Pharmacotherapy in detrusor underactivity: A new challenge for urologists and pharmacologists (from lab to clinic)

Chlorogenic Acid Intravesical Therapy Changes Acute Voiding Behavior of Systemic Lipopolysaccharide Inflammation-Induced Cystitis Bladder in Mice

This study explores the potential efficacy of chlorogenic acid (CGA) in mitigating lipopolysaccharide (LPS)-induced cystitis in a mice model. C57BL/6J mice were divided into four groups: normal control (NC), LPS, LPS + low CGA, and LPS + high CGA. Evaluation methods included cystometrogram (CMG), histopathological, western blot, and immunohistological analysis. In the LPS group, CMG revealed abnormal voiding behavior with increased micturition pressure, voided volume (VV), and decreased voided frequency. Low CGA treatment in LPS mice demonstrated improved micturition pressure and inter-contraction intervals (ICI). However, high CGA treatment exhibited prolonged ICI and increased VV, suggesting potential adverse effects. Histological analysis of LPS-treated mice displayed bladder inflammation and interstitial edema. Low CGA treatment reduced interstitial edema and bladder inflammation, confirmed by Masson's trichrome staining. Western blotting revealed increased cytokeratin 20 (K20) expression in the low CGA group, indicating structural abnormalities in the bladder umbrella layer after LPS administration. In conclusion, low CGA treatment positively impacted voiding behavior and decreased bladder edema and inflammation in the LPS-induced cystitis mice model, suggesting its potential as a supplement for inflammation cystitis prevention. However, high CGA treatment exhibited adverse effects, emphasizing the importance of dosage considerations in therapeutic applications.

Efficacy of single and repeated transurethral bladder neck incisions for female voiding dysfunction

OBJECTIVE

This study aimed to assess the efficacy of single and repeat transurethral bladder neck incision (TUI-BN) for female voiding dysfunction caused by bladder outlet obstruction (BNO). Further, the predictive factors associated with better treatment outcomes were identified.

METHODS

Women with voiding difficulty due to BNO who underwent TUI-BN were included in this research. All patients underwent videourodynamics study at baseline and after TUI-BN. Successful outcome was defined as a voiding efficiency of ≥ 66.7% and a global response assessment score of ≥ 2 after treatment. Repeat TUI-BN was considered for patients with insufficient improvement. The outcomes of repeat surgery, surgical complications, and predictive factors of successful outcomes were evaluated.

RESULTS

In total 158 cases, the success rates were 61.4% and 45.2% after the first and second TUI-BN, respectively, with an overall cumulative rate of 70.3%. The success rates were comparable between patients with detrusor underactivity (DU) and those without (54.9% vs. 68.4%). The absence of a previous history of suburethral sling and a high baseline corrected maximum flow rate were a significant predictor of favorable outcomes. The cumulative rate of regaining self-voiding function was 95.1%. The incidence rates of vesico-vaginal fistula and de novo stress urinary incontinence requiring surgery were 1.2% and 2.5%, respectively.

CONCLUSIONS

Regardless of the presence of DU, TUI-BN is effective against female voiding dysfunction caused by BNO. Repeat procedures are beneficial and can improve self-voiding function. A high corrected maximum flow rate and the absence of a previous history of suburethral sling can contribute to greater success rates.

Transurethral Incision of the Bladder Neck with or without Additional Procedure Resumes Spontaneous Voiding in Female Voiding Dysfunction-A Long-Term Retrospective Follow-Up

AIM

This study evaluated the long-term effectiveness of transurethral incision of the bladder neck (TUI-BN) with or without an additional procedure for female voiding dysfunction.

METHODS

Women with voiding difficulty who underwent TUI-BN in the last 12 years were included. All patients underwent a videourodynamics study (VUDS) at baseline and after TUI-BN. A successful outcome was defined as having a voiding efficiency (VE) increase by ≥50% after treatment. Patients with insufficient improvement were chosen for repeated TUI-BN, urethral onabotulinumtoxinA injection, or transurethral external sphincter incision (TUI-ES). The current voiding status, surgical complications, and additional surgeries were evaluated.

