Recent Advances in treatment of urethral stricture disease in men

Shear Wave Elastography in Assessing Spongiofibrosis of Urethral Stricture: Is It Clinically Useful?

RATIONALE AND OBJECTIVES

To compare urethral stricture shear wave elastography (SWE) with normal areas and assess its association with other explanatory variables.

SUBJECTS AND METHODS

we recruited all men with urethral stricture disease referred to our center between December 2021 and July 2023. Patients underwent SWE and elasticity in the stricture area, and one and three centimeters distant from the stricture were measured. Gathered data were analyzed using Freidman and post hoc analysis, correlation methods, student t-tests, and one-way ANOVA.

RESULTS

22 patients were recruited for our study. Spongiofibrosis was significantly higher in the stricture area relative to the one-centimeter-distant adjacent area (p < .0005), in the one-centimeter-distant compared to the three-centimeter-distant area (p = .002), and in the stricture area relative to the three-centimeter-distant area (p < .0005). There was no association between elasticity ratio and patient age or stricture location. Likewise, there was no difference in elasticity ratios between bulbar and pendulous strictures (p = 0.19) or among different etiologies of urethral strictures (p = 0.76).

CONCLUSION

There is a significant difference in elasticity between the urethral stricture area and other parts of the corpus spongiosum. Normal areas closer to strictures are stiffer. The elasticity ratio is unrelated to patient age or prior internal urethromies. Neither stricture locations nor distinct urethral stricture etiologies differed in elasticity ratios.

Follow-up and histocompatibility observation of urethral reconstruction with different materials

OBJECTIVE

Our objective is to observe the long-term surgical results of urethral reconstruction using either pedicled penile flaps or lingual mucosa grafts. We also assess the histocompatibility of the reconstructed urethra.

MATERIALS AND METHODS

Clinical data of patients with anterior urethral stenosis undergoing urethra reconstruction by applying different materials were collected from 2014 to 2022 in the Second Hospital of Hebei Medical University. We assessed their efficacy and the occurrence of complications. Patients who required reoperation due to complications were selected. Sections of the reconstructed urethra created with various materials were excised during repair procedures. The excised tissues underwent hematoxylin-eosin staining and immunohistochemistry. Comparison with the original histological morphology was conducted to evaluate histocompatibility.

RESULTS

42 of the 55 patients were cured which showed a surgical success rate of 76.36%. The success rate of urethra reconstruction surgery utilizing lingual mucosa is 71.43% and that of surgeries using pedicled penis flaps is 79.41%. The long-term prognosis of the two groups is similar (P > 0.05). Observations show that the histological morphology of the original epithelium gradually disappeared, leading to adaptive changes to the urinary environment with favorable histocompatibility.

CONCLUSION

The application of lingual mucosal and pedicled penis flaps for urethral reconstruction both have a high surgical success rate. The long-term follow-up results are positive. Both methods are viable for urethral reconstruction and exhibit favorable histocompatibility.

Assessment of YouTube Videos about Urethral Stricture and Its Management

PURPOSE

To evaluate the reliability, transparency, usability and technical quality of videos about urethral stricture and its management in the most common video-sharing website "YouTube".

METHODS

We performed a video search on YouTube using the keywords "Urethral Stricture", "Internal Urethrotomy" and "Urethroplasty". After excluding the videos that did not meet the inclusion criteria, demographic data of each video was recorded and assessed with the validated DISCERN questionnaire, the Journal of the American Medical Association Benchmark Score (JAMAs) and the Global Quality Score (GQS). Additionally, the Urethral Stricture Video Score was developed by two experienced surgeons to assess the technical aspects. Videos were also compared with a view to their source of upload.

RESULTS

A total of 177 videos were analysed. Videos from "University" and "Other" had a significantly higher view ratio and video power index (VPI) than the rest (all p<0.05). For all mentioned scores, even though the video sources of "Society" and "University" had significantly higher scores than the rest (all p<0.05), all scores remained at a low to moderate level at each group.

CONCLUSION

Even though universities, societies and organisations tend to upload better videos about the management of urethral stricture in terms of general quality, reliability, transparency and technical aspects, the online visual content about urethral stricture and its management needs to be improved in order to provide more reliable and qualified information for both clinicians and patients.

Is testosterone deficiency a predictive factor for recurrence of urethral stricture?

