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Background: Postoperative pain management remains a significant challenge for patients undergoing posterior urethroplasty (PU). In a previous study, we proposed a novel technique of combined pudendal nerve (PN) and spermatic cord (SC) block to manage pain after PU. The present trial was conducted to test the hypothesis that this technique is effective for pain control after PU and provides longer-lasting analgesia than caudal epidural block (CB)., Methods: Sixty patients undergoing PU were randomized into two groups: Group NB received combined PN and SC block, and Group CB received CB. General anesthesia with a laryngeal mask was performed. The primary outcome was the postoperative analgesic duration, and the secondary outcomes included the Numeric Rating Scale (NRS) scores for pain and the number of patients with different motor scores of the lower limb at 3, 6, 12, and 24 h postoperatively., Results: Two patients in Group CB were withdrawn due to block failure. The postoperative analgesic duration was statistically longer in Group NB compared with Group CB (mean difference [95% confidence interval], 115.78 min [17.80, 213.75]; P = 0.021). The NRS scores for pain at 12 and 24 h after surgery were statistically lower in Group NB compared with Group CB. Group NB had statistically more patients with motor score 0 at 3 h postoperatively than Group CB., Conclusions: PN combined with SC block is an effective technique for postoperative analgesia in PU. This technique can achieve a longer duration of analgesia and lower pain scores, especially 12 h after surgery, than a CB., Trial Registration: This study was registered in the Chinese Clinical Trial Register (registration no. ChiCTR2100042971, registration date on 2/2/2021)., (© 2024. The Author(s).)

Urethral smooth muscle cells (USMC) contract to occlude the internal urethral sphincter during bladder filling. Interstitial cells also exist in urethral smooth muscles and are hypothesized to influence USMC behaviours and neural responses. These cells are similar to Kit + interstitial cells of Cajal (ICC), which are gastrointestinal pacemakers and neuroeffectors. Isolated urethral ICC-like cells (ICC-LC) exhibit spontaneous intracellular Ca 2+ signalling behaviours that suggest these cells may serve as pacemakers or neuromodulators similar to ICC in the gut, although observation and direct stimulation of ICC-LC within intact urethral tissues is lacking. We used mice with cell-specific expression of the Ca 2+ indicator, GCaMP6f, driven off the endogenous promoter for Kit (Kit-GCaMP6f mice) to identify ICC-LC in situ within urethra muscles and to characterize spontaneous and nerve-evoked Ca 2+ signalling. ICC-LC generated Ca 2+ waves spontaneously that propagated on average 40.1 ± 0.7 μm, with varying amplitudes, durations, and spatial spread. These events originated from multiple firing sites in cells and the activity between sites was not coordinated. ICC-LC in urethra formed clusters but not interconnected networks. No evidence for entrainment of Ca 2+ signalling between ICC-LC was obtained. Ca 2+ events in ICC-LC were unaffected by nifedipine but were abolished by cyclopiazonic acid and decreased by an antagonist of Orai Ca 2+ channels (GSK-7975A). Phenylephrine increased Ca 2+ event frequency but a nitric oxide donor (DEA-NONOate) had no effect. Electrical field stimulation (EFS, 10 Hz) of intrinsic nerves, which evoked contractions of urethral rings and increased Ca 2+ event firing in USMC, failed to evoke responses in ICC-LC. Our data suggest that urethral ICC-LC are spontaneously active but are not regulated by autonomic neurons., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest in relation to this work., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Spinal cord injury (SCI) disrupts coordination between the bladder and the external urinary sphincter (EUS), leading to transient or permanent voiding impairment, which is more severe in males. Male versus female differences in spinal circuits related to the EUS as well as post-SCI rewiring are essential for understanding of sex-/gender-specific impairments and possible recovery mechanisms. To quantitatively assess differences between EUS circuits in males versus females and in spinal intact (SI) versus SCI animals, we retrogradely traced and counted EUS-related neurons. In transgenic ChAT-GFP mice, motoneurons (MNs), interneurons (INs), and propriospinal neurons (PPNs) were retrogradely trans-synaptically traced with PRV614-red fluorescent protein (RFP) injected into EUS. EUS-MNs in dorsolateral nucleus (DLN) were separated from other GFP + MNs by tracing them with FluoroGold (FG). We found two morphologically distinct cell types in DLN: FG + spindle-shaped bipolar (SB-MNs) and FG - rounded multipolar (RM-MNs) cholinergic cells. Number of MNs of both types in males was twice as large as in females. SCI caused a partial loss of MNs in all spinal nuclei. After SCI, males showed a fourfold rise in the number of RFP-labeled cells in retro-DLN (RDLN) innervating hind limbs. This suggests (a) an existence of direct synaptic interactions between spinal nuclei and (b) a post-SCI increase of non-specific inputs to EUS-MNs from other motor nuclei. Number of INs and PPNs deferred between males and females: In SI males, the numbers of INs and PPNs were ∼10 times larger than in SI females. SCI caused a twofold decrease of INs and PPNs in males but not in females., (© 2024 The Author(s). The Journal of Comparative Neurology published by Wiley Periodicals LLC.)

In pilot work, we showed that somatic nerve transfers can restore motor function in long-term decentralized dogs. We continue to explore the effectiveness of motor reinnervation in 30 female dogs. After anesthesia, 12 underwent bilateral transection of coccygeal and sacral (S) spinal roots, dorsal roots of lumbar (L)7, and hypogastric nerves. Twelve months postdecentralization, eight underwent transfer of obturator nerve branches to pelvic nerve vesical branches, and sciatic nerve branches to pudendal nerves, followed by 10 mo recovery (ObNT-ScNT Reinn). The remaining four were euthanized 18 mo postdecentralization (Decentralized). Results were compared with 18 Controls. Squat-and-void postures were tracked during awake cystometry. None showed squat-and-void postures during the decentralization phase. Seven of eight ObNT-ScNT Reinn began showing such postures by 6 mo postreinnervation; one showed a return of defecation postures. Retrograde dyes were injected into the bladder and urethra 3 wk before euthanasia, at which point, roots and transferred nerves were electrically stimulated to evaluate motor function. Upon L2-L6 root stimulation, five of eight ObNT-ScNT Reinn showed elevated detrusor pressure and four showed elevated urethral pressure, compared with L7-S3 root stimulation. After stimulation of sciatic-to-pudendal transferred nerves, three of eight ObNT-ScNT Reinn showed elevated urethral pressure; all showed elevated anal sphincter pressure. Retrogradely labeled neurons were observed in L2-L6 ventral horns (in laminae VI, VIII, and IX) of ObNT-ScNT Reinn versus Controls in which labeled neurons were observed in L7-S3 ventral horns (in lamina VII). This data supports the use of nerve transfer techniques for the restoration of bladder function. NEW & NOTEWORTHY This data supports the use of nerve transfer techniques for the restoration of bladder function.

During the urine storage phase, tonically contracting urethral musculature would have a higher energy consumption than bladder muscle that develops phasic contractions. However, ischaemic dysfunction is less prevalent in the urethra than in the bladder, suggesting that urethral vasculature has intrinsic properties ensuring an adequate blood supply. Diameter changes in rat or mouse urethral arterioles were measured using a video-tracking system. Intercellular Ca 2+ dynamics in arteriolar smooth muscle (SMCs) and endothelial cells were visualised using NG2- and parvalbumin-GCaMP6 mice, respectively. Fluorescence immunohistochemistry was used to visualise the perivascular innervation. In rat urethral arterioles, sympathetic vasoconstrictions were predominantly suppressed by α,β-methylene ATP (10 μM) but not prazosin (1 μM). Tadalafil (100 nM), a PDE5 inhibitor, diminished the vasoconstrictions in a manner reversed by N-ω-propyl-l-arginine hydrochloride (l-NPA, 1 μM), a neuronal NO synthesis (nNOS) inhibitor. Vesicular acetylcholine transporter immunoreactive perivascular nerve fibres co-expressing nNOS were intertwined with tyrosine hydroxylase immunoreactive sympathetic nerve fibres. In phenylephrine (1 μM) pre-constricted rat or mouse urethral arterioles, nerve-evoked vasodilatations or transient SMC Ca 2+ reductions were largely diminished by l-nitroarginine (l-NA, 10 μM), a broad-spectrum NOS inhibitor, but not by l-NPA. The CGRP receptor antagonist BIBN-4096 (1 μM) shortened the vasodilatory responses, while atropine (1 μM) abolished the l-NA-resistant transient vasodilatory responses. Nerve-evoked endothelial Ca 2+ transients were abolished by atropine plus guanethidine (10 μM), indicating its neurotransmitter origin and absence of non-adrenergic non-cholinergic endothelial NO release. In urethral arterioles, NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions pre- and post-synaptically to restrict arteriolar contractility. KEY POINTS: Despite a higher energy consumption of the urethral musculature than the bladder detrusor muscle, ischaemic dysfunction of the urethra is less prevalent than that of the bladder. In the urethral arterioles, sympathetic vasoconstrictions are predominately mediated by ATP, not noradrenaline. NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions by its pre-synaptic inhibition of sympathetic transmission as well as post-synaptic arteriolar smooth muscle relaxation. Acetylcholine released from parasympathetic nerves contributes to endothelium-dependent, transient vasodilatations, while CGRP released from sensory nerves prolongs NO-mediated vasodilatations. PDE5 inhibitors could be beneficial to maintain and/or improve urethral blood supply and in turn the volume and contractility of urethral musculature., (© 2024 The Authors. The Journal of Physiology © 2024 The Physiological Society.)