RESULTS

A total of 102 women with VUDS evidence of a narrow bladder neck during voiding were enrolled. The long-term success rate of the first TUI-BN was 29.4% (30/102) and increased to 66.7% (34/51) after combining TUI-BN and an additional procedure. The overall long-term success rates were 74.6% in women with detrusor underactivity (DU), 52.0% in detrusor overactivity and low contractility, 50.0% in bladder neck obstruction, 20.0% in hypersensitive bladder, and 75% in stable bladder (p = 0.022). Patients with a lower maximum flow rate (Qmax), (p = 0.002), lower voided volume (p < 0.001), lower corrected Qmax (p < 0.001), lower ladder contractility index (p = 0.003), lower voiding efficiency (p < 0.001), but larger post-void residual volume (p < 0.001) had a satisfactory surgical outcome. Spontaneous voiding was achieved in 66 (64.7%) patients, de novo urinary incontinence in 21 (20.6%), and vesicovaginal fistula in 4 (3.9%), all were repaired.

CONCLUSIONS

TUI-BN alone or in combination with an additional procedure was safe, effective, and durable in patients with DU to resume spontaneous voiding.

Superficial peroneal neuromodulation of nonobstructive urinary retention induced by prolonged pudendal afferent activity in cats

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR) induced by prolonged pudendal nerve stimulation (PNS). In this exploratory acute study using eight cats under anesthesia, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. A double lumen catheter was inserted via the bladder dome for bladder infusion and pressure measurement and to allow voiding without a physical urethral outlet obstruction. The voided and postvoid residual (PVR) volumes were also recorded. NOUR induced by repetitive (4-13 times) application of 30-min PNS significantly (P < 0.05) reduced voiding efficiency by 49.5 ± 16.8% of control (78.3 ± 7.9%), with a large PVR volume at 208.2 ± 82.6% of control bladder capacity. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during cystometrograms to improve the PNS-induced NOUR. SPNSc and SPNSi applied by nerve cuff electrodes significantly (P < 0.05) increased voiding efficiency to 74.5 ± 18.9% and 67.0 ± 15.3%, respectively, and reduced PVR volume to 54.5 ± 39.0% and 88.3 ± 56.0%, respectively. SPNSc and SPNSi applied noninvasively by skin surface electrodes also improved NOUR similar to the stimulation applied by a cuff electrode. This study indicates that abnormal pudendal afferent activity could be a pathophysiological cause for the NOUR occurring in Fowler's syndrome and a noninvasive superficial peroneal neuromodulation therapy might be developed to treat NOUR in patients with Fowler's syndrome.

Superficial peroneal neuromodulation of persistent bladder underactivity induced by prolonged pudendal afferent nerve stimulation in cats

The purpose of this study is to determine whether superficial peroneal nerve stimulation (SPNS) can reverse persistent bladder underactivity induced by prolonged pudendal nerve stimulation (PNS). In 16 α-chloralose-anesthetized cats, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. Bladder underactivity consisting of a significant increase in bladder capacity to 157.8 ± 10.9% of control and a significant reduction in bladder contraction amplitude to 56.0 ± 5.0% of control was induced by repetitive (4-16 times) application of 30-min PNS. SPNS (1 Hz, 0.2 ms) at 1.5-2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during a cystometrogram (CMG) to determine whether the stimulation can reverse the PNS-induced bladder underactivity. SPNSc or SPNSi applied by nerve cuff electrodes during the prolonged PNS inhibition significantly reduced bladder capacity to 124.4 ± 10.7% and 132.4 ± 14.2% of control, respectively, and increased contraction amplitude to 85.3 ± 6.2% and 75.8 ± 4.7%, respectively. Transcutaneous SPNSc and SPNSi also significantly reduced bladder capacity and increased contraction amplitude. Additional PNS applied during the bladder underactivity further increased bladder capacity, whereas SPNSc applied simultaneously with the PNS reversed the increase in bladder capacity. This study indicates that a noninvasive superficial peroneal neuromodulation therapy might be developed to treat bladder underactivity caused by abnormal pudendal nerve somatic afferent activation that is hypothesized to occur in patients with Fowler's syndrome.

