Collagenase Clostridium histolyticum (Xiaflex) for the Treatment of Urethral Stricture Disease in a Rat Model of Urethral Fibrosis

Standardizing urethral stricture models in rats: a comprehensive study on histomorphologic and molecular approach

PURPOSE

To create a reproducible and standardized urethral stricture model in rats, evaluating both histomorphologic findings and gene expression data. In studies involving experimental animals, more standardization is needed for the creation of a urethral stricture model.

METHODS

Sixteen male rats were randomized into two groups. The Sham group (n:8) underwent only a penoscrotal incision, while the stricture group (n:8) had their urethras exposed through a penoscrotal incision, followed by electrocauterization to the corpus spongiosum. On the 15th day, blood and urethral tissues were harvested for histologic and molecular analyses. Histomorphologic, immunohistochemical, and reverse transcription polymerase chain reaction analyses were performed.

RESULTS

The stricture group exhibited more severe and intense spongiofibrosis, inflammation, epithelial desquamation, and congestion in vascular structures compared to the controls (p < 0.05). The urethral tissue in the stricture group showed an increased ratio of inflammation parameters, including Collagen 1A1, Collagen 3A1, elastin, Transforming growth factor β1, α Smooth muscle actin, Platelet-derived growth factor α, and Platelet-derived growth factor β. Transforming growth factor β1, Platelet-derived growth factor α, and Platelet-derived growth factor β each correlated highly with the other six parameters (r > 0.60, p < 0.05).

CONCLUSION

Developing electrocoagulation-induced urethral stricture in rats is a simple, reliable, inexpensive, and reproducible. Reporting histologic data with qualitative and semi-quantitative scoring will enhance data standardization, aiding reader understanding and analysis. Transforming growth factor β and Platelet-derived growth factor play key roles in fibrosis during stricture development. Incorporating these cytokines in urethral stricture animal model studies can demonstrate successful stenosis creation.

A novel trauma induced urethral stricture in rat model

Urethral stricture (US) is a longstanding disease, while there has not existed a suitable animal model to mimic the condition. We aimed to establish a trauma-induced US animal model to simulate this clinical scenario. A total of 30 rats were equally distributed into two groups, sham and US group. All rats were anesthetized with isoflurane and undergone cystostomy. In the US group, a 2 mm incision was made in the urethra and sutured to induce US. The sham group only make a skin incision on the ventral side of the anterior urethra. 4 weeks later, ultrasound and cystourethrography were performed to evaluate the degree of urethral stricture, pathological examinations were carried out to evaluate the degree of fibrosis. Urodynamic evaluation and mechanical tissue testing were performed to evaluate the bladder function and urethral tissue stiffness. The results showed that the urethral mucosa was disrupted and urethral lumen was stenosed in the US group. Additionally, the US group showed elevated bladder pressure, prolonged micturition intervals and increased tissue stiffness. In conclusion, the rat urethral stricture model induced by trauma provides a closer representation of the real clinical scenario. This model will significantly contribute to advancing research on the mechanisms underlying traumatic urethral stricture.

Minimal invasive treatment of urethral strictures: An experimental study of the effect of paclitaxel coated balloons in the wall of strictured rabbit's urethra

PURPOSE

The aim of this study is the evaluation of the distribution of paclitaxel (PTX) released by a coated balloon in the layers of rabbit's urethra.

METHODS

18 rabbits were included. A laser device was used for the stricture formation. After two weeks, dilation of the strictured urethra was performed by using Advance 35LP PTA balloons and Advance 18 PTX PTA balloons. The experimental models were divided into 3 groups. The group Α included two rabbits without any intervention except for the stenosis procedure. Group B compromised six rabbits that underwent dilation with Advance 35LP PTA balloons. Group C consisted of 10 rabbits to which dilation with both Advance 35LP PTA balloons and Advance 18 PTX PTA balloons was applied. Histological evaluation and Immunohistochemistry were performed on all specimens.

RESULTS

Inflammation, fibrosis and ruptures were detected in the specimens of the study. In specimens of Group C the decrease of inflammation and fibrosis rate was greater. Anti-PTX antibody was detected in the epithelium, lamina propria and smooth muscle layer of all specimens of urethras that have been harvested immediately and 1 day after the dilation with Advance 18 PTX PTA balloon and it was not observed in any layer of the urethral wall of the rest of the examined specimens of Group C.