BACKGROUND

Testosterone plays a vital role in maintaining tissue homeostasis, and testosterone deficiency may potentially influence the likelihood of urethral stricture recurrence.

OBJECTIVES

To evaluate the prognostic value of testosterone levels in the recurrence after direct visual internal urethrotomy in primary short segment bulbar urethral strictures and its clinical reflections.

MATERIALS AND METHODS

A total of 723 patients who underwent direct vision internal urethrotomy between January 2000 and October 2022 were retrospectively analyzed. After implying exclusion criteria, 116 patients with available data were enrolled. Patients were divided into two groups as recurrence and no recurrence. Age, stricture length, etiology, time of recurrence, diagnosis of previous diabetes mellitus, hypertension, smoking, body mass index, and total testosterone levels were recorded. Free testosterone and bioavailable testosterone values were calculated using total testosterone, albumin, and sex hormone binding globulin values. Hypogonadism was considered as a total testosterone level less than 300 ng/dL. Demographic characteristics and total testosterone, free testosterone, and bioavailable testosterone levels were compared between the two groups for statistical significance. The recurrence rates of patients with and without hypogonadism were compared.

RESULTS

Recurrence was observed in 41.4% of the cases (n = 48). There was no statistically significant difference between the groups in terms of age, body mass index values, diabetes mellitus, hypertension, smoking status, presence of hypogonadism, and etiology (p = 0.745, 0.863, 0.621, 0.622, 0.168, 0.051, and 0.232). In terms of total testosterone levels and bioavailable testosterone levels, the recurrence group had significantly lower values (p = 0.018 and 0.04). There was no significant difference between the two groups in terms of stricture length (p = 0.071). Sixteen of 28 patients with hypogonadism had recurrence, whereas 32 of 88 patients without hypogonadism had recurrence (p = 0.051).

DISCUSSION

Testosterone levels have potential to predict recurrence in primary short-segment bulbar urethral strictures. This study represents the inaugural analysis of the impact of testosterone deficiency on recurrence within the cohort of patients with primary short-segment bulbar urethral strictures.

CONCLUSION

Testosterone levels and ratios may serve as predictive factors for identifying recurrent cases in primary short-segment bulbar strictures. For patients at a higher risk of recurrence, urethroplasty may be considered as an initial treatment option, even in cases of primary and short-segment strictures.

Inhibition of urethral stricture by a catheter loaded with nanoparticle/ pirfenidone complexes

Background: Urethral strictures are common injurious conditions of the urinary system. Reducing and preventing urethral strictures has become a hot and challenging topic for urological surgeons and related researchers. In this study, we developed a catheter loaded with nanoparticle/pirfenidone (NP/PFD) complexes and evaluated its effectiveness at inhibiting urethral stricture in rabbits, providing more references for the clinical prevention and reduction of urethral stenosis. Methods: Twelve adult male New Zealand rabbits were selected and divided into the following four groups in a ratio of 1:1:1:1 using the random number table method: Group A, sham; Group B, urethral stricture (US); Group C, US + unmodified catheter; and Group D, US + NP/PFD catheter. On the 30th day after modelling, retrograde urethrography was performed to evaluate urethral stricture formation, and histopathological examination was performed on the tissues of the corresponding surgical site. Meanwhile, changes in the expression level of Transforming growth factor β1 (TGF-β1) in the tissues were detected by immunohistochemistry. Results: The NP/PFD complexes adhered uniformly to the catheter surface. They remained on the surface of the catheter after insertion into the urethra. In addition, the NP/PFD complexes spread into the urethral epithelium 2 weeks after surgery. Ultimately, urethral strictures were significantly reduced with the placement of the NP/PFD complex catheter. Conclusion: Our catheter loaded with NP/PFD complexes effectively delivered PFD to the urethral epithelium through continuous local delivery, thereby reducing fibrosis and stricture after urethral injury, which may be associated with the inhibition of TGF-β1 expression.

Delineating Which Patient-reported Symptoms Are Associated with Satisfaction After Urethroplasty

OBJECTIVE

To determine which patient-reported symptoms are associated with satisfaction after urethroplasty.

METHODS

From 2011 to 2018, patients were offered enrollment in a prospective study assessing patient-reported outcomes after urethroplasty. Outcomes were assessed preoperatively and 6-months postoperatively including patient satisfaction, voiding function (International Prostate Symptom Score), erectile function (International Index of Erectile Function 5) and ejaculatory function (ejaculatory component of brief sexual function inventory). Additionally, penile curvature/appearance, genitourinary pain, postvoid dribbling, and standing voiding function were also evaluated using either 3 or 5 point Likert scales. Stricture recurrence was defined as the inability to easily pass a 16Fr flexible videocystoscope. Multivariable binary logistic regression was used to examine the associations between outcomes and patient satisfaction.