Bladder underactivity induced by prolonged pudendal afferent activity in cats

The purpose of this study was to determine the effects of pudendal nerve stimulation (PNS) on reflex bladder activity and develop an animal model of underactive bladder (UAB). In six anesthetized cats, a bladder catheter was inserted via the urethra to infuse saline and measure pressure. A cuff electrode was implanted on the pudendal nerve. After determination of the threshold intensity (T) for PNS to induce an anal twitch, PNS (5 Hz, 0.2 ms, 2 T or 4 T) was applied during cystometrograms (CMGs). PNS (4-6 T) of 30-min duration was then applied repeatedly until bladder underactivity was produced. Following stimulation, control CMGs were performed over 1.5-2 h to determine the duration of bladder underactivity. When applied during CMGs, PNS (2 T and 4 T) significantly (P < 0.05) increased bladder capacity while PNS at 4 T also significantly (P < 0.05) reduced bladder contraction amplitude, duration, and area under contraction curve. Repeated application of 30-min PNS for a cumulative period of 3-8 h produced bladder underactivity exhibiting a significantly (P < 0.05) increased bladder capacity (173 ± 14% of control) and a significantly (P < 0.05) reduced contraction amplitude (50 ± 7% of control). The bladder underactivity lasted more than 1.5-2 h after termination of the prolonged PNS. These results provide basic science evidence supporting the proposal that abnormal afferent activity from external urethral/anal sphincter could produce central inhibition that underlies nonobstructive urinary retention (NOUR) in Fowler's syndrome. This cat model of UAB may be useful to investigate the mechanism by which sacral neuromodulation reverses NOUR in Fowler's syndrome.

New mouse model of underactive bladder developed by placement of a metal ring around the bladder neck

OBJECTIVE

To develop a new mouse model of underactive bladder (UAB) caused by chronic bladder outlet obstruction (BOO).

METHODS

BOO was created in 6-week-old male C57BL/6 mice using surgery to loosely place a silver jump ring around the bladder neck of each mouse. Micturition behavior (assessed with a metabolic cage) and cystometry were used to evaluate bladder function at 8 and 16 weeks after BOO. Following completion of the functional studies, the bladders of the mice were excised, weighed, and subjected to histological analysis.

RESULTS

Micturition behavior analysis showed that mice subjected to BOO for 16 weeks had a lower frequency of micturition (7.3 ± 1.1 vs 12.5 ± 3.0 times/d, P < .05) and volume per void (106.0 ± 0.1 vs 133.9 ± 3.2 μL, P < .05) than mice subjected to BOO for 8 weeks. Cystometry revealed that mice subjected to BOO for 16 weeks had lower baseline pressure (8.4 ± 0.6 vs 14.0 ± 0.7 cmH₂ O, P < .01) and micturition pressure (13.9 ± 1.1 vs 42.8 ± 1.7 cmH₂ O, P < .05) than mice subjected to BOO for 8 weeks. BOO caused progressive increases in bladder mass and collagen deposition over time.

CONCLUSIONS

We successfully established a novel mouse model of UAB using surgery to place a silver jump ring loosely on the bladder neck. BOO initially induced bladder overactivity but subsequently resulted in UAB due to deterioration of detrusor smooth muscle contractility and progressive deposition of collagen in the bladder wall.

Will detrusor acontractility recover after medical or surgical treatment? A longitudinal long-term urodynamic follow-up

AIMS

Patients with urinary retention due to detrusor acontractility (DA) might regain voiding efficiency (VE) after treatment. This study investigated the long-term outcomes and predictors of recovery following treatment.

METHODS

A total of 32 patients with DA were retrospectively identified and enrolled. DA was defined by P_det .Q_max  = 0 cmH₂ O and postvoid residual (PVR) > 300 ml determined through videourodynamic study (VUDS). All patients received medical or surgical treatment and were followed up for at least 3 months, during which repeat VUDS was conducted. Detrusor contractility recovery was confirmed when patients were able to void with a P_det .Q_max  ≥ 10 cmH₂ O after treatment.

