Ultrasound detrusor wall thickness measurement in combination with bladder capacity can safely detect detrusor underactivity in adult men

Summary Paper on Underactive Bladder from the European Association of Urology Guidelines on Non-neurogenic Male Lower Urinary Tract Symptoms

BACKGROUND AND OBJECTIVE

The European Association of Urology (EAU) Guidelines Panel on non-neurogenic male lower urinary tract symptoms (LUTS) aimed to develop a new subchapter on underactive bladder (UAB) in non-neurogenic men to inform health care providers of current best evidence and practice. Here, we present a summary of the UAB subchapter that is incorporated into the 2024 version of the EAU guidelines on non-neurogenic male LUTS.

METHODS

A systematic literature search was conducted from 2002 to 2022, and articles with the highest certainty evidence were selected. A strength rating has been provided for each recommendation according to the EAU Guideline Office methodology.

KEY FINDINGS AND LIMITATIONS

Detrusor underactivity (DU) is a urodynamic diagnosis defined as a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or failure to achieve complete bladder emptying within a normal time span. UAB is a terminology that should be reserved for describing symptoms and clinical features related to DU. Invasive urodynamics is the only widely accepted method for diagnosing DU. In patients with persistently elevated postvoid residual (ie, >300 ml), intermittent catheterization is indicated and preferred to indwelling catheters. Alpha-adrenergic blockers are recommended before more invasive techniques, but the level of evidence is low. In men with DU and concomitant benign prostatic obstruction (BPO), benign prostatic surgery should be considered only after appropriate counseling. In men with DU and no BPO, a test phase of sacral neuromodulation may be considered.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The current text represents a summary of the new subchapter on UAB. For more detailed information, refer to the full-text version available on the EAU website (https://uroweb.org/guidelines/management-of-non-neurogenic-male-luts).

PATIENT SUMMARY

The European Association of Urology guidelines on underactive bladder in non-neurogenic adult men are presented here. Patients must be fully informed of all relevant options and, together with their treating physicians, decide on the most optimal management for them.

Novel clinical diagnostic criteria based on noninvasive examination findings to predict the presence of urodynamic detrusor underactivity in men

AIMS

To investigate the usefulness of novel clinical diagnostic criteria based on noninvasive examination findings to diagnose urodynamic detrusor underactivity (DU) in men.

METHODS

We developed clinical diagnostic criteria to predict the presence of urodynamic DU in men as follows: (a) bladder voiding efficiency <70% on uroflowmetry, (b) existence of "sawtooth and interrupted waveforms" on uroflowmetry, and (c) ultrasonography-documented intravesical prostatic protrusion <10 mm. We analyzed the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these clinical criteria for diagnosing urodynamic DU in men aged 50 years or above with lower urinary tract symptoms who underwent urodynamic studies.

RESULTS

Of the 314 men analyzed (mean age, 72.4 years; mean detrusor contraction index [DCI], 98.8; and mean bladder outlet obstruction index [BOOI], 43.9), 89 men met this clinical DU diagnostic criteria. Of these, 79 men (88.8%) had urodynamic DU (DCI < 100 and BOOI < 40), nine (10.1%) had DU + BOO (DCI < 100 and BOOI ≥ 40), and one (1.1%) had normal voiding functions. None of the men with urodynamic BOO (DCI ≥ 100 and BOOI ≥ 40) met the clinical DU diagnostic criteria. The sensitivity, specificity, PPV, and NPV of these clinical diagnostic criteria for urodynamic DU were 69.3%, 95.0%, 88.8%, and 84.4%, respectively.

CONCLUSION

The proposed clinical DU diagnostic criteria showed a high PPV (88.8%) for diagnosing urodynamic DU. None of the patients with BOO met the clinical diagnostic criteria for DU. These clinical DU diagnostic criteria may be useful in identifying men with urodynamic DU in clinical practice.

Underactive Bladder and Detrusor Underactivity: New Advances and Prospectives

Underactive bladder (UAB) is a prevalent but under-researched lower urinary tract symptom that typically occurs alongside detrusor underactivity (DU). Unlike UAB, DU is a urodynamic diagnosis which the International Continence Society (ICS) defines as "a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span". Despite the widespread prevalence of UAB/DU, there are significant gaps in our understanding of its pathophysiological mechanisms, diagnosis, and treatment compared with overactive bladder (OAB) and detrusor overactivity (DO). These gaps are such that clinicians regard UAB/DU as an incurable condition. In recent years, the understanding of UAB has increased. The definition of UAB has been clarified, and the diagnostic criteria for DU have been considered more comprehensively. Meanwhile, a number of non-invasive diagnostic methods have also been reported. Clinical trials involving novel drugs, electrical stimulation, and stem cell therapy have shown promising results. Therefore, this review summarizes recent reports on UAB and DU and highlights the latest advances in their diagnosis and treatment.

