Nitrergic inhibition of sympathetic arteriolar constrictions in the female rodent urethra

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 Ca2+ 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 Ca2+ 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 Ca2+ 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.

Primary mucinous adenocarcinoma of the urethra: A clinicopathological analysis of 35 cases

AIM

Primary mucinous adenocarcinoma of the urethra represents an extremely rare entity. We sought to characterise further these tumours' clinicopathological, immunohistochemical and molecular features.

METHODS AND RESULTS

Thirty-five cases were identified, occurring in 18 males and 17 females. The mean age at diagnosis was 65 years (28-89 years). The main presentation symptoms were haematuria and urinary outlet obstruction. Microscopic analysis revealed that all 35 tumours have stromal dissection by mucin. Ten tumours showed villoglandular dysplasia, nine showed mucinous metaplasia, two showed adenocarcinoma in situ and four showed signet ring cell features. All tumours were immunopositive for CEA, while immunonegative for nuclear β-catenin; 19 of 23 (83%) expressed high molecular weight cytokeratin; 19 of 33 (58%) CK7; 28 of 34 (82%) CK20; 32 of 35 (91%) CDX2; 22 of 27 (81%) cadherin-17 (CDH-17); 26 of 29 (90%) SATB2; and one of 31 (3%) GATA3. Mismatch repair gene products, including MLH1, PMS2, MSH2 and MSH6, were immunopositive, suggesting the MSI-low genotype of mucinous adenocarcinoma of the urethra. BRAF V600E and ALK rearrangements were not detected. During the mean follow-up of 20 months, nine patients either developed distant metastasis or succumbed to the illness.

CONCLUSION

Our study, encompassing the most extensive series of 35 cases of primary mucinous adenocarcinoma of the urethra, provides crucial insights into its precise diagnosis, management and potential targeted treatments. We found a greater CDX2, SATB2 and CDH17 sensitivity in these urethral tumours for the first time, to our knowledge. We identified characteristics such as an MSI-low profile, non-V600E BRAF mutations and an absence of ALK rearrangements.

Isolated Male Epispadias Repair: Long-Term Outcomes

Isolated male epispadias is one of the most severe congenital genital anomalies that require surgical correction. The goals of the surgery are to reach good aesthetic and functional outcomes. The aim of this retrospective study was to analyze the long-term outcomes of surgical reconstruction of male epispadias. A total of 31 patients with a mean age of 17 years, who underwent surgical repair of isolated male epispadias from January 2000 to January 2015, were involved. The main outcome measures were defined as: aesthetic outcome, continence, postoperative complications, sexual function, and quality of life. The follow-up period ranged from 8 to 23 years, with an average of 14.4 years. Each patients underwent an average of 2.2 surgical procedures in this period. The most common postoperative complications were urethral fistula and residual curvature, in 22.6% and 12.9%, respectively. Satisfactory aesthetic outcome was reported in 71.4% of cases. The repair of male epispadias usually includes more than two procedures with satisfactory aesthetic outcome. Unsolved urinary incontinence remains a significant issue and has a high impact on the quality of life. Follow-up should be extended even after complete sexual maturity. Comprehensive long-term evaluation is necessary for proper treatment of isolated epispadias.

Anatomy of muscle connections in the male urethra and anorectal canal

OBJECTIVES

To elucidate the male urethral muscular structure and its relationship with the anorectal canal muscles, as establishing an anatomical foundation for urethral function will contribute to the prevention, diagnosis, and treatment of urinary incontinence.

METHODS

Eight male cadavers were used. Using a multifaceted approach, we performed macroscopic anatomical examination, histological analysis of wide-range serial sectioning and immunostaining, and three-dimensional (3D) reconstruction from histological sections. In the macroscopic anatomical examination, pelvic halves were meticulously dissected in layers from the medial aspect. In the histological analysis, the tissue, including the urethra and anorectal canal, was serially sectioned in the horizontal plane. The muscular structures were reconstructed and visualised in 3D.

RESULTS

The membranous portion of the urethra had three muscle layers: the longitudinal and circular muscles (smooth muscle) and the external urethral sphincter (skeletal muscle). The circular muscle was connected posteriorly to the longitudinal rectal muscle. The external urethral sphincter had a horseshoe shape, with its posterior ends continuing to the external anal sphincter, forming a 3D ring-like sphincter.

CONCLUSION

This study revealed skeletal and smooth muscle connections between the male urethra and anorectal canal, enabling urethral compression and closure. These anatomical muscle connections suggest a functional linkage between them.

Ultrasound for the evaluation of the urethra in pediatric patients

Urethral lesions in pediatric patients can be visualized using ultrasonography. Therefore, sonographers and physicians should be familiar with the technique.

Symmetric dimethylarginine correlates with the urea, creatinine, potassium, and clinical scores in feline urethral obstructions

BACKGROUND

A urethral obstruction (UO) is an emergency commonly observed in male cats, which can result in significant clinical and laboratory alterations, leading to complications and death.

OBJECTIVES

This study aimed to correlate symmetric dimethylarginine (SDMA) with the urea, creatinine, potassium, and bicarbonate levels in cats with UO. In addition, the correlation between clinical score and time of obstruction was evaluated.

METHODS

Thirty male cats were selected and allocated into a control group (CG, n = 13) and an obstruction group (OG, n = 17). The laboratory analyses were conducted before treatment (M0) and at different times after treatment (12 h [M12], 24 h [M24], and 48 h [M48]). Correlations were established between SDMA and creatinine, urea, bicarbonate, potassium, time of obstruction, and the clinical score.

RESULTS

A strong correlation (r > 0.6) was observed between SDMA and creatinine, urea, and potassium in the OG. Furthermore, there was substantial agreement (kappa value) between SDMA and creatinine at M24. A higher clinical score was associated with a longer time of obstruction. In the OG, at M48, the SDMA and creatinine levels were 50% and 41.2% higher, respectively.

CONCLUSIONS

A correlation was observed between SDMA and creatinine in obstructed cats, and significant agreement between these values was observed 24 h after the unblocking treatment. A correlation among SDMA, urea, and potassium was observed. Approximately 9% more cats continued to have elevated SDMA levels after 48 h of treatment compared to creatinine. This suggests a slightly lower sensitivity of the latter biomarker but does not exclude the possibility of congruent and normalized values after a longer evaluation period.

Age-Related Changes in Urethral Structure and Responds to Injury: Single-Cell Atlas of a Rat Model of Vaginal Birth Injury induced Stress Urinary Incontinence

Stress urinary incontinence (SUI) greatly affects the daily life of numerous women and is closely related to a history of vaginal delivery and aging. We used vaginal balloon dilation to simulate vaginal birth injury in young and middle-aged rats to produce a SUI animal model, and found that young rats restored urethral structure and function well, but not the middle-aged rats. To identify the characteristics of cellular and molecular changes in the urethral microenvironment during the repair process of SUI. We profiled 51,690 individual female rat urethra cells from 24 and 48 weeks old, with or without simulated vaginal birth injury. Cell interaction analysis showed that signal networks during repair process changed from resting to active, and aging altered the distribution but not the overall level of cell interaction in the repair process. Similarity analysis showed that muscle, fibroblasts, and immune cells underwent large transcriptional changes during aging and repair. In middle-aged rats, cell senescence occurs mainly in the superficial and middle urothelium due to cellular death and shedding, and the basal urothelium expressed many Senescence-Associated Secretory Phenotype (SASP) genes. In conclusion, we established the aging and vaginal balloon dilation (VBD) model of female urethral cell anatomy and the signal network landscape, which provides an insight into the normal or disordered urethra repair process and the scientific basis for developing novel SUI therapies.

An assessment of the relationship between urethral hypermobility as measured by ultrasound and the symptoms of stress urinary incontinence in primiparous women 9-18 months postpartum

Aim

The aim of the study was to estimate the relationship between bladder neck hypermobility as assessed by ultrasound and the occurrence of stress urinary incontinence as measured with the UDI-6 questionnaire in primiparous women 9-18 months postpartum.