CONCLUSIONS

PTX's enrichment was detected in the smooth muscle layer of all specimens that have been harvested immediately and 24h after the dilation with Advance 18 PTX PTA balloons. PTX may play an inhibitive role in the recurrence of the stenosis.

Pharmacotherapy of urethral stricture

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.

Safety of Xiaflex® (Collagenase Clostridium histolyticum) Treatment for Adult Anterior Urethral Stricture Disease

Male urethral stricture disease is highly prevalent and difficult to treat due to potential complications. Minimally invasive treatments tend to have high recurrence rates, keeping urethroplasty as the gold standard. Collagenase Clostridium histolyticum (CCH) has been used in humans to treat fibrosis in a minimally invasive manner. Herein, we present the preliminary results from treatments of three males with urethral stricture as a feasibility and safety evaluation of the first-in-human CCH treatment for male urethral stricture disease.

Resveratrol plays an anti-fibrotic and anti-autophagy role by stimulating miR-192-5p expression in urethral fibrosis

BACKGROUND

Resveratrol (RSV) exerts anti-fibrotic effects on various fibrotic diseases. Whereas the biological role of RSV on urethral fibrosis remains to be elucidated. This study aimed to determine the mechanisms by which RSV affects urethral fibrosis and autophagy.

METHODS

Sprague‒Dawley rats and primary fibroblasts were treated with transforming growth factor-β1 (TGFβ1) to generate in vivo and in vitro fibrosis models. Then, those were treated with RSV, and autophagy and fibrosis-related indicators were tested.

RESULTS

Firstly, we found that RSV reversed the upregulation of indicators related to TGFβ1-induced fibrosis (TGFβ1, α-smooth muscle actin, collagen type I, and collagen type III), autophagy (TFEB and LC3), and TGFβR1/Smad4 pathway, as well as the downregulation of p62 and miR-192-5p expression both in vivo and in vitro. Overexpression of miR-192-5p suppressed the upregulation of fibrosis-related markers expression, as well as TFEB and LC3 expression, induced by TGFβ1, while the expression trend of p62 was the opposite. Inhibiting miR-192-5p reversed the effects of RSV on the model group cells. It was also shown that RSV combined with sh-Smad4 inhibited autophagy more effectively than RSV alone.

CONCLUSION

These results suggest that RSV inhibits urinary fibrosis and autophagy via the miR-192-5p/TGFβR1/Smad4 pathway. RAV may be a potential drug for alleviating urethral fibrosis.

Expanded Utilization of Intralesional Therapies for Treatment of Peyronie's Disease

Purpose

In this narrative review we explore additional indications for which intralesional collagenase Clostridium histolyticum (CCH) injection therapy may be used, in addition to those utilized in the IMPRESS trials. The goal is to provide updated assessment of available intralesional therapies and justify whether to expand clinical indications based on advancements over the last decade.

Results

Patients receiving CCH in the acute phase of PD have shown significant improvement in penile curvature - which may be even more significant than reported due to progressive curvature over the longitudinal course of injection therapy. Across studies, patients with ventral plaques achieved the greatest curvature improvement (~30°) compared to PD patients with dorsal or lateral plaques. Patients with curvature > 90° have been minimally documented. However, the concept of patients with higher degree of curvature achieving more significant degrees of improvement prevails across studies. Studies including PD patients with volume loss deformities or indentation(s) focus on curvature improvement and do not gauge improvement in these girth loss or indentation features specifically. PD patients with calcification may benefit from CCH, however, critical analysis of included study designs and results compared to placebo do not lend for strong support of CCH in PD at this time.

Conclusion

Based on the most recent research, the use of CCH in the acute phase of PD and patients with ventral penile plaques may be effective and safe. The limited available research on the efficacy of CCH on calcified plaque(s) and curvature greater than 90° is promising, however, more research is needed to ensure safety and success in this patient cohort. Finally, the current literature continues to show the use of CCH is not effective in PD patients with volume loss, indentation, or hourglass deformity. When expanding the use of CCH to patients not originally included in the IMPRESS trials, providers must prioritize minimizing chances of potential injury to urethral tissue. Finally, further investigation is required to determine whether CCH has utility for curvature greater than 90° or calcified plaques, although the limited available literature is promising.