RESULTS

A total of 387 patients completed the study with a mean age of 49.5 years and a mean stricture length of 4.5 cm. Location was bulbar (59.4%), penile (19.6%), posterior (13.7%) and pan-urethral (7.2%). At 6-months, 96.1% of patients were stricture-free, 81.6% reported being satisfied with surgery and 8% were unsatisfied. On multivariable binary logistic regression, improvement in International Prostate Symptom Score (odds ratio [OR]: 1.1, 95% confidence interval [CI]: 1.1-1.2, P = .04), new erectile dysfunction (OR: 0.5, 95% CI: 0.2-0.9, P = .04), new penile curvature (OR: 0.4, 95% CI: 0.2-0.9, P = .03) and improved standing voiding function (OR: 1.3, 95% CI: 1.1-1.5, P = .004) were associated with patient satisfaction. Cystoscopic success (P = .60), change in pain score (P = .14), postvoid dribbling (P = .69), change in penile length (P = .44), and ejaculatory dysfunction (P = .51) were not.

CONCLUSION

Improved voiding function, patient-reported penile curvature, new erectile dysfunction and improved standing voiding are independently associated with patient satisfaction after urethroplasty and should be incorporated into any patient-centered approach to urethral stricture management.

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.

Three new experimental models of anterior urethral stricture in rabbits

Background

This study describes and compares three surgical procedures for the construction of urethral stricture (US) models in rabbits.

Methods

Forty adult male rabbits were allocated to four groups: 36 rabbits were randomly assigned to three experimental groups, while the remaining 4 were assigned to a sham group. The penis was separated from the rectum. Then along the ventral midline, a longitudinal penile skin incision was made while ensuring that the urethral mucosa was intact and the muscular layer was not completely incised. In group 1 (n=12), ventral semi-circumferential mucosa electrocoagulation of a 1-cm length of the anterior urethra was performed until ulceration occurred. In group 2 (n=12), the ventral urethral mucosa was incised, and electrocoagulation of the dorsal semi-circumferential mucosa was performed. In group 3 (n=12), whole-circumferential mucosa electrocoagulation was performed. In group 4 (n=4), no special treatment was performed. Four weeks later, urethrography, urethroscopy, and histological evaluation were carried out.

Results

The weights of the rabbits in the four groups were comparable. There was no significant difference between groups 2 and 3 with regard to operative time, but the operative time in these groups was significantly longer than that in group 1 (group 2 vs. group 1: P<0.05, group 3 vs. group 1: P<0.001). After the surgery, urinary fistula with infection occurred in one rabbit in group 1, and one rabbit died due to urethral atresia in group 3. According to the urethrography and urethroscopy findings, 9 out of 12 rabbits in group 1, 5 out of 12 rabbits in group 2, and 11 out of 11 rabbits in group 3 developed US, while no rabbits in the sham group developed US. Histopathological examination revealed injury to the urothelium, inflammatory infiltration, a decrease in the amount of blood vessels and smooth muscle fibers, and a decrease in the amount of collagen fibers.

Conclusions

Compared with the semi-circumferential procedures, the whole-circumferential procedure had a higher success rate. Therefore, this procedure seems to have potential for the construction of long-segment rabbit US models.

[Pirfenidone alleviates urethral stricture following urethral injury in rats by suppressing TGF-β1 signaling and inflammatory response]

OBJECTIVE

To investigate the effect of pirfenidone for reducing urethral stricture following urethral injury in rats and explore the possible mechanism.

METHODS

Thirty male SD rats were randomly assigned into negative control group, positive control group and pirfenidone group (n=10). In pirfenidone and positive control groups, the rats were subjected to incision of the posterior urethral cavernous body followed by daily intraperitoneal injection of pirfenidone (100 mg/kg) and an equivalent volume of solvent, respectively. The rats in the negative control group were given intraperitoneal injections of solvent without urethral injury. At two weeks after modeling, retrograde urethrography was performed for observing urethral stricture, and the injured urethral tissues were harvested for HE staining, Masson staining, immunohistochemical staining and Western blotting for detecting the protein expressions of α-SMA and TGF-β1. The mRNA expressions of the inflammatory factors TNF-α, IL-6, and IL-1β were detected using qRT-PCR.