RESULTS

Our patients comprised 22 women and 10 men (mean age, 73.2 ± 9.7 years; mean follow-up duration, 1.6 ± 1.8 [0.3-7.4] years). Follow-up VUDS revealed that 14 (43.9%) patients recovered from detrusor contractility, with five patients recovering within 1 year and nine after 1 year. P_det .Q_max , voided volume, PVR, maximum flow rate, and VE significantly improved in both the recovery and nonrecovery groups. The recovery group had significantly better VE (p = .039) and significantly lower bladder compliance (74.2 ± 83.2 vs. 119 ± 82.6; p = .007) than the nonrecovery group. Receiver operating characteristic (ROC) analysis revealed an optimum bladder compliance cutoff value of <80 ml/cmH₂ O for predicting detrusor contractility recovery with an area under the ROC curve of 0.780.

CONCLUSIONS

Among the included patients with DA, 43.9% had detrusor contractility recovery after treatment, with bladder compliance of <80 ml/cmH₂ O predicting bladder function recovery.

Prolonged nonobstructive urinary retention induced by tibial nerve stimulation in cats

Nonobstructive urinary retention (NOUR) is a medical condition without an effective drug treatment, but few basic science studies have focused on this condition. In α-chloralose-anesthetized cats, the bladder was cannulated via the dome and infused with saline to induce voiding that could occur without urethral outlet obstruction. A nerve cuff electrode was implanted for tibial nerve stimulation (TNS). The threshold (T) intensity for TNS to induce toe twitch was determined initially. Repeated (6 times) application of 30-min TNS (5 Hz, 0.2 ms, 4-6T) significantly (P < 0.05) increased bladder capacity to 180% of control and reduced the duration of the micturition contraction to 30% of control with a small decrease in contraction amplitude (80% of control), which resulted in urinary retention with a low-voiding efficiency of 30% and a large amount of residual volume equivalent to 130% of control bladder capacity. This NOUR condition persisted for >2 h after the end of repeated TNS. However, lower frequency TNS (1 Hz, 0.2 ms, 4T) applied during voiding partially reversed the NOUR by significantly (P < 0.05) increasing voiding efficiency to 60% and reducing residual volume to 70% of control bladder capacity without changing bladder capacity. These results revealed that tibial nerve afferent input can activate either an excitatory or an inhibitory central nervous system mechanism depending on afferent firing frequencies (1 vs. 5 Hz). This study established the first NOUR animal model that will be useful for basic science research aimed at developing new treatments for NOUR.

Predictive factors for recovery of voiding function after transurethral prostate surgery in men with small prostate volume and very low detrusor contractility

OBJECTIVES

Detrusor underactivity (DU) is a common but poorly understood clinical problem. The diagnosis and treatment are difficult and full of uncertainties. There are many overlaps between DU and bladder outlet obstruction (BOO) in men. Prostatic surgery might improve voiding efficiency (VE). This study aims to investigate effectiveness and predictors of voiding function recovery after prostate surgery in patients with DU.

METHODS

Male patients with DU and small total prostate volume (TPV, <40 mL) who had undergone transurethral prostate surgery were retrospectively reviewed over the past two decades. Video-urodynamic studies were performed before and after the operation. The urodynamic parameters were recorded, and change of VE was used to determine treatment outcome. A postoperative VE of ≥50% was considered successful.

RESULTS

A total of 48 patients were included, with a mean age of 74.4 ± 10.0 years. The mean follow-up period was 24.9 ± 30.5 months. At the most recent follow-up, 29 (60.4%) patients had positive results. Among them, 21 (72.4%) patients recovered within 1 month, and only one recovered later than 6 months after the operation. After surgery, the maximum flow rate, voided volume, postvoid residual urine, and VE all showed improvement. Patients with successful outcome had a higher baseline detrusor pressure (p = .029) and greater maximum flow rate (p = .034) than the nonrecovery group. The age and other parameters were not significantly different between recovery and nonrecovery group.

CONCLUSIONS

Patients with DU and small TPV might also benefit from prostatic surgery if they had a higher detrusor pressure and maximum flow rate at baseline.