Oral doxycycline prevents skin-associated adverse effects induced by injectable collagenase in a rodent model of capsular contracture around silicone implants

Background

The collagenase of the bacterium Clostridium histolyticum (CCH) is already an established treatment for fibroproliferative diseases like M. Dupuytren and M. Peyronie Although results are comparable to surgical intervention, skin laceration is a severe and relevant side effect. Doxycycline (DOX) recently rose interest as an inhibitor of matrix-metalloproteinases alongside its capabilities of skin accumulation. It therefore might be a potential skin protective agent in the use of CCH.

Methods

For simulation of a fibroproliferative disease adjacent to the skin, we utilized a rodent model of capsular fibrosis involving silicone implants and subsequent fibrotic capsule formation. For in-vitro studies, fibrotic capsules were excised and incubated with 0.9 mg/ml CCH and four different doses of DOX. For in-vivo experiments, animals received 0.0, 0.3 or 0.9 mg/ml CCH injections into the fibrotic capsules with or without prior oral DOX administration. Outcome analysis included histology, immunohistochemistry, gene expression analysis, chemical collagen and DOX concentration measurements as well as μCT imaging.

Results

In-vitro, DOX showed a dose-dependent inhibition of CCH activity associated with increasing capsule thickness and collagen density and content. In-vivo, oral DOX administration did neither interfere with capsule formation nor in effectiveness of CCH dissolving fibrotic capsule tissue. However, skin thickness and especially collagen density was significantly higher compared to control groups. This led to a reduced rate of clinical skin lacerations after DOX administration.

Conclusion

DOX inhibits CCH and accumulates in the skin. Thereby, DOX can effectively reduce skin laceration after CCH treatment.

Prevention of urethral fibrosis induced by transforming growth factor beta 1 using selective Wnt/β-catenin signaling inhibitors in a rat model

OBJECTIVES

To determine the anti-fibrotic effects of Wnt/β-catenin signaling inhibitors on urethral stricture.

METHODS

Human fibroblasts were exposed to transforming growth factor beta 1 combined with various concentrations of Wnt/β-catenin inhibitors (ICG-001, IWR-1, and PRI-724), and cell proliferation and migration were evaluated. Urethral fibrosis was induced in male Sprague-Dawley rats by urethral injection of transforming growth factor beta 1 and co-treatement with inhibitors. Urethral tissues were harvested 2 weeks after the injection. The messenger ribonucleic acid and protein expression was examined for fibrosis markers Axin-1, collagen type 1, alpha smooth muscle actin, and β-catenin. Histological analysis of fibrosis and collagen deposition was also performed.

RESULTS

Cell migration was ameliorated by ICG-001 and PRI-724. Protein and messenger ribonucleic acid expression of collagen type 1 and alpha smooth muscle actin in transforming growth factor beta 1-treated fibroblasts decreased in a concentration-dependent manner with the ICG-001 and PRI-724 treatments (P < 0.05). However, there were no significant changes with the IWR-1 treatment. Collagen type I and alpha smooth muscle actin messenger ribonucleic acid and protein expression were both significantly increased in the urethral tissues of rats with transforming growth factor beta 1-induced urethral fibrosis. Rats co-treated with ICG-001 or PRI-724 showed relatively mild fibrosis and significantly reduced collagen type I and alpha smooth muscle actin messenger ribonucleic acid and protein expression (P < 0.05).

CONCLUSIONS

ICG-001 and PRI-724 significantly ameliorated urethral fibrosis induced by transforming growth factor beta 1 in rats. These results suggest that ICG-001 and PRI-724 can be developed as therapeutics for treating urethral stricture.

The use of local therapy in preventing urethral strictures: A systematic review

Background

Urethral stricture disease is a common problem amongst men in Western countries often leading to a decreased quality of life. Current endoscopic treatment procedure shows an unsatisfying stricture recurrence rate which could be improved by addition of local therapies.

Objectives

To provide an overview of both preclinical and clinical studies in order to investigate current level of evidence on the addition of local therapy to improve urethral stricture recurrence rates after endoscopic procedures.

