Bladder wall thickness in normal adults and men with mild lower urinary tract symptoms and benign prostatic enlargement

Overview of bladder heating technology: matching capabilities with clinical requirements

Moderate temperature hyperthermia (40-45°C for 1 h) is emerging as an effective treatment to enhance best available chemotherapy strategies for bladder cancer. A rapidly increasing number of clinical trials have investigated the feasibility and efficacy of treating bladder cancer with combined intravesical chemotherapy and moderate temperature hyperthermia. To date, most studies have concerned treatment of non-muscle-invasive bladder cancer (NMIBC) limited to the interior wall of the bladder. Following the promising results of initial clinical trials, investigators are now considering protocols for treatment of muscle-invasive bladder cancer (MIBC). This paper provides a brief overview of the devices and techniques used for heating bladder cancer. Systems are described for thermal conduction heating of the bladder wall via circulation of hot fluid, intravesical microwave antenna heating, capacitively coupled radio-frequency current heating, and radiofrequency phased array deep regional heating of the pelvis. Relative heating characteristics of the available technologies are compared based on published feasibility studies, and the systems correlated with clinical requirements for effective treatment of MIBC and NMIBC.

Potential Biomarkers Utilized to Define and Manage Overactive Bladder Syndrome

Clinical diagnosis of overactive bladder (OAB) syndrome has great variation and usually can only be based on subjective symptoms. Measurement of urgency severity score in adjunct with voiding diary may reflect the occurrence of OAB and incontinence severity in daily life. Urodynamic study can detect detrusor overactivity (DO), but not in all OAB patients. A more objective way and less invasive tool to diagnose and assess therapeutic outcome in OAB patients is needed. Recent investigations of the potential biomarkers for OAB include urinary and serum biomarkers and bladder wall thickness. Evidence has also shown that urinary proteins, such as nerve growth factor (NGF) and prostaglandin E2 (PGE2 ) levels increase in patients with OAB, bladder outlet obstruction (BOO) and DO. Patients with OAB have significantly higher urinary NGFlevels and urinary NGF levels decrease after antimuscarinic therapy and further decrease after detrusor botulinum toxin injections. However, the sensitivity of single urinary protein in the diagnosis of OAB is not high and several lower urinary tract diseases may also have elevated urinary NGF levels. Searching for a group of inflammatory biomarkers by microsphere-based array in urine might be a better method in differential diagnosis of OAB from interstitial cystitis, urinary tract infection (UTI) or urolithiasis. Bladder wall thickness has been widely investigated in the diagnosis of BOO and pediatric voiding dysfunction.The role of bladder wall thickness in the diagnosis of OAB, however, has not reach a consistent conclusion. We hereby review the latest medical advances in this field.

Sonographic Parameters Predicting the Outcome of Patients With Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia Treated With Alpha1-Adrenoreceptor Antagonist

OBJECTIVE

To define prostate and bladder sono-morphologic parameters that best predict the outcome of benign prostatic hyperplasia (BPH) in men treated with alpha1-adrenoreceptor antagonist.

MATERIALS AND METHODS

Patients with BPH, candidates for medical treatment, were prospectively enrolled. Besides basic evaluation measures, all patients underwent transrectal ultrasonography. The main outcome was the response to treatment on the basis of International Prostatic Symptom Score, quality of life score, and maximum urine flow rate after taking daily oral dose of tamsulosin 0.4 mg for 6 months. The influences of baseline parameters on treatment response were statistically analyzed.

RESULTS

A total of 166 patients completed the study. From these, 59 (35.5%) had ineffective treatment after 6 months. According to logistic regression analysis, baseline International Prostatic Symptom Score storage subscore, maximum urine flow rate, and transrectal ultrasonography-measured sono-morphologic parameters (bladder wall thickness [BWT], ultrasound estimated bladder weight [UEBW], and intravesical prostatic protrusion [IPP]) were the independent predictors of ineffective treatment (P < .05). Using receiver operating characteristics analysis, BWT, UEBW, and IPP had adequate area under the curve (0.939, 0.897, and 0.876, respectively). At cutoff values of 9.3 mm, 34.5 g, and 12.9 mm, the positive and negative predictive values for BWT, UEBW, and IPP were 83.6% and 92.4%; 78.2% and 85.6%; 80.3% and 90.5%; respectively. Combination of these sono-morphologic parameters increased their positive predictive value to 97.6%.

CONCLUSION

Sonographic measurements of BWT, UEBW, and IPP might aid in determining patients with BPH at high risk of alpha1-adrenoreceptor antagonist monotherapy failure, in turn determining the initial need for additional medical therapy or surgical intervention.