Characteristics of uroflowmetry patterns in men with detrusor underactivity revealed by artificial intelligence

OBJECTIVES

To elucidate the characteristics of uroflowmetry (UFM) observed in men with detrusor underactivity (DU) using our developed artificial intelligence (AI) diagnostic algorithm to distinguish between DU and bladder outlet obstruction (BOO).

METHODS

Subjective and objective parameters, including four UFM parameters (first peak flow rate, time to first peak, gradient to first peak, and the ratio of first peak flow rate to maximum flow rate [Qmax ]) selected by analyzing the judgment basis of the AI diagnostic system, were compared in 266 treatment-naive men with lower urinary tract symptoms (LUTS). Patients were divided into the DU (70; 26.32%) and non-DU (196; 73.68%) groups, and the UFM parameters for predicting the presence of DU were determined by multivariate analysis and receiver operating characteristic (ROC) curve analysis. Detrusor underactivity was defined as a bladder contractility index <100 and a BOO index <40.

RESULTS

Most parameters on the first peak flow of UFM were significantly lower in the DU group. On multivariate analysis, lower first peak flow rate and lower ratio of first peak flow rate to Qmax were significant parameters to predict DU. In the ROC analysis, the ratio of the first peak flow rate to Qmax showed the highest area under the curve (0.848) and yielded sensitivities of 76% and specificities of 83% for DU diagnosis, with cutoff values of 0.8.

CONCLUSIONS

Parameters on the first peak flow of UFM, especially the ratio of the first peak flow rate to Qmax , can diagnose DU with high accuracy in men with LUTS.

Mesenchymal Stromal Cell Therapy Reverses Detrusor Hypoactivity in a Chronic Kidney Patient

Detrusor hypoactivity (DH) is characterized by low detrusor pressure or a short contraction associated with low urinary flow. This condition can progress to chronic renal failure (CRF) and result in the need for dialysis. The present case report demonstrates that a patient diagnosed with DH and CRF who received two transplants with 2 × 10⁶ autologous mesenchymal stromal cells at an interval of 30 days recovered the contractile strength of the bladder and normalized his renal function. The patient had a score of 19 on the ICIQ-SF before cell therapy, and that score was reduced to 1 after transplantation. These results demonstrate that there was an improvement in his voiding function, urinary stream and urine volume as evaluated by urofluxometry. In addition, a urodynamic study carried out after treatment showed an increase in the maximum flow from 2 mL/s to 23 mL/s, the detrusor pressure in the maximum flow from 21 cm H₂O to 46 cm H₂O and a BCI that went from 31 to 161, characterizing good detrusor contraction. Thus, in the present case, the transplantation of autologous mesenchymal stromal cells proved to be a viable therapeutic option to allow the patient to recover the contractile strength of the bladder, and reversed the CRF.

Detrusor Underactivity in Men with Bladder Outlet Obstruction

Detrusor underactivity (DU) and bladder outlet obstruction (BOO) are both common troublesome causes of lower urinary tract symptoms (LUTS) and often impact on quality of life simultaneously in men. This article aims to focus on DU with BOO in male patients.

METHODS

Original articles concerning DU with BOO were identified through literature research from PubMed and EMBASE database. We selected 38 articles in our review, including those concerning pathophysiology, evaluation, treatment and predictors for a successful BOO surgery for DU.

RESULTS

DU from BOO can result from several pathophysiological mechanisms. Although urodynamic study (UDS) is considered as a precise method to diagnose DU and BOO, there are some previous studies which proposed a non-invasive method to identify DU related to BOO. The treatment goal of DU is restoring bladder contractility using medication or surgery. Releasing outlet obstruction and resistance is the main strategy to restore bladder contractility when medication to directly increase bladder contractility has had limited efficacy.

CONCLUSIONS

DU from BOO is poorly understood and is largely under-researched. The etiology and pathophysiology still need to be evaluated. Effective and safe medication to restore bladder contractility is also lacking. It remains valuable to perform further research to reveal the unknown aspects of DU.