Materials and methods

The study included 100 women 9-18 months after their first delivery, 19% of whom (study group) presented with urethral hypermobility. Ultrasound was used to determine the position and mobility of the bladder neck in order to assess the urethral hypermobility. A vector of ≥15 mm was defined as urethral hypermobility. Symptoms of stress urinary incontinence were assessed using question 3 of the UDI-6 questionnaire, in which the presence of symptoms was defined as a response rated from 1 to 4.

Results

We demonstrated a statistically significant relationship between urethral hypermobility and the symptoms of stress urinary incontinence with a statistical significance level of p <0.002.

Conclusions

Stress urinary incontinence is a common disorder in women, the pathophysiology of which is not fully understood. It has adverse effects on the quality of life, perception of one's own body and sexual function. Impairment of urethral fixation may play an important role in the pathophysiology of this common form of urinary incontinence. The study showed that urethral hypermobility, as assessed by ultrasound, contributes to stress urinary incontinence, as measured with the UDI-6 score. Although stress urinary incontinence is a multifactorial disorder influenced by anatomical changes and congenital anatomical features, it is easily diagnosed. Suburethral slings are an effective surgical technique; however, the incidence of postoperative voiding dysfunction or recurrent stress urinary incontinence is 10-20%. Therefore, an assessment of anatomical changes in stress urinary incontinence may help individualize the surgical strategy.

Dosimetric predictors for genitourinary toxicity in MR-guided stereotactic body radiation therapy (SBRT): Substructure with fraction-wise analysis

BACKGROUND

MR-guided radiation therapy (MRgRT) systems provide superior soft tissue contrast than x-ray based systems and can acquire real-time cine for treatment gating. These features allow treatment planning margins to be reduced, allowing for improved critical structure sparing and reduced treatment toxicity. Despite this improvement, genitourinary (GU) toxicity continues to affect many patients.

PURPOSE

(1) To identify dosimetric predictors, potentially in combination with clinical parameters, of GU toxicity following SBRT by leveraging MRgRT to accurately monitor daily dose, beyond predicted dose calculated during planning. (2) Improve awareness of toxicity-sensitive bladder substructures, specifically the trigone and urethra.

METHODS

Sixty-nine prostate cancer patients (NCT04384770 clinical trial) were treated on a ViewRay MRIdian MRgRT system, with 40 Gy prescribed to 95% of the PTV in over five fractions. Overall, 17 (24.6%) prostate patients reported acute grade 2 GU toxicity. The CTV, PTV, bladder, bladder wall, trigone, urethra, rectum, and rectal wall were contoured on the planning and daily treatment MRIs. Planning and daily treatment DVHs (0.1 Gy increments), organ doses (min, max, mean), and organ volumes were recorded. Daily dose was estimated by transferring the planning dose distributions to the daily MRI based on the daily setup alignment. Patients were partitioned into a training (55) and testing set (14). Dose features were pre-filtered using a t-test followed by maximum relevance minimum redundancy (MRMR) algorithm. Logistic regression was investigated with regularization to select dosimetric predictors. Specifically, two approaches: time-group least absolute shrinkage and selection (LASSO), and interactive grouped greedy algorithm (IGA) were investigated. Shared features across the planning and five treatment fractions were grouped to encourage consistency and stability. The conventional flat non-temporally grouped LASSO was also evaluated to provide a solid benchmark. After feature selection, a final logistic regression model was trained. Dosimetric regression models were compared to a clinical regression model with only clinical parameters (age, baseline IPSS, prostate gland size, ADT usage, etc.) and a hybrid model, combining the best performing dosimetric features with the clinical parameters, was evaluated. Final model performance was evaluated on the testing set using accuracy, sensitivity, and specificity determined by the optimal threshold of the training set.

RESULTS

IGA had the best testing performance with an accuracy/sensitivity/specificity of 0.79/0.67/0.82, selecting 12 groups covering the bladder (V19.8 Gy, V20.5 Gy), bladder wall (19.7 Gy), trigone (15.9, 18.2, 43.3 Gy), urethra (V41.4 Gy, V41.7 Gy), CTV (V41.9 Gy), rectum (V8.5 Gy), and rectal wall (1.2, 44.1 Gy) dose features. Absolute bladder V19.8 Gy and V20.5 Gy were the most important features, followed by relative trigone 15.9  and 18.2 Gy. Inclusion of clinical parameters in the hybrid model with IGA did not significantly change regression performance.

CONCLUSION

Overall, IGA feature selection resulted in the best GU toxicity prediction performance. This exploratory study demonstrated the feasibility of identification and analysis of dosimetric toxicity predictors with awareness to sensitive substructures and daily dose to potentially provide consistent and stable dosimetric metrics to guide treatment planning. Further patient accruement is warranted to further assess dosimetric predictor and perform validation.

Congenital Urethrocutaneous Fistula

ABSTRACT

Male congenital urethrocutaneous fistula is an extremely rare anomaly that is commonly associated with chordee or anorectal malformations. It is characterised by an abnormal urethral opening on the ventral aspect of the penis with well-formed distal urethra and meatus at the tip of the glans. The treatment is individualised according to the site of the fistula, associated anomalies and condition of the distal urethra. The principles of hypospadias surgery should be strictly followed.

Is the time right for a new initiative in mathematical modeling of the lower urinary tract? ICI-RS 2023

INTRODUCTION

A session at the 2023 International Consultation on Incontinence - Research Society (ICI-RS) held in Bristol, UK, focused on the question: Is the time right for a new initiative in mathematical modeling of the lower urinary tract (LUT)? The LUT is a complex system, comprising various synergetic components (i.e., bladder, urethra, neural control), each with its own dynamic functioning and high interindividual variability. This has led to a variety of different types of models for different purposes, each with advantages and disadvantages.

METHODS

When addressing the LUT, the modeling approach should be selected and sized according to the specific purpose, the targeted level of detail, and the available computational resources. Four areas were selected as examples to discuss: utility of nomograms in clinical use, value of fluid mechanical modeling, applications of models to simplify urodynamics, and utility of statistical models.

RESULTS

A brief literature review is provided along with discussion of the merits of different types of models for different applications. Remaining research questions are provided.

CONCLUSIONS

Inadequacies in current (outdated) models of the LUT as well as recent advances in computing power (e.g., quantum computing) and methods (e.g., artificial intelligence/machine learning), would dictate that the answer is an emphatic "Yes, the time is right for a new initiative in mathematical modeling of the LUT."

Advances in 3D bioprinting for urethral tissue reconstruction

Urethral conditions affect children and adults, increasing the risk of urinary tract infections, voiding and sexual dysfunction, and renal failure. Current tissue replacements differ from healthy urethral tissues in structural and mechanical characteristics, causing high risk of postoperative complications. 3D bioprinting can overcome these limitations through the creation of complex, layered architectures using materials with location-specific biomechanical properties. This review highlights prior research and describes the potential for these emerging technologies to address ongoing challenges in urethral tissue engineering, including biomechanical and structural mismatch, lack of individualized repair solutions, and inadequate wound healing and vascularization. In the future, the integration of 3D bioprinting technology with advanced biomaterials, computational modeling, and 3D imaging could transform personalized urethral surgical procedures.

Part 2]

Recent advances in the treatment of urethral strictures are associated with regenerative medicine and tissue engineering. Urethral reconstruction in some cases is a difficult task for urologists due to the insufficient amount of autologous tissue and relapses, which encourages clinicians to search for alternatives. The purpose of this work is to review the latest achievements in the use of regenerative technologies, biomaterials and cell therapy in urethroplasty. The second part of the literature review presents the prospects of using the stromal vascular fraction (SVF) of autologous adipose tissue during reconstructive operations on the urethra, especially considering the availability of these cells through lipoaspiration. Tissue engineering technologies are reflected, which offer their own solutions to problems and limitations of their use. The article also provides examples of experimental studies in which cell-free and cellular biomaterials were used for urethral reconstruction. We believe that the approach of using SVF and biomatrix can become a potentially safe and effective method of therapy associated with the acceleration of regeneration processes, and can be of great benefit to patients with urethral diseases in the future.

