Clinical diagnosis of bladder outlet obstruction in men with lower urinary tract symptoms: reliability of commonly measured parameters and the role of idiopathic detrusor overactivity

Changes of proapoptotic and antiapoptotic genes affect sensitivity to apoptotic stimuli in impaired contractility due to long term bladder outlet obstruction

INTRODUCTION

The normal biological process that necessitates cell removal greatly depends on apoptosis. Long term bladder outlet obstruction (BOO) causes damaged smooth muscle cells to undergo apoptosis. However, smooth muscle cell apoptosis that BOO causes is not well known in impaired bladder contractility. Therefore, we designed this study to investigate whether long-term BOO could induce apoptosis activities and to obtain an expression profile of apoptosis related genes.

MATERIALS AND METHODS

We used 10 Sprague-Dawley six-week-old female rats. We separated them equally into two groups: a sham intervention group (group 1) and an eight-week BOO group (group 2). We conducted cystometric evaluation eight weeks following BOO onset, with processing of bladder tissue for PCR array. Every array comprised 84 genes, which were established to contribute to an apoptosis response, cell differentiation and metabolism, and 12 sequences were established for the regulation of loading and the quality of cDNA. We performed real-time PCR. Changes in gene expression presented as a fold increase/decrease. Alterations of more than two-fold constituted the cut-off determining expression.

RESULTS

Group 2 had a greater bladder weight and Impaired bladder contractility. Immunofluorescent staining with CAS3, TUNEL showed increased in the BOO group. In comparison to group 1, group 2 exhibited an at least two-fold upregulation in five genes, the Bcl-2 (15.1), Birc5 (5.8), Cd40lg (7.5), Il10 (16.2), and Naip2 (13.2). They also demonstrated at least a two-fold downregulation in the PRLR (-18.1) gene. Genes Bcl2ald, Circ5, Cd40lg, Il10, Naip2, and PRLR were among the genes with activity against apoptosis. TNF, STAT3 and TP53 mediated the effect that genes had on one another.

CONCLUSION

This study demonstrated that the relative ratios of pro- and antiapoptotic genes determine bladder cell sensitivity cells to apoptotic stimuli in impaired contractility caused by long term BOO. Although we cannot confirm whether this finding is the result of the decompensated phase of the bladder or the process, the gene expression profiles could explain molecular mechanisms of apoptosis in impaired bladder contractility caused by long-term BOO with further studies.

Modulation of urinary frequency via type 1 lysophosphatidic acid receptors: Effect of the novel antagonist ASP6432 in conscious rats

Bladder dysfunctions associated with benign prostatic hyperplasia are not sufficiently alleviated by current pharmacotherapies. Lysophosphatidic acid (LPA) is a phospholipid with diverse biological effects. LPA modulates prostate and urethral contraction via the type 1 LPA (LPA₁) receptor, suggesting the potential of the LPA₁ receptor as a therapeutic target. However, the role of LPA and the LPA₁ receptor in bladder function has not been studied in vivo. We investigated the effects of LPA and the novel LPA₁ receptor antagonist ASP6432 (potassium 1-(2-{[3,5-dimethoxy-4-methyl-N-(3-phenylpropyl)benzamido]methyl}- 1,3-thiazole-4-carbonyl)- 3-ethyl-2,2-dioxo-2λ⁶-diazathian-1-ide) on the micturition reflex in conscious rats using cystometry. Intravenous infusion of LPA decreased the micturition interval and threshold pressure with no apparent changes in baseline pressure or maximum intravesical pressure. ASP6432 inhibited the LPA-induced decrease in MI. In contrast, ASP6432 had no effect on the LPA-induced decrease in threshold pressure. Similarly, ASP6432 had no effect on either baseline pressure or maximum intravesical pressure. We also evaluated the effect of ASP6432 on the urinary frequency induced by the nitric oxide synthase inhibitor L-N^ω-nitro arginine methyl ester (L-NAME). Intravenous L-NAME administration decreased the micturition interval. ASP6432 dose-dependently reversed the L-NAME-induced decrease in micturition interval. Our findings demonstrate for the first time that LPA causes bladder overactivity in rats. ASP6432 inhibited the LPA- and L-NAME-induced decrease in micturition interval, suggesting a significant role for the LPA₁ receptor in regulating the functional capacity of the bladder. Our results also suggest the potential of ASP6432 as a novel therapy for the treatment of bladder dysfunction associated with lower urinary tract diseases.

Urethroplasty Improves Overactive Bladder Symptoms in Men With Anterior Urethral Strictures

OBJECTIVE

To assess the effect of urethroplasty on overactive bladder (OAB) symptoms.

MATERIALS AND METHODS

From March 2011 to November 2014, 47 anterior urethroplasties were performed by a single surgeon (RSP). Of these, 42 men prospectively completed the validated Overactive Bladder Symptom Score (OABSS) prior to and after urethroplasty. Comparative analysis of preoperative to postoperative OABSS results was performed.