Reliability and validity of assessment methods available in primary care for bladder outlet obstruction and benign prostatic obstruction in men with lower urinary tract symptoms: a systematic review

OBJECTIVES

To systematically review the literature regarding the reliability and validity of assessment methods available in primary care for bladder outlet obstruction or benign prostatic obstruction in men with lower urinary tract symptoms (LUTS).

DESIGN

Systematic review with best evidence synthesis.

SETTING

Primary care.

PARTICIPANTS

Men with LUTS due to bladder outlet obstruction or benign prostatic obstruction.

REVIEW METHODS

PubMed, Ebsco/CINAHL and Embase databases were searched for studies on the validity and reliability of assessment methods for bladder outlet obstruction and benign prostatic obstruction in primary care. Methodological quality was assessed with the COSMIN checklist. Studies with poor methodology were excluded from the best evidence synthesis.

RESULTS

Of the 5644 studies identified, 61 were scored with the COSMIN checklist, 37 studies were included in the best evidence synthesis, 18 evaluated bladder outlet obstruction and 17 benign prostatic obstruction, 2 evaluated both. Overall, reliability was poorly evaluated. Transrectal and transabdominal ultrasound showed moderate to good validity to evaluate bladder outlet obstruction. Measured prostate volume with these ultrasound methods, to identify benign prostatic obstruction, showed moderate to good accuracy, supported by a moderate to high level of evidence. Uroflowmetry for bladder outlet obstruction showed poor to moderate diagnostic accuracy, depending on used cut-off values. Questionnaires were supported by high-quality evidence, although correlations and diagnostic accuracy were poor to moderate compared with criterion tests. Other methods were supported by low level evidence.

CONCLUSION

Clinicians in primary care can incorporate transabdominal and transrectal ultrasound or uroflowmetry in the evaluation of men with LUTS but should not solely rely on these methods as the diagnostic accuracy is insufficient and reliability remains insufficiently researched. Low-to-moderate levels of evidence for most assessment methods were due to methodological shortcomings and inconsistency in the studies. This highlights the need for better study designs in this domain.

Significance of a decrease in the proportion of detrusor muscle to bladder wall for non-invasive diagnosis of detrusor underactivity in men with lower urinary tract symptoms

To investigate the significance of detrusor muscle thickness (DMT) to bladder wall thickness (BWT) ratio as a detrusor-sarcopenia and a consistently applicable factor for noninvasive diagnosis of detrusor underactivity (DU). We prospectively performed a urodynamic study of 100 male with medical refractory lower-urinary-tract-symptoms during 2017–2019. The DMT, BWT and DMT/BWT ratio were measured by ultrasonography every 50 mL during bladder filling, and were analyzed for non-invasive diagnosis of DU and prediction of prostate surgery outcome with questionnaire and the maximum-flow-rate. Of the 94 patients, DU was urodynamically diagnosed in 24 (25.5%). The DMT/BWT ratio was maintained in all patients until the 50% of the maximum cystometric capacity (MCC), and then rapidly decreased. At 20% of the MCC, the DMT/BWT ratio was significantly lower in the DU group (44.0 ± 4.9% vs. 49.4 ± 6.7%, p = 0.008). The DMT/BWT ratio of less than 47.5% at 20% of the MCC showed the ideal accuracy for diagnosing DU (AUC = 0.763), and was a predictor of failure at 12 months after prostate surgery (OR 8.78, p = 0.024). A DMT/BWT ratio of less than 47.5% at 20% of the MCC is a consistently applicable factor for non-invasive diagnosis of DU and could also be considered detrusor-sarcopenia.

Correlations between bladder wall thickness and clinical manifestations in female patients with detrusor underactivity and detrusor overactivity-with-detrusor underactivity

BACKGROUND

Among female patients with lower urinary tract symptoms, detrusor underactivity (DU), and detrusor overactivity-with-detrusor underactivity (DO-DU) are two common diagnoses. Here, we investigated the correlations between bladder wall thickness (BWT) and clinical manifestations of the two diagnoses.

METHODS

From 2011 to 2016, female patients with DU or DO-DU, diagnosed at our institute, were recruited. We analyzed their urodynamic parameters and collected three questionnaires (IPSS, UDI-6, OABSS). Using transabdominal sonography, the BWT was recorded. DU was defined as follows: maximum free flow rate (Qmax) ≤ 15 cc/s; detrusor pressure at maximum flow (PdetQmax) ≤ 20 cmH2O; bladder capacity > 150 cc. DO-DU was defined as follows: Qmax ≤ 15 cc/s; PdetQmax ≤ 20 cmH2O; bladder capacity ≤ 150 cc. The BWTs of the two groups were compared using the Mann-Whitney U test; the correlations among the BWTs and the results of three questionnaires were analyzed using Spearman's rank correlation coefficient.