Melanoma of glans penis and urethra: A case report and systematic review of the literature of a rare and complex neoplasm

OBJECTIVE

To evaluate the features and prognosis of melanoma of glans penis and urethra, with the presentation of a significant case report.

MATERIALS AND METHODS

A systematic literature review was performed using the MEDLINE (PubMed) and Cochrane Libraries databases to identify all cases of male mucosal melanoma reported.

RESULTS

Two hundred fifty-two patients with male mucosal primary melanoma were found. Glans penis and fossa navicularis as primary site includes the 81.6% of all lesions considered. Median Breslow's depth is 2.1 mm, whereas nine in situ melanomas have been reported. At the diagnosis, the disease was at a non-localized stage in 21.4% for glans penis melanomas and 11.7% urethral lesions, respectively. The 2 and 5-year survival for glans melanoma is 62.5% and 38.4%; higher rates were observed in the 2012-2020 period (76% and 58.8%, respectively). Two-year survival for urethral melanomas is 66.7%, while 5-year survival is 12.5%. 22 patients survived over 5 years with a Breslow's depth reported always < 3.3 mm.

CONCLUSION

Melanoma of the glans penis and urethra is a rare neoplasm associated with a poor prognosis, however recent reports show higher survival rates. Surgery remains the mainstay for a localized disease. Taking into account the small number of cases reported, topical imiquimod seems to be a valid non-surgical alterative for melanoma in situ. The use of immunotherapy and targeted therapy should be considered only in an adjuvant setting according to the recommendations of cutaneous melanoma; however, additional clinical data on male mucosal melanoma are needed to draw definitive conclusions.

Severe penile torsion of 180 degrees in an adult patient: a uro-radiological case report

Penile torsion is the abnormal three-dimensional twisting of penile corporal bodies. It can be classified as mild, moderate, or severe, depending on the degree of torsion. Severe penile torsion (>90°) is a very rare condition, with an estimated incidence of 0.4%-1% among all penile torsion cases. Our patient was a 37-year-old man complaining of a 2-year history of lower urinary tract symptoms. These symptoms appeared after the patient sustained an iatrogenic injury during Foley catheter insertion. Physical examination incidentally revealed an obvious counterclockwise penile rotation of 180°. Several theories have been proposed to explain the etiology of penile torsion, including theories based on genetic factors, abnormal urethral development, and abnormal attachment of the dartos fascia to the skin. Penile torsion may be associated with other penile anomalies, including chordee, hypospadias, and epispadias; however, it is often detected as an isolated finding. Clinical examination is sufficient to confirm its diagnosis without the need for further imaging. While no standardized procedure has been indicated for all penile torsion cases, the severity of torsion and the presence of other anomalies determine the most suitable procedure. No reports on the imaging features of penile torsion (irrespective of the degree of torsion) are available. We present the first such report on the imaging features, including advanced magnetic resonance imaging findings, of a 180° penile torsion in an adult patient.

A sewing needle as a urethral foreign body: A case report and literature review

Foreign bodies in the urethra can occur by self-insertion, and patients often hide the symptoms due to embarrassment. Foreign bodies act as a focus for infection and abscess formation and result in perforation or fistula when not detected on time. Foreign bodies can display symptoms such as frequent urination, dysuria, hematuria, urethrorrhagia, and obstruction. This case discusses a self-inserted urethral sewing needle that was removed cystoscopically from an adolescent.

Pharmacotherapy of urethral stricture

ABSTRACT

Urethral stricture is characterized by the chronic formation of fibrous tissue, leading to the narrowing of the urethral lumen. Despite the availability of various endoscopic treatments, the recurrence of urethral strictures remains a common challenge. Postsurgery pharmacotherapy targeting tissue fibrosis is a promising option for reducing recurrence rates. Although drugs cannot replace surgery, they can be used as adjuvant therapies to improve outcomes. In this regard, many drugs have been proposed based on the mechanisms underlying the pathophysiology of urethral stricture. Ongoing studies have obtained substantial progress in treating urethral strictures, highlighting the potential for improved drug effectiveness through appropriate clinical delivery methods. Therefore, this review summarizes the latest researches on the mechanisms related to the pathophysiology of urethral stricture and the drugs to provide a theoretical basis and new insights for the effective use and future advancements in drug therapy for urethral stricture.

Effect of Perineal Urethrostomy on the Length of the Urethra of the Cat: A Cadaveric Study

Perineal urethrostomy in cats is indicated for urethral pathologies located distal to the bulbourethral glands. The description of the bulbourethral glands as the cranial landmark when performing a PU is based on the increased urethral diameter at this location, rather than on an anatomical limitation. This suggests that urethral pathologies cranial to the bulbourethral glands could potentially be treated with PU. At present, the extent to which the pelvic urethra can be mobilized is unknown. Characterization and quantification of the effect of PU on the pelvic urethra is required prior to attempting to define the location of the pelvic urethra, cranial to the bulbourethral glands, which can be exteriorized when performing a PU. Our aim was to characterize and quantify the effect of performing a PU on the location and length of the pelvic urethra.

METHODS

Ten male feline cadavers were used, and four markers were placed on the pelvic urethra via a ventral approach to the peritoneal and pelvic cavities. Two orthogonal radiographic views were acquired prior and subsequent to performing a PU. The distance of each marker to a predefined landmark/origin and the distances of the markers relative to each other were measured on all radiographs.

RESULTS

PU resulted in significant caudal translation of the markers relative to the predefined landmark on all radiographic views; however, PU did not result in a significant change in the distances between the markers.

CONCLUSIONS

Performing a PU results in caudal translation and minimal stretching of the mobilized pelvic urethra.

Circular Penile Skin Fasciocutaneous Ventral Onlay Flap Urethroplasty as an Alternative to Dorsal Onlay Buccal Mucosal Graft Urethroplasty in Complex Long-Segment Urethral Stricture: A Retrospective Study

Background A urethral stricture is the narrowing of the urethra that results in symptoms of obstruction. It can appear anywhere along the male urethra's length and has a variety of causes. The circular penile fasciocutaneous flap is employed in the successful single-stage reconstruction of long-segment complex anterior urethral strictures especially when the buccal mucosa is unavailable due to various reasons. The study has tried to identify a surgical technique that is more beneficial for the treatment of urethral strictures. Objective The objective of this research was to evaluate the outcomes of circular penile skin fasciocutaneous ventral onlay flap urethroplasty (group A) and the outcomes of dorsal onlay buccal mucosal graft urethroplasty (group B) in the management of complex long-segment penile urethral stricture. Methods In this retrospective study between December 2012 and December 2022, 60 patients with long-segment complex penile urethral stricture who underwent urethroplasty at our center were evaluated. Patients were divided into two groups according to the flap used (dorsal onlay buccal mucosal graft urethroplasty was used in 30 patients (group B), and circular penile fasciocutaneous flap (single stage) was used in 30 patients (group A)). The success rate and the mean peak flow rate were also calculated post-operation to identify the effectiveness of the surgical procedure used for urethral strictures. Results The study consisted of 60 patients in total. Group A's mean age was determined to be 51.2±16.2 years, whereas group B's mean age was determined to be 40.7±16.8 years. Preoperatively, the median urethral stricture length was 69 mm in group A (range: 20-100 mm) and 56 mm in group B (range: 30-110 mm). The intraoperative median length of the urethral stricture was 82 mm in group A (range: 20-120 mm) and 65 mm in group B (range: 40-140 mm). The mean peak flow rate was 30.9±6.8 mL/s in group A compared to 18.1±4.9 mL/s in group B. The success rate for group A was 89.7%, while the success rate for group B was 75.9%. Conclusion For complex long-segment urethral strictures, circular penile skin fasciocutaneous ventral onlay flap urethroplasty has a higher rate of success and fewer complications than dorsal onlay buccal mucosal graft urethroplasty. Along with success rate, it has a better mean peak flow rate and lower complications.

