODUCTION AND HYPOTHESIS

The aim of the current study was to determine if sonographic bladder wall thickness diminishes after symptomatic obstruction is resolved in female patients after stress incontinence surgery.

METHODS

Between December 2008 and December 2010, 62 female patients with symptomatic bladder outlet obstruction, as defined by Blaivas, who had undergone prior surgery for urinary stress incontinence were included in the study. The patients' history was taken and symptoms were noted. Patients underwent gynaecological examination, and multichannel urodynamic assessment was performed. Vaginal sonographic assessment of the bladder wall thickness (BWT) was performed before and after urethrolysis.

RESULTS

62 patients were included in this study, 55 of whom had undergone suburethral sling insertion and seven had Burch colposuspension. Postoperatively, BWT decreased significantly from 9.1 mm  ±  2.1 to 7.6 mm  ±  2.2 (p < 0.0001). In seven patients, obstruction was still unresolved postoperatively; of these, two had undergone a retropubic sling insertion and two had a Burch colposuspension. An ROC curve analysis showed a significant positive association between residual urine and persistent obstruction before surgery (AUC 0.76, 95%CI 0.58-0.94; p < 0.05).

CONCLUSIONS

If obstruction is resolved, bladder wall thickness decreases. Preoperatively elevated residual urine may increase the risk of persistent obstruction after urethrolysis.

Prevalence and risk factors of urinary incontinence in Chinese women: a population-based study

To estimate the current prevalence rate of urinary incontinence (UI) and to identify risk factors in Chinese women, we conducted a population-based survey in 3058 women in Beijing, China, in 2009. The prevalence rate of UI was estimated to be 22.1%, with stress UI (12.9%) being more prevalent than urgency UI (1.7%) and mixed UI (7.5%). The prevalence rates of UI, urgency UI, and mixed UI increased with age, with the highest recorded in participants aged ≥70 years. However, stress UI was most commonly seen in participants aged 50 to 69 years. Risk factors for UI included aging, lower education background, older age of menarche, menstrual disorder, pregnancy history, episiotomy, chronic pelvic pain, gynecological disease, other chronic diseases, constipation, fecal incontinence, lower daily water intake, and frequency of high protein intake. UI is a common disorder in Chinese women, and many risk factors are able to affect the development of UI.