Further characterization of a novel EP2 and EP3 receptor dual agonist, ONO-8055, on lower urinary tract function in normal and lumbar canal stenosis rats

AIMS

To further explore the effects of a novel EP2 and EP3 dual agonist, ONO-8055, on detrusor contractility, we investigated the responses of bladder strips from sham and lumbar canal stenosis (LCS) rats to this agonist, its effects on lower urinary tract function in normal rats, and mRNA expression of EP2 and EP3 receptors in the sham and LCS rats.

METHODS

The responses of bladder strips from sham and LCS rats to ONO-8055 were measured. The effects of ONO-8055 on LUT function of normal rats were investigated with awake cystometry and intraurethral perfusion pressure (Pura) measurements. The relative mRNA of bladder and urethral tissue of the sham and LCS rats was quantified using specific probes for EP1, EP2, EP3, and EP4 genes.

RESULTS

Compared with the vehicle, the muscle tensions of both the sham and LCS rats were significantly increased after adding this agonist. On awake cystometry of normal rats, bladder capacity and Pura were decreased in the ONO-8055 groups, but a statistically significant difference in mean changes was demonstrated only between the vehicle group and the group receiving the highest dose. Compared with the sham rats, mRNA expressions of the four EP receptors in the lower urinary tract of the LCS rats did not show a statistically significant difference.

CONCLUSIONS

This agonist did not augment bladder contractility or urethral relaxation in normal rats.

Bladder underactivity after prolonged stimulation of somatic afferent axons in the tibial nerve in cats

AIMS

To establish an animal model of bladder underactivity induced by prolonged and intense stimulation of somatic afferent axons in the tibial nerve.

METHODS

In seven cats under α-chloralose anesthesia, tibial nerve stimulation (TNS) of 30-min duration was repeatedly (3-8 times) applied at 4-6 times threshold (T) intensity for inducing a toe twitch to produce bladder underactivity determined by cystometry. Naloxone (1 mg/kg, i.v.) was administered to examine the role of opioid receptors in TNS-induced bladder underactivity.

RESULTS

After prolonged (1.5-4 h) and intense (4-6T) TNS, a complete suppression of the micturition reflex occurred in six cats and an increase in bladder capacity to about 150% of control and a decrease in the micturition contraction amplitude to 50% of control occurred in one cat. The bladder underactivity was maintained for at least 1-1.5 h. Naloxone reversed the bladder underactivity, but an additional 30-min TNS removed the naloxone effect.

CONCLUSIONS

The results indicate that prolonged and intense activation of somatic afferent axons in the tibial nerve can suppress the central reflex mechanisms controlling micturition. This animal model may be useful for examining the pathophysiology of neurogenic bladder underactivity and for development of new treatments for underactive bladder symptoms.

Frequency Dependent Tibial Neuromodulation of Bladder Underactivity and Overactivity in Cats

OBJECTIVE

This study is aimed at determining if tibial nerve stimulation (TNS) can modulate both bladder underactivity and overactivity.

METHODS

In α-chloralose anesthetized cats, tripolar cuff electrodes were implanted on both tibial nerves and TNS threshold (T) for inducing toe twitching was determined for each nerve. Normal bladder activity was elicited by slow intravesical infusion of saline; while bladder overactivity was induced by infusion of 0.25% acetic acid to irritate the bladder. Bladder underactivity was induced during saline infusion by repeated application (2-6 times) of 30-min TNS (5 Hz, 4-8T, 0.2 msec) to the left tibial nerve, while TNS (1 Hz, 4T, 0.2 msec) was applied to the right tibial nerve to reverse the bladder underactivity.

RESULTS

Prolonged 5-Hz TNS induced bladder underactivity by significantly increasing bladder capacity to 173.8% ± 10.4% of control and reducing the contraction amplitude to 40.1% ± 15.3% of control, while 1 Hz TNS normalized the contraction amplitude and significantly reduced the bladder capacity to 130%-140% of control. TNS at 1 Hz in normal bladders did not change contraction amplitude and only slightly changed the capacity, but in both normal and underactive bladders significantly increased contraction duration. The effects of 1 Hz TNS did not persist following stimulation. Under isovolumetric conditions when the bladder was underactive, TNS (0.5-3 Hz; 1-4T) induced large amplitude and sustained bladder contractions. In overactive bladders, TNS during cystometry inhibited bladder overactivity at 5 Hz but not at 1 Hz.