Extracellular matrix stiffness aggravates urethral stricture through Igfbp3/Smad pathway

Urethral stricture refers to the narrowing of the urethral lumen. While previous studies have hinted at inflammation as the initial driver of this condition, the reasons and mechanisms behind its progression remain largely unknown. By Atomic force microscope (AFM), researchers measured the matrix stiffness of urethra to be 5.23 ± 0.37 kPa for normal tissue and 41.59 ± 2.48 kPa for stricture urethral scar. Similar results were observed in rat urethral stricture models, where the matrix stiffness of normal urethra was 4.29 ± 0.82 kPa, while 32.94 ± 7.12 kPa for urethral stricture scar. Notably, the matrix stiffness increased in rat models over time. To further investigate, polyacrylamide hydrogels were employed to mimic different levels of stiffness for normal and stricture condition. Interestingly, higher matrix stiffness led to an increased fibroblast-to-myofibroblast transition (FMT) in rat urethral fibroblasts, indicated by enhanced expression of α-SMA and Collagen I, as well as changing in the morphology of fibroblast. RNA-seq analysis suggested that Igfbp3/Smads might regulate the progressive FMT in urethral stricture. In the experiment where the expression of Igfbp3 was inhibited, increasing matrix stiffness lose the potential to stimulate FMT progression and the expression of p-Smad2/3 decreased. On the contrary, overexpression of Igfbp3 promoted the process of FMT in urethral fibroblasts. In conclusion, Igfbp3/Smad pathway appeared to be involved in the progression of urethral fibrosis. This finding suggested that Igfbp3/Smad might be an promising target for future research and treatment in this filed.

Labeling PIEZO2 activity in the peripheral nervous system

Sensory neurons detect mechanical forces from both the environment and internal organs to regulate physiology. PIEZO2 is a mechanosensory ion channel critical for touch, proprioception, and bladder stretch sensation, yet its broad expression in sensory neurons suggests it has undiscovered physiological roles. To fully understand mechanosensory physiology, we must know where and when PIEZO2-expressing neurons detect force. The fluorescent styryl dye FM 1-43 was previously shown to label sensory neurons. Surprisingly, we find that the vast majority of FM 1-43 somatosensory neuron labeling in mice in vivo is dependent on PIEZO2 activity within the peripheral nerve endings. We illustrate the potential of FM 1-43 by using it to identify novel PIEZO2-expressing urethral neurons that are engaged by urination. These data reveal that FM 1-43 is a functional probe for mechanosensitivity via PIEZO2 activation in vivo and will facilitate the characterization of known and novel mechanosensory processes in multiple organ systems.

Unusual intravesical foreign bodies: a report of two cases

The introduction of a foreign body into the urethra is an exceptionally rare occurrence. It is often secondary, either to erotic curiosity or to psychiatric disorders. The symptomatology is multiple and the diagnosis is aided by radiologic imaging. The extraction is most often done by endoscopic. The management of these patients must be done systematically and will need psychiatric assessment. We report the case of two patients who inserted a foreign body into their urinary bladder. One was 22-year-old and the second was 20-year-old and all with no history of psychiatric disorders. The first accidentally inserted a pencil into the urethra while trying to flatten a vulvar papule. The second inserted a piece of broom through playful games. The foreign bodies were extracted endoscopically in both cases under rachianesthesia. The postoperative course was uneventful and both patients were referred to a psychiatric clinic for evaluation after discharge.

A Retrospective Clinico-Pathologic Study of 35 Dogs with Urethral Transitional Cell Carcinoma Undergoing Treatment

Chemotherapy and cyclooxygenase inhibitors (COXi) are primary treatments for canine urethral transitional cell carcinoma (uTCC), a tumor known for its aggressiveness and poor prognosis. This retrospective study aimed to evaluate the clinico-pathological characteristics, treatment modalities, and prognostic factors of 35 dogs with confirmed uTCC that received chemotherapy and COXi. Upon admission, urethral obstruction (UO) and urinary tract infection (UTI) were observed in seven (20%) dogs each. Gemcitabine (n = 20; 57.1%) and vinblastine (n = 10; 28.6%) were commonly used as first-line therapies, with four dogs also receiving radiation therapy. Based on RECIST, one (2.9%) dog achieved complete remission, nine (25.7%) partial remission, 20 (57.14%) showed stable disease, and five (14.3%) progressed. Among dogs with UO, six (85.7%) showed resolution or improvement after the first chemotherapy dose. The median time to local progression was 171 days (range: 107-235), and the median survival time was 333 days (range: 158-508). Dogs with UO upon admission had a higher risk of local progression, while both UO and UTI were associated with an increased risk of overall disease progression and tumor-related death. Additionally, gemcitabine significantly improved metastatic control. This study identified UO and UTI as negative prognostic factors, highlighting the importance of a multimodal approach in managing uTCC.

Development of a Wound-Healing Protocol for In Vitro Evaluation of Urothelial Cell Growth

Urethral healing is plagued by strictures, impacting quality of life and medical costs. Various growth factors (GFs) have shown promise as therapeutic approaches to improve healing, but there is no protocol for in vitro comparison between GFs. This study focuses the development of a biomimetic in vitro urothelial healing assay designed to mimic early in vivo healing, followed by an evaluation of urothelial cell growth in response to GFs.

METHODS

Wound-healing assays were developed with human urothelial cells and used to compared six GFs (EGF, FGF-2, IGF-1, PDGF, TGF-β1, and VEGF) at three concentrations (1 ng/mL, 10 ng/mL, and 100 ng/mL) over a 48 h period. A commercial GF-containing medium (EGF, TGF-α, KGF, and Extract P) and a GF-free medium were used as controls.

RESULTS

There was a statistically significant increase in cell growth for IGF-1 at 10 and 100 ng/mL compared to both controls (p < 0.05). There was a statistically significant increase in cell growth for EGF at all concentrations compared to the GF-free medium control (p < 0.05).

CONCLUSION

This study shows the development of a clinically relevant wound-healing assay to evaluate urothelial cell growth. It is the first to compare GFs for future use in reconstructive techniques to improve urethral healing.

A long non-coding RNA Leat1 mediates the hormone responsiveness of EfnB2 during male urogenital development

The novel long non-coding RNA (lncRNA) Leat1 is extraordinarily conserved in both its location (syntenic with EfnB2, an essential gene in anogenital patterning) and sequence. Here we show that Leat1 is upregulated following the testosterone surge from the developing testis and directly interacts with EfnB2, positively regulating its expression. Leat1 expression is suppressed by estrogen, which in turn suppresses the expression of EfnB2. Moreover, the loss of Leat1 leads to reduced EfnB2, resulting in a severe hypospadias phenotype. The human LEAT1 gene is also co-expressed with EFNB2 in the developing human penis suggesting a conserved function for this gene in urethral closure. Together our data identify Leat1 as a novel molecular regulator of urethral closure and implicate it as a target of endocrine disruption in the etiology of hypospadias.

First in Human Subjects Testing of the UroMonitor: A Catheter-free Wireless Ambulatory Bladder Pressure Monitor

PURPOSE

Urodynamics is the standard method of diagnosing bladder dysfunction, but involves catheters and retrograde bladder filling. With these artificial conditions, urodynamics cannot always reproduce patient complaints. We have developed a wireless, catheter-free intravesical pressure sensor, the UroMonitor, which enables catheter-free telemetric ambulatory bladder monitoring. The purpose of this study was twofold: to evaluate accuracy of UroMonitor pressure data, and assess safety and feasibility of use in humans.

MATERIALS AND METHODS

Eleven adult female patients undergoing urodynamics for overactive bladder symptoms were enrolled. After baseline urodynamics, the UroMonitor was transurethrally inserted into the bladder and position was confirmed cystoscopically. A second urodynamics was then performed with the UroMonitor simultaneously transmitting bladder pressure. Following removal of urodynamics catheters, the UroMonitor transmitted bladder pressure during ambulation and voiding in private. Visual analogue pain scales (0-5) were used to assess patient discomfort.

RESULTS

The UroMonitor did not significantly alter capacity, sensation, or flow during urodynamics. The UroMonitor was also easily inserted and removed in all subjects. The UroMonitor reproduced bladder pressure, capturing 98% (85/87) of voiding and nonvoiding urodynamic events. All subjects voided with only the UroMonitor in place with low post-void residual volume. Median ambulatory pain score with the UroMonitor was rated 0 (0-2). There were no post-procedural infections or changes to voiding behavior.