RESULTS

Forty-eight female patients with DU and 13 with DO-DU were recruited. Demographic data revealed no differences between the two groups. The mean BWT of the DO-DU patients was significantly larger than that of the DU patients (4.11 vs 3.42 mm; p = 0.001). In the DO-DU group, a high correlation existed between the BWT and some of the UDI-6 items (urgency incontinence: r = 0.831, p = 0.006; incontinence related to activity: r = 0.884, p = 0.002; small amounts of leakage: r = 0.809, p = 0.008). The BWT of the DO-DU patients also exhibited a moderate correlation with the urgency incontinence from the OABSS questionnaire (r = 0.679; p = 0.044). No correlations existed between the BWT of the DU patients and any of the data from the three questionnaires.

CONCLUSION

The BWT in the DO-DU patients was significantly thicker than that in the DU patients. The DO-DU patients with thicker bladder walls also had higher UDI-6 scores for both urgency and urgency incontinence.

Development of an artificial intelligence diagnostic system for lower urinary tract dysfunction in men

OBJECTIVES

To establish an artificial intelligence diagnostic system for lower urinary tract function in men with lower urinary tract symptoms using only uroflowmetry data and to evaluate its usefulness.

METHODS

Uroflowmetry data of 256 treatment-naive men with detrusor underactivity, bladder outlet obstruction, or detrusor underactivity + bladder outlet obstruction were used for artificial intelligence learning and validation using neural networks. An optimal artificial intelligence diagnostic model was established using 10-fold stratified cross-validation and data augmentation. Correlations of bladder contractility index and bladder outlet obstruction index values for the artificial intelligence system and pressure flow study values were examined using Spearman's correlation coefficients. Additionally, diagnostic accuracy was compared between the established artificial intelligence system and trained urologists with uroflowmetry data of 25 additional patients by χ² -tests. Detrusor underactivity was defined as bladder contractility index ≤100 and bladder outlet obstruction index ≤40, bladder outlet obstruction was defined as bladder contractility index >100 and bladder outlet obstruction index >40, and detrusor underactivity + bladder outlet obstruction was defined as bladder contractility index ≤100 and bladder outlet obstruction index >40.

RESULTS

The artificial intelligence system's estimated bladder contractility index and bladder outlet obstruction index values showed significant positive correlations with pressure flow study values (bladder contractility index: r = 0.60, P < 0.001; bladder outlet obstruction index: r = 0.46, P < 0.001). The artificial intelligence system's detrusor underactivity diagnosis had a sensitivity and specificity of 79.7% and 88.7%, respectively, and those for bladder outlet obstruction diagnosis were 76.8% and 84.7%, respectively. The artificial intelligence system's average diagnostic accuracy was 84%, which was significantly higher than that of urologists (56%).

CONCLUSIONS

Our artificial intelligence diagnostic system developed using the uroflowmetry waveform distinguished between detrusor underactivity and bladder outlet obstruction with high sensitivity and specificity in men with lower urinary tract symptoms.

Detrusor underactivity prevalence and risk factors according to different definitions in women attending urogynecology clinic

INTRODUCTION AND HYPOTHESIS

There is still no consensus on definitions of detrusor underactivity; therefore, it is difficult to estimate the prevalence. The primary objective of the study was to evaluate the prevalence of detrusor underactivity in a cohort of patients with pelvic floor disorders according to different proposed urodynamics definitions. The secondary objectives were to estimate the association between detrusor underactivity and symptoms, anatomy and urodynamic findings and to build predictive models.

METHODS

Patients who performed urodynamic evaluation for pelvic floor disorders between 2008 and 2016 were retrospectively analyzed. Detrusor underactivity was evaluated according to Schafer's detrusor factor, Abrams' bladder contractility index and Jeong cut-offs. The degree of concordance between each method was measured with Cohen's kappa, and differences were tested using Student's t test, Wilcoxon test and Pearson's chi-squared test.