RESULTS

The body weight of the rats in pirfenidone group was significantly decreased compared with that in the other two groups (P < 0.05). Retrograde urethrography showed significant narrowing of the urethra in the positive control group but not in the pirfenidone group. HE staining of the injured urethral tissues showed obvious proliferation of urethral epithelial cells with narrow urethral cavity and increased inflammatory cells in positive control group. The pathological findings of the urethra were similar between pirfenidone group and the negative control group. Masson staining revealed obviously reduced collagen fibers and regular arrangement of the fibers in pirfenidone group as compared to the positive control group. Compared with those in the negative control group, the expressions of α-SMA and TGF-β1 were significantly increased in the positive control group, and pirfenidone treatment significantly inhibited their expressions (P < 0.05 or 0.01). Pirfenidone also significantly inhibited the mRNA expressions of TNF-α, IL-6, and IL-1β in the injured urethral tissue (P < 0.05 or 0.01).

CONCLUSION

Pirfenidone can prevent urethral fibrosis and stricture after urethral injury possibly by inhibiting the TGF-β1 pathway and inflammatory response.

A Systematic Review and Meta-analysis of Adjuncts to Minimally Invasive Treatment of Urethral Stricture in Men

CONTEXT

Urethral stricture disease (USD) is initially managed with minimally invasive techniques such as urethrotomy and urethral dilatation. Minimally invasive techniques are associated with a high recurrence rate, especially in recurrent USD. Adjunctive measures, such as local drug injection, have been used in an attempt to reduce recurrence rates.

OBJECTIVE

To systematically review evidence for the efficacy and safety of adjuncts used alongside minimally invasive treatment of USD.

EVIDENCE ACQUISITION

A systematic review of the literature published between 1990 and 2020 was conducted in accordance with the PRISMA checklist.

EVIDENCE SYNTHESIS

A total of 26 studies were included in the systematic review, from which 13 different adjuncts were identified, including intralesional injection (triamcinolone, n = 135; prednisolone, n = 58; mitomycin C, n = 142; steroid-mitomycin C-hyaluronidase, n = 103, triamcinolone-mitomycin C-N-acetyl cysteine, n = 50; platelet-rich plasma, n = 44), intraluminal instillation (mitomycin C, n = 20; hyaluronic acid and carboxymethylcellulose, n = 70; captopril, n = 37; 192-iridium brachytherapy, n = 10), application via a lubricated catheter (triamcinolone, n = 124), application via a coated balloon (paclitaxel, n = 106), and enteral application (tamoxifen, n = 30; deflazacort, n = 36). Overall, 13 randomised controlled trials were included in the meta-analysis. Use of any adjunct was associated with a lower rate of USD recurrence (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.27-0.50; p <  0.001) compared to no adjunct use. Of all the adjuncts, mitomycin C was associated with the lowest rate of USD recurrence (intralesional injection: OR 0.23, 95% CI 0.11-0.48; p <  0.001; intraluminal injection: OR 0.11, 95% CI 0.02-0.61; p =  0.01). Urinary tract infection (2.9-14%), bleeding (8.8%), and extravasation (5.8%) were associated with steroid injection; pruritis of the urethra (61%) occurred after instillation of captopril; mild gynaecomastia (6.7%) and gastrointestinal side effects (6.7%) were associated with oral tamoxifen.

CONCLUSIONS

Adjuncts to minimally invasive treatment of USD appear to lower the recurrence rate and are associated with a low adjunct-specific complication rate. However, the studies included were at high risk of bias. Mitomycin C is the adjunct supported by the highest level of evidence.

PATIENT SUMMARY

We reviewed studies on additional therapies (called adjuncts) to minimally invasive treatments for narrowing of the urethra in men. Adjuncts such as mitomycin C injection result in a lower recurrence rate compared to no adjunct use. The use of adjuncts appeared to be safe and complications are uncommon; however, the studies were small and of low quality.

