Urethral Stricture is Frequently a Morbid Condition: Incidence and Factors Associated With Complications Related to Urethral Stricture

Current Trends in the Use of Buccal Grafts during Urethroplasty Among Society of Genitourinary Reconstructive Surgeons

OBJECTIVES

To analyze current standards in urethroplasty by urologists employing buccal mucosal grafts (BMG) for treating urethral stricture disease (USD).

METHODS

An IRB-approved online survey was distributed to members of the Society of Genitourinary Reconstructive Surgeons (GURS) between July and October 2022 to assess BMG utilization in urethroplasty. Questions covered surgeon experience, graft harvest site, graft length, surgical technique, and perceived success rates.

RESULTS

Of 350 invited GURS members, 134 responded (38%). 69% were GURS fellowship-trained, performing 10-30 urethroplasties annually. 95% harvested their own grafts, with 99% preferring buccal mucosa as the primary site. Buccal mucosa was favored over fasciocutaneous flap for penile urethroplasty, regardless of circumcision status (95% with, 84% without). For bulbar urethroplasty with BMG, dorsal graft placement was favored (66%) over ventral (34%). Most surgeons (90%) preferred multiple BMGs over combined graft/flap for panurethral strictures. When harvesting long grafts, 56% preferred using both cheeks. Anastomotic urethroplasty was preferred over buccal graft urethroplasty for short bulbomembranous stenosis post-radiotherapy (63% vs. 37%). Surgeons reported a success rate of 80-90% (53%).

CONCLUSIONS

The expanded scope of reconstructive urology has led to increased use of BMG