Objectives: We investigated the correlation between surgical outcomes and postoperative urinary continence recovery in robot-assisted radical prostatectomy (RARP)., Methods: Patients who underwent RARP in our institution (n = 195) were included in this study. Preserved urethral length (PUL) was assessed during the procedure. Other outcomes of the surgical procedure were collected from operative records. Kaplan-Meier analysis with log-rank test was used to compare urinary continence recovery rate with the PUL, sparing of the neurovascular bundle (NVB), and other surgical procedures. Univariate and multivariate analyses were performed using Cox proportional hazards model, and p-values of <0.05 were considered significant., Results: Patients with a PUL ≥26 mm had 10.0%, 24.7%, 36.6%, and 89.0% continence recovery rates at 30, 60, 90, and 365 days after surgery, respectively, while patients with a PUL <26 mm had 0%, 17.8%, 26.1%, and 80.9% recovery rates, respectively. Kaplan-Meier curves showed significantly better postoperative urinary continence recovery at 30 days after RARP in patients with a PUL ≥26 mm than those with a PUL <26 mm (p = 0.0028) and in patients with NVB preservation than those with no NVB preservation (p = 0.014). Urinary continence recovery within 30, 60, and 90 days after surgery was 90.6% for patients with a PUL of ≥26 mm and NVB preservation, while only 82.3% for patients with a PUL of <26 mm or no NVB preservation., Conclusion: Our results suggest that a PUL ≥26 mm and NVB preservation after RARP correlate with a significantly higher postoperative rate of recovery of urinary continence., (© 2024 The Authors. International Journal of Urology published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Urological Association.)

Purpose: Postoperative urinary dysfunction following untethering surgery for spinal lipoma is devastating. To assess urinary function, we invented a pediatric urinary catheter equipped with electrodes for the direct transurethral recording of myogenic potential from the external urethral sphincter (EUS). This paper presents two cases in which urinary function was monitored intraoperatively by recording of motor-evoked potential (MEP) from EUS during untethering surgery in children., Methods: Two children (aged 2 and 6 years) were included in this study. One patient had no preoperative neurological dysfunction, while the other had frequent urination and urinary incontinence. A pair of surface electrodes was attached to a silicone rubber urethral catheter (6 or 8 Fr; diameter, 2 or 2.6 mm). The MEP from the EUS was recorded to assess the function of the centrifugal tract from the motor cortex to the pudendal nerve., Results: Baseline MEP waveforms from the EUS were successfully recorded with latency and amplitude of 39.5 ms and 66 µV in patient 1 and 39.0 ms and 113 µV in patient 2, respectively. A significant decrease in amplitude was not observed during surgery in the two cases. No new urinary dysfunction and complications associated with the urinary catheter-equipped electrodes developed postoperatively., Conclusion: Using an electrode-equipped urinary catheter, monitoring of MEP from the EUS could be applicable during untethering surgery in pediatric patients., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective. Epidural spinal cord stimulation (SCS) is a potential intervention to improve limb and autonomic functions, with lumbar stimulation improving locomotion and thoracic stimulation regulating blood pressure. Here, we asked whether sacral SCS could be used to target the lower urinary tract (LUT) and used a high-density epidural electrode array to test whether individual electrodes could selectively recruit LUT nerves. Approach . We placed a high-density epidural SCS array on the dorsal surface of the sacral spinal cord and cauda equina of anesthetized cats and recorded the stimulation-evoked activity from nerve cuffs on the pelvic, pudendal and sciatic nerves. Main results . Here we show that sacral SCS evokes responses in nerves innervating the bladder and urethra and that these nerves can be activated selectively. Sacral SCS always recruited the pelvic and pudendal nerves and selectively recruited both of these nerves in all but one animal. Individual branches of the pudendal nerve were always recruited as well. Electrodes that selectively recruited specific peripheral nerves were spatially clustered on the arrays, suggesting anatomically organized sensory pathways. Significance. This selective recruitment demonstrates a mechanism to directly modulate bladder and urethral function through known reflex pathways, which could be used to restore bladder and urethral function after injury or disease., (Creative Commons Attribution license.)

The recovery of lower-urinary-tract activity is a top priority for patients with spinal-cord injury. Historically, locomotor training improved micturition function in both patients with spinal cord injury and animal models. We explore whether training augments such as the supraspinal control of the external urethral sphincter results in enhanced coordination in detrusor-sphincter activity. We implemented a clinically relevant contusive spinal-cord injury at the 12th thoracic level in rats and administered forced wheel running exercise for 11 weeks. Awake rats then underwent bladder cystometrogram and sphincter electromyography recordings to examine the micturition reflex. Subsequently, pseudorabies-virus-encoding red fluorescent protein was injected into the sphincter to trans-synaptically trace the supraspinal innervation of Onuf's motoneurons. Training in the injury group reduced the occurrence of bladder nonvoiding contractions, decreased the voiding threshold and peak intravesical pressure, and shortened the latency of sphincter bursting during voiding, leading to enhanced voiding efficiency. Histological analysis demonstrated that the training increased the extent of spared spinal-cord tissue around the epicenter of lesions. Compared to the group of injury without exercise, training elicited denser 5-hydroxytryptamine-positive axon terminals in the vicinity of Onuf's motoneurons in the cord; more pseudorabies virus-labeled or c-fos expressing neurons were detected in the brainstem, suggesting the enhanced supraspinal control of sphincter activity. Thus, locomotor training promotes tissue sparing and axon innervation of spinal motoneurons to improve voiding function following contusive spinal-cord injury.

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.

Detrusor underactivity (DU) could be resulted from many different etiologies. Patients with DU might have reduced bladder sensation, low detrusor contractility, and large post-void residual volume. This study analyzed therapeutic outcome of active management for male DU patients, based on clinical and urodynamic characteristics. Male DU patients aged > 18 years old were retrospectively reviewed from the videourodynamic study (VUDS) records in recent 10 years. The patients' demographics, VUDS results, treatment modalities, and treatment outcome were analyzed. The treatment outcomes were compared among patients with different DU subgroups, clinical diagnosis and treatment modalities. Patients with voiding efficiency of > 66.7% were considered having a successful treatment outcome. For comparison, 30 men with normal VUDS finding served as the control arm. Most of the DU patients had reduced bladder sensation. The reduced bladder sensation is closely associated with low detrusor contractility. After active treatment, a successful outcome was achieved in 68.4% of patients after bladder outlet surgery, 59.1% after urethral botulinum toxin A injection, and 57.6% after medical treatment, but only 18.2% after conservative treatment. A successful treatment outcome was achieved in patients with an intact detrusor contractility, either low (69.2%) or normal voiding pressure (81.8%), and in patients with a normal or increased bladder sensation (78.1%). However, patients with detrusor acontractile (41.3%) or absent bladder sensation (17.9%) had less favorable treatment outcome after any kind of urological management. This study revealed that active management can effectively improve voiding efficiency in patients with DU. The normal bladder sensation, presence of adequate detrusor contractility, and bladder outlet narrowing during VUDS provide effective treatment strategy for DU patients. Among all management, BOO surgery provides the best treatment outcome., (© 2022. The Author(s).)