RESULTS

The median (range) age of men who comprised our cohort was 49 (22-90). Questionnaires were completed preoperatively and at a median of 12 months (2.3-74.6) postoperatively. Stricture location included the following: bulbar (75%), penile (15%), and membranous (7.5%) urethra. Median stricture length was 3 cm (1-6). Half of the men underwent an excision and anastomotic repair, and half underwent buccal mucosal graft. Men experienced significant improvement in urinary flow rate, postvoid residual urine, and OAB symptoms reported on the OABSS. Of the 28/42 men with preoperative, clinically significant OAB (ie, OABSS ≥ 8), 25/28 reported a 54.2% (0%-100%) median reduction in OABSS, with only 1 patient reporting worsening of symptoms following surgery. Those men with the highest preoperative OABSS experienced the greatest improvement in OAB symptoms postoperatively.

CONCLUSION

In men with anterior urethral strictures and OAB, urethroplasty decreased reported OABSS by >50% and cured 90% of men with clinically significant OAB symptoms.

Bladder function in obstructed men - does age matter?

AIM

The high prevalence of diseases and disabilities in the elderly will therefore impose major future challenges for governments, particularly in social security, health system and social care.

METHODS

Nine hundred and seventy-one men, 40 years or older referred for low urinary tract symptoms (LUTS) evaluation who underwent full urodynamic investigation, were reviewed. Urodynamic parameters were obtained, such as Uroflowmetry, those of Filling Cystometry and those of pressure flow study (PFS).

RESULTS

Mean age was of 66.1 years old. Most the patients included in the analysis were categorized as Schafer score 2-4. Correlation analysis of uroflowmetry parameters revealed statistically significant decrease in voided volume (p = 0.013), Qmax (p = 0.023) with aging. Cystometric parameters revealed significant age-related decrease in bladder capacity (p < 0.001) and bladder compliance (p = 0.004). PFS revealed significant decrease in voiding efficiency (p = 0.029), voided volume (p < 0.001), Qave (p = 0.008) and Qmax (p = 0.048) with progressing age. Age subgroup analyses showed significant differences in voiding efficiency (KW, p = 0.032), voided volume (KW, p < 0.001) and Qave (KW, p = 0.036).

CONCLUSIONS

Age-related changes in voiding function might not be a result of impaired detrusor contractility or increased outflow obstruction, intrinsic causes must be suspected. Changes in the storage function of the bladder represent specific pathophysiological mechanisms influenced by aging.

Influence of age and bladder dysfunction on the contractile properties of isolated human detrusor smooth muscle

OBJECTIVE

To test the hypothesis that the in vitro contractile properties of human detrusor smooth muscle are dependent on the age, gender and lower urinary tract pathology of the patient.

MATERIALS AND METHODS

Contractions were elicited in isolated human detrusor smooth muscle preparations by nerve-mediated electrical field stimulation, agonist application (carbachol, α,β-methylene ATP and high-K solutions) or direct muscle electrical stimulation. Biopsies (n = 227) were obtained from four groups of patients with: stable bladders (control), bladder outlet obstruction (BOO), idiopathic (IDO), or neurogenic (NDO) detrusor overactivity.

RESULTS

The magnitude of nerve-mediated contractions declined as a function of patients' age in each of the BOO, IDO and NDO groups but not in the control group. Contractions elicited by direct muscle activation (10 µM carbachol or electrical stimulation with 20 ms pulses in the presence of 1 µM tetrodotoxin) did not vary with patient age. Carbachol contractions were significantly smaller in samples from NDO bladders. Atropine resistance was more prevalent in the pathology groups compared with the control group and was greatest in the IDO group. There was no influence of age in the prevalence or magnitude of atropine-resistant contractions in any group. Muscle excitability to direct electrical stimulation was similar in all groups.

CONCLUSIONS

In the human bladder there is no evidence for a decline of detrusor smooth muscle contractility or excitability as a function of age, nor any gender difference or presence of pathology. In the pathology groups there was evidence for a decline of functional innervation with age.

Non-invasive parameters predicting bladder outlet obstruction in Korean men with lower urinary tract symptoms

The goal of this study was to evaluate the clinical and urodynamic features in Korean men with lower urinary tract symptoms (LUTS) and to determine non-invasive parameters for predicting bladder outlet obstruction (BOO). Four hundred twenty nine Korean men with LUTS over 50 yr of age underwent clinical evaluations for LUTS including urodynamic study. The patients were divided into two groups according to the presence of BOO. These two groups were compared with regard to age, the results of the uroflowmetry, serum prostate-specific antigen (PSA) level, prostate volume, International Prostate Symptom Score (I-PSS), and the results of the urodynamic study. Patients with BOO had a lower maximal flow rate (Q(max)), lower voided volume, higher serum PSA level and larger prostate volume (P<0.05). BOO group had a significantly higher rate of involuntary detrusor contraction and poor compliance compared to the patients without BOO (P<0.05). The multivariate analysis showed that Q(max) and poor compliance were significant factors for predicting BOO. Our results show that Q(max) plays a significant role in predicting BOO in Korean men with LUTS. In addition, BOO is significantly associated with detrusor dysfunction, therefore, secondary bladder dysfunction must be emphasized in the management of male patients with LUTS.