Activation of common signaling pathways during remodeling of the heart and the bladder

The heart and the urinary bladder are hollow muscular organs, which can be afflicted by pressure overload injury due to pathological conditions such as hypertension and bladder outlet obstruction. This increased outflow resistance induces hypertrophy, marked by dramatic changes in the organs' phenotype and function. The end result in both the heart and the bladder can be acute organ failure due to advanced fibrosis and the subsequent loss of contractility. There is emerging evidence that microRNAs (miRNAs) play an important role in the pathogenesis of heart failure and bladder dysfunction. MiRNAs are endogenous non-coding single-stranded RNAs, which regulate gene expression and control adaptive and maladaptive organ remodeling processes. This Review summarizes the current knowledge of molecular alterations in the heart and the bladder and highlights common signaling pathways and regulatory events. The miRNA expression analysis and experimental target validation done in the heart provide a valuable source of information for investigators working on the bladder and other organs undergoing the process of fibrotic remodeling. Aberrantly expressed miRNA are amendable to pharmacological manipulation, offering an opportunity for development of new therapies for cardiac and bladder hypertrophy and failure.

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.

Delineating the inner bladder surface using uniform contractions from the outer surface under variable bladder filling conditions

OBJECTIVE

To evaluate the methods to delineate the inner bladder (IB) surface using a uniform contraction from the outer bladder (OB) surface, assuming the bladder wall (BW) is either of constant thickness, constant volume or variable volume.

METHODS

14 prostate intensity-modulated radiotherapy patients with 2 planning CTs were identified. For both CTs, OB was delineated using model-based segmentation. IB was delineated manually. Then, using uniform contractions from OB, the position of IB was approximated using a: 2.5-mm contraction, patient-specific contraction, patient-specific constant wall volume method and variable wall volume method. The structures created using those strategies were compared against the manual IB contours using geometric and dosimetric indices.

RESULTS

In the presence of variable bladder filling, use of a generic or patient-specific constant contraction resulted in a significant overestimation of IB volume (+12 and +13 cm(3), respectively; p < 0.001) that was inversely correlated with the difference in urine volume between the scans (R(2) > 0.86). Mean differences across 95% of IB surfaces were ≤2 mm for methods using either constant or variable wall volume. Mean dose-volume histogram (DVH) differences were <1 cm(3) across the whole BW DVH when using the method that assumed a variable wall volume.

CONCLUSION

The variable volume BW model provided the best approximation of the IB surface position under varying filling conditions, based on geometric and dosimetric indices.

ADVANCES IN KNOWLEDGE

Use of the equation derived in this research provides a quick and accurate method to delineate the hollow BW on serial imaging for the purposes of dose reconstruction.

Ureteroscopy and cystoscopy training: comparison between transparent and non-transparent simulators

BACKGROUND

Simulators have been widely used to train operational skills in urology, how to improve its effectiveness deserves further investigation. In this paper, we evaluated training using a novel transparent anatomic simulator, an opaque model or no simulator training, with regard to post-training ureteroscopy and cystoscopy proficiency.

METHODS

Anatomically correct transparent and non-transparent endourological simulators were fabricated. Ten experienced urologists provided a preliminary evaluation of the models as teaching tools. 36 first-year medical students underwent identical theoretical training and a 50-point examination of theoretical knowledge. The students were randomly assigned to receive training with the transparent simulator (Group 1), the non-transparent simulator (Group 2) or detailed verbal instruction only (Group 3). 12 days after the training session, the trainees' skills at ureteral stent insertion and removal were evaluated using the Uro-Scopic Trainer and rated on an Objective Structured Assessment of Technical Skills (OSATS) scale.

RESULTS

The new simulators were successfully fabricated in accordance with the design parameters. Of the ten urologists invited to evaluate the devices, 100% rated the devices as anatomically accurate, 90% thought both models were easy to use and 80% thought they were good ureteroscopy and cystoscopy training tools. The scores on the theoretical knowledge test were comparable among the training groups, and all students were able to perform ureteral stent insertion and removal. The mean OSATS scores of groups 1, 2 and 3 were 21.83 ± 3.64, 18.50 ± 4.03 and 15.58 ± 2.23 points, respectively, (p = 0.001).

CONCLUSIONS

Simulator training allowed students to achieve higher ureteroscopic and cystoscopic proficiency, and transparent simulators were more effective than non-transparent simulators.