Methods

We performed a literature search in December 2020 and August 2021 using Cochrane, Embase, PubMed, Scopus and Web of Science and identified articles through combinations of search terms for ‘urethral stricture disease’, ‘stricture formation’ and ‘local interventions’. We used the SYRCLE, RoB-2 and ROBINS-I tools to assess risk of bias across included studies. We did not perform a meta-analysis due to methodological differences between studies.

Results

We included 32 articles in the qualitative analysis, 20 of which were preclinical studies and 12 clinical studies. Regarding preclinical articles using an animal model, nearly all interventions showed to have a positive effect on either urethral fibrosis, urethral stricture formation and/or fibrotic protein expression levels. Here, immunosuppressants and chemotherapeutics seemed most promising for possible clinical purposes. Regarding clinical studies, mitomycin-C and hyaluronic acid and carboxymethylcellulose showed positive effects on urethral stricture recurrence rates with low to intermediate risk of bias across studies. However, the positive clinical effects of mitomycin-C and steroids seemed to decrease in studies with a longer follow-up time.

Conclusion

Although local adjuvant use of mitomycin-C or hyaluronic acid and carboxymethylcellulose may carry clinical potential to improve urethral structure recurrence rates after endoscopic procedures, we believe that a large, well-designed RCT with a yearlong follow-up time is necessary to identify the true clinical value.

Ectopic Germinal Centres with B and T Cells and Follicular Dendritic Cell Networks in Urethral Stricture Tissue: Possible Avenue for Immunological Treatments

Background

The underlying cause of a urethral stricture can sometimes be obscure. It is possible that an injury to the urethra induces an immunological cascade that generates scar tissue and fibrosis, eventually resulting in a stricture. If such immunological reactions could be better elucidated, immunological therapies could possibly emerge.

Objective

To evaluate if ectopic germinal centres exist in urethral stricture disease.

Design, setting, and participants

Resected stricture specimens from 45 patients undergoing open bulbar urethroplasty with excision and anastomosis were assessed. Histopathological characteristics, such as fibrosis (grade I–III), inflammation, and sclerosis, were evaluated using immunostaining for CD3 (T cells), CD20 (B cells), and CD21 (follicular dendritic cells).

Outcome measurements and statistical analysis

The primary outcome measure was the presence or absence of a germinal centre. The secondary outcome was evaluation of any correlation between the degree of fibrosis and germinal centres. Fisher’s exact test was used for univariate analysis.

Results and limitations

In six patients, ectopic germinal centres were found. In ten patients, there was no inflammation at all. There was no correlation found between the degree of fibrosis and the abundance of immunohistochemically detected immune cells.

Conclusions

Ectopic germinal centres, with B and T cells as well as follicular dendritic cell networks, do exist in urethral stricture disease. This finding may open up for novel research avenues on the possibility of adopting immunological treatments for urethral stricture disease.

Patient summary

In patients with a narrowing of the urethra due to any kind of trauma, we looked for the presence of centres of immunological reaction in urethral tissue. We identified these immunological centres (also called germinal centres) in some patients. This intriguing finding suggests that immunological treatments may have potential for men with scar tissue in a narrowed urethra.

Treatment-related Outcomes for Patients With Atypical Peyronie's Disease Using Xiaflex Injections

OBJECTIVE

To evaluate the efficacy and safety of collagenase Clostridium histolyticum (CCH) for the management of penile deformities in patients presenting with different categories of atypical Peyronie's disease (PD).

METHODS

We conducted a retrospective review of charts of patients who presented to a men's health clinic with atypical PD between October 2016 and June 2019. We included patients in the stable phase of the disease, had completed a penile duplex Doppler ultrasound before any intervention, and proceeded with CCH treatment. Gathered data included patient demographics, treatment details, outcomes, and complications. Outcomes collected were both quantitative (curvature assessments) and qualitative using the symptom bother domain (last 6 questions; Q10 to Q15) of the Peyronie's Disease Questionnaire.

RESULTS

Twenty-one men with stable PD underwent CCH inject therapy after penile duplex Doppler ultrasound. The mean number of injections was 8.4 (standard deviation [SD] = 3.3), and the mean follow-up was 20.5 months (SD = 5.9). The overall mean change in penile curvature was -19.2° ± 8.3°, which corresponded to a -39% ± 13% improvement in curvature (P = .0079). In men who presented with an indentation or hourglass deformity, 11 of 17 (64%) were satisfied and reported subjective improvement in narrowing/indentation after receiving CCH injections. The average composite symptom bother domain of the Peyronie's Disease Questionnaire decreased by 6.7 (P = .0029).