Age-related changes in the lower urinary tract (LUT) can affect the coordination of reflexes and increase the incidence of bladder disorders in elderly. This study examines the age-related loss of urethral signaling capability by measuring the afferent activity directly. We find that less urethral pressure develops in response to fluid flow in old rats compared to young rats and that pressure and flow evoke less urethral afferent activation. These findings are consistent with our previous study demonstrating that the urethra-to-bladder reflex, which is required for efficient voiding, becomes weaker with age. We measured the pudendal afferent response in young (4-7 months) and old (18-24 months) rats to fluid flow in the urethra across a range of flow rates. We used paraffin embedding and hematoxylin and eosin staining to quantify age-related changes in the sensory branch of the pudendal nerve. Urethral afferent signaling in response to the same urethral flow rates was weaker in older animals. That is, the sensitivity of urethra afferents to flow decreased with age, and higher flow rates were required in older animals to recruit urethra afferents. There was also a reduction in the myelin thickness of pudendal afferents in old rats, which is a possible contributing factor to the sensory activity. Furthermore, the same flow rates evoked less pressure in the urethras of old animals, indicating there is an age-related change of the urethral tissue that reduces the pressure stimulus to which these afferents respond. These results help characterize the underlying changes in LUT system with age., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Under healthy conditions, more than one urethra-closing reflex, including both bladder afferent-independent and -dependent actions, function during momentary elevation of intravesical (bladder) pressure to prevent urinary incontinence . In the current study, the effects of a novel selective 5-hydroxytryptamine type 2C (5-HT 2C ) receptor agonist, TAK-233, on evoked momentary urethra-closing functions were investigated in female rats and humans to elucidate 5-HT 2C receptor functions. In anesthetized female rats, TAK-233 dose-dependently and significantly increased urethral resistance during sneezing in rats with distended vaginas and bilaterally transected pelvic nerves. The drug also dose-dependently and significantly increased urethral resistance during momentary intravesical pressure elevation by electrical stimulation of abdominal muscles in rats with a transected spinal cord at the T8-T9 level and intact pelvic nerves. The increased effects observed during electrical stimulation were abolished by either an intravenously administered selective 5-HT 2C receptor antagonist, SB 242084, or bilateral transection of the pelvic nerves or somatic nerves innervating the external urethral sphincter and pelvic floor muscles. In the spinal cord-transected and pelvic nerve-intact rats, TAK-233 enlarged the urethra-closing responses induced by both passive and abrupt intravesical pressure elevation, measured by a microtip transducer located in the middle urethra. Additionally, the effects of TAK-233 on the stimulus threshold of urethral contractile responses induced by transcranial magnetic stimulation were investigated in healthy female volunteers. The drug dose-dependently and significantly lowered this stimulus threshold, indicating an increased sensitivity of the response. These results demonstrate that 5-HT 2C receptor stimulation enhances the evoked momentary urethra-closing functions in both female rats and humans. SIGNIFICANCE STATEMENT: 5-hydroxytryptamine (serotonin) type 2C (5-HT 2C ) receptor stimulation by TAK-233 enhanced urethral resistance in rats during an evoked momentary event in which the bladder afferent-independent or -dependent reflex functions via striated muscle-mediated mechanisms. The increases in sensitivity of transcranial magnetic stimulation-evoked urethral contractile responses in healthy female subjects indicates that this mechanism also functions in humans. The evoked momentary conditions activating these reflexes provide a suitable model to demonstrate the effects of 5-HT 2C receptor stimulation., (Copyright © 2021 by The Author(s).)

Objective: To understand the structures around the vesicourethral junction and to improve functional outcomes after nerve-sparing radical cystectomy with orthotopic urinary diversion for female patients, we histologically elucidated the fibromuscular construction and nerve distribution around the vesicourethral junction., Methods: Pelvic specimens containing all the pelvic viscera were obtained from 33 donated female cadavers. Macroslices that included the urethra, the anterior wall of the vagina, and the inferomedial edge of the levator ani muscle were made and performed elastica Masson and immunohistochemical staining. The intraoperative findings were collected in 3 female patients undergoing nerve-sparing radical cystectomy., Results: In 18 out of the 33 cadavers, smooth muscle mass occupied a space between the urethra and the inferomedial edge of the levator ani muscle and covered the inferior margin of the bladder detrusor. We termed this mass the hiatal smooth muscle. The detrusor nerves entered the bladder, and the cavernous and sphincter nerves ran between the hiatal smooth muscle and vesicourethral junction. The boundary between hiatal smooth muscle and urethral smooth muscle was easily distinguished intraoperatively during dissection of the vesicourethral junction., Conclusion: We found that more than half of elderly women have hiatal smooth muscle between the urethra and inferior edge of the levator ani. Autonomic nerve fibers innervating the urethral sphincter, run between the hiatal smooth muscle and vesicourethral junction in female cadavers with hiatal smooth muscle. When performing female radical cystectomy before neobladder reconstruction, nerve sparing can be reliably performed using the hiatal smooth muscle as a landmark., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: The aim of the present study was to describe autonomic urethral sphincter (US) innervation using specific muscular and neuronal antibody markers and 3D reconstruction., Material and Methods: We performed en-bloc removal of the entire pelvis of three male human fetuses between 18 and 40 weeks. Serial whole mount sections (5 μm intervals) were stained and investigated. The sections were stained with Masson's trichrome and Eosin Hematoxylin, and immunostained with: anti-SMA antibody for smooth muscle; anti-S100 antibody for all nerves; and anti-PMP22 antibody, anti-TH antibody, anti-CGRP antibody, anti-NOS antibody for somatic, adrenergic, sensory and nitrergic nerve fibers, respectively. The slides were digitized for 3D reconstruction to improve topographical understanding. An animated reconstruction of the autonomic innervation of the US was generated., Results: The external and internal US are innervated by autonomic nerves of the inferior hypogastric plexus (IHP). These nerves are sympathetic (positive anti-TH antibody), sensory (positive anti-CGRP antibody), and nitrergic (positive anti-NOS antibody). Some autonomic fibers run within the neurovascular bundles, posterolaterally. Others run from the IHP to the posteromedial aspect of the prostate apex, above an through the rectourethral muscle. The external US is also innervated by somatic nerves (positive anti-PMP22 antibody) arising from the pudendal nerve, joining the midline but remaining below the rectourethral., Conclusions: This study provides anatomical evidence of an autonomic component in the innervation of the external US that travels in the neurovascular bundle. During radical prostatectomy, the rectourethral muscle and the neurovascular bundles are to be preserved, particularly during apical dissection., (© 2020 American Association of Clinical Anatomists.)

Purpose of the Review: The goal of this paper was to evaluate the impact on erectile and ejaculatory function after anterior and posterior urethroplasty., Recent Findings: With a rise in the use of urethroplasty, its impact on sexual function has come into question. For anterior urethroplasties, some degree of erectile dysfunction is common, but this tends to be transient, with most patients having a resolution of any de novo dysfunction by 12 months. Patients with posterior urethral strictures have a very high rate of erectile dysfunction prior to surgery and may show improvement after urethroplasty. Ejaculatory function tends to improve in patients due to alleviation of obstruction while some patients notice degradation in force of ejaculation. While urethroplasty has a minimal permanent effect on sexual function for most patients, there are some patients who notice improvement and others worsening. Patients should be counseled on these risks prior to urethroplasty.

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.

Objective: To determine the relationship between various parameters of high-frequency biphasic stimulation (HFBS) and the recovery period of post-HFBS block of the pudendal nerve in cats., Materials and Methods: A tripolar cuff electrode was implanted on the pudendal nerve to deliver HFBS in ten cats. Two hook electrodes were placed central or distal to the cuff electrode to stimulate the pudendal nerve and induce contractions of external urethral sphincter (EUS). A catheter was inserted toward the distal urethra to slowly perfuse the urethra and record the back-up pressure generated by EUS contractions. After determining the block threshold (T), HFBS (6 or 10 kHz) of different durations (1, 5, 10, 20, 30 min) and intensities (1T or 2T) was used to produce the post-HFBS block., Results: HFBS at 10 kHz and 1T intensity must be applied for at least 30 min to induce post-HFBS block. However, 10 kHz HFBS at a higher intensity (2T) elicited post-HFBS block after stimulation of only 10 min; and 10 kHz HFBS at 2T for 30 min induced a longer-lasting (1-3 h) post-HFBS block that fully recovered with time. HFBS of 5-min duration at 6 kHz produced a longer period (20.4 ± 2.1 min, p < 0.05, N = 5 cats) of post-HFBS block than HFBS at 10 kHz (9.5 ± 2.1 min)., Conclusion: HFBS of longer duration, higher intensity, and lower frequency can produce longer-lasting reversible post-HFBS block. This study is important for developing new methods to block nerve conduction by HFBS., (© 2019 International Neuromodulation Society.)

Purpose: We examined the associations between urethral sensation and storage/voiding function in female patients with detrusor overactivity (DO) by measuring urethral current perception threshold (CPT)., Materials and Methods: We retrospectively investigated the medical records of 27 consecutive patients with lower urinary tract symptoms who underwent cystometry, uroflowmetry (UFM), and urethral CPT tests from 2000 to 2015. Patients were classified into 2 groups: with/without DO. Seven DO-negative cases were selected as normal controls on cystometrogram (CMG) matching the inclusion criteria: bladder compliance ?12.5 mL/cmH2O, volume <275 mL at first sensation, and no comorbidities possibly influencing micturition. Finally, 17 patients were included. Urethral CPT was evaluated with intraurethral square-wave impulses at 3 Hz to stimulate C-fibers. Urethral loss coefficient (LC), reflecting urethral resistance during voiding, was calculated by curve-fitting a mathematical model to a UFM waveform., Results: Urge incontinence (UI) was observed in 7 DO-positive patients, but not in those with normal CMG. Urethral CPT and LC were significantly higher in patients with DO than in those with normal CMG. Median urethral CPT significantly increased in patients with both DO and UI than in those without these symptoms (p<0.005). CPT values were correlated with the volume at first sensation (?=0.53, p<0.05) and LC (?=0.59, p<0.05). LC was not calculated in 3 cases due to poor curve-fitting., Conclusions: In females, urethral C-fiber afferents may become hyposensitive as the detrusor becomes overactive with UI in the storage phase. During voiding, C-fiber hyposensitivity may relate to increased functional resistance of the urethra to urine outflow.