The impact of the bladder wall thickness on the outcome of the medical treatment using alpha-blocker of BPH patients with LUTS

OBJECTIVES

To evaluate whether the outcome of medical treatment with α 1 receptor blocker in Benign prostatic hyperplasia (BPH) patients with lower urinary tract symptoms (LUTS) is affected by the bladder wall thickness (BWT) Methods: A total of 125 male BPH patients with LUTS were enrolled. All patients were assessed using The International Prostatic Symptom Score (IPSS), prostate specific antigen (PSA), prostate volume, uroflowmetry, post voiding residual (PVR). BWT was measured by Trans-abdominal ultrasound, and patients were divided into two groups group 1 (patients with BWT <5 mm) and group 2 (patients with BWT ≥5 mm). The patients were reassessed after 2 months of treatment with α 1 receptor blocker (alfuzosin 10 mg). Clinical parameters were analyzed and compared between groups.

RESULTS

There were significant difference between both groups as regard IPSS, voiding symptoms, and storage symptoms (p = 0.005), (p = 0.010) and (p = 0.041) respectively. After medication, there were improvements in the total IPSS, voiding symptoms, storage symptoms, Qmax, PVR and Qol in both groups and these improvements were more effectively in (group 1) than (group 2) with statistically significant differences (p < 0.05).

CONCLUSION

BWT has positive correlation with the total IPSS, voiding symptoms subscores and storage symptoms subscores. The response to medical treatment is found statistically less in patients with BWT greater than 5 mm.

Biodistribution of Evans blue in an orthotopic AY-27 rat bladder urothelial cell carcinoma model: implication for the improved diagnosis of non-muscle-invasive bladder cancer (NMIBC) using dye-guided white-light cystoscopy

OBJECTIVES

To investigate the possibility of using Evans blue (EB) as a novel diagnostic tool to detect bladder tumours with white-light (WL) cystoscopy, in this preclinical study we examine the biodistribution of EB in the different layers (urothelium, submucosa, muscle) of a normal rat bladder and a rat bladder bearing a malignant urothelium composed of syngeneic AY-27 tumour cells.

MATERIALS AND METHODS

EB was instilled into both normal as well as tumour-bearing rat bladders. After instillation, bladders were removed and snap frozen in liquid nitrogen. The distribution of EB in the different layers was quantified using fluorescence microscopy. To gain more insight into the mechanism underlying the selective accumulation of EB in tumour tissue, bladder sections were prepared for ultrastructural investigations by means of transmission electron microscopy (TEM). In addition, we also examined the expression of E-cadherin, claudin-1 and desmoglein-1 by immunohistochemistry to study the integrity of the bladder wall, as these molecules are key constituents of adherens junctions, tight junctions and desmosomes, respectively.

RESULTS

In most cases, the accumulation of EB in malignant bladders was substantially higher than in healthy bladders, at least when 1 mm EB instillations were used. In case of a 1 mm EB instillation for 2 h, the EB-associated fluorescence in malignant urothelial tissue was 55-times higher than the fluorescence found in normal urothelium. Ultrastructurally, malignant tissue displayed wider intercellular spaces and a decreased number of cell junction components compared with normal tissue, pointing to defects in the urothelial barrier. There were no differences in the expression of E-cadherin, whereas desmoglein-1 staining was stronger in the membranes of healthy bladder urothelium compared with tumour tissue. Claudin-1 expression was negative in all samples tested.

CONCLUSION

EB is selectively taken up by tumour tissue after intravesical instillations in rats bearing bladder tumours. The lower expression of desmoglein-1 in tumour samples, together with the reduced presence of desmosomes seen with TEM, likely imply that desmosomes play an important role in the ultrastructural differences between healthy rat urothelium and tumour tissue, and secondary to that, to the differential uptake of EB in both tissues. We consider that our findings could be useful for future clinical developments in the field of diagnostics for bladder cancer.

Physiological and pathophysiological implications of micromotion activity in urinary bladder function

'Micromotions' is a term signifying the presence of localized microcontractions and microelongations, alongside non-motile areas. The motile areas tend to shift over the bladder surface with time, and the intravesical pressure reflects moment-by-moment summation of the interplay between net contractile force generated by micromotions and general bladder tone. Functionally, the bladder structure may comprise modules with variable linkage, which supports presence of localized micromotions (no functional linkage between modules), propagating contractions (where emergence of linkage allows sequential activation) and the shifting of micromotions over time. Detrusor muscle, interstitial cells and intramural innervation have properties potentially relevant for initiating, coordinating and modulating micromotions. Conceptually, such activity could facilitate the generation of afferent activity (filling state reporting) in the absence of intravesical pressure change and the ability to transition to voiding at any bladder volume. This autonomous activity is an intrinsic property, seen in various experimental contexts including the clinical setting of human (female) overactive bladder. 'Disinhibited autonomy' may explain the obvious micromotions in isolated bladders and perhaps contribute clinically in neurological disease causing detrusor overactivity. Furthermore, any process that could increase the initiation or propagation of microcontractions might be anticipated to have a functional effect, increasing the likelihood of urinary urgency and detrusor overactivity respectively. Thus, models of bladder outlet obstruction, neurological trauma and ageing provide a useful framework for detecting cellular changes in smooth muscle, interstitial cells and innervation, and the consequent effects on micromotions.