CONCLUSION

Our results suggest that CCH appears to be safe and provide significant clinical improvements in men presenting with atypical PD.

Intralesional steroid injection combined with bladder neck incision is efficacious in the treatment of recurrent bladder neck contracture

OBJECTIVES

Bladder neck contracture (BNC) is a well-recognized complication following radical prostatectomy (RP). This problem may recur after failing initial endoscopic management. This study evaluated the efficacy of intralesional steroid injection combined with bladder neck incision (BNI) for recurrent BNC following RP.

METHODS

Between November 2011 and March 2018, data from all men who underwent BNI and intralesional steroid injection for recurrent BNC from a single regional center were collected. BNC was diagnosed endoscopically and identified as recurrent if having previously failed endoscopic management with BNI alone. Follow up was initially performed at 3 months with an International Prostate Symptom Score and urinary flow rate. Patients were noted to be recurrence-free when discharged from follow up or after having undergone a continence procedure indicating stability of the contracture.

RESULTS

Thirty patients underwent BNI and intralesional steroid injection for recurrent BNC over the study period. All patients had received prior endoscopic incision of BNC without lasting success. Seventy percent (21/30) of patients were recurrence-free post-procedure, and this increased to 83.3% (25/30) after a repeat procedure in four patients. All five patients who had previous salvage radiotherapy had their recurrent BNC successfully managed with one BNI and intralesional steroid injection. The mean follow up was 33.4 months (range 7-75). There were no adverse events recorded.

CONCLUSIONS

BNI combined with injection of intralesional steroids is a simple, cost-effective intervention which requires no specialist equipment/skills outside the realm of a general urologist. It is safe and has an excellent success rate.

Targeting Cell Contractile Forces: A Novel Minimally Invasive Treatment Strategy for Fibrosis

Fibrosis is a complication of tendon injury where excessive scar tissue accumulates in and around the injured tissue, leading to painful and restricted joint motion. Unfortunately, fibrosis tends to recur after surgery, creating a need for alternative approaches to disrupt scar tissue. We posited a strategy founded on mechanobiological principles that collagen under tension generated by fibroblasts is resistant to degradation by collagenases. In this study, we tested the hypothesis that blebbistatin, a drug that inhibits cellular contractile forces, would increase the susceptibility of scar tissue to collagenase degradation. Decellularized tendon scaffolds (DTS) were treated with bacterial collagenase with or without external or cell-mediated internal tension. External tension producing strains of 2-4% significantly reduced collagen degradation compared with non-tensioned controls. Internal tension exerted by human fibroblasts seeded on DTS significantly reduced the area of the scaffolds compared to acellular controls and inhibited collagen degradation compared to free-floating DTS. Treatment of cell-seeded DTS with 50 mM blebbistatin restored susceptibility to collagenase degradation, which was significantly greater than in untreated controls (p < 0.01). These findings suggest that therapies combining collagenases with drugs that reduce cell force generation should be considered in cases of tendon fibrosis that do not respond to physiotherapy.

Collagenolytic Enzymes and their Applications in Biomedicine

Nowadays, enzymatic therapy is a very promising line of treatment for many different diseases. There is a group of disorders and conditions, caused by fibrotic and scar processes and associated with the excessive accumulation of collagen that needs to be catabolized to normalize the connective tissue content. The human body normally synthesizes special extracellular enzymes, matrix metalloproteases (MMPs) by itself. These enzymes can cleave components of extracellular matrix (ECM) and different types of collagen and thus maintain the balance of the connective tissue components. MMPs are multifunctional enzymes and are involved in a variety of organism processes. However, under pathological conditions, the function of MMPs is not sufficient, and these enzymes fail to deal with disease. Thus, medical intervention is required. Enzymatic therapy is a very effective way of treating such collagen-associated conditions. It involves the application of exogenous collagenolytic enzymes that catabolize excessive collagen at the affected site and lead to the successful elimination of disease. Such collagenolytic enzymes are synthesized by many organisms: bacteria, animals (especially marine organisms), plants and fungi. The most studied and commercially available are collagenases from Clostridium histolyticum and from the pancreas of the crab Paralithodes camtschatica, due to their ability to effectively hydrolyse human collagen without affecting other tissues, and their wide pH ranges of collagenolytic activity. In the present review, we summarize not only the data concerning existing collagenase-based medications and their applications in different collagen-related diseases and conditions, but we also propose collagenases from different sources for their potential application in enzymatic therapy.