Objective: To determine the outcomes and mechanisms of delayed low-intensity extracorporeal shock wave therapy (Li-ESWT) in a rat model of irreversible stress urinary incontinence (SUI)., Materials and Methods: Twenty-four female Sprague-Dawley rats were randomly assigned into 3 groups: sham control, vaginal balloon dilation + β-aminopropionitrile (BAPN; SUI group), and vaginal balloon dilation + BAPN + treatment with Li-ESWT (SUI-Li-ESWT group). An irreversible SUI model was developed by inhibiting the urethral structural recovery with BAPN daily for 5 weeks. Thereafter, in the SUI-Li-ESWT group, Li-ESWT was administered twice per week for 2 weeks. After a 1-week washout, all 24 rats were evaluated with functional and histologic studies at 17 weeks of age. Endogenous progenitor cells were detected via the EdU-labeling method., Results: Functional analysis with leak point pressure testing showed that the SUI-Li-ESWT group had significantly higher leak point pressures compared with untreated rats. Increased urethral and vaginal smooth and striated muscle content and increased thickness of the vaginal wall were noted in the SUI-Li-ESWT group. The SUI group had significantly decreased neuronal nitric oxide /tyrosine hydroxylase positive nerves ratio in the smooth muscle layers of the urethra, while the SUI-Li-ESWT group had neuronal nitric oxide/tyrosine hydroxylase+ nerves ratio similar to that of the control group. The continuality of urothelial cell lining was also improved in the SUI-Li-ESWT group. In addition, there were significantly increased EdU-positive cells in the SUI-Li-ESWT group., Conclusion: Li-ESWT appears to increase smooth muscle content in the urethra and the vagina, increase the thickness of urethral wall, improve striated muscle content and neuromuscular junctions, restore the integrity of the urothelium, and increase the number of EdU-retaining progenitor cells in the urethral wall., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The prevalence of underactive bladder (UAB) increases with age, suggesting a link between age-related processes and lower urinary tract (LUT) symptoms; however, the underlying mechanisms of age-related UAB are poorly understood. Understanding how aging affects LUT reflexes may help in the development of new treatments by identifying mechanistic targets. In this work, we studied the relationship between age and systems-level function of the LUT and tested the hypothesis that aging is related to weakening of reflexes that control voiding. Three groups of anesthetized female rats, young (4-7 mo old), mature (11-14 mo old), and old (18-24 mo old), were used to quantify the effect of aging on LUT reflexes. A double-lumen catheter enabled us to control the bladder volume and urethral flow rate independently, under quasi-isovolumetric bladder conditions. We systematically investigated the reflex bladder contractions evoked by combinations of rates of urethral infusion and bladder fill volumes as a function of age. Urethral infusion with the same flow rate evoked bladder contractions (via the augmenting reflex) in old animals less often than in younger animals. Furthermore, old animals needed more fluid in their bladders (relative to their bladder capacity) before urethra flow-evoked bladder contractions could be triggered at all, suggesting a delay in the switch of the LUT to "voiding mode." Old rats also showed longer and weaker bladder contractions than young or mature rats. Taken together, this suggests there is an age-related functional weakening and loss of sensitivity in LUT reflexes, which may contribute to age-related UAB symptoms.

Aims: The urethral dysfunction produced by a rat model of peripheral neurogenic detrusor underactivity (DU) using pelvic nerve crush (PNC) injury was characterized and then tested with the administration of tadalafil, a phosphodiesterase type 5 (PDE 5) inhibitor., Methods: Ten days after producing PNC rats, awake cystometrograms (CMGs) and isovolumetric cystometrograms with urethral perfusion pressure (IC-UPP) measurements were performed. Also, in control rats, IC-UPP was recorded before and after intravenous atropine administration to determine if the reduction of bladder contraction pressure affects urethral relaxation during voiding. Then, CMG and IC-UPP measurements in PNC rats were recorded after intravenous administration of tadalafil. Lastly, real-time polymerase chain reaction was used to measure transcript levels of neuronal nitric oxide synthases (nNOS), endothelial nitric oxide synthases, and PDE 5 in urethral specimens from PNC and control rats., Results: PNC rats demonstrated the characteristics of DU in CMG. Also, PNC rats exhibited significant decreases in isovolumetric bladder contraction amplitudes and urethral relaxation. Atropine attenuated the amplitude of isovolumetric bladder contractions; however, atropine did not affect urethral relaxation in control rats. Tadalafil decreased postvoid residual and increased voiding efficiency without changing bladder contraction amplitude in PNC rats. Also, tadalafil improved the amplitude of urethral relaxation during bladder contraction in PNC rats. Urethral nNOS transcript levels were upregulated in PNC rats compared to control rats., Conclusions: PNC rats revealed both DU and impaired urethral relaxation. PDE 5 inhibition in PNC rats enhanced urethral relaxation during voiding, resulting in improved voiding efficiency. Thus, urethral dysfunction could be a potential target for the treatment of inefficient voiding associated with neurogenic DU., (© 2020 Wiley Periodicals, Inc.)

Objective: To characterize the bulbospongiosus muscle (BSM) in patients with bulbar urethral strictures., Materials and Methods: We studied 21 patients divided into 2 groups: Stricture Group (n = 14; mean age = 62.00 years) with bulbar stricture submitted to open urethroplasty; and Control Group (n = 7; mean age = 60.14 years) with penile strictures (hypospadias cripples, penile cancer and/or penile infection) who were submitted to perineal urethrostomy. Samples of the BSM were dissected and histologic sections were stained by histochemical and immunohistochemical techniques. Histomorphometric analyzes were performed on photomicrographs. Means were statistically compared using the unpaired Student t test and the Mann-Whitney test (P <.05)., Results: The etiology of bulbar urethral stricture was idiopathic in 2 cases (14.29%), post-TURP in 6 (42.86%), post open radical prostatectomy in 5 (35.71%) and post open prostatectomy in 1 case (7.14%). The average length of the stricture was 2.08 cm. The only parameter analyzed with significant difference between the groups was the vessels (significant difference between the control group: 5.11 ± 1.98% and stricture group: 3.57 ± 1.32%, P = .0460). The quantitative analysis of collagen (Control Group: 10.63 ± 5.37% and Stricture Group: 10.83 ± 4.55%, P = .9296); diameter of BSM muscle fibers (Control Group: 41.71 ± 14.63 µm and Stricture Group: 40.11 ± 8.59 µm, P = .76 and elastic system fibers (Control Group; 3.83 ± 1.54% and Stricture Group: 5.43 ± 2.90%, P = .2601) showed no significant difference., Conclusions: Histologic analysis showed a significant decrease of the BSM vessels in urethral stricture, without changes in elastic fibers, collagen, nerves, and muscle fiber diameter. These findings show that the bulbar urethral stricture causes minimal alterations in the structure of the BSM., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A damaged sphincteric unit or support system, unstable urethral deformability or damaged sensory innervation are all potential causes of a dysfunctional urethral sphincter. With the current improvement in pharmacological targets and urodynamic understanding, studies have begun quantifying individual structures and their importance in closure pressure and consequently urethral continence. However, when it comes to the function of the longitudinal urethral smooth muscle layer, there is currently no consensus. The intent of this structured review is to critically examine literature regarding the female urethral anatomy and closure mechanism. We hypothesized that the longitudinal smooth muscle is a prerequisite for sufficient urethral closure and not merely involved during micturition. Overall opinions on a dysfunctional closure mechanism are controversial. Nonetheless, basic mechanics may be applied to understand simple urodynamics. With the assumption of longitudinal muscles forming a plug when contracted, this could have a substantial effect on the continence mechanism.

Aims: We sought to determine whether somatic lumbar nerve transfer to the pelvic nerve's anterior vesical branch after sacral decentralization for detrusor muscle reinnervation also leads to aberrant innervation of the bladder outlet., Methods: Twenty-six female mongrel hound dogs underwent transection of sacral dorsal and ventral spinal roots (ie, sacral decentralization). Immediately afterward, 12 received genitofemoral nerve transfer and 9 received femoral nerve branch transfer. Five were left sacrally decentralized. Controls included 3 sham-operated and 6 unoperated. Eight months postsurgery, the bladder and urethra were injected with retrograde tracing dyes cystoscopically. After 3 weeks, detrusor and urethral pressures were assayed electrophysiologically immediately before euthanasia and characterization of neural reinnervation., Results: Electrical stimulation of spinal cords or roots did not lead to increased urethral sphincter pressure in nerve transfer animals, compared with decentralized animals, confirming a lack of functional reinnervation of the bladder outlet. In contrast, mean detrusor pressure increased after lumbar cord/root stimulation. In sham/unoperated animals, urethral and bladder dye injections resulted in labeled neurons in sacral level neural structures (dorsal root ganglia [DRG], sympathetic trunk ganglia [STG], and spinal cord ventral horns); labeling absent in decentralized animals. Urethral dye injections did not result in labeling in lumbar or sacral level neural structures in either nerve transfer group while bladder dye injections lead to increased labeled neurons in lumbar level DRG, STG, and ventral horns, compared to sacrally decentralized animals., Conclusion: Pelvic nerve transfer for bladder reinnervation does not impact urethral sphincter innervation., (© 2019 The Authors. Neurourology and Urodynamics published by Wiley Periodicals, Inc.)