Pelvic ultrasound evaluation for benign prostatic hyperplasia: prediction of obstruction

Global improvements in water quality, management of infectious diseases, and other medical therapeutics have resulted in a growing population of healthy aging men. One obligate anatomic consequence of aging for these men is the development of benign prostatic hyperplasia (BPH) with secondary bladder outlet obstruction. Although the voiding symptoms associated with the change in bladder health over time predominantly impact the quality of a man's daily experience, there are also significant medical consequences of BPH that require intervention. It is a challenge to distinguish men who are at risk for these medical consequences from the much larger population of older men with voiding symptoms (lower urinary tract symptoms, LUTS). A variety of national guidelines have been developed to establish a diagnostic paradigm for meeting this challenge, but all suffer from inadequate sensitivity for the early identification of men at risk for permanent bladder injury. It is likely that the application of a thorough pelvic ultrasound designed to identify the pertinent anatomic aspects of both the bladder and prostate will improve the sensitivity of these diagnostic paradigms, with subsequent improvement in the outcomes for men with BPH/LUTS.

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.

The relationship between bladder wall thickness and lower urinary tract symptoms: Does bladder wall thickness change after alpha-blocker therapy with alfuzosin?

INTRODUCTION

We evaluate the association between lower urinary tract symptoms (LUTS) and bladder wall thickness (BWT) and investigate whether alfuzosin might improve BWT.

METHODS

We retrospectively reviewed the data of 164 patients with LUTS. Patients were divided into 2 groups according to BWT (Group 1: BWT ≤5 mm, n = 69; Group 2: BWT >5 mm, n = 95). Age, international prostate symptom score (IPSS), maximum and average urinary flow rates (Qmax and Qave), quality of life (QoL), postvoid residual (PVR) urine volume, prostate volume and prostate-specific antigen (PSA) were compared between the 2 groups. In total, 102 patients underwent transurethral resection of the prostate (TURP) and 62 patients were treated with alfuzosin. We compared BWT, Qmax, Qave, IPSS, QoL, PVR and PSA before and at the sixth month of alfuzosin therapy. A p value of <0.05 was considered statistically significant.

RESULTS

The mean BWT of Group 1 was 3.72 ± 0.56 mm and Group 2 was 6.43 ± 1.13 mm. There was a significant difference between the 2 groups in terms of mean Qmax and PVR. There was no statistical difference between the groups in terms of Qave, IPSS, QoL, prostate volume and PSA. There was significant difference between BWT before (6.8 ± 2.1) and after (4.6 ± 1.3) treatment with alfuzosin in 62 patients (p = 0.02). There was a significant difference between pre- and post-treatment values of mean Qmax, Qave, IPSS, QoL score, and PVR with alfuzosin.

CONCLUSION

BWT is a non-invasive and effective test to evaluate patients with lower urinary tract obstruction and may be used for showing the effectiveness of alpha-blocker therapy in patients with LUTS.

Bladder wall thickness mapping for magnetic resonance cystography

Clinical studies have shown evidence that the bladder wall thickness is an effective biomarker for bladder abnormalities. Clinical optical cystoscopy, the current gold standard, cannot show the wall thickness. The use of ultrasound by experts may generate some local thickness information, but the information is limited in field-of-view and is user dependent. Recent advances in magnetic resonance (MR) imaging technologies lead MR-based virtual cystoscopy or MR cystography toward a potential alternative to map the wall thickness for the entire bladder. From a high-resolution structural MR volumetric image of the abdomen, a reasonable segmentation of the inner and outer borders of the bladder wall can be achievable. Starting from here, this paper reviews the limitation of a previous distance field-based approach of measuring the thickness between the two borders and then provides a solution to overcome the limitation by an electric field-based strategy. In addition, this paper further investigates a surface-fitting strategy to minimize the discretization errors on the voxel-like borders and facilitate the thickness mapping on the three-dimensional patient-specific bladder model. The presented thickness calculation and mapping were tested on both phantom and human subject datasets. The results are preliminary but very promising with a noticeable improvement over the previous distance field-based approach.

Investigating the effect of tamsulosin on the measurement of bladder wall thickness and International Prostate Symptom Score in benign prostatic hyperplasia

INTRODUCTION

According to previous studies, aging, gender, bladder volume and pathological states, such as bladder outflow obstruction, affect bladder wall thickness (BWT). The aim of this study was to evaluate the correlation between BWT and the International Prostatic Symptom Score (IPSS) in patients with benign prostatic hyperplasia (BPH) before and after tamsulosin treatment.