CONCLUSIONS

The UroMonitor is the first device to enable catheter-free telemetric ambulatory bladder pressure monitoring in humans. The UroMonitor appears safe and well tolerated, does not impede lower urinary tract function, and can reliably identify bladder events compared to urodynamics.

Wound healing responses of urinary extravasation after urethral injury

The post-surgical fluid leakage from the tubular tissues is a critical symptom after gastrointestinal or urinary tract surgeries. Elucidating the mechanism for such abnormalities is vital in surgical and medical science. The exposure of the fluid such as peritonitis due to urinary or gastrointestinal perforation has been reported to induce severe inflammation to the surrounding tissue. However, there have been no reports for the tissue responses by fluid extravasation and assessment of post-surgical and injury complication processes is therefore vital. The current model mouse study aims to investigate the effect of the urinary extravasation of the urethral injuries. Analyses on the urinary extravasation affecting both urethral mesenchyme and epithelium and the resultant spongio-fibrosis/urethral stricture were performed. The urine was injected from the lumen of urethra exposing the surrounding mesenchyme after the injury. The wound healing responses with urinary extravasation were shown as severe edematous mesenchymal lesions with the narrow urethral lumen. The epithelial cell proliferation was significantly increased in the wide layers. The mesenchymal spongio-fibrosis was induced by urethral injury with subsequent extravasation. The current report thus offers a novel research tool for surgical sciences on the urinary tract.

Laparoscopic extraction of a urethral self-inflicted needle from pelvis in a boy: a case report

Introduction

Self-insertion of foreign bodies in the urethra is an infrequent occurrence in children, and their management aims to minimize urethral morbidity. Endoscopic removal presents a significant challenge, particularly in boys. Currently, there are few reports on laparoscopic management of urethral foreign bodies that have migrated to the pelvic cavity.

Case description

An 11-year-old boy presented to the emergency department with complaints of increased frequency of micturition and dysuria. A sharp sewing needle was discovered lodged in the posterior urethra mucosa during cystoscopy. Attempts to remove the needle using an endoscopic grasping forceps were unsuccessful due to the forceps' weak biting power. During a digital rectal examination, the needle migrated into the pelvic region, wedged between the prostatic urethra and the rectal ampulla. After careful inspection of the peritoneal reflection over the fundus of the bladder, the needle was identified and successfully removed through laparoscopy without any complications. Psychiatric counseling was advised for this patient, who was in good condition during an 8-week follow-up.

Conclusions

Our case demonstrates the first recorded use of laparoscopy to remove a self-inserted urethral needle that had migrated into the pelvic region, after failed attempts at endoscopic extraction. Future cases may benefit from considering laparoscopic interventions for similar circumstances.

Urinary flow through urethras with a rough lumen

AIMS

This study investigates how lumen roughness and urethral length influence urinary flow speed.

METHODS

We used micro-computed tomography scans to measure the lumen roughness and dimensions for rabbits, cats, and pigs. We designed and fabricated three-dimensional-printed urethra mimics of varying roughness and length to perform flow experiments. We also developed a corresponding mathematical model to rationalize the observed flow speed.

RESULTS

We update the previously reported relationship between body mass and urethra length and diameter, now including 41 measurements for urethra length and 10 measurements for diameter. We report the relationship between lumen diameter and roughness as a function of position down the urethra for rabbits, cats, and pigs. The time course of urinary speed from our mimics is reported, as well as the average speed as a function of urethra length.

CONCLUSIONS

Based on the behavior of our mimics, we conclude that the lumen roughness in mammals reduces flow speed by up to 25% compared to smooth urethras. Urine flows fastest when the urethra length exceeds 25 times its diameter. Longer urethras do not drain faster due to viscous effects counteracting the additional gravitational head. However, flows with our urethra mimics are still 6 times faster than those observed in nature, suggesting that further work is needed to understand flow resistance in the urethra.

Sexual behavior shapes male genitourinary microbiome composition

The origin, composition, and significance of the distal male urethral microbiome are unclear, but vaginal microbiome dysbiosis is linked to new sex partners and several urogynecological syndromes. We characterized 110 urethral specimens from men without urethral symptoms, infections, or inflammation using shotgun metagenomics. Most urethral specimens contain characteristic lactic acid bacteria and Corynebacterium spp. In contrast, several bacteria associated with vaginal dysbiosis were present only in specimens from men who reported vaginal intercourse. Sexual behavior, but not other evaluated behavioral, demographic, or clinical variables, strongly associated with inter-specimen variance in urethral microbiome composition. Thus, the male urethra supports a simple core microbiome that is established independent of sexual exposures but can be re-shaped by vaginal sex. Overall, the results suggest that urogenital microbiology and sexual behavior are inexorably intertwined, and show that the male urethra harbors female urogenital pathobionts.

Prostate MRI for Improving Personalized Risk Prediction of Incontinence and Surgical Planning: The Role of Membranous Urethral Length Measurements and the Use of 3D Models

Prostate MRI has an important role in prostate cancer diagnosis and treatment, including detection, the targeting of prostate biopsies, staging and guiding radiotherapy and active surveillance. However, there are other ''less well-known'' applications which are being studied and frequently used in our highly specialized medical center. In this review, we focus on two research topics that lie within the expertise of this study group: (1) anatomical parameters predicting the risk of urinary incontinence after radical prostatectomy, allowing more personalized shared decision-making, with special emphasis on the membranous urethral length (MUL); (2) the use of three-dimensional models to help the surgical planning. These models may be used for training, patient counselling, personalized estimation of nerve sparing and extracapsular extension and may help to achieve negative surgical margins and undetectable postoperative PSA values.

Possible Use of a Safety-Valve with a Foley Catheter During Catheterisation of Male Spinal Cord Injury Patients for Prevention of Urethral Trauma Caused by Inflation of the Catheter Balloon in the Urethra

We used a safety-valve (Trans-Urethral Catheterisation Safety Valve, Class Medical, Limerick, Ireland) to prevent urethral trauma due to inflation of the anchoring balloon in the urethra during catheterisation of male spinal cord injury patients in a spinal unit. The safety-valve is attached to the balloon channel of a Foley catheter. If the balloon is inflated when it is in the urethra, the pressure valve is activated. Any fluid pushed into the balloon channel leaks out and balloon inflation stops, indicating that the balloon is not inside the bladder. The safety-valve was used in 44 catheterisations. There was leakage of water during three catheterisations. In the first case, the health professional did not inflate and deflate the balloon prior to its use. This "pre-valve inflation" step overcomes the baseline resistance pressure of the balloon and prevents fluid leaking from the valve when the catheter is in the correct position. In the second instance, the valve was found to be defective. In the third case, the catheter had been misplaced; it was removed and repositioned; there was no leakage of water during inflation of the balloon. In one out of 44 catheterisations, the catheter had been misplaced; leakage of water from the safety-valve stopped inflation of the balloon and prevented iatrogenic urethral trauma. The safety-valve may be used during catheterisation of male patients in the spinal unit to prevent urethral trauma caused by inflation of the balloon of Foley catheter in the urethra. However, health professionals should remember the few shortcomings of the catheter safety-valve.

Determining the outcomes of urethral construction in phalloplasty

OBJECTIVE

To evaluate the surgical and functional outcomes of urethral reconstruction associated with phalloplasty, depending on the surgical techniques and patient history.

MATERIALS AND METHODS

We conducted a single-centre retrospective study including 89 patients who underwent phalloplasty with urethral reconstruction between 2007 and 2018. Patients included were trans-male patients undergoing gender-affirming surgery and cis-male patients undergoing penile reconstruction after trauma, congenital malformation, or cancer. Urethral reconstructions were performed by free flap or skin graft (total or thin). Secondary urethroplasty may include direct vision urethrotomy, excision-anastomosis, or augmentation urethroplasty (skin graft, buccal mucosa graft). Patient demographics, medical history, peri- and postoperative data were collected from patient files. Functional results were evaluated using individual questionnaires.