RESULTS

The prevalence of detrusor underactivity among a cohort of 2092 women, concerning the three urodynamic definitions, was 33.7%, 37.0% and 4.1%, respectively. Age, menopausal status, voiding/bulging symptoms, anterior and central prolapse, first desire to void and positive postvoid residual were directly related to detrusor underactivity. Conversely, stress urinary incontinence, detrusor pressures during voiding and maximum flow were inversely associated. Final models for detrusor underactivity resulted in poor accuracy for all considered definitions.

CONCLUSIONS

The prevalence of detrusor underactivity varies depending on the definition considered. Although several clinical variables resulted as independent predictors of detrusor underactivity, instrumental evaluation still plays a key role in the diagnosis.

Comprehensive non-invasive analysis of lower urinary tract anatomy using MRI

PURPOSE

Anatomic changes that coincide with aging including benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) negatively impact quality of life. Use of MRI with its exquisite soft tissue contrast, full field-of-view capabilities, and lack of radiation is uniquely suited for quantifying specific lower urinary tract features and providing comprehensive measurements such as total bladder wall volume (BWV), bladder wall thickness (BWT), and prostate volume (PV). We present a technique for generating 3D anatomical renderings from MRI to perform quantitative analysis of lower urinary tract anatomy.

METHODS

T2-weighted fast-spin echo MRI of the pelvis in 117 subjects (59F;58 M) aged 30-69 (49.5 ± 11.3) without known lower urinary tract symptoms was retrospectively segmented using Materialise software. Virtual 3D models were used to measure BWV, BWT, and PV.

RESULTS

BWV increased significantly between the 30-39 and 60-69 year age group in women (p = 0.01), but not men (p = 0.32). BWV was higher in men than women aged 30-39 and 40-49 (p = 0.02, 0.05, respectively) ,but not 50-59 or 60-69 (p = 0.18, 0.16, respectively). BWT was thicker in men than women across all age groups. Regional differences in BWT were observed both between men and women and between opposing bladder wall halves (anterior/posterior, dome/base, left/right) within each sex in the 50-59 and 60-69 year groups. PV increased from the 30-39 to 60-69 year groups (p = 0.05). BWT was higher in subjects with enlarged prostates (> 40cm³) (p = 0.05).

CONCLUSION

Virtual 3D MRI models of the lower urinary tract reliably quantify sex-specific and age-associated changes of the bladder wall and prostate.

[Sophisticated surgical management of distinctive patients with benign prostatic hyperplasia (BPH)]

Herein we describe four clinical scenarios. For the standard patient (prostate volume 30-80 ml, life expectancy >10 years) transurethral resection of the prostate (TURP) remains the standard of care, while endoscopic enucleation is a valuable alternative. Patients with a relevant middle lobe profit most from TURP, endourological enucleation procedures, or laser vaporization. In the case of the absence or a moderate-sized middle lobe and the absence of severe bladder outlet obstruction (BOO), minimally invasive procedures such as Rezūm®, UroLift® or prostate artery embolization (PAE) can be offered. Patients have to be informed that long-term data on this specific indication are lacking. Particularly younger men requiring BPH surgery are interested in preserving ejaculatory function. In the presence of severe BOO, ejaculatory-protective TURP or endoscopic enucleation by preserving the pericollicular region or aquablation are the methods of choice providing an antegrade ejaculation in 60-90% of cases. Rezūm®, AquaBeam®, and UroLift® enable preservation of ejaculation in almost 100%; data on PAE with this respect are more controversial. For patients with a small prostate and significant post void residual, a thorough preoperative work-up, including urodynamics and bladder/detrusor wall thickness measurement, is of great importance. Desobstructive surgery provides satisfactory short- and midterm outcome, yet the long-term outcome is disappointing and remains to be determined in greater detail. The broad spectrum of therapeutic options enables today an individualized minimally invasive or surgical management of BPH considering patient wishes, anatomical factors or urodynamic factors. The time of a "one therapy fits all" strategy is definitely history.

The role of bladder wall thickness in the evaluation of detrusor underactivity: Development of a clinical nomogram

AIMS

The aim of our study was to investigate noninvasive predictors for detrusor underactivity (DUA) in male patients with lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE).

METHODS

A consecutive series of patients aged 45 years or older with non-neurogenic LUTS were prospectively enrolled. Patients underwent standard diagnostic assessment including International Prostatic Symptoms Score, uroflowmetry, urodynamic studies (cystometry and pressure-flow studies), transrectal ultrasound of the prostate, and ultrasound measurements of the bladder wall thickness (BWT). Logistic regression analysis was used to investigate predictors of DUA, defined as a bladder contractility index < 100 mm H₂ O. A nomogram was developed based on the multivariable logistic regression model.