Application of artificial neural network in prediction of bladder outlet obstruction: a model based on objective, noninvasive parameters

OBJECTIVES

An artificial neural network model previously described by us that was based on lower urinary tract symptoms yielded a modest prediction of bladder outlet obstruction. The aim of this study was to establish another model, using more objective parameters, that could better predict for bladder outlet obstruction.

METHODS

The records of 457 patients were used in the construction of the model. Of the 457 records, 300 were allocated to the training phase and 157 to the testing phase. All patients had the average flow rate, maximal flow rate, postvoid residual urine volume (PVR), and total prostate volume recorded. The results of the pressure flow study of those patients were considered the reference standard against which the artificial neural network was tested.

RESULTS

Three models were tested. Models 1 and 2 were based on a three-output design (ie, nonobstructed, equivocal, and obstructed). The only difference was the number of iterations. The accuracy of the first model was 60.5% compared with 46.5% for the second. For a third model, in which the equivocal pressure flow study results were added to the nonobstructed group, the accuracy rose to 72%. Deletion of equivocal cases (around 19% of the total) was associated with an accuracy of 76% in the prediction of obstruction.

CONCLUSIONS

An artificial neural network based on objective and noninvasive parameters could replace the pressure flow study in only 72% of cases. An accuracy of 76% in the detection of bladder outlet obstruction is rather impractical, because an equivocal zone has always been available on pressure flow study nomograms.

TURP and low-energy TUMT treatment in men with LUTS suggestive of bladder outlet obstruction selected by means of pressure-flow studies: 8-year follow-up

AIMS

To evaluate the long-term outcome of transurethral resection of the prostate (TURP) and transurethral microwave thermotherapy (TUMT) in men with symptomatic benign prostatic hyperplasia (BPH), when allocation to the treatment-group was based on urodynamic diagnosis of bladder outlet obstruction (BOO).

METHODS

A total of 231 elderly men with symptomatic BPH were treated either by TURP or by low-energy TUMT. A pressure-flow study was performed to detect the obstruction and to help in the selection of the two treatments. The patients were examined at baseline then checked again after 2 and 8 years.

RESULTS

At 2 years of follow-up there was a significant improvement for both IPSS and QoL (P < 0.0001) in both groups of treatment. This was accompanied by a significant improvement (P < 0.0001) in the maximum flow rate from 10.0 (5.8) to 16.4 (7.6) in the TURP group and from 12.1 (5.2) to 14.9 (5.7) in the TUMT group. These findings persisted at 8 years, they were, however, more pronounced after TURP. The overall retreatment rate reached a value of 11% in the TURP group and 27% in the TUMT group, respectively. At the follow-up, 95% of the patients who underwent TURP and 70% of the patients treated by TUMT claimed to be satisfied with that choice.

CONCLUSIONS

With durable symptomatic improvement and lowest retreatment rate, TURP still presents a standard treatment option for patients with severe BOO. Low-energy TUMT has sufficiently relieved patients' symptoms and can be offered to less obstructed patients as an alternative.

LONGITUDINAL CHANGES IN POST-VOID RESIDUAL AND VOIDED VOLUME AMONG COMMUNITY DWELLING MEN

PURPOSE

We describe the natural history of post-void residual (PVR) and voided volume (VV) in men.

MATERIALS AND METHODS

A random sample of community dwelling men (529 men 40 to 79 years old) were followed with a sonographic PVR and VV every 2 years for up to 12 years (median 5 examinations). Men were censored at the time of treatment for a prostate condition.

RESULTS

The median annual change (slope) for PVR was 2.2% (p=0.03) and for VV was -2.1% (p <0.0001). There was considerable variability in PVR slopes (25th percentile -11%, 75th percentile 18%). A rapid increase in PVR slope (greater than 80th percentile) was more likely in men with a baseline American Urological Association Symptom Index greater than 7 (age adjusted odds ratio [OR]1.6, 95% CI 1.0 to 2.5). There was less variability in VV slopes (25th percentile -8.0%, 75th percentile 3.1%). A rapid decrease in VV slope (less than 20th percentile) was more likely in men with baseline age 70 to 79 years than 40 to 49 years (OR 3.9, 95% CI 2.1 to 7.2) and in men with a baseline PVR greater than 50 ml (age adjusted OR 2.1, 95% CI 1.2 to 3.6).

CONCLUSIONS

Although it is highly variable, there is progressive bladder dysfunction in community dwelling men as they age. In addition, signs and symptoms attributed to benign prostatic hyperplasia were modest predictors of the development of bladder dysfunction. A baseline increased PVR predicted a rapid decrease in VV, consistent with a bladder outlet obstruction contributing to the development of detrusor overactivity and decreased bladder compliance.