Novel Concept and Method of Endoscopic Urethral Stricture Treatment Using Liquid Buccal Mucosal Graft

Advances in urethroplasty

There has been rapid evolution in management of urethral strictures in the last 3 decades. From the era of dilatation, we have moved to urethral reconstruction. Reinvention of buccal grafts changed the outcomes of urethroplasty. Barbaglis dorsal onlay popularised stricture management across the globe. Kulkarni described a single stage surgery for panurethral stricture. Advances have taken place, and we have moved from transecting to the non-transecting approaches. We describe the various advances in urethral reconstruction in the last decade.

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.

Advancements in transurethral management of urethral stricture disease

PURPOSE OF REVIEW

To explore and report the recent evolution of transurethral management of urethral stricture disease.

RECENT FINDINGS

In recent years, new promising techniques in the transurethral management of urethral stricture disease have emerged including adjuvant therapies to direct vision internal urethrotomy, regenerative therapy with buccal mucosa cells and minimally invasive transurethral urethroplasty procedures that avoid skin incisions.

SUMMARY

Although further work is needed, the expanding field of transurethral therapies for urethral stricture disease demonstrates early promising results through a variety of modalities.

AK, Pennisi CP. Quality of Reporting in Preclinical Urethral Tissue Engineering Studies: A Systematic Review to Assess Adherence to the ARRIVE Guidelines

Preclinical research within the area of urethral tissue engineering has not yet been successfully translated into an efficient therapeutic option for patients. This gap could be attributed, in part, to inadequate design and reporting of the studies employing laboratory animals. In this study, a systematic review was conducted to investigate the quality of reporting in preclinical studies utilizing tissue engineering approaches for urethral repair. The scope was on studies performed in rabbits, published between January 2014 and March 2020. Quality assessment of the data was conducted according to the Animal Research: Reporting of in Vivo Experiments (ARRIVE) guidelines by the scoring of a 38-item checklist in different categories. A total of 28 articles that fulfilled the eligibility criteria were included in the study. The range of ARRIVE score was from 0 to 100, taking into consideration having reported the item in question or not. The mean checklist score was 53%. The items that attained the highest scores included the number of animals utilized, the size of control and experimental groups, and the definition of experimental outcomes. The least frequently reported items included the data regarding the experimental procedure, housing and husbandry, determination and justification of the number of animals, and reporting of adverse events. Surprisingly, full disclosure about ethical guidelines and animal protocol approval was missing in 54% of the studies. No paper stated the sample size estimation. Overall, our study found that a large number of studies display inadequate reporting of fundamental information and that the quality of reporting improved marginally over the study period. We encourage a comprehensive implementation of the ARRIVE guidelines in animal studies exploring tissue engineering for urethral repair, not only to facilitate effective translation of preclinical research findings into clinical therapies, but also to ensure compliance with ethical principles and to minimize unnecessary animal studies.

Liquid buccal mucosa graft endoscopic urethroplasty: a validation animal study

PURPOSE

To validate a novel method of urethral stricture treatment using liquid buccal mucosal grafts (LBMG) to augment direct vision internal urethrotomy (DVIU) in an animal model.

MATERIALS AND METHODS

A rabbit stricture model was used to test this method. Strictures were induced in 26 rabbits using electroresection of urethral epithelium. The animals were randomized into two groups: Group-1, treated with DVIU and LBMG in fibrin glue, and Group-2, DVIU with fibrin glue only. LBMG was prepared by suspension of mechanically minced buccal mucosa micrografts in fibrin glue. This LBMG-fibrin glue mixture was later injected into the urethrotomies of Group-1 animals. All animals were killed at 24 weeks after repeat retrograde urethrogram (RUG) and urethroscopy by surgeon blinded to the treatment arm. Radiographic images and histological specimens were reviewed by a radiologist and a pathologist, respectively, blinded to the treatment arm. Stricture treatment was considered a success if a diameter measured on RUG increased by ≥ 50% compared to pre-treatment RUG diameter. Histological specimens were assessed for the presence of BMG engraftment.

RESULTS

In Group-1, 8/12(67%) animals demonstrated engraftment of LBMG, compared to none in Group-2 (p = 0.0005). 7/12(58%) in Group-1 showed radiographic resolution/improvement of strictures compared to 5/13 Group-2 rabbits (38%, p = 0.145). The median percent change for the Group-1 was 59%, compared to 41.6% for Group-2 (p = 0.29).

CONCLUSION

This proof-of-concept study demonstrates feasibility of LBMG for endoscopic urethral stricture repairs. Further studies are needed to establish the role of this novel concept in treatment of urethral strictures.

Endoscopic Management of Urethral Stricture: Review and Practice Algorithm for Management of Male Urethral Stricture Disease

PURPOSE OF REVIEW

Male urethral stricture disease is characterized by the formation of scar tissue within the urethra resulting in lower urinary tract symptoms, infection, and potentially kidney dysfunction. There is significant variability in clinical practice for the treatment of urethral stricture. We sought to summarize the known data on endoscopic management of urethral stricture disease as part of this larger edition on urethral stricture management.

RECENT FINDINGS

Older studies quoted high rates of success with endoscopic management of urethral stricture, including repeated DVIU. There is now evidence to support a limited role of endoscopic intervention in the management of urethral stricture, and especially strong evidence that repeated endoscopic procedures are not effective. There is poor evidence to support the long-term efficacy of endoscopic urethral stricture management. Furthermore, novel advances in adjunctive therapies have not yet demonstrated durable patency. We discuss the limited role of endoscopic management and suggest an algorithm for its use in stricture management.