RESULTS

Overall 448 patients with a mean age of 66 ± 11 years were enrolled. In a multivariable logistic age-adjusted regression model BWT (odds ratio [OR]: 0.50 per mm; 95% confidence interval [CI], 0.30-0-66; P = .001) and Qmax (OR: 0.75 per mL/s; 95% CI, 0.70-0.81; P = .001) were significant predictors for DUA. The nomogram based on the model presented good discrimination (area under the curve [AUC]: 0.82), good calibration (Hosmer-Lemeshow test, P > .05) and a net benefit in the range of probabilities between 10% and 80%.

CONCLUSIONS

According to our results, BWT and Qmax can noninvasively predict the presence of DUA in patients with LUTS and BPE. Although our study should be confirmed in a larger prospective cohort, we present the first available nomogram for the prediction of DUA in patients with LUTS.

Is coexistent overactive-underactive bladder (with or without detrusor overactivity and underactivity) a real clinical syndrome? ICI-RS 2019

AIMS

Lower urinary tract symptoms (LUTS) can be classified into symptom syndromes based on which symptoms are predominant. Overactive bladder (OAB) syndrome, a storage dysfunction, and underactive bladder (UAB) syndrome, a voiding dysfunction, are common syndromes, which urodynamic tests may show to be caused by detrusor overactivity (DO) and detrusor underactivity (DU), but can also be associated with other urethro-vesical dysfunctions. Sometimes OAB and UAB can coexist in the same patient and, if so, need a specific approach beyond treatment of the single and apparently opposing syndromes.

METHODS

During its 2019 meeting in Bristol, the International Consultation on Incontinence Research Society held a literature review and expert consensus discussion focused on the emerging awareness of the coexisting overactive-underactive bladder (COUB).

RESULTS

The consensus considered whether COUB is the combination of OAB and UAB syndromes, or a real unique clinical syndrome in the same patient, possibly with a common etiology. Definitions, pathophysiology, diagnosis, and treatment were discussed, and high-priority research questions were identified.

CONCLUSIONS

COUB (with or without urodynamic evidence of DO and DU) may be considered a real clinical syndrome, because it differs from single OAB and UAB, and may not be the combination of both syndromes. Urodynamic tests may be necessary in unclear cases or in cases not responding to initial treatment of the most troublesome symptoms. It is pivotal to define the evolution of the syndrome and the characteristic population, and to recognize predictive or phenotyping factors to develop a specific approach and adequate outcome measures.

Clinical characteristics and useful signs to differentiate detrusor underactivity from bladder outlet obstruction in men with non-neurogenic lower urinary tract symptoms

OBJECTIVE

To investigate the clinical characteristics and useful signs to differentiate detrusor underactivity from bladder outlet obstruction in men with non-neurogenic lower urinary tract symptoms.

METHODS

A total of 638 treatment-naive men with non-neurogenic lower urinary tract symptoms who underwent subjective and objective evaluations were reviewed retrospectively. We divided the patients into detrusor underactivity and bladder outlet obstruction groups based on urodynamic findings, and compared parameters obtained from questionnaires and non-invasive tests. Detrusor underactivity was defined as bladder contractility index ≤100 and bladder outlet obstruction index ≤40, whereas bladder outlet obstruction was defined as bladder contractility index >100 and bladder outlet obstruction index >40.

RESULTS

Of 638 patients, 145 (22.7%) had detrusor underactivity and 273 (42.8%) had bladder outlet obstruction. Total international prostate symptom score and international prostate symptom score-voiding subscore were significantly higher in the detrusor underactivity group. There were significant differences in prostate volume, intravesical prostatic protrusion, and all uroflowmetry parameters between the two groups. In multivariate logistic regression analysis, lower intravesical prostatic protrusion (cut-off value 8.2 mm), lower bladder voiding efficiency (cut-off value 70%), and the presence of sawtooth and interrupted waveform on uroflowmetry were significant predictive factors for detrusor underactivity. In particular, the incidence of sawtooth and interrupted waveform was significantly higher in the detrusor underactivity group (80%) than in the bladder outlet obstruction group (12.8%), which showed both high sensitivity (80%) and specificity (87.2%) in differentiating detrusor underactivity from bladder outlet obstruction.

