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.

Evaluation of pre-operative bladder contractility as a predictor of improved response rate to a staged trial of sacral neuromodulation in patients with detrusor underactivity.

PURPOSE: Sacral neuromodulation (SNM) is one of the few management options shown to improve outcomes in patients with detrusor underactivity (DU). This original research will investigate if preserved bladder contractility can predict a successful treatment with SNM. METHODS: This is a retrospective study of a prospectively collected database of consecutive patients with DU, who had a staged SNM trial from January 2013 to December 2018, with a minimum of 12 months follow-up. The primary outcome was the success of stage 1 SNM trial. RESULTS: In total, 69 patients with DU were followed. The median age was 67 [interquartile range (IQR) 74-55], median baseline bladder contractility index (BCI) 18 (IQR 67-0), and median post-void residual 200 mL (IQR 300-130). There were 35 patients (51%) that responded to a SNM trial. At a median follow-up of 23 months (IQR 39-12), three were removed for poor efficacy. In patients with detrusor acontractility (DAC), six responded (33%), compared to 29 patients (57%) with BCI > 0. This was statistically significant, p value 0.03. Younger age was also a predictive factor for SNM response, p value 0.02. There were no differences noted in those with gender, neurogenic history, previous pelvic surgery, diabetes, or pre-operative voiding history. CONCLUSION: Our study showed that patients with preserved bladder contractility are more likely to respond to a trial of SNM compared with those that have DAC. Younger age was also predictive of SNM response. UDS is the only method to accurately identify DAC patients. This information will help in patient selection and pre-operative counselling.

Outcomes of transurethral resection of the prostate in unobstructed patients with concomitant detrusor underactivity.

AIMS: The aim of the study was to evaluate the transurethral resection of the prostate (TURP) outcomes of unobstructed patients with detrusor underactivity (DUA), comparing the surgical results between obstructed and unobstructed males with concomitant DUA, at midterm follow-up. METHODS: This was an observational, prospective, comparative, nonrandomized study. Candidates to TURP underwent preoperative urodynamics (UD), with a diagnosis of DUA, were divided in two cohorts: Group A unobstructed men, group B males with bladder outlet obstruction (BOO). Males were evaluated yearly with uroflowmetry (UF), post-void residual (PVR), and bladder voiding efficiency (BVE), International Prostate Symptom Score (IPSS) questionnaire, visual analogic scale (VAS) for subjective assessment of the quality of life. The degree of the variation of maximum flow rate (Qmax), PVR, BVE, IPSS, VAS between baseline and follow-up (Δ) was evaluated. RESULTS: Patients in group A were 28 and in group B 23. Overall patient's mean ± SD age was 63.37 ± 12.41 years. Preoperative urodynamics characteristics: mean bladder contractility index (BCI) of 61.15 and 76.25 in group A and B, respectively; mean bladder outlet obstruction index (BOOI) of 17.25 and 50.15 in group A and group B, respectively. After surgery, overall patient group, group A, and group B showed a statistical improvement in IPSS score (P < .0001), Qmax (P < .0001), PVR (P < .0008), BVE (P < .03) and VAS (P < .0001). CONCLUSIONS: BOO had an important impact on the degree of improvement of Qmax and PVR/BVE, while had a poor influence on lower urinary tract symptoms amelioration. The most relevant outcomes were found when BOO was associated with DUA, which was not a contraindication to surgery.

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.

Recovery of Voiding Efficiency and Bladder Function in Male Patients With Non-neurogenic Detrusor Underactivity After Transurethral Bladder Outlet Surgery.

OBJECTIVE: The aim of this study is to investigate the treatment outcome in men with detrusor underactivity (DU) and voiding dysfunction who underwent transurethral resection or incision of the prostate (TURP or TUIP). DU usually affects decision making whether bladder outlet surgery is necessary. MATERIALS AND METHODS: A total of 60 men with urodynamic DU and voiding dysfunction who underwent TURP or TUIP from 1998 to 2015 were retrospectively analyzed for their treatment outcome after follow-up for more than 1 year. DU was defined as urodynamic evidence of low detrusor pressure (<40 cm H2O), low flow rate (<10 mL/s), a postvoid residual urine volume >300 mL, and a voiding efficiency (VE) of <33%. Satisfactory outcome was defined as improved quality of life and having a VE of >50% after treatment. Predictive factor for a successful outcome was also analyzed. RESULTS: At a mean follow-up of 31 months, 49 (81.7%) patients had achieved a satisfactory treatment outcome. Among the patients who received TURP and TUIP, 38/44 (86.4%) and 11/16 (68.8%) had satisfactory outcome, respectively. The satisfactory group had significantly higher detrusor pressure and greater bladder compliance at baseline than the unsatisfactory group. There was significant improvement in the urodynamic parameters after treatment in the satisfactory group. Among the patients with satisfactory outcome, 34 (69.4%) patients had recovery of detrusor function within 3 months. CONCLUSION: Active surgical treatment such as TURP or TUIP results in recovery of VE and detrusor function within 3 months after treatment in the majority of patients with DU.

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.

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.