CONCLUSIONS

This study indicates that TNS at different frequencies might be used to treat bladder underactivity and overactivity.

Current pharmacological and surgical treatment of underactive bladder

Underactive bladder (UAB) or detrusor underactivity (DU) is a common yet still poorly understood urological problem. In addition to true detrusor failure and neuropathy, the inhibitory effects of detrusor contraction by the striated urethral sphincter and the bladder neck through alpha-adrenergic activity may also play a role in the development of UAB or DU. Treatment of UAB or DU aims to reduce the postvoid residual (PVR) urine volume and increase voiding efficiency, either by spontaneous voiding or abdominal straining. Pharmacotherapy with parasympathomimetics or cholinesterase inhibitors might be tried, and benefits can be achieved in combination with alpha-blockers. Bladder outlet surgeries, including urethral onabotulinumtoxinA injection, transurethral incision of the bladder neck, and transurethral incision or resection of the prostate can effectively improve voiding efficiency and decrease the PVR in most patients with DU. The mechanisms have not been well elucidated. It is likely that ablation of the bladder neck or prostatic urethra might not only decrease bladder outlet resistance but also abolish the sympathetic hyperactivity which inhibits detrusor contractility in patients with idiopathic UAB or DU.

Suppression of Oxidative Stress of Modified Gongjin-Dan (WSY-1075) in Detrusor Underactivity Rat Model Bladder Outlet Induced by Obstruction

OBJECTIVE

To investigate the anti-oxidative stress and preventive effect of modified Gongjin-dan (WSY-1075) in a detrusor underactivity rat model.

METHODS

Rats were randomly allocated to three groups: shamoperated (control), bladder outlet obstruction-induced detrusor underactivity (BOO-DU), and BOO-DU with WSY-1075 (WSY) groups. WSY-1075 was orally administrated to rats 200 mg daily for 2 weeks prior to the operation and 4 weeks after the operation. Bladder outlet obstruction was surgically induced in rats by ligation around the urethra avoiding total obstruction. Cystometrography was conducted on rats in each group for examination of bladders.

RESULTS

Compared with the control group, bladder outlet obstruction led to a significant increase in oxidative stress with consequent changes to molecular composition, and decrease in maximal detrusor pressure (P<0.05). WSY-1075 treatment significantly suppressed oxidative stress and prevented degenerative and dysfunctional changes in bladder, as compared with BOO-DU group (P<0.05).

CONCLUSION

WSY-1075 had beneficial effect on prevention of BOO-DU.

Saphenous nerve stimulation normalizes bladder underactivity induced by tibial nerve stimulation in cats

This study in α-chloralose-anesthetized cats aimed at investigating the bladder responses to saphenous nerve stimulation (SNS). A urethral catheter was used to infuse the bladder with saline and to record changes in bladder pressure. With the bladder fully distended, SNS at 1-Hz frequency and an intensity slightly below the threshold (T) for inducing an observable motor response of the hindlimb muscles induced large amplitude (40-150 cmH₂O) bladder contractions. Application of SNS (1 Hz, 2-4T) during cystometrograms (CMGs), when the bladder was slowly (1-3 ml/min) infused with saline, significantly ( P < 0.05) increased the duration of the micturition contraction to >200% of the control without changing bladder capacity or contraction amplitude. Repeated application (1-8 times) of intense (4-8T intensity) 30-min tibial nerve stimulation (TNS) produced prolonged post-TNS inhibition that significantly ( P < 0.01) increased bladder capacity to 135.9 ± 7.6% and decreased the contraction amplitude to 44.1 ± 16.5% of the pre-TNS control level. During the period of post-TNS inhibition, SNS (1 Hz, 2-4T) applied during CMGs completely restored the bladder capacity and the contraction amplitude to the pre-TNS control level and almost doubled the duration of the micturition contraction. These results indicate that SNS at 1 Hz can facilitate the normal micturition reflex and normalize the reflex when it is suppressed during post-TNS inhibition. This study provides an opportunity to develop a novel neuromodulation therapy for underactive bladder using SNS.