Sclerosis as a predictive factor for failure after bulbar urethroplasty: a prospective single-centre study

OBJECTIVE

The aim of this study was to assess whether sclerosis in histology following bulbar urethroplasty is a predictive factor for failure of surgery.

MATERIALS AND METHODS

Resected stricture specimens from 45 patients undergoing open urethroplasty with excision and anastomosis were collected prospectively during 2011-2014. Histopathological characteristics, including fibrosis (grade I-III), inflammation and sclerosis, were evaluated using different routine staining. These specimens were compared to normal urethral resection specimens from patients undergoing sex-correction surgery. The uropathologist who conducted the analyses was blinded to the study design.

RESULTS

The outcomes of the histological classifications were as follows: 19 patients had grade I fibrosis, of whom three had failures; 13 patients had grade II fibrosis, without any failures; and the most severe fibrosis, grade III, including sclerosis, was found in 13 patients (11 with sclerosis), with failure in eight. Sclerosis was a significant risk factor for restricture when comparing patients with sclerosis and those without sclerosis, and likewise when adjusting for age, inflammation and stricture length.

CONCLUSION

Histological findings of sclerosis in the resected urethral stricture specimen indicate a significantly higher risk for restricture after urethroplasty surgery.

Associations of TGFBR1 and TGFBR2 gene polymorphisms with the risk of hypospadias: a case-control study in a Chinese population

This case-control study investigated the association of transforming growth factor-β (TGF-β) receptor type I and II (TGFBR1 and TGFBR2) gene polymorphisms with the risk of hypospadias in a Chinese population. One hundred and sixty two patients suffering from hypospadias were enrolled as case group and 165 children who underwent circumcision were recruited as control group. Single nucleotide polymorphisms (SNPs) in TGFBR1 and TGFBR2 genes were selected on the basis of genetic data obtained from HapMap. PCR-restriction fragment length polymorphism (PCR-RFLP) was performed to identify TGFBR1 and TGFBR2 gene polymorphisms and analyze genotype distribution and allele frequency. Logistic regression analysis was conducted to estimate the risk factors for hypospadias. No significant difference was found concerning the genotype and allele frequencies of TGFBR1 rs4743325 polymorphism between the case and control groups. However, genotype and allele frequencies of TGFBR2 rs6785358 in the case group were significantly different in contrast with those in the control group. Patients carrying the G allele of TGFBR2 rs6785358 polymorphism exhibited a higher risk of hypospadias compared with the patients carrying the A allele (P<0.05). The TGFBR2 rs6785358 genotype was found to be significantly related to abnormal pregnancy and preterm birth (both P<0.05). The frequency of TGFBR2 rs6785358 GG genotype exhibited significant differences amongst patients suffering from four different pathological types of hypospadias. Logistic regression analysis revealed that preterm birth, abnormal pregnancy, and TGFBR2 rs6785358 were the independent risk factors for hypospadias. Our study provides evidence that TGFBR2 rs6785358 polymorphism might be associated with the risk of hypospadias.

The predictive value of platelet to lymphocyte and neutrophil to lymphocyte ratio in determining urethral stricture after transurethral resection of prostate

OBJECTIVE

The pathology of urethral stricture disease is still unclear however progressive inflammation may contribute to the development of urethral stricture. The platelet-to- lymphocyte ratio (PLR) is a new and simple marker that indicates inflammation. In this study we aimed to investigate the predictive value of neutrophil to lymphocyte ratio (NLR) and PLR in patients with urethral stricture who underwent transurethral resection of prostate (TURP).

MATERIAL AND METHODS

A total of 208 patients who underwent bipolar-TURP were included in this study. Patients who had previously undergone surgery due to any urethral pathology, posterior urethral strictures, previous or ongoing treatment for any cancer, hematologic disorders, presence of an active infection at the time of surgical intervention, and prior blood transfusion were excluded. PLR, NLR and red cell distribution width (RDW) levels were measured. In order to investigate the predictive values of NLR and PLR variables, binary logistic regression analysis was performed.