Development of the human prepuce was studied over the course of 9-17 weeks of gestation in 30 specimens. Scanning electron microscopy revealed subtle surface features that were associated with preputial development, namely the appearance of epidermal aggregates that appeared to be associated with formation of the preputial fold. Transverse and sagittal sections revealed that the epidermis of the glans is considerably thicker than that of the penile shaft. We described a novel morphogenetic mechanism of formation of the preputial lamina, namely the splitting of the thick epidermis of the glans into the preputial lamina and the epidermis via the intrusion of mesenchyme containing red blood cells and CD31-positive blood vessels. This process begins at 10-11 weeks of gestation in the proximal aspect of the glans and extends distally. The process is likely to be androgen-dependent and mediated via androgen receptors strategically localized to the morphogenetic process, but signaling through estrogen receptor may play a role. Estrogen receptor alpha (ESR1) has a very limited expression in the developing human glans and prepuce, while estrogen receptor beta (ESR2) is expressed more broadly in the developing preputial lamina, epidermis and urethra. Examination of the ontogeny of innervation of the glans penis and prepuce reveals the presence of the dorsal nerve of the penis as early as 9 weeks of gestation. Nerve fibers enter the glans penis proximally and extend distally over several weeks to eventually reach the distal aspect of the glans and prepuce by 14-16 weeks of gestation., (Copyright © 2019 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.)

Objective: Previous patient surveys have shown that patients with spinal cord or cauda equina injuries prioritize recovery of bladder function. The authors sought to determine if nerve transfer after long-term decentralization restores bladder and sphincter function in canines., Methods: Twenty-four female canines were included in this study. Transection of sacral roots and hypogastric nerves (S Dec) was performed in 6 animals, and 7 animals underwent this procedure with additional transection of the L7 dorsal roots (L7d+S Dec). Twelve months later, 3 L7d+S Dec animals underwent obturator-to-pelvic nerve and sciatic-to-pudendal nerve transfers (L7d+S Dec+Reinn). Eleven animals served as controls. Squat-and-void behaviors were tracked before and after decentralization, after reinnervation, and following awake bladder-filling procedures. Bladders were cystoscopically injected with Fluoro-Gold 3 weeks before euthanasia. Immediately before euthanasia, transferred nerves were stimulated to evaluate motor function. Dorsal root ganglia were assessed for retrogradely labeled neurons., Results: Transection of only sacral roots failed to reduce squat-and-void postures; L7 dorsal root transection was necessary for significant reduction. Three L7d+S Dec animals showing loss of squat-and-void postures post-decentralization were chosen for reinnervation and recovered these postures 4-6 months after reinnervation. Each showed obturator nerve stimulation-induced bladder contractions and sciatic nerve stimulation-induced anal sphincter contractions immediately prior to euthanasia. One showed sciatic nerve stimulation-induced external urethral sphincter contractions and voluntarily voided twice following nonanesthetized bladder filling. Reinnervation was confirmed by increased labeled cells in L2 and the L4-6 dorsal root ganglia (source of obturator nerve in canines) of L7d+S Dec+Reinn animals, compared with controls., Conclusions: New neuronal pathways created by nerve transfer can restore bladder sensation and motor function in lower motor neuron-lesioned canines even 12 months after decentralization.

Stress urinary incontinence (SUI) is more prevalent among women who deliver vaginally than women who have had a cesarean section, suggesting that tissue repair after vaginal delivery is insufficient. A single dose of mesenchymal stem cells (MSCs) has been shown to partially restore urethral function in a model of SUI. The aim of the present study was to determine if increasing the number of doses of MSCs improves urethral and pudendal nerve function and anatomy. We hypothesized that increasing the number of MSC doses would accelerate recovery from SUI compared with vehicle treatment. Rats underwent pudendal nerve crush and vaginal distension or a sham injury and were treated intravenously with vehicle or one, two, or three doses of 2 × 10 6 MSCs at 1 h, 7 days, and 14 days after injury. Urethral leak point pressure testing with simultaneous external urethral sphincter electromyography and pudendal nerve electroneurography were performed 21 days after injury, and the urethrovaginal complex and pudendal nerve were harvested for semiquantitative morphometry of the external urethral sphincter, urethral elastin, and pudendal nerve. Two and three doses of MSCs significantly improved peak pressure; however, a single dose of MSCs did not. Single, as well as repeated, MSC doses improved urethral integrity by restoring urethral connective tissue composition and neuromuscular structures. MSC treatment improved elastogenesis, prevented disruption of the external urethral sphincter, and enhanced pudendal nerve morphology. These results suggest that MSC therapy for postpartum incontinence and SUI can be enhanced with multiple doses.

Patients suffer bilateral sacral plexus injuries experience severe problems with incontinence. We performed a cadaveric study to explore the anatomical feasibility of transferring ipsilateral S2 nerve root combined with a sural nerve graft to pudendal nerve for restoration of external anal and urethral sphincter function. The sacral nerve roots and pudendal nerve roots on the right side were exposed in 10 cadavers. The length from S2 nerve root origin to pudendal nerve at inferior border of piriformis was measured. The sural nerve was used as nerve graft. The diameters and nerve cross-sectional areas of S2 nerve root, pudendal nerve and sural nerve were measured and calculated, so as the number of myelinated axons of three nerves on each cadaver specimen. The length from S2 nerve root to pudendal nerve was 10.69 ± 1.67 cm. The cross-sectional areas of the three nerves were 8.57 ± 3.03 mm 2 for S2, 7.02 ± 2.04 mm 2 for pudendal nerve and 6.33 ± 1.61 mm 2 for sural nerve. The pudendal nerve contained approximately the same number of axons (5708 ± 1143) as the sural nerve (5607 ± 1305), which was a bit less than that of the S2 nerve root (6005 ± 1479). The S2 nerve root in combination with a sural nerve graft is surgically feasible to transfer to the pudendal nerve for return of external urethral and anal sphincter function, and may be suitable for clinical application in patients suffering from incontinence following sacral plexus injuries.

Background: The applicability of the sphincter complex integral theory to robotic-assisted radical prostatectomy (RARP) is unclear, with little known about the long-term effect of sphincter complex integrity on continence., Objective: To determine whether the preoperative anatomical and functional features of the sphincter complex and the degree of nerve-sparing affect long-term continence after RARP., Design, Setting, and Participants: Prospective study of 529 patients who underwent RARP at a single tertiary center., Outcome Measurements and Statistical Analysis: Anatomical factors, including membranous urethral length (MUL) and pelvic diaphragm length (PDL), were assessed using sagittal views of preoperative magnetic resonance imaging. MUL was defined as the distance from the posterior prostate apex to the urethra level at the penile bulb, and PDL was defined as the length of the urethra that met the planes created by the pelvic floor muscles. Functional parameters including maximum urethral closure pressure (MUCP) and functional urethral length were evaluated using preoperative measurements of the urethral pressure profiles. The degree of nerve-sparing was stratified as bilateral, unilateral, or none. Continence (pad-free status) was assessed according to anatomical and functional factors and nerve-sparing. We used binary logistic regression to assess factors predicting continence return 12 mo after RARP., Results and Limitations: Continence return rates 1, 3, 6, and 12 mo after RARP were 39.7%, 66.0%, 80.2%, and 87.0%, respectively. Continence return rates at 12 mo differed significantly in patients with MUL ≥11.7mm (91.9%) and <11.7mm (79.9%), PDL ≥9.9mm (96.7%) and <9.9mm (74.5%), and MUCP ≥66 cmH 2 O (89.7%) and <66 cmH 2 O (79.4%). The continence return rate was significantly higher in patients with bilateral (93.0%) than in patients with unilateral (78.1%) or no (76.7%) nerve-sparing. Multivariate analysis showed that PDL (odds ratio [OR]=2.187 per mm), MUCP (OR=1.037 per cmH 2 O), and bilateral nerve-sparing (OR=3.671) were independently associated with continence return 12 mo after RALP., Conclusions: The anatomical length and static pressure of the sphincter complex affected continence after RARP. Bilateral nerve-sparing was independently associated with long-term continence., Patient Summary: Predisposing length and static pressure of the urinary sphincter affect continence after robotic-assisted radical prostatectomy. Nerve bundle preservation during surgery enhances postoperative return of continence., (Copyright © 2018. Published by Elsevier B.V.)