CONCLUSIONS

Sawtooth and interrupted waveform on uroflowmetry can be a useful predictive factor for detrusor underactivity. In addition, lower intravesical prostatic protrusion and bladder voiding efficiency can be of supplementary use.

Do functional changes occur in the bladder due to bladder outlet obstruction? - ICI-RS 2018

Studies on bladder dysfunction (BD), more specifically functional‐urodynamic changes in the bladder as a result of bladder outlet obstruction (BOO) have been summarized for this TT. Based on available, but limited evidence from human studies a three‐stage model can be hypothesized to characterize BOO‐induced bladder remodeling: hypertrophy, compensation (increased detrusor contractility during the voiding phase, often in combination with filling phase detrusor overactivity) followed by the phase of decompensation [detrusor underactivity]. The time between the start of compensation and eventual decompensation seems to be determined by age of onset, severity, and type of obstruction and clinical mitigating factors such as vascular and metabolic problems. Understanding the relative contributions of these factors may allow the development of personalized timelines and probabilities for these obstructed patients.

Urodynamic factors associated with the large capacity bladder and incomplete emptying after prolapse repair (2009-2015)

AIMS

To identify the clinical and urodynamic factors associated with the large capacity bladder and incomplete bladder emptying after prolapse repair.

METHODS

We identified 592 women who underwent anterior and/or apical prolapse repair at our institution from 2009 to 2015. Women were stratified by urodynamic capacity. The primary outcome was incomplete emptying at the longest follow-up (postvoid residual [PVR] > 200 mL). Data were analyzed in the Statistical Analysis System software.

RESULTS

Two hundred and sixty-six women (mean age, 61 years) had preoperative urodynamic tracings available for review. After surgery, there were 519 PVRs in 239 women recorded at up to 2949 days (mean, 396) and nine time points (median, 2; IQR, 1-3). The receiver operator curve for predicted probability of longest follow-up PVR greater than 200 mL (area under curve = 0.67) identified the 600 mL cutpoint which defined large capacity bladder. Large capacity bladders (capacity, >600 mL [n=79] vs ≤600 mL, [n=160]) had a mean: detrusor pressure at maximum flow (21 vs 22 cm H₂ O; P = 0.717), maximum flow rate (19 vs 17 mL/s; P = 0.148), significantly elevated PVR (202 vs 73 mL; P < 0.001), and significantly lower voiding efficiency (VE) (74 vs 82%, P < 0.05). Following prolapse repair, elevated PVR was associated with large capacity (PVR 101 vs 49 mL, P < 0.05). Large bladders had a two- to three-fold risk of longest follow-up PVR greater than 200 mL (14.3%-20.3% [capacity, >600 mL] vs 4.1%-7.0% [capacity, ≤600 mL]). VE was similar after surgery regardless of the capacity (87% vs 88%, P = 0.772).

CONCLUSIONS

The decision to pursue prolapse repair should be individualized and take into account, the bladder capacity and goals for PVR improvement after surgery.

Oxidative stress in the bladder of men with LUTS undergoing open prostatectomy: a pilot study

Purpose:

This study aims to evaluate the link between preoperative parameters and oxidative stress (OS) markers in the bladder wall of men undergoing open prostatectomy.

Materials and Methods:

From July 2014 to August 2016, men aged ≥ 50 years and presenting with LUTS were prospectively enrolled. Preoperative assessment included validated questionnaires (IPSS and OAB - V8), lower urinary tract ultrasound and urodynamics. Bladder biopsies were taken during open prostatectomy for determination of OS markers. Increased OS was defined by increased concentration of malondialdehyde (MDA) and / or decreased concentration of antioxidant enzymes (superoxide dismutase and / or catalase). P<0.05 was regarded as statistically significant.

Results:

Thirty - eight consecutive patients were included. Mean age was 66.36 ± 6.44 years, mean prostate volume was 77.7 ± 20.63 cm3, and mean IPSS was 11.05 ± 8.72 points. MDA concentration was increased in men with severe bladder outlet obstruction (BOO grade V - VI according to the Schaefer's nomogram) in comparison with BOO grade III - IV (p = 0.022). Patients with severe LUTS also had higher MDA concentration when compared to those with mild LUTS (p = 0.031). There was a statistically significant association between increased post - void residual urine (cut off ≥ 50 mL) and not only higher levels of MDA, but also reduced activity of SOD and catalase (p < 0.05).

