Safety and efficacy of Intraurethral Mitomycin C Hydrogel for prevention of post-traumatic anterior urethral stricture recurrence after internal urethrotomy

Prospects and Challenges of Electrospun Cell and Drug Delivery Vehicles to Correct Urethral Stricture

Current therapeutic modalities to treat urethral strictures are associated with several challenges and shortcomings. Therefore, significant strides have been made to develop strategies with minimal side effects and the highest therapeutic potential. In this framework, electrospun scaffolds incorporated with various cells or bioactive agents have provided promising vistas to repair urethral defects. Due to the biomimetic nature of these constructs, they can efficiently mimic the native cells’ niches and provide essential microenvironmental cues for the safe transplantation of multiple cell types. Furthermore, these scaffolds are versatile platforms for delivering various drug molecules, growth factors, and nucleic acids. This review discusses the recent progress, applications, and challenges of electrospun scaffolds to deliver cells or bioactive agents during the urethral defect repair process. First, the current status of electrospinning in urethral tissue engineering is presented. Then, the principles of electrospinning in drug and cell delivery applications are reviewed. Finally, the recent preclinical studies are summarized and the current challenges are discussed.

Efficacy of Mitomycin C Combined with Direct Vision Internal Urethrotomy for Urethral Strictures: A Systematic Review and Meta-Analysis

BACKGROUND

The high recurrence of a urethral stricture after direct vision internal urethrotomy (DVIU) has been a problem for years. Mitomycin C (MMC) is an excellent antifibrosis antigen that has been used in many fields, but its effect on a urethral stricture remains controversial. The purpose of this review was to investigate the effectiveness of MMC in reducing the recurrence rate of a urethral stricture after the first urethrotomy.

METHODS

Common databases were searched for publications prior to November 30, 2020. Randomized controlled and cohort trials were all included. Recurrence and success rates after the first urethrotomy of the posterior urethra were the main outcomes. Revman 5.3 was used for statistical analysis. Two evaluation systems, the Cochrane risk of bias tool and the Newcastle Ottawa Scale, were used to examine the risk of bias for RCTs and all studies. The quality of evidence was assessed by the Grading of Recommendations, Assessment, Development, and Evaluation standard.

RESULTS

Sixteen trials were included, the reporting quality of which was generally poor, and the evidence level was very low to moderate. The addition of MMC could significantly reduce the recurrence rate of urethral strictures (risk ratio [RR] = 0.42; 95% confidence interval [CI]: 0.26, 0.67; p = 0.0002; 9 trials; 550 participants). The results of the subgroup analysis suggested that the effect of MMC combined with DVIU was significant in short (≤2 cm) anterior urethral strictures (RR = 0.39; 95% CI: 0.20, 0.78; p = 0.008), >12-month follow-up (RR = 0.45; 95% CI: 0.26, 0.76; p = 0.003). It also increased the success rate of the first urethrotomy procedure for posterior urethral contracture (RR = 0.74; 95% CI: 0.65, 0.84; p < 0.00001; 7 trials; 342 participants). Low-dose local injection of MMC was the most commonly used method.

CONCLUSION

MMC combined with DVIU is a promising way to reduce the long-term recurrence rate of a short-segment anterior urethral stricture. It also increases the success rate of the first urethrotomy of the posterior urethra. However, more high-quality randomized controlled trials are needed.

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.

Hyaluronic Acid Reduces Fibrosis in a Rabbit Model of Urethral Anastomosis

INTRODUCTION

Urethral stricture caused by fibrosis is a common medical condition, but top-line therapy for this pathology has a high recurrence rate. This study aimed to determine the efficacy of hyaluronic acid (HA) treatment in preventing the development of fibrosis in a rabbit model of urethral anastomosis.

MATERIALS AND METHODS

This experimental study involved 20 rabbits. HA (0.5 mL, 25 μg/mL) was applied in the experimental group (n = 10) during an experimental urethral anastomosis, and sterile saline (0.9%) solution was applied in the control group (n = 10). Animals underwent reoperation 12 weeks later for urethral resection. Fibrosis, inflammation, and urethral diameter were measured by two blinded pathologists at the site of the anastomosis.

RESULTS

The amount of inflammatory infiltrate was similar in both groups. The thicknesses of the collagen fiber band were 275.9 ± 62.3 and 373.4 ± 44.3 μm in the study and control groups (p = 0.001), respectively, and the urethral lumen diameters at the anastomosis site at follow-up were 2575 ± 167 and 2382 ± 214 μm, respectively (p = 0.04).