Objective: Stress urinary incontinence (SUI) is a common disease condition in elderly women, suggesting that its etiology may be linked to aging. To investigate the hypothesis that urethral dysfunction and histopathological changes are possible contributors to SUI in elderly women, several parameters of urethral function, as well as histological parameters, were compared between young and aged rats., Methods: Virgin female rats were examined at 3 different ages, namely 3, 12, and 24 months, corresponding to young, middle-aged, and aged rats, respectively. Urethral function was assessed by measuring the leak point pressure (LPP), pudendal nerve stimulation (PNS)-induced elevation in urethral pressure, and phenylephrine-induced increase in urethral perfusion pressure (UPP). Histopathological assessments were performed following hematoxylin and eosin (HE), Masson's trichrome, and immunofluorescence staining of urethral tissue., Results: LPP of aged rats was significantly reduced compared to that of both young and middle-aged rats. PNS-induced elevation in urethral pressure in aged rats was also significantly lower than that in young rats. In contrast, there were no significant differences in the phenylephrine-induced increase in UPP between young and aged rats. Connective tissue area in the external urethral sphincter (EUS) layer was increased in aged rats, whereas the smooth muscle layer was histologically similar to that in young rats. The number of EUS fibers was significantly reduced in aged rats, whereas the cross-sectional area of EUS fibers increased from differed compared with young rats., Conclusion: We have demonstrated age-related changes in EUS function and morphology in the rat urethra, which are considered to be etiological risk factors for SUI in humans., (© 2017 John Wiley & Sons Australia, Ltd.)

Objective: The aim of the present study was to investigate associations between urethral sensation and urge urinary incontinence (UUI) in patients with and without detrusor overactivity (DO)., Methods: The medical records of 80 consecutive patients who underwent filling cystometry and urethral current perception threshold (CPT) tests were examined retrospectively. Following the exclusion of 4 patients not eligible for analysis, patients were classified into neurogenic DO, idiopathic DO, or DO-negative groups based on neurological and cystometric findings (n = 30, 12, and 34, respectively). Eleven DO-negative patients were defined as normal controls on cystometrograms (CMG) using the following exclusion criteria: bladder compliance <12.5 mL/cmH 2 O, volume >275 mL at first filling sensation, and comorbidities possibly affecting lower urinary tract function. Thus, 53 patients were finally included in the study. Proximal urethral CPT was evaluated with intraurethral square-wave stimulation at 3 Hz to activate C-fiber afferents., Results: Median CPT was higher in neurogenic and idiopathic DO than in the normal CMG group (11.3 and 9.0 vs. 2.8 mA, respectively; P < .05), as well as in patients with UUI (n = 19) compared with non-UUI patients (n = 34; 12.5 vs. 5.4 mA, respectively; P < .05). The proportion of UUI patients was significantly greater in the DO-positive groups than in the normal CMG group (P < .05). CPTs were not associated with bladder capacity at the first filling sensation (r = 0.11)., Conclusion: Hyposensitive C-fibers of the proximal urethra may contribute to the development of urodynamic DO as well as UUI in patients complaining of lower urinary tract symptoms., (© 2017 John Wiley & Sons Australia, Ltd.)

The pharmacological profile of ASP2205 fumarate (ASP2205), a novel 5-HT 2C receptor agonist, was evaluated in vitro and in vivo. ASP2205 showed potent and selective agonistic activity for the human 5-HT 2C receptor, with an EC 50 of 0.85 nM in the intracellular Ca 2+ mobilization assay. Rat 5-HT 2C receptor was also activated by ASP2205 with an EC 50 of 2.5 nM. Intraduodenal administration (i.d.) of ASP2205 (0.1-1 mg/kg) significantly elevated the leak point pressure (LPP) in anesthetized rats in a dose-dependent manner. This ASP2205 (0.3 mg/kg i.d.)-induced LPP elevation was inhibited by SB242084 (0.3 mg/kg i.v.), a selective 5-HT 2C receptor antagonist. Urethral closure responses induced by intravesical pressure loading in rats were enhanced by ASP2205 (0.3 mg/kg i.v.), which was abolished by pretreatment with SB242084 (0.3 mg/kg i.v.) and bilateral transection of the pudendal nerve. In contrast, ASP2205 (0.3 mg/kg i.v.) did not change the resting urethral pressure in rats. These results indicate that ASP2205 can enhance the pudendal nerve-mediated urethral closure reflex via the 5-HT 2C receptor, resulting in the prevention of involuntary urine loss., (Copyright © 2019 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Aims: To analyze, in female rats, the anatomical and histological features of the urethra and its relationship with the vagina and clitoris, and its innervation., Methods: Seventeen adult female Wistar rats were used. Gross anatomy and acetylcholinesterase (AchE) histochemistry were performed to describe the urethral features, adjacent structures, and innervation. The histomorphometric characteristics of the urethra were determined in transversal, longitudinal, or coronal sections stained with Masson's Trichrome., Results: The female rat urethra is not a homogeneous tubular organ. The pre-pelvic and pelvic regions are firmly attached to the vagina with belt-like striated fibers forming a urethra-vaginal complex. The bulbar regions have curved segments and a narrow lumen. The clitoral region is characterized by a urethra-clitoral complex surrounded by a vascular plexus. The lumen area and thickness of the urethral layers significantly varied between regions (P < 0.05). Innervation of the urethra arrives from the major pelvic ganglion, the dorsal nerve of the clitoris (DNC), and the motor branch of the sacral plexus (MBSP)., Conclusions: Differential tissular composition of the urethra may underlie urinary continence and voiding dysfunction through different physiological mechanisms. The urethra-vagina complex seems to be the main site controlling urinary continence through active muscular mechanisms, while the bulbar urethra provides passive mechanisms and the urethra-clitoris complex seems to be crucial for distal urethral closure by means of a periurethral vascular network., (© 2019 Wiley Periodicals, Inc.)

The aim of this study was to characterize the number, type and distribution of immunochemically identified nerves in epithelium and lamina propria of the female rat urethra. Urethras from female Sprague-Dawley rats (n = 12) were fixed, frozen and sectioned (8 μm). Standard immunohistochemical techniques were used to identify putative nerves using the following antibodies: calcitonin gene related peptide (cgrp), neuronal nitric oxide synthase (nNos), tyrosine hydroxylase (TH) and vesicular acetylcholine transporter (vacht). The number, distribution and characteristics of all immunoreactive (IR) structures adjacent to the urethral epithelium and in the lamina propria was assessed. In the bladder, few cgrp-IR and vacht-IR fibers were associated with the urothelium or suburothelium of the lateral wall. In contrast, large numbers of vacht-IR, nNos-IR and cgrp-IR fibers were found close to the epithelium and subepithelium of the bladder neck and throughout the urethra. The number of cgrp-IR fibers was significantly higher in the urethra in comparison with the bladder neck. A population of undescribed cgrp-IR cells associated with the bladder neck and proximal urethra has been characterized. Each of these cells appears to be associated with a nerve fiber. In the distal urethra, the number of peptidergic fibers penetrating the epithelium was significantly higher than the rest of the urethra. Clearly, this study has revealed a highly complex and heterogeneous network of putative afferent nerves fibers along the length of the urethra. These structural specializations need to be taken into account when probing the different functions of the urethra. Anat Rec, 302:201-214, 2019. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Aims: To assess the afferent innervation of various locations in the male lower urinary tract (LUT) using sensory evoked cortical potentials (SEPs)., Methods: Twelve healthy men (mean age: 29.6 ± 7.2 years, mean height: 1.8 ± 0.1 m) underwent repetitive slow (0.5 Hz/1 ms) and fast (3 Hz/0.2 ms) electrical stimulations of bladder (dome/trigone) and urethral (proximal/membranous/distal) locations with simultaneous cortical SEP recording (Cz-Fz). Latencies (ms) and peak-to-peak amplitudes (μV) for SEP components P1, N1, and P2 were analyzed. Tibial SEPs were assessed as methodological control. The reproducibility was investigated from between visits and inter-rater assessments using Bland-Altman plots. Statistical tests comprised analysis of variance (ANOVA), linear regressions, and paired t-tests. Values are given as mean ± standard deviation., Results: Typical LUTSEPs with P1, N1, and P2 components were successfully detected (100% responder rate) for slow but less successfully for fast stimulation. The slow stimulation provided reproducible LUTSEPs with position specific N1 latencies: dome 125.6 ± 21.3 ms, trigone 122.9 ± 20.5 ms, proximal- 116.1 ± 21.4 ms, membraneous- 118.8 ± 29.3 ms, and distal urethra 108.8 ± 17.8 ms. Despite good inter-rater agreement, latency variability between and within subjects was higher for LUTSEPs than for tibial SEPs. N1 latencies became shorter (P < 0.01) with increasing subject age for bladder dome and distal urethra stimulation., Conclusions: LUTSEPs can be successfully obtained for different LUT locations in men using slow electrical stimulation. Location specific differences in N1 latencies may indicate different local afferent innervation. Larger variability of LUTSEPs versus tibial SEPs may be related to the more challenging approach and afferent fibre access within the LUT. Further studies optimizing measurement and analysis approach are required., (© 2018 Wiley Periodicals, Inc.)