METHODS

In this study, 60 BPH patients were included. After obtaining informed consent, data were gathered using questionnaires to determine IPSS. After that, prostate-specific antigen was measured and a clinical examination, including a digital rectal examination, was performed for all patients. BWT was determined by transabdominal ultrasound. Finally, all patients were treated with tamsulosin (0.4 mg/day) for 2 months. After completing treatment, the IPSS and BWT were measured again and compared with the initial findings.

RESULTS

In total, 44 patients completed treatment. Patients aged 61.7 ± 9.2 years old. The mean ± standard deviation of IPSS and BWT were 14.6 ± 5.0 and 5.36 ± 1.28 mm before treatment, while they significantly (p < 0.0001) decreased to 8.2 ± 4.7 and 4.69 ± 1.23 mm, respectively, after treatment. Chi-square test showed that the decrease in BWT was significantly correlated with the improvement in IPSS (p = 0.002; r = 0.449).

CONCLUSION

After treatment with tamsulosin, patients experienced a reduction in their BWT which was significantly correlated with improvement in their IPSS. We conclude that transabdominal evaluation of BWT could be included in the follow-up assessment in BPH.

Treatment planning methodology for the Miami Multichannel Applicator following the American Brachytherapy Society recently published guidelines: the Lahey Clinic experience

The objective of this study was to develop a standardized procedure from simulation to treatment delivery for the multichannel Miami applicator, in order to increase planning consistency and reduce errors. A plan is generated prior to the 1st treatment using the CT images acquired with the applicator in place, and used for all 3 fractions. To confirm the application placement before each treatment fraction, an AP image is acquired and compared with the AP baseline image taken at simulation. A preplanning table is generated using the EBRT doses and is used to compute the maximum allowable D2cc for bladder, rectum, and sigmoid, and the mean allowable dose for the upper vaginal wall per HDR brachytherapy fraction. These data are used to establish the criteria for treatment planning dose optimization. A step‐by‐step treatment planning approach was developed to ensure appropriate coverage for the tumor (D90>100% prescribed dose of 700 cGy/fraction) and the uninvolved vaginal surface (dose for the entire treatment length > 600 cGy/fraction), while keeping the organs at risk below the tolerance doses. The equivalent dose 2 Gy (EQD2) tolerances for the critical structures are based on the American Brachytherapy Society (ABS) recently published guidelines. An independent second check is performed before the 1st treatment using an in‐house Excel spreadsheet. This methodology was successfully applied for our first few cases. For these patients: the cumulative tumor dose was 74–79 EQD2 Gy10 (ABS recommended range 70–85); tumor D90 was >100% of prescribed dose (range 101%–105%); cumulative D2cc for bladder, rectum, and sigmoid were lower than the tolerances of 90, 75, and 75 EQD2 Gy3, respectively; cumulative upper vaginal wall mean dose was below the tolerance of 120 EQD2 Gy3; the second check agreement was within 5%. By using a standardized procedure the planning consistency was increased and all dosimetric criteria were met.

PACS numbers: 87.55‐x, 87.56 bg

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.

Predictive value of resistive index, detrusor wall thickness and ultrasound estimated bladder weight regarding the outcome after transurethral prostatectomy for patients with lower urinary tract symptoms suggestive of benign prostatic obstruction

OBJECTIVES

To evaluate the value of three parameters from preoperative ultrasonography in predicting the outcome of transurethral prostatectomy in patients with lower urinary tract symptoms suggestive of benign prostatic obstruction.

METHODS

A total of 239 patients with lower urinary tract symptoms suggestive of benign prostatic obstruction entering our department for surgical therapy were prospectively recruited. All of them underwent both ultrasound and urodynamics before receiving standard transurethral prostatectomy by the same team of surgeons. For 202 patients, 6-month follow-up data were available after the surgery, including the International Prostate Symptom Score, the Quality of Life score and the maximum flow rate. Preoperative data stratified by different degree of recovery were compared and the influence of ultrasound parameters on the surgical outcome was analyzed by using logistic regression and receiver-operator characteristic curve analyses.

RESULTS

Baseline transitional zone index, intravesical prostatic protrusion, resistive index, detrusor wall thickness and ultrasonic estimation of bladder weight were significantly different between patients with an effective outcome and those with an ineffective outcome (P < 0.05). Resistive index, detrusor wall thickness and ultrasonic estimation of bladder weight were selected as independent factors correlated with the efficacy of transurethral prostatectomy by logistic regression (P < 0.05). All three factors had adequate area under receiver-operator characteristic curve with resistive index having the largest area (0.816, 95% CI 0.759-0.874). The combined positive predictive value in effective surgical outcome of resistive index, detrusor wall thickness and ultrasonic estimation was 96.3%.

