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.