Aim: To study the contribution of urethral serotonin for the urethro-vesical crosstalk METHODS: Urethane-anesthetized female rats and TPH1 -/- mice underwent isovolumetric or urethral-opened cystometries during intravesical or intraurethral infusion of saline or serotonin solutions. Human and rat bladders and urethrae were immunoreacted against serotonin and neuronal markers. Serotonin concentration and TPH1 mRNA were determined in rat tissue by HPLC and qPCR., Results: In rats, under isovolumetric conditions, intraurethral serotonin infusion, but not saline, evoked bladder contractions. This was abolished by urethral anesthesia and by treatment with serotonin receptor antagonists. Serotonin infusion into the bladder had no effect. Under urethral-opened conditions, serotonin infusion reduced the frequency and increased the amplitude of reflex voiding contractions, compared to saline infusion. TPH1 -/- mice, under urethral-opened conditions, exhibited increased frequency and reduced amplitude of voiding contractions compared to WT. Serotonin concentration and TPH1 mRNA expression were higher in the urethra than in the bladder. Cells 5-HT + were found in the human and rat urethral epithelium, close to a sub-epithelial network of cholinergic and sensory fibers, but not in the bladder., Conclusions: Serotonin, produced and released by urethral cells activates an urethro-vesical pathway that enhances bladder reflex contractions., (© 2018 Wiley Periodicals, Inc.)

Voluntary urination ensures that waste is eliminated when safe and socially appropriate, even without a pressing urge. Uncontrolled urination, or incontinence, is a common problem with few treatment options. Normal urine release requires a small region in the brainstem known as Barrington's nucleus (Bar), but specific neurons that relax the urethral sphincter and enable urine flow are unknown. Here we identify a small subset of Bar neurons that control the urethral sphincter in mice. These excitatory neurons express estrogen receptor 1 (Bar ESR1 ), project to sphincter-relaxing interneurons in the spinal cord and are active during natural urination. Optogenetic stimulation of Bar ESR1 neurons rapidly initiates sphincter bursting and efficient voiding in anesthetized and behaving animals. Conversely, optogenetic and chemogenetic inhibition reveals their necessity in motivated urination behavior. The identification of these cells provides an expanded model for the control of urination and its dysfunction.

The aim of this study was to investigate the nerve supply to the structures in the male lesser pelvis and review its clinical relevance, especially during nerve sparing surgery. Three formalin-embalmed and 16 Thiel-embalmed male hemipelves were used. They were microdissected after repeated treatments with nitric acid diluted 1:10 with milliQ-water. The inferior hypogastric plexus (IHP) is a fan-like structure lateral from the rectum on the fascia of the levator ani. Nerves emerging from the proximal, solid part of the plexus follow the internal iliacal vessels and reach the prostate from dorsolateral. The innervation of the urethra and the corpora cavernosa derives from two origins: one follows the ejaculatory duct and the seminal vesicle, reaching the proximal urethra and the prostate from dorsal; the other follows the inferior vesical artery to reach the prostate from lateral, and then forms the neurovascular bundle on both sides of the prostatic fascia, spreading to the pelvic floor muscles and the corpora cavernosa along with the distal urethra. A connection between the two parts was demonstrated in approximately one third of the samples investigated. The nerve supply to the urinary bladder, the urethra, and the corpora cavernosa emerges mainly from the IHP. The innervation of the proximal urethra and its autonomic muscular structures has a dorsal (ejaculatory duct) and lateral (inferior vesical artery) origin. To maintain good erectile and continence function it is important to save both the dorsal and lateral neurovascular roots. Clin. Anat. 31:788-796, 2018. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Many studies examining the innervation of genitourinary structures focus on either afferent or efferent inputs, or on only one structure of the system. We aimed to clarify innervation of the bladder, external urethral sphincter (EUS) and clitoris. Retrograde dyes were injected into each end organ in female dogs. Spinal cord, mid-bladder, and spinal, caudal mesenteric, sympathetic trunk and pelvic plexus ganglia were examined for retrograde dye-labeled neurons. Neurons retrogradely labeled from the bladder were found primarily in L7-S2 spinal ganglia, spinal cord lateral zona intermedia at S1-S3 levels, caudal mesenteric ganglia, T11-L2 and L6-S2 sympathetic trunk ganglia, and pelvic plexus ganglia. The mid-bladder wall contained many intramural ganglia neurons labeled anterogradely from the pelvic nerve, and intramural ganglia retrogradely labeled from dye labeling sites surrounding ureteral orifices. Neurons retrogradely labeled from the clitoris were found only in L7 and S1 spinal ganglia, L7-S3 spinal cord lateral zona intermedia, and S1 sympathetic trunk ganglia, and caudal mesenteric ganglia. Neurons retrogradely labeled from the EUS were found in primarily at S1 and S2 spinal ganglia, spinal cord lamina IX at S1-S3, caudal mesenteric ganglia, and S1-S2 sympathetic trunk ganglia. Thus, direct inputs from the spinal cord to each end organ were identified, as well as multisynaptic circuits involving several ganglia, including intramural ganglia in the bladder wall. Knowledge of this complex circuitry of afferent and efferent inputs to genitourinary structures is necessary to understand and treat genitourinary dysfunction. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Aim: The morphologic mechanism of orgasmic sensation has not yet been understood. Taste roseas may be stimulated by fructose via pudendal nerves, which has not been studied yet., Methods: In this study, 27 male adult rabbits were used, which were divided into three groups: 5 as control; 5 as SHAM and 17 used as study group. We injected 0.2 cc of distilled water to SHAM and 0.2 cc of fructose solution to the study group of their urethral orifices, and examined the occurrence of penile erection. The relationship between erection and pudendal nerve ganglia and penile tissues was statistically compared., Results: In animals with high neuron density of pudendal ganglia, more erection phenomenon was observed than those animals with low neuron density. Interestingly, neuron density of pudendal ganglia was 9.243 ± 542 /mm 3 in hypoactive and was 5.980 ± 463 /mm 3 in non-active animals (p < 0.05)., Conclusions: The seminal fructose may stimulate taste roseas of the urethra and glans penis via pudendal nerves. The present study describes a new neuro-morpho-chemical mechanism of orgasmic sensation with its neurosurgical aspect.

To clarify the role of serotonin (5-HT) in the prevention of stress urinary incontinence (SUI) during sneezing, we investigated the effect of intraperitoneal application of p-chlorophenylalanine (PCPA; a serotonin synthesis inhibitor) and intravenous application of CP-809101 (a 5-HT 2C agonist) or LP44 (a 5-HT 7 agonist) using female rats, in which the neurally evoked continence reflex during sneezing was examined. Amplitudes of urethral pressure response during sneezing (A-URS), urethral baseline pressure (UBP) at the middle urethra, and sneeze-induced leak point pressure (S-LPP) were measured in normal female adult rats with or without drug administration. PCPA decreased A-URS by 35.1 cmH 2 O and UBP by 13.3 cmH 2 O compared with normal rats. In PCPA-administrated rats, CP-809101 increased A-URS by 24.1 cmH 2 O and UBP by 15.1 cmH 2 O, and LP44 also increased A-URS by 20.6 cmH 2 O and UBP by 11.4 cmH 2 O compared with rats treated with PCPA alone. SUI was observed with S-LPP of 40.1 cmH 2 O in PCPA-administrated rats, in which CP-809101 and LP44 increased S-LPP by 28.0 and 15.2 cmH 2 O, respectively, compared with rats treated with PCPA alone. The effects of CP-809101 and LP44 were antagonized by SB-242084 (a selective 5-HT 2C antagonist) and SB-269970 (a selective 5-HT 7 antagonist), respectively. These results indicate that activation of 5-HT receptors enhances the active urethral closure reflex during sneezing, at least in part via 5-HT 2C and 5-HT 7 receptors.