Conclusions:

This pilot study showed that severity of LUTS and BOO were associated with increased MDA concentration in the bladder wall of men undergoing open prostatectomy. Further studies are still needed to assess the role of non - invasive biomarkers of OS in predicting bladder dysfunction in men with LUTS.

Correlation of Ultrasonically Determined Bladder Wall Thickness and Prostatic Calcification With the Urinary, Psychosocial Dysfunction, Organ Specific, Infection and Neurological/Systemic Symptoms, and Tenderness Scoring System

OBJECTIVE

To evaluate ultrasonically determined bladder wall thickness (BWT) and prostatic calcification presence, in men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), and to correlate the findings with patient characteristics and the urinary, psychosocial dysfunction, organ specific, infection and neurological/systemic symptoms, and tenderness (UPOINT) classification system.

MATERIAL AND METHODS

Between January 2008 and December 2017, data of 1294 patients diagnosed with chronic prostatitis, in a single urology clinic, meeting a number of selective inclusion/exclusion criteria, were retrospectively analyzed. Patients, compliant to fill out all requested questionnaires, between the ages of 21-65 years were included to the study. Exclusion criteria were noncompliance of filling out required questionnaires, acute and/or chronic bacterial prostatitis, history of genitourinary cancer, history of recent prostate surgery, and diagnosis of neurological diseases affecting the bladder.

RESULTS

The median patient age and UPOINT subdomain was determined as 37 (IQR = 13, range 21-65) and 2 (IQR = 1, range 0-5), respectively. Median values for BWT, National Institute of Health-Chronic Prostatitis Symptom Index (NIH-CPSI), and International Index of Erectile Function were 3 (IQR = 1, range 2-6, 7), 4 (IQR = 6, range 1-23), and 25 (IQR = 10, range 1-30), respectively. The presence of calcification demonstrated a significant association with total NIH-CPSI score and BWT, whereas its relation with age and total UPOINT score was insignificant. However in contrast to calcification status, BWT ≥3.3 showed a strong and statistically significant relation to all the described measurements.

CONCLUSION

Measurement of BWT can be used as an accessible and objective method for the diagnose of CP/CPPS according to UPOINT scoring system.

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

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

STATEMENT OF SIGNIFICANCE

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

Intravesical Activation of the Cation Channel TRPV4 Improves Bladder Function in a Rat Model for Detrusor Underactivity

BACKGROUND

Improvement of bladder emptying by modulating afferent nerve activity is an attractive therapeutic strategy for detrusor underactivity. Transient receptor potential vanilloid 4 (TRPV4) is a sensory ion channel in urothelial cells that contribute to the detection of bladder filling.

OBJECTIVE

To investigate the potential benefit of intravesical TRPV4 agonists in a pelvic nerve injury rat model for detrusor underactivity.

DESIGN, SETTING, AND PARTICIPANTS

Female wild-type and Trpv4 knockout rats underwent sham surgery or bilateral pelvic nerve injury (bPNI). Four weeks later, rats underwent cystometry with infusion of the TRPV4 agonist GSK1016790A. Bladders were harvested for in vitro pharmacological studies, quantitative reverse polymerase chain reaction and immunohistochemistry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Data are expressed as median ± interquartile range. Statistical comparisons were made using the Mann-Witney U test and Wilcoxon signed rank test as appropriate.

RESULTS AND LIMITATIONS

Rats with bPNI showed a phenotype characteristic of detrusor underactivity with lower-amplitude voiding contractions, decreased voiding frequency, and increased postvoid residual. Intravesical application of GSK1016790A increased voiding frequency and reduced postvoid residual in wild-type, but not Trpv4^-/-, rats. In isolated bladder strips, GSK1016790A did not induce relevant contractions, indicating that the observed improvements in bladder function are the result of increased afferent signalling through TRPV4 activation, rather than a local effect on the detrusor. The altered urinary phenotype of Trpv4^-/- mice was not apparent in the Trpv4^-/- rat model, suggesting species-related functional variations. Our results are limited to the preclinical setting in rodents.

CONCLUSIONS

Intravesical activation of TRPV4 improves bladder dysfunction after bPNI by increasing afferent signalling.

PATIENT SUMMARY

We demonstrate that the sensory protein transient receptor potential vanilloid 4 (TRPV4) can be targeted to improve bladder function in animals that have iatrogenic injury to the nerves innervating the bladder. Further research is required to determine whether these results can be translated to patients with an underactive bladder.

Definition and symptoms of underactive bladder

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