RESULTS

The mean (±sd) follow-up duration was 5.5 (±3.7) years. No significant difference was found for total urethral complication rate (fistula and/or stricture) according to type of urethral construction (70.9% for free flap urethra vs 73.5% for skin graft urethra; P = 0.911), nor according to the patient's grounds for surgery (72.7% for cis-male vs 71.8% for trans-male patients; P = 1). A total of 36 patients (40.5%) answered the functional questionnaire, of whom 80.5% reported usually voiding while standing and 47.5% were comfortable with urinating in public.

CONCLUSIONS

Urethral construction in phalloplasty is associated with a high complication and revision rate regardless of the type of urethral reconstruction. Voiding in a standing position is generally possible but should not conceal feeble functional results.

Anatomic relationships of the clitoral body, bulbs of the vestibule, and urethra

BACKGROUND

Although recent studies have enhanced our understanding of the anatomy of the clitoris and its somatic innervation, less emphasis has been placed on the anatomic relationships of the clitoris to its surrounding structures.

OBJECTIVE

This study aimed to further characterize the gross and histologic relationships of the clitoris, vestibular bulbs, and urethra.

STUDY DESIGN

Detailed dissections were performed in 30 unembalmed female cadavers. In 23 specimens, gross dissections were performed, and relationships of the clitoris, vestibular bulbs, and urethra were annotated. Histologic evaluation was performed in 7 specimens, in which tissues were harvested within 24 hours from death. Descriptive statistics were used for data analyses.

RESULTS

The clitoral body consisted of 2 components, the proximal body and the distal body. The distal body was oriented ≤90° from the proximal body, forming an outer and inner angle at the inflection point. A "septumlike" arrangement of fibroconnective and vascular tissues was noted between the inner angle of the clitoral body and the urethra. Neurovascular bundles coursed laterally along the clitoral body and the surfaces of the crura and vestibular bulbs. The vestibular bulbs approached each other over the ventral surface of the urethra, at the commissure of the vestibular bulbs. Each bulb was separated by fibrous tissue and did not merge along the midline. The vestibular bulbs approximated the clitoral body, but the erectile tissue of the vestibular bulbs was separated from the corpora cavernosa of the clitoral body by the tunica albuginea. The erectile tissue of the vestibular bulbs abutted the ventrolateral walls of the urethra but was separated from the urethral mucosa by an indiscrete layer of erectilelike tissue with dense stroma.

CONCLUSION

This study provided gross and histological confirmation of the relationships of the clitoris, vestibular bulbs, and urethra. Detailed knowledge of the anatomy of the clitoris is crucial for reducing surgical complications associated with periclitoral and distal urethral procedures, which may adversely affect sexual arousal and sexual function.

Combining Transurethral Resection of Fibrous Tissue and Temporary Urethral Stent Insertion Is an Optimal Strategy for Minimally Invasive Treatment of Recurrent and Long Urethral Strictures

This study investigated the optimal strategy for the treatment of chronic recurrent urethral strictures longer than 3 cm, using a temporary urethral stent. Between September 2011 and June 2021, 36 patients with chronic bulbomembranous urethral strictures underwent temporary urethral stent placement. Retrievable self-expandable polymer-coated bulbar urethral stents (BUSs) were placed in 21 patients (group A), and thermo-expandable nickel-titanium alloy urethral stents were placed in 15 patients (group M). Each group was subdivided into those with and without transurethral resection (TUR) of fibrotic scar tissue. The urethral patency rates at 1 year after stent removal were compared between the groups. The patients in group A showed a higher urethral patency maintenance rate at 1 year after stent removal than those in group M (81.0% vs. 40.0%, log rank test p = 0.012). Analysis of subgroups in which TUR was performed due to severe fibrotic scar, showed that the patients in group A showed a significantly higher patency rate than patients in group M (90.9% vs. 44.4%, log rank test p = 0.028). In the treatment of chronic urethral strictures with a long fibrotic scar, temporary BUS combined with TUR of fibrotic tissue seems to be the optimal minimally invasive treatment strategy.

Correlation between trans-perineal ultra-sonography, urodynamic study and physical examination findings in female patients with stress urinary incontinence: Single center experience

BACKGROUND

To evaluate the efficacy of Trans-perineal ultrasonography (TPUS) in assessment of stress urinary incontinence (SUI) and its correlation with urodynamic study (UDS) and physical examination in women with SUI.

METHODS

The study enrolled a total of 91 females including 66 women with SUI and 25 women with no history of urinary incontinence as control group. The α and β angles (anterior urethral and posterior urethro-vesical angle respectively) were recorded both at rest and at straining, using TPUS. The differences between these angles at rest and during the straining were considered as the rotational angles (Rα and Rβ). Urethral length and caliber, bladder neck funneling, and pubo-urethral distance were measured as well.

RESULTS

The mean (SD) α angle at rest of the SUI group was 49.0 (±14.3)°, which was higher than the same parameter in the control group: 47.6 (±9.7)°. Similarly, the α angle at straining was significantly higher in the SUI group versus the control group, 61.0 (±15.4)° versus 55.8 (±15.8)°. The mean (SD) β angle in the SUI group at rest was 124.6 (±28.5)°, which was significantly higher than that of the control group at 114.0 (±22.5)°. The mean (SD) β angle at straining was also higher in the SUI group versus the control group: 151.8 (±90.6) versus 136.0 (±27)°. Moreover, higher Rα and Rβ angels were documented in the SUI group.

CONCLUSION

Our data suggest that TPUS can be considered as a non-invasive, easily conducted, and accurate modality in early diagnosis of female SUI. It may reduce the need for performing relatively invasive UDS. However, the role of TPUS in assessment of SUI severity remains to be studied probably with a larger sample size.

Lower urinary tract injuries in patients with pelvic fractures at a level 1 trauma center - an 11-year experience

BACKGROUND

Urological injuries can occur in patients with pelvic fractures. Treatment recommendations lack solid evidence and is often pragmatical. There is a continuous need to describe short- and long-term morbidity following lower urinary tract trauma.

OBJECTIVE

To describe incidence, diagnosis, treatment, and morbidity following lower urinary tract injuries in pelvic fractures.

PATIENTS AND METHODS

Retrospective study including patients with pelvic, including acetabular, fractures admitted to a Level I Trauma Centre covering 2.8 million citizens between 2009 and 2020. Outcome measurements comprised primary management, treatment trajectory, short- and long-term complications and outcomes.

RESULTS

A total of 39 (5%) patients with pelvic fractures had concomitant urethral and/or bladder injuries, and one patient with an acetabular fracture had a bladder injury. The management of urethral injuries varied vastly, and complete urethral ruptures were associated with severe short- and long-term complications. Only one patient with bladder injury experienced severe long-term complications.

CONCLUSIONS

Management of lower urinary tract injuries in patients with major pelvic fractures remains a major challenge. Special attention should be focused on urethral injuries where we uncovered an unsystematic treatment and follow-up even in a highly experienced centre, although this is also attributed to complicated multidisciplinary patient trajectories. There is a continuous need to reduce long-term complications following urethral trauma which should be addressed in multicenter studies.

Outcomes and predictive factors for re-stricture with urethroplasty methods for anterior urethra stricture

OBJECTIVES

We wished to compare the treatment success of urethroplasty methods (EPA and BMG) used for anterior urethra stricture after unsuccessful internal urethrotomy.

METHODS

A total of 85 and 51 patients, respectively, who underwent excision and primary anastomosis (EPA) and buccal mucosal graft (BMG) urethroplasty due to recurrent strictures after direct vision internal urethrotomy (DVIU) were evaluated retrospectively. On the uroflowmetry test, >15 ml/s urine flow and residual urine (PVR) below 50 ml were determined as success criteria. Cox regression analysis investigated the probable predictive factors for surgery success. Kaplan-Meier analysis assessed stricture free survival after redo-urethroplasty.