Spinal cord epidural stimulation (SCS) represents a form of neuromodulation for the management of spasticity and pain. This technology has recently emerged as a new approach for potentially augmenting locomotion and voiding function in humans and rodents after spinal cord injury. However, the effect of SCS on micturition has not been studied extensively. Here, SCS was first applied as a direct stimulus onto individual segmental levels of the lumbar spinal cord in rats to map evoked external urethral sphincter (EUS) electromyography activity and SCS-induced voiding contractions. SCS of L2-3 inhibited EUS tonic activity, and SCS on L3 (L3/SCS) inhibited EUS tonic activity and elicited EUS bursting. In contrast, SCS of L1 and L4-6 evoked EUS tonic contractions, which resembled the urethral guarding reflex during bladder storage. Next, the effects of a bilateral pelvic nerve crush (PNC) injury on urodynamic function were examined at 14 days post-operatively. The PNC injury resulted in decreased voiding efficiency and maximum intravesical pressure, whereas the post-voiding residual volume was increased, suggestive of an underactive bladder. Finally, L3/SCS was performed to induce a voiding contraction and enable voiding in rats with a PNC injury. Voiding efficiency was significantly increased, and the residual volume was decreased by L3/SCS in rats after the PNC injury. We conclude that L3/SCS may be used to induce micturition reflexes in a partially filled bladder, reduce urethral resistance, and augment bladder emptying after PNC injury., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Peptidergic nerve fibers provide important contributions to urethral function. Urethral innervation of female mice is not well documented., Aims: To determine the distribution and projection sites of nerve fibers immunoreactive for vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP), and neuropeptide Y (NPY) in the urethra of wild-type control mice and compare innervation characteristics between the proximal and distal urethra of young nullipara and older multipara mice. Furthermore, to identify the location and neurochemical coding of the spinal afferent nerve endings in the urethra, whose sensory neurons reside in lumbosacral dorsal root ganglia (DRG)., Methods: Multiple labeling immunohistochemistry of urethral sections of nulliparous (6-8 weeks old), and multiparous (9-12 months old) mice, and anterograde axonal tracing from L5-S2 (DRG) in vivo., Results: Abundant VIP-, CGRP-, SP-, and NPY-immunoreactive nerve fibers were identified in the adventitia, muscularis, and lamina propria of proximal and distal segments of the urethra. A proportion of fibers were closely associated with blood vessels, glands, and cells immunoreactive for PGP9.5. The epithelium contained abundant nerve fibers immunoreactive for CGRP and/or SP. Epithelial innervation was increased in the distal urethra of multipara mice. Abundant fibers were traced from L5-S2 DRG to all urethral regions., Conclusions: We present the first identification of spinal afferent endings in the urethra. Peptidergic nerve fibers, including multiple populations of spinal afferents, provide rich innervation of the female mouse urethra. The morphology of fibers in the epithelium and other regions suggests multiple nerve-cell interactions impacting on urethral function., (© 2017 Wiley Periodicals, Inc.)

Aim: The mechanisms underlying detection and transmission of sensory signals arising from visceral organs, such as the urethra, are poorly understood. Recently, specialized ACh-expressing cells embedded in the urethral epithelium have been proposed as chemosensory sentinels for detection of bacterial infection. Here, we examined the morphology and potential role in sensory signalling of a different class of specialized cells that express serotonin (5-HT), termed paraneurones., Methods: Urethrae, dorsal root ganglia neurones and spinal cords were isolated from adult female mice and used for immunohistochemistry and calcium imaging. Visceromotor reflexes (VMRs) were recorded in vivo., Results: We identified two morphologically distinct groups of 5-HT + cells with distinct regional locations: bipolar-like cells predominant in the mid-urethra and multipolar-like cells predominant in the proximal and distal urethra. Sensory nerve fibres positive for calcitonin gene-related peptide, substance P, and TRPV1 were found in close proximity to 5-HT + paraneurones. In vitro 5-HT (1 μm) stimulation of urethral primary afferent neurones, mimicking 5-HT release from paraneurones, elicited changes in the intracellular calcium concentration ([Ca 2+ ] i ) mediated by 5-HT 2 and 5-HT 3 receptors. Approximately 50% of 5-HT responding cells also responded to capsaicin with changes in the [Ca 2+ ] i . In vivo intra-urethral 5-HT application increased VMRs induced by urethral distention and activated pERK in lumbosacral spinal cord neurones., Conclusion: These morphological and functional findings provide insights into a putative paraneurone-neural network within the urethra that utilizes 5-HT signalling, presumably from paraneurones, to modulate primary sensory pathways carrying nociceptive and non-nociceptive (mechano-sensitive) information to the central nervous system., (© 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.)

This study tested the hypothesis that sacral neuromodulation, i.e., electrical stimulation of afferent axons in sacral spinal root, can block pudendal afferent inhibition of the micturition reflex. In α-chloralose-anesthetized cats, pudendal nerve stimulation (PNS) at 3-5 Hz was used to inhibit bladder reflex activity while the sacral S1 or S2 dorsal root was stimulated at 15-30 Hz to mimic sacral neuromodulation and to block the bladder inhibition induced by PNS. The intensity threshold (T) for PNS or S1/S2 dorsal root stimulation (DRS) to induce muscle twitch of anal sphincter or toe was determined. PNS at 1.5-2T intensity inhibited the micturition reflex by significantly ( P < 0.01) increasing bladder capacity to 150-170% of control capacity. S1 DRS alone at 1-1.5T intensity did not inhibit bladder activity but completely blocked PNS inhibition and restored bladder capacity to control level. At higher intensity (1.5-2T), S1 DRS alone inhibited the micturition reflex and significantly increased bladder capacity to 135.8 ± 6.6% of control capacity. However, the same higher intensity S1 DRS applied simultaneously with PNS, suppressed PNS inhibition and significantly ( P < 0.01) reduced bladder capacity to 126.8 ± 9.7% of control capacity. S2 DRS at both low (1T) and high (1.5-2T) intensity failed to significantly reduce PNS inhibition. PNS and S1 DRS did not change the amplitude and duration of micturition reflex contractions, but S2 DRS at 1.5-2T intensity doubled the duration of the contractions and increased bladder capacity. These results are important for understanding the mechanisms underlying sacral neuromodulation of nonobstructive urinary retention in Fowler's syndrome.

Objective: To measure the urodynamic effects of electrical co-stimulation of 2 individual sites in the proximal and distal urethra in persons with spinal cord injury (SCI). This work was motivated by preclinical findings that selective co-stimulation of the cranial urethral sensory nerve and the dorsal genital nerve, which innervate the proximal and distal portions of the urethra, respectively, increased reflex bladder activation and voiding efficiency., Materials and Methods: Electrical co-stimulation of urethral afferents was conducted in persons with chronic SCI during urodynamics. The effects of different frequencies of intraurethral stimulation at multiple urethral locations on bladder pressure and pelvic floor electromyographic activity were measured., Results: Electromyographic activity indicated that multiple reflex pathways were recruited through stimulation that contributed to bladder activation. The size of reflex bladder contractions evoked by stimulation was dependent on stimulation location or reflex activated and stimulation frequency., Conclusion: Pudendal nerve afferents are a promising target to restore lost bladder control, as stimulation with different frequencies may be used to treat urinary incontinence and increase continent volumes or to generate stimulation-evoked bladder contractions for on-demand voiding. This work identified that co-stimulation of multiple afferent reflex pathways can enhance activation of spinal circuits and may enable improved bladder emptying in SCI when stimulation of a single pathway is not sufficient., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The rat is a commonly used model for the study of lower urinary tract function before and after spinal cord injury. We have previously reported that in unanesthetized freely moving rats, although phasic external urethral sphincter (EUS) activity (bursting) is most common during micturition, productive voiding can occur in the absence of bursting, which differs from results seen in anesthetized or unanesthetized restrained animals. The purpose of the present study was to characterize EUS behavior in unanesthetized, freely moving rats before and after mid-thoracic (T8) or thoraco-lumbar (T13-L1) spinal transection to determine how EUS behavior after spinal cord injury differs from that seen in anesthetized or unanesthetized restrained rats. Several abnormalities became evident that were comparable after transection at either level, including the following: repetitive non-voiding EUS contractions; increased prevalence, intensity, and duration of EUS bursting; decreased rate of urine evacuation during bursting; increased void size and decreased number of daily voids; shorter inter-burst silent period and increased frequency of bursting; and loss of the direct linear relationships that are evident in intact animals between void size and bursting silent period. These data suggest that transection-induced delayed initiation of EUS bursting allows co-contraction of the bladder and the EUS that prevents or limits urine evacuation, resulting in a detrusor-sphincter dyssynergia-like phenomenon. In addition, the higher-than-normal frequency at which EUS bursting occurs after transection is associated with shorter silent periods during which urine typically flows, which interferes with voiding by slowing the rate of urine evacuation. That results were comparable after either transection suggests that the central pattern generator responsible for EUS bursting is located caudal to the L1 spinal segment.

CASE DESCRIPTION A 15-year-old spayed female mixed-breed dog was evaluated for a 7-week history of stranguria, pollakiuria, and intermittent urethral obstruction. CLINICAL FINDINGS On initial evaluation, the patient had persistent stranguria with lack of urine production; after multiple unsuccessful attempts to urinate, a large volume of urine was produced. Prior to voiding the large volume, the urinary bladder was not palpable during examination. Abdominal ultrasonography confirmed caudal displacement of the urinary bladder, and the urethra and trigone could not be located ultrasonographically. Positive-contrast cystourethrography and CT confirmed caudal displacement of the urinary bladder and also revealed trigonal invagination and urethral kinking; dysuria was attributed to these findings. TREATMENT AND OUTCOME Surgical repositioning of the lower urinary tract was performed. The urinary bladder was moved cranially and was fixed in place along the left lateral aspect of the body wall by cystopexy. After surgery, positive-contrast cystourethrography revealed a more cranial positioning of the urinary bladder and straightening of the urethra with no urethral kinking or trigonal invagination. Immediately after surgery, stranguria had resolved and the patient was able to void normally. Two years after surgery, the dog was reported to be urinating normally. CLINICAL RELEVANCE Surgical correction of caudal urinary bladder displacement with cystopexy led to resolution of trigonal invagination, urethral kinking, and urethral obstruction in the dog of the present report. Trigonal invagination and urethral kinking, although uncommon findings, should be considered as possible causes of dysuria in dogs.