CONCLUSIONS

Resistive index, detrusor wall thickness and ultrasonic estimation adequately predict the outcome of transurethral prostatectomy. Measuring these parameters by preoperative ultrasound might aid in determining the need for surgical intervention.

Correlation between intravesical pressure and prostatic obstruction grade using computational fluid dynamics in benign prostatic hyperplasia

An urodynamic test which measures various physiologic variables during voiding is generally used for accurate diagnosis of a bladder outlet obstruction (BOO) resulting from benign prostatic hyperplasia (BHP). However, this method is difficult to directly apply to all patients because it is an invasive test and many patients suffer from anxiety and embarrassment during the test. Thus, other diagnosis methods such as uroflowmetry and prostatic symptom score are performed to measure the degree of BOO prior to the urodynamic test, and it is necessary to construct a quantitative relationship among the obstruction level, the intravesical pressure, and the uroflow rate. The aim of this paper is to analyse the variation of intravesical pressure as a function of the extent of the obstruction and the uroflow rate from given information on the size of the bladder and the urodynamic test using a computational fluid dynamics approach. In order to analyse the intravesical pressure, a two-dimensional axisymmetric model of the bladder including a narrowed region, i.e. the prostatic obstruction, is created. Then the variation of the intravesical pressure is quantitatively obtained as a function of the magnitude of the uroflow rate and the extent of the obstruction. It is shown that the intravesical pressure significantly increases even for small obstructions and that at large obstructions it can reach values higher than 100 cm H2O, which is a dangerous value. It is shown that the intravesical pressure decreases as the uroflow rate decreases. This study can form the basis of a non-invasive test for the diagnosis of BHP.

Improvement of prostate treatment by anterior proton fields

PURPOSE

We performed a treatment planning study to demonstrate the potential dosimetric benefits of anterior-oriented fields for prostate irradiation by proton beam. A novel in vivo beam range control method shows millimeter accuracy, suggesting that such fields could be safely used to spare the rectum given the sharp distal penumbra of protons.

METHODS AND MATERIALS

Ten prostate patients treated with water-filled endorectal balloon were selected. Bilateral fields were planned following the conventional treatment protocol. Three anterior-oriented fields (0, +30, -30°) were planned, with the range compensators manually adjusted to improve rectal sparing. Dose distributions to the clinical target volume, rectum, anterior rectal wall (ARW), bladder, bladder wall (BW), and femoral heads were compared for: A) equally weighted bilateral fields, B) a single straight anterior field, and C) two equally weighted anterior-oblique fields.

RESULTS

The anterior-oriented fields required much less beam energy, ∼10 cm water equivalent path length less than lateral fields. For ARW, the V(95%) for Plans A, B, and C were 39%, 8%, and 6%, respectively; the corresponding V(80%) were 59%, 27%, and 26%, respectively (p = 0.002 when Plan A was compared with B or C). Plan B irradiated a larger volume of BW than did Plan A by 3% at V(95%), 11% at V(80%), and 16% at V(50%) (p = 0.002), whereas Plan C differs little from Plan A for BW at these dose levels. The femoral heads received ∼40% of the prescription dose in Plan A, but negligible dose in Plans B and C.

CONCLUSIONS

Compared to lateral fields, anterior-oriented fields can significantly reduce dose to the ARW, particularly at high dose levels. These fields alone, or in combination with lateral fields, allow for the possibility of either reducing treatment toxicity at current prescription doses or further dose escalation in the treatment of prostate cancer.

Automatic evaluation of ultrasonography-estimated bladder weight and bladder wall thickness in community-dwelling men with presumably normal bladder function

OBJECTIVE

To identify measurements of ultrasonography (US)-derived bladder wall thickness (BWT) and bladder weight in community-dwelling men with presumably normal bladder function.

SUBJECTS AND METHODS

A total of 100 male volunteers underwent transabdominal US measurements of BWT and bladder weight, using the BVM 9500 bladder scanner (Verathon Medical, Bothell, WA, USA), at a variety of bladder filling volumes. The data were explored for any correlation between measurements of BWT and US-estimated bladder weight (UEBW) with subject age, height, weight, body mass index (BMI), International Consultation on Incontinence Questionnaire-Male Lower Urinary Tract Symptoms (ICIQ M-LUTS) score, International Prostate Symptom Score (IPSS) and IPSS Quality of Life index (IPSS QoL).