RESULTS

No statistically significant differences were observed between the groups in terms of age, NLR, RDW, prostate size and operative times. Statistically significant differences were presented only in the median PLR- values. For predicting urethral stricture, the optimal cut-off value was 112.5, (sensitivity: 0.84, specificity: 0.64; AUC=0.762, 95% CI 0.684-0.84).

CONCLUSION

In this study we showed that PLR can be used to determine urethral stricture as a cost-effective, common, and simple biomarker in patients after TURP.

Management of bladder neck stenosis and urethral stricture and stenosis following treatment for prostate cancer

The aim of this review is to examine all urethral strictures and stenoses subsequent to treatment for prostate cancer, including radical prostatectomy (RP), radiotherapy, high intensity focused ultrasound (HIFU) and cryotherapy. The overall majority respond to endoscopic treatment, including dilatation, direct visual internal urethrotomy (DVIU) or bladder neck incision (BNI). There are adjunct treatments to endoscopic management, including injections of corticosteroids and mitomycin C (MMC) and urethral stents, which remain controversial and are not currently mainstay of treatment. Recalcitrant strictures are most commonly managed with urethroplasty, while recalcitrant stenosis is relatively rare yet almost always associated with bothersome urinary incontinence, requiring bladder neck reconstruction and subsequent artificial urinary sphincter (AUS) implantation, or urinary diversion for the devastated outlet.

Collagenase Clostridium histolyticum in the treatment of Peyronie's disease: patient selection and perspectives

The safety and efficacy of the use of collagenase Clostridium histolyticum (CCH) for the treatment of Peyronie's disease has been confirmed over the past several years. However, identification of the ideal patient population for use of this treatment is not well established. Multiple studies have attempted to delineate various patient-specific factors that may predict response to treatment with CCH, with the intent of enhancing patient selection. To date, these include baseline curvature severity, duration of disease, disease phase at presentation, plaque calcification, baseline erectile function, plaque size, age, comorbid diabetes, previous penile trauma, responsiveness to first treatment cycle, baseline penile shortening or pain, prior treatment with intralesional injection, compliance with plaque modeling, and atypical curvature. In addition, other studies have sought to explore various aspects of treatment with CCH that may affect patient perspective of treatment. They have focused on patient-reported outcomes, female partner considerations, cost of treatment, and potential confounders of patient satisfaction. This review provides a summary and analysis of currently available literature on topics of patient selection and perspectives in regard to treatment of Peyronie's disease with CCH.

The effect of rapamycin on TGFβ1 and MMP1 expression in a rabbit model of urethral stricture

PURPOSE

To investigate the effect of rapamycin on TGFβ1 and MMP1 expression in a rabbit model of urethral stricture.

METHODS

Twenty-four adult New Zealand male rabbits underwent an electrocoagulation of the bulbar urethra with a 13Fr pediatric resectoscope. Then rabbits were randomly divided into three groups: (1) normal control group: normal saline (NS), (2) the vehicle control group: dimethyl sulfoxide (DMSO), and (3) the treatment group: effective-dose rapamycin in DMSO (Ra), with 12, 6, and 6 rabbits in each group, respectively. Drugs were given by urethral irrigation daily for 4 weeks. Urethral tissue was harvested for histological and molecular analyses. TGFβ1 and MMP1 expression levels were evaluated by real-time quantitative PCR and immunohistochemistry.

RESULTS

Ten, six, and six rabbits were evaluated finally in Ra, DMSO, and NS group, respectively. Histological examination revealed the distribution of fibrosis and the degree of collagen deposition in the Ra group were smaller and slighter than the two control groups. Collagen content was significantly less in the Ra group than in the DMSO group (P < 0.001) and the NS group (P < 0.001). qRT-PCR analysis showed a higher expression of MMP1 mRNA in the Ra group than in the DMSO group (P < 0.001) and the NS group (P < 0.001). Immunohistochemistry showed the protein levels of MMP1 in the Ra group were significantly increased when compared with the DMSO group (P < 0.01) and the NS group (P < 0.01). On the other hand, no statistical difference could be found between every two groups in both mRNA and protein levels of TGFβ1.

CONCLUSIONS

Rapamycin enhances the expression of MMP1 in a rabbit model of urethral stricture, but has no direct effect on the expression of TGFβ1.