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.

Current concepts of the acontractile bladder.

The acontractile bladder (AcB) is a urodynamic-based diagnosis wherein the bladder is unable to demonstrate any contraction during a pressure flow study. Although it is often grouped with underactive bladder, it is a unique phenomenon and should be investigated independently. The purpose of the present review was to examine the current literature on AcB regarding its pathology, diagnosis, current management guidelines, and future developments. We performed a review of the PubMed database, classifying the evidence for AcB pathology, diagnosis, treatment, and potential future treatments. Over the 67 years covered in our review period, 42 studies were identified that met our criteria. Studies were largely poor quality and mainly consisted of retrospective review or animal models. The underlying pathology of AcB is variable with both neurological and myogenic aetiologies. Treatment is largely tailored for renal preservation and reduction of infection. Although future developments may allow more functional restorative treatments, current treatments mainly focus on bladder drainage. AcB is a unique and understudied bladder phenomenon. Treatment is largely based on symptoms and presentation. While cellular therapy and neuromodulation may hold promise, further research is needed into the underlying neuro-urological pathophysiology of this disease so that we may better develop future treatments.

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.

Effect of Preoperative Urodynamic Detrusor Underactivity on Transurethral Surgery for Benign Prostatic Hyperplasia: A Systematic Review and Meta-Analysis.

PURPOSE: We investigated the effect of preoperative urodynamic detrusor underactivity on the transurethral surgery outcomes of benign prostatic hyperplasia. MATERIALS AND METHODS: We systematically searched the online PubMed®, Embase® and Cochrane Library databases for articles published between January 1989 and June 2017. RESULTS: A total of 10 articles met the eligibility criteria for this systematic review. The eligible studies included a total of 1,113 patients with a median of 73 per study (range 40 to 382). Five of the 10 studies involved conventional transurethral prostatectomy and 5 described laser surgery. In patients with detrusor underactivity the pooled mean difference was significant for the poorer I-PSS (International Prostate Symptom Score) (pooled mean difference -3.73, 95% CI -5.65--1.80 for 9 studies and 936 participants) and maximal flow rate improvement (pooled mean difference -3.92, 95% CI -4.85--3.00 for 8 studies and 951 participants) but not for quality of life score (pooled mean difference -0.15, 95% CI -0.56-0.25 for 7 studies and 858 participants) or post-void residual volume (pooled mean difference -5.57, 95% CI -20.65-9.50 for 9 studies and 971 participants). Some comparisons showed interstudy heterogeneity despite strict selection criteria for the included studies. However, there was no clear evidence of publication bias in this meta-analysis. CONCLUSIONS: Our meta-analysis results showed that preoperative detrusor underactivity correlated with poorer I-PSS and maximal flow rate improvement. Preoperative urodynamic detrusor underactivity is a valuable finding for excluding patients who are inappropriate candidates for transurethral surgery.