RESULTS

Several statistically significant but weak correlations were observed: BWT and weight (r = 0.216, P = 0.032); BWT and BMI (r = 0.246, P = 0.014); UEBW and weight (r = 0.304, P = 0.002); and UEBW and BMI (r = 0.260, P = 0.009). Bladder filling volume appeared to have a greater effect on BWT than on UEBW, although this could not be determined accurately. There was a substantial difference in measurements of BWT and UEBW in the assessment of inter- and intra-observer reliability testing.

CONCLUSION

Further studies are required to validate automated measurements of BWT and UEBW and to investigate such measurements in the symptomatic and asymptomatic male population.

Manual versus automatic bladder wall thickness measurements: a method comparison study

PURPOSE

To compare repeatability and agreement of conventional ultrasound bladder wall thickness (BWT) measurements with automatically obtained BWT measurements by the BVM 6500 device.

METHODS

Adult patients with lower urinary tract symptoms, urinary incontinence, or postvoid residual urine were urodynamically assessed. During two subsequent cystometry sessions the infusion pump was temporarily stopped at 150 and 250 ml bladder filling to measure BWT with conventional ultrasound and the BVM 6500 device. For each method and each bladder filling, repeatability and variation was assessed by the method of Bland and Altman.

RESULTS

Fifty unselected patients (30 men, 20 women) aged 21–86 years (median 62.5 years) were prospectively evaluated. Invalid BWT measurements were encountered in 2.1–14% of patients when using the BVM 6500 versus 0% with conventional ultrasound (significant only during the second measurement at 150 ml bladder filling). Mean difference in BWT values between the measurements of one technique was −0.1 to +0.01 mm. Measurement variation between replicate measurements was smaller for conventional ultrasound and the smallest for 250 ml bladder filling. Mean difference between the two techniques was 0.11–0.23 mm and did not differ significantly. The BVM 6500 device was not able to correctly measure BWTs above 4 mm.

CONCLUSIONS

Both BWT measurements are repeatable and agree with each other. However, conventional ultrasound measurements have a smaller measurement variance, can measure BWT in all patients, and BWTs above 4 mm.

Transabdominal ultrasonography of detrusor wall thickness in women with overactive bladder

OBJECTIVE

To determine the clinical usefulness of measuring detrusor wall thickness (DWT) as a noninvasive test in women with overactive bladder (OAB).

PATIENTS, SUBJECTS AND METHODS

We prospectively enrolled 122 women with dry OAB, wet OAB, and women with no OAB symptoms (control group). A 3-day voiding diary was used to differentiate between wet and dry OAB. Transabdominal ultrasonography (TAUS) measurements of DWT were taken at bladder volumes of 250-300 mL and the maximal bladder capacity by both catheter- and natural-filling. Video-urodynamic studies (VUDS) were used to classify bladder dysfunction in 88 of the women.

RESULTS

The mean (range) age of the women was 58 (20-94) years. There were 39 'normal' controls, 44 women had dry OAB, and 39 had wet OAB. Of the 88 women who had VUDS, 28 had a 'normal' test, 30 had increased bladder sensation (IBS), and 30 had detrusor overactivity (DO). The mean DWT at 250-300 mL among three symptomatic subgroups or urodynamic subgroups showed no significant difference by either catheter- or natural-filling methods. The women with wet OAB had significantly greater DWTs than the controls at maximal bladder volume. The maximal bladder capacity was significantly greater in 'normal' women than in those with OAB. If we corrected maximal bladder volume to 250 mL, DWT at corrected 250 mL showed no significant difference among three symptomatic subgroups.

CONCLUSIONS

DWT measured by TAUS in women with OAB and without OAB was not different and did not differ with urodynamic status. Thus, TAUS measurement of DWT is not recommended as a useful diagnostic test for DO in women with OAB.

Three-dimensional ultrasound bladder characteristics and their association with prostate size and lower urinary tract dysfunction among men in the community

OBJECTIVES

To characterize ultrasound bladder measures, and to determine whether these measures were associated with measures of lower urinary tract dysfunction.

METHODS

Three-dimensional ultrasounds were used to assess bladder surface area (SA), bladder wall thickness (BWT), and estimated bladder weight (EBW) in a random sample of the Olmsted County, Minnesota, male population. Uroflowometry was used to determine maximum urinary flow rates, and ultrasound was used to assess postvoid residual volume. Prostate volume was assessed with transrectal ultrasound and prostate-specific antigen (PSA) levels were assessed from serum samples. Correlation and linear regression analyses assessed relationships between bladder measures and prostate volume, PSA, maximum flow rate, and postvoid residual.