Successful engraftment of epithelial cells derived from autologous rabbit buccal mucosal tissue, encapsulated in a polymer scaffold in a rabbit model of a urethral stricture, transplanted using the transurethral approach

Background

A pilot study reported an autologous buccal mucosal cell transplant in humans through the trans-urethral route using the buccal epithelium expanded and encapsulated in scaffold-hybrid approach to urethral stricture (BEES-HAUS), a minimally invasive approach to treat urethral stricture. Although successful outcomes were achieved in that study, for further validation, it is essential to prove that the transplanted buccal epithelium was engrafted over the urothelium through histological examination of the urethra, harvested post-transplant, which is infeasible in humans. Herein, we report the successful creation of an animal model of urethral stricture and the engraftment of epithelial cells derived from autologous buccal mucosal tissue, encapsulated in a thermo-reversible gelation polymer (TGP) scaffold, transplanted by trans-urethral route.

Methods

An animal model of urethral stricture was created in Japanese white male rabbits using electro-coagulation. Buccal tissue was harvested from the rabbits and subjected to enzyme digestion, followed by 5-7 days of in vitro culture in conventional two-dimensional (2D) culture and in a 3D platform of thermo-reversible gelation polymer (3D-TGP) culture. The cells harvested from the groups were mixed and encapsulated and transplanted with TGP, by transurethral catheterization. Fourteen days later, the urethra was harvested and subjected to histological examination. The buccal biopsy tissue, cells after digestion and cells post-culture were also subjected to histological examination. Urethrogram and endoscopy images were recorded at different time points.

Results

The stricture was successfully created, with the coagulated area markedly stenosed. Histological staining of the cells after in vitro processing showed that the cells grew with native epithelial and rounded cell morphology in 3D-TGP while they differentiated into fibroblast like-cells in 2D culture. Histological staining of the urethral tissue after transplantation revealed the engraftment of the transplanted buccal mucosal cells, with stratified squamous epithelium over the specialized stratified urothelium in the urethrotomy site.

Conclusion

We used histology to prove the successful engraftment of TGP-encapsulated buccal mucosal epithelial cells in an animal model of urethral injury with healing of the injured tissue. The model of urethral stricture and cell therapy, using a transurethral approach, recapitulates the previously reported BEES-HAUS approach and lays the foundation for larger multi-centric translational clinical studies.

Therapeutic Applications of Functional Nanomaterials for Prostatitis

Prostatitis is a common disease in adult males, with characteristics of a poor treatment response and easy recurrence, which seriously affects the patient's quality of life. The prostate is located deep in the pelvic cavity, and thus a traditional infusion or other treatment methods are unable to easily act directly on the prostate, leading to poor therapeutic effects. Therefore, the development of new diagnostic and treatment strategies has become a research hotspot in the field of prostatitis treatment. In recent years, nanomaterials have been widely used in the diagnosis and treatment of various infectious diseases. Nanotechnology is a promising tool for 1) the accurate diagnosis of diseases; 2) improving the targeting of drug delivery systems; 3) intelligent, controlled drug release; and 4) multimode collaborative treatment, which is expected to be applied in the diagnosis and treatment of prostatitis. Nanotechnology is attracting attention in the diagnosis, prevention and treatment of prostatitis. However, as a new research area, systematic reviews on the application of nanomaterials in the diagnosis and treatment of prostatitis are still lacking. In this mini-review, we will highlight the treatment approaches for and challenges associated with prostatitis and describe the advantages of functional nanoparticles in improving treatment effectiveness and overcoming side effects.

Therapeutic Applications of Functional Nanomaterials for Prostatitis

Prostatitis is a common disease in adult males, with characteristics of a poor treatment response and easy recurrence, which seriously affects the patient’s quality of life. The prostate is located deep in the pelvic cavity, and thus a traditional infusion or other treatment methods are unable to easily act directly on the prostate, leading to poor therapeutic effects. Therefore, the development of new diagnostic and treatment strategies has become a research hotspot in the field of prostatitis treatment. In recent years, nanomaterials have been widely used in the diagnosis and treatment of various infectious diseases. Nanotechnology is a promising tool for 1) the accurate diagnosis of diseases; 2) improving the targeting of drug delivery systems; 3) intelligent, controlled drug release; and 4) multimode collaborative treatment, which is expected to be applied in the diagnosis and treatment of prostatitis. Nanotechnology is attracting attention in the diagnosis, prevention and treatment of prostatitis. However, as a new research area, systematic reviews on the application of nanomaterials in the diagnosis and treatment of prostatitis are still lacking. In this mini-review, we will highlight the treatment approaches for and challenges associated with prostatitis and describe the advantages of functional nanoparticles in improving treatment effectiveness and overcoming side effects.