CONCLUSION

HA treatment reduced fibrosis at the anastomosis site during this experiment; we suggest further research to corroborate its efficacy in the treatment of urethral stricture.

Efficacy of mitomycin-C on anterior urethral stricture after internal urethrotomy: A systematic review and meta-analysis

Background and Aim Mitomycin-C is a potent agent that plays an important role in tissue healing and scar formation. This study aims to investigate the efficacy of Mitomycin-C in treating anterior urethral stricture after internal urethrotomy. Methods Studies evaluating efficacy of mitomycin-c for anterior urethral stricture post urethrotomy were searched using Pubmed, Scopus, Sciencedirect, MEDLINE, and Cochrane Reviews as directory databases. The search was done in March 15th 2020. Terms being used in the searching process were "mitomycin-c" or "mitomycin", "urethral stricture", "urethral stenosis", "internal urethrotomy", "optical urethrotomy" and its synonyms. Every study with the design of retrospective or prospective clinical study being done in human subject was included. Study appraisal conducted in accordance to Oxford University Center for Evidence-Based Medicine. The conclusion of each study was summarized and the calculation of random effects from every study was conducted in meta-analysis. Random effects model is chosen because small number of studies and quite different. Results Three studies involving 311patients were included in this review, all of them reported less recurrence of in patients treated with mitomycin-c post urethrotomy (p<0.001). Risk ratio of all studies was 0.41 with 95% confidence interval (0.25-0.68).   Conclusion Mitomycin-C has the potential of efficacy in treating anterior urethral stricture post internal urethrotomy. Relatively few numbers of studies may impact in the strength of this review and further studies need to be done.

Efficacy of mitomycin-C on anterior urethral stricture after internal urethrotomy: A systematic review and meta-analysis

Background: Mitomycin-C is an agent that plays an important role in the tissue healing process and scar formation. This study aims to investigate the efficacy of mitomycin-C in treating anterior urethral stricture following internal urethrotomy. Methods: Studies evaluating the efficacy of mitomycin-c for anterior urethral stricture post urethrotomy were searched using PubMed, Scopus, ScienceDirect, EBSCOHost, Cochrane Reviews, and OVID as directory databases. Terms used in the searching process were "mitomycin-c" or "mitomycin", "urethral stricture", "urethral stenosis", "internal urethrotomy", "optical urethrotomy" and its synonyms. Every randomized controlled trial study conducted in human subjects was included. Study appraisals were conducted in accordance with Oxford University Center for Evidence-Based Medicine guidelines. The conclusion of each study was summarized and the calculation of fixed effect from every study was conducted in meta-analysis. Results: Included in this study were three studies involving 231 patients. All of them reported less recurrence of in patients treated with mitomycin-c post urethrotomy (p<0.001). The fixed risk ratio of all studies was 0.32 with 95% confidence interval (0.19-0.54). All studies also reported less stricture length after treatment with mitomycin-c, but there were not statistical differences between with or without treatment group. Conclusion: Mitomycin-C has efficacy in treating anterior urethral stricture after internal urethrotomy. However, the inclusion of relatively few studies may affect the strength of this review and further studies need to be done.

Efficacy of mitomycin-C on anterior urethral stricture after internal urethrotomy: A systematic review and meta-analysis

Background and Aim Mitomycin-C is a potent agent that plays an important role in tissue healing and scar formation. This study aims to investigate the efficacy of Mitomycin-C in treating anterior urethral stricture after internal urethrotomy. Methods Studies evaluating efficacy of mitomycin-c for anterior urethral stricture post urethrotomy were searched using Pubmed, Scopus, Sciencedirect, MEDLINE, and Cochrane Reviews as directory databases. The search was done in March 15th 2020. Terms being used in the searching process were "mitomycin-c" or "mitomycin", "urethral stricture", "urethral stenosis", "internal urethrotomy", "optical urethrotomy" and its synonyms. Every study with the design of retrospective or prospective clinical study being done in human subject was included. Study appraisal conducted in accordance to Oxford University Center for Evidence-Based Medicine. The conclusion of each study was summarized and the calculation of random effect from every study was conducted in meta-analysis. Random effect model is chosen because small number of studies and quite different. Results Three studies involving 311patients were included in this review, all of them reported less recurrence of in patients treated with mitomycin-c post urethrotomy (p<0.001). Risk ratio of all studies was 0.41 with 95% confidence interval (0.25-0.68).   Conclusion Mitomycin-C has the potential of efficacy in treating anterior urethral stricture post internal urethrotomy. Relatively few numbers of studies may impact in the strength of this review and further studies need to be done.