RESULTS

Among 259 men, median bladder SA was 228 cm(2) (25th, 75th percentiles: 180, 279), median BWT was 2.3 mm (25th, 75th percentiles: 1.8, 2.7), and median EBW was 48.5 g (25th, 75th percentiles: 43.7, 53.0). Decreased bladder SA was correlated with increased PSA level, increased prostate volume, higher American Urological Association Symptom Index (AUASI) scores (r(s) = -0.13 to -0.21; P = .03-.001), and decreased maximum flow rate (r(s) = 0.21, P = .001). Increased BWT was correlated with increased PSA level (r(s) = 0.22, P = .0003), increased prostate volume (r(s) = 0.17, P = .01), and decreased maximum flow rate (r(s) = -0.14, P = .03). Increased EBW was correlated with increased maximum flow rate (r(s) = 0.14, P = .03) and decreased AUASI score (r(s) = -0.13, P = .04).

CONCLUSIONS

Decreased SA and EBW were moderately associated with decreased maximum flow rate and increased AUASI scores, suggesting that such measures may provide insight into detrusor dysfunction.

Measurement of detrusor wall thickness in women with overactive bladder by transvaginal and transabdominal sonography

INTRODUCTION AND HYPOTHESIS

Women with overactive bladder (OAB) might have a greater detrusor wall thickness (DWT) suggestive of detrusor overactivity (DO).

METHODS

DWT was measured by transabdominal ultrasonography (TAU) and transvaginal ultrasonography (TVU) in normal and women with OAB-dry and OAB-wet. The subjects were further classified as normal, hypersensitive bladder, or DO by urodynamic results. DWT measured by TVU at empty bladder, and TAU at 250 ml and bladder capacity were compared among symptom and urodynamic subgroups.

RESULTS

TVU-measured DWT was significantly greater at the bladder neck than other sites of the bladder wall. No significant difference of TVU-measured DWT was noted among subgroups. No significant difference of TAU-measured DWT among subgroups at 250 ml, but DWT at bladder capacity was significantly greater in OAB-wet or DO than other subgroups.

CONCLUSIONS

A greater DWT at bladder capacity measured by TAU can be useful as biomarker for DO in patients with OAB.

Lower urinary tract symptoms, prostate volume, uroflowmetry, residual urine volume and bladder wall thickness in Turkish men: a comparative analysis

AIM

To evaluate the association between lower urinary tract symptoms (LUTS) severity and bladder wall thickness (BWT).

MATERIALS AND METHODS

The study included 155 patients referred to outpatient clinics for LUTS. Patients were divided into three groups due to their IPSS. Group A included the patients with mild symptoms, group B included patients with moderate symptoms and group C included patients with severe symptoms. The patients were again divided into two groups due to their uroflowmetry results. Group 1 included the patients whose Q (max) </= 10 ml/s and group 2 included the patients whose Q (max) > 10 ml/s.

RESULTS

The mean BWT was 4.14 + 1.03 mm (from 3 to 9 mm). Although there was no difference between the IPSS groups in BWT (P = 0.325), it was statistically significant between uroflowmetry study groups (P < 0.01).

CONCLUSIONS

BWT seems to be significantly increased in men who have Q (max) values smaller than 10 ml/s.

Is it possible to improve elderly male bladder function by having them drink more water? A randomized trial of effects of increased fluid intake/urine output on male lower urinary tract function

OBJECTIVES

Several animal studies have shown that bladder performance improves as a result of diuresis. Whether increased urine output also has beneficial effects on elderly male bladder function and lower urinary tract symptoms is unknown.

METHODS

We performed a randomized placebo-controlled trial of 141 men, 55 to 75 years of age, with moderate lower urinary tract symptoms. The experimental group drank 1.5 L of extra water daily. The control group consumed one tablespoon of placebo syrup daily. After 6 months, we evaluated bladder contractility, voided volumes, and the severity of lower urinary tract symptoms. The actual increase in water consumption was measured using the deuterium urine dilution method.

RESULTS

Water consumption in the intervention group increased by 359 mL (95% confidence interval [CI] 171 to 548) per 24 hours compared with the control group. At 6 months, no statistically significant effect was found in the maximal flow rate (0.9 mL/s, 95% CI -0.4 to 2.2) compared with placebo. A statistically significant effect was found for bladder pressure (20 cm H2O, 95% CI 6 to 34) and bladder wall stress (1.9 N/cm2, 95% CI 0.3 to 3.5). In addition, it showed that the experimental group had greater maximal (44 mL, 95% CI -1 to 90) and average (26 mL, 95% CI 1 to 51) voided volumes per urination. The subjective effect parameters improved in both groups, but no statistically significant differences were found between the two groups.

CONCLUSIONS

It seems possible to improve some aspects of male bladder function by drinking more water. However, the effects are too small to be clinically relevant.