RESULTS

After surgery, EPA and BMG patients were followed for 31.9 ± 9.8 (4-40) and 30.7 ± 10.3 (4-40) months. At the end of this follow-up duration, success was obtained for 71 (83.5%) and 44 (86.3%) patients. Mean re-stricture times were 13.9 ± 6.0 (4-19) and 10.2 ± 5.1 (4-26) months. Most re-strictures had penile location (10 (71.5%) and 7 (100%)). After one session of DVIU, there was 100% success in both groups, but after >3 sessions of DVIU, success fell to 70.3% and 78.3% in the groups respectively. Patients with high numbers of DVIU sessions had longer durations for urethroplasty surgery. Apart from complications related to the donor field in the oral region with BMG and four patients who developed fistula (7.8%), complications were similar in both groups.

CONCLUSIONS

In this series of cases, it was not possible to identify which of the techniques employed provides the best result or predictive factors for stenosis recurrence after correction procedures for anterior urethral stenosis.

"Urethral-Sparing" Robotic Radical Prostatectomy: Critical Appraisal of the Safety of the Technique Based on the Histologic Characteristics of the Prostatic Urethra

BACKGROUND

The prostatic urethra (PU) is conventionally resected during robot-assisted radical prostatectomy (RALP). Recent studies demonstrated the feasibility of the extended PU preservation (EPUP).

AIMS

To describe the histologic features of the PU.

METHODS

The PU was evaluated using cystoprostatectomy and RALP specimens. Cases of PU infiltration by prostate cancer or distortion by benign hyperplastic nodules were excluded. The thickness of the chorion and distance between the urothelium and prostate glands were measured. Prostate-specific antigen expression in the PU epithelium was evaluated with immunohistochemistry. Descriptive statistics were used.

RESULTS

Six specimens of PU were examined. Histologically, the following layers of the PU were observed: (1) urothelium with basal membrane, (2) chorion, and (3) prostatic peri-urethral fibromuscular tissue. The chorion measures between 0.2 and 0.4 mm. There is not a distinct urethral muscle layer, but rather muscular fibers that originate near the prostatic stroma and are distributed around the PU. This muscular tissue appears to be mainly represented in the basal and apical urethra, but not in the middle urethra. The mean distance between the chorion and prostatic glands is 1.74 mm, with significant differences between base of the prostate, middle urethral portion, and apex (2.5 vs. 1.49 vs. 1.23 mm, respectively). PSA-expressing cells are abundant in the PU epithelium, coexisting with urothelial cells.

CONCLUSIONS

The exiguity of thickness of the PU chorion, short distance from glandular tissue, and coexistence of PSA-expressing cells in the epithelium raise important concerns about the oncologic safety of EPUP.

Spinal Cord Injury Causes Marked Tissue Rearrangement in the Urethra-Experimental Study in the Rat

Traumatic spinal cord injury (SCI) results in the time-dependent development of urinary impairment due to neurogenic detrusor overactivity (NDO) and detrusor-sphincter-dyssynergia (DSD). This is known to be accompanied by massive changes in the bladder wall. It is presently less clear if the urethra wall also undergoes remodelling. To investigate this issue, female rats were submitted to complete spinal transection at the T8/T9 level and left to recover for 1 week and 4 weeks. To confirm the presence of SCI-induced NDO, bladder function was assessed by cystometry under urethane anesthesia before euthanasia. Spinal intact animals were used as controls. Urethras were collected and processed for further analysis. Following thoracic SCI, time-dependent changes in the urethra wall were observed. Histological assessment revealed marked urethral epithelium reorganization in response to SCI, as evidenced by an increase in epithelial thickness. At the muscular layer, SCI resulted in strong atrophy of the smooth muscle present in the urethral sphincter. Innervation was also affected, as evidenced by a pronounced decrease in the expression of markers of general innervation, particularly those present in sensory and sympathetic nerve fibres. The present data show an evident impact of SCI on the urethra, with significant histological rearrangement, accompanied by sensory and sympathetic denervation. It is likely that these changes will affect urethral function and contribute to SCI-induced urinary dysfunction, and they deserve further investigation.

Engineered human organ-specific urethra as a functional substitute

Urologic patients may be affected by pathologies requiring surgical reconstruction to re-establish a normal function. The lack of autologous tissues to reconstruct the urethra led clinicians toward new solutions, such as tissue engineering. Tridimensional tissues were produced and characterized from a clinical perspective. The balance was optimized between increasing the mechanical resistance of urethral-engineered tissue and preserving the urothelium's barrier function, essential to avoid urine extravasation and subsequent inflammation and fibrosis. The substitutes produced using a mix of vesical (VF) and dermal fibroblasts (DF) in either 90%:10% or 80%:20% showed mechanical resistance values comparable to human native bladder tissue while maintaining functionality. The presence of mature urothelium markers such as uroplakins and tight junctions were documented. All substitutes showed similar histological features except for the noticeable decrease in polysaccharide globules for the substitutes made with a higher proportion of DF. The degree of maturation evaluated with electron microscopy was positively correlated with the increased concentration of VF in the stroma. Substitutes produced with VF and at least 10% of DF showed sufficient mechanical resistance to withstand surgeon manipulation and high functionality, which may improve long-term patients' quality of life, representing a great future alternative to current treatments.

Evaluation of urethral thickness using ultrasonography in healthy small-breed dogs

Introduction

Urethral thickness measurements can be indicative of the pathological state of a patient; however to the best of our knowledge, no measurement reference range has been established in small-breed dogs. This study aimed to establish reference ranges for total urethral thickness and urethral wall thickness in healthy small-breed dogs; "urethral wall thickness" was assumed to be 1/2 of the "total urethral thickness."

Methods

Total urethral thickness was measured by ultrasonography in 240 healthy small-breed dogs. In both female and male dogs, the thickness was measured in the mid-sagittal plane. In female dogs, it was measured immediately before the pelvic bone. In male dogs, it was measured caudal to the prostate and cranial to the pelvic bone. The total urethral thickness we measured is the total thickness of the collapsed urethra, which is the sum of the thicknesses of the dorsal and ventral urethral wall.

Results

The mean value of total urethral thickness was 3.15 ± 0.83 mm (urethral wall thickness, 1.58 ± 0.41 mm) in 240 small-breed dogs. The total urethral thickness was significantly greater in male dogs than in female dogs (p < 0.001), even when compared among the same breeds (p < 0.05). The mean value of the total urethral thickness in females was 2.78 ± 0.60 mm (urethral wall thickness, 1.39 ± 0.30 mm), and 3.53 ± 0.86 mm (urethral wall thickness, 1.76 ± 0.43 mm) in males. There was very weak positive correlation between body weight (BW) and total urethral thickness (R2 = 0.109; β = 0.330; p < 0.001). Intraobserver reliability measured by intraclass correlation coefficient (ICC) was 0.986 (p < 0.001) and interobserver reliability measured by ICC was 0.966 (p < 0.001).

Discussion

This study described the differences in total urethral thickness between breeds, sexes, and sterilization status, and the correlation between BW and total urethral thickness. Furthermore, this is the first study to provide reference ranges of total urethral thickness and urethral wall thickness in small-breed dogs using ultrasonography, and is expected to be useful for urethral evaluation in veterinary diagnostic imaging.

Current status of stem cell treatments and innovative approaches for stress urinary incontinence

Stem cells are capable of self-renewal, differentiation, and the promotion of the release of chemokines and progenitor cells essential for tissue regeneration. Stem cells have the potential to develop into specialized cells if given the right conditions, to self-renew and maintain themselves, to generate a large number of new differentiated cells if injured, and to either generate new tissues or repair existing ones. In the last decade, it has become clear that treating lower urinary tract dysfunction with the patient's own adult stem cells is an effective, root-cause method. Regenerative medicine is predicated on the idea that a damaged rhabdosphincter can be repaired, leading to enhanced blood flow and improved function of the sphincter's exterior (striated) and internal (smooth) muscles. Stem cell therapy has the potential to cure stress urinary incontinence according to preclinical models. In contrast, stem cell treatment has not been licensed for routine clinical usage. This article reviews the current state of stem cell for stres urinary incontinence research and recommends future avenues to facilitate practical uses of this potential therapy modality.

Sources, Selection, and Microenvironmental Preconditioning of Cells for Urethral Tissue Engineering

Urethral stricture is a common urinary tract disorder in men that can be caused by iatrogenic causes, trauma, inflammation, or infection and often requires reconstructive surgery. The current therapeutic approach for complex urethral strictures usually involves reconstruction with autologous tissue from the oral mucosa. With the goal of overcoming the lack of sufficient autologous tissue and donor site morbidity, research over the past two decades has focused on cell-based tissue-engineered substitutes. While the main focus has been on autologous cells from the penile tissue, bladder, and oral cavity, stem cells from sources such as adipose tissue and urine are competing candidates for future urethral regeneration due to their ease of collection, high proliferative capacity, maturation potential, and paracrine function. This review addresses the sources, advantages, and limitations of cells for tissue engineering in the urethra and discusses recent approaches to improve cell survival, growth, and differentiation by mimicking the mechanical and biophysical properties of the extracellular environment.

Artificial Urinary Sphincter in a High-Risk Urethra: Transcorporal Gullwing Modification Description of the Technique

BACKGROUND

In this report, we describe a modification of transcorporal artificial urinary sphincter place ment known as Gullwing modification.

DESCRIPTION OF TECHNIQUE

Using a penoscrotal approach, bilateral corpora cavernosa flaps are harvested and sutured in the midline covering the lateral and ventral surfaces of the urethra. Transcorporal cuff placement provides dorsal reinforcement, thus having extra tissue buttressing all the circumference in cases of a fragile urethra due to previous urethral cuff erosion, urethroplasty, or pelvic radiotherapy.

PATIENT AND METHODS

After previous urethral cuff erosion, radiotherapy, and urethral reconstruction, our patient complained of severe stress urinary incontinence. Due to the high risk of urethral complications, we proceed to a transcorporal artificial sphincter placement with urethral reinforcement through a bilateral cavernosal flap.

RESULTS

The surgery was successfully completed, and after 6 weeks, sphincter was activated with satisfac tory results. Two years after surgery, his continence status is stable without complications.

CONCLUSION

Urethral complications associated with artificial urinary sphincter surgery remain a challenge for the reconstructive surgeon. Reinforcement of the ventral aspect of the urethra through corpora cavernosal flaps may reduce the likelihood of urethral erosion in high-risk cases.

Development of an ex-vivo porcine lower urinary tract model to evaluate the performance of urinary catheters

Intermittent catheterization is the gold standard method for bladder management in individuals with urinary retention and/or incontinence. It is therefore important to understand the performance of urinary catheters, especially on parameters associated to risks of developing urinary tract infections, and that may impact the quality of life for urinary catheter users. Examples of such parameters include, urine flowrate, occurrence of flow-stops, and residual urine left in the bladder after flow-stop. Reliable in-vitro and/or ex-vivo laboratory models represent a strong asset to assess the performance of urinary catheters, preceding and guiding in-vivo animal studies and/or human clinical studies. Existing laboratory models are generally simplified, covering only portions of the catheterization process, or poorly reflect clinical procedures. In this work, we developed an ex-vivo porcine lower urinary tract model that better reflects the catheterization procedure in humans and allows to investigate the performance of standard of care catheters. The performance of three standard of care catheters was investigated in the developed model showing significant differences in terms of flowrate. No differences were detected in terms of residual volume in the bladder at first flow-stop also when tuning the abdominal pressure to mimic a sitting down and standing up position. A newly discovered phenomenon named hammering was detected and measured. Lastly, mucosal suction was observed and measured in all standard of care catheters, raising the concern for microtrauma during catheterization and a need for new and improved urinary catheter designs. Results obtained with the ex-vivo model were compared to in-vivo studies, highlighting similar concerns.

Transurethral Renal Pelvic Denervation: A Feasibility Trial in Patients with Uncontrolled Hypertension

BACKGROUND

Endovascular renal denervation reduces blood pressure (BP). We explored an alternative approach to renal denervation using radiofrequency energy delivered across the renal pelvis utilizing the natural orifice of the urethra and the ureters.

METHODS

This open-label, single-arm feasibility study enrolled patients with uncontrolled hypertension despite antihypertensive drug therapy. The primary effectiveness endpoint was the change in ambulatory daytime systolic BP (SBP) 2 months following renal pelvic denervation.

RESULTS

The 18 patients (mean age 56±12 years) enrolled were taking an average of 2.7 antihypertensive drugs daily. Renal pelvic denervation reduced mean daytime SBP by 19.4 mm Hg (95% CI, -24.9 to -14.0, P<0.001) from its baseline of 148.4±8.7 mm Hg. Mean nighttime (-21.4 mm Hg [95% CI, -29.5 to -13.3]) and 24-hour (-20.3 mm Hg [95% CI, -26.2 to -14.5]) SBP each fell significantly (P<0.001) as did the corresponding diastolic BPs (P<0.001). Office SBP decreased from 156.5±12.3 mm Hg to 22.4 mm Hg (95% CI, -31.5 to -13.3, P<0.001) by 2 months. Office SBP decreased over time (P=0.001 by linear trend test) starting by day 1 with a decrease of 8.3 mm Hg (95% CI, -16.9 to 0.3, P=0.057). There were no serious adverse events. Mild transitory back pain followed the procedure. Serum creatinine decreased by 0.08 mg/dL (P=0.02) and estimated glomerular filtration rate increased by 7.2 mL/min/1.73m² (P=0.03) 2 months following ablation procedure.

CONCLUSIONS

Based on these initial findings, a well-powered, sham-controlled trial of renal pelvic denervation to more fully establish its safety and effectiveness is now justified in patients with uncontrolled hypertension despite drug therapy.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05440513.

M inverted V glansplasty: an update on technique and outcomes 30 years later

Distal hypospadias is a common congenital urology anomaly for which numerous corrective procedures have been described. Over the last 40 years, the gold-standard operative technique for distal hypospadias has switched from the meatal advancement and glanuloplasty (MAGPI) procedure to the tubularized incised plate (TIP) urethroplasty. A modification to the MAGPI procedure, first described 30 years ago, is the M inverted V (MIV) glansplasty, which improved upon the MAGPI procedure to reduce instances of meatal retraction. The MIV glansplasty is unique compared to many commonly used procedures as it does not require a formal urethroplasty or incorporation of a dartos flap, and it does not always necessitate as extensive mobilization of the glans wings. We describe our updated technique and outcomes of the MIV glansplasty and delineate situations where the MIV is best employed.

A Prospective Multi-Institutional Evaluation of Iatrogenic Urethral Catheterization Injuries

OBJECTIVES

To perform a multi-institutional investigation of incidence and outcomes of urethral trauma sustained during attempted catheterization.

PATIENTS & METHODS

A prospective, multi-center study was conducted over a designated 3-4 month period, incorporating seven academic hospitals across the UK and Ireland. Cases of urethral trauma arising from attempted catheterization were recorded. Variables included sites of injury, management strategies and short-term clinical outcomes. The catheterization injury rate was calculated based on the estimated total number of catheterizations occurring in each center per month. Anonymised data were collated, evaluated and described.

RESULTS

Sixty-six urethral catheterization injuries were identified (7 centers; mean 3.43 months). The mean injury rate was 6.2 ± 3.8 per 1000 catheterizations (3.18-14.42/1000). All injured patients were male, mean age 76.1 ± 13.1 years. Urethral catheterization injuries occurred in multiple hospital/community settings, most commonly Emergency Departments (36%) and medical/surgical wards (30%). Urological intervention was required in 94.7% (54/57), with suprapubic catheterization required in 12.3% (n = 7). More than half of patients (55.56%) were discharged with an urethral catheter, fully or partially attributable to the urethral catheter injury. At least one further healthcare encounter on account of the injury was required for 90% of patients post-discharge.

CONCLUSIONS

This is the largest study of its kind and confirms that iatrogenic urethral trauma is a recurring medical error seen universally across institutions, healthcare systems and countries. In addition, urethral catheter injury results in significant patient morbidity with a substantial financial burden to healthcare services. Future innovation to improve the safety of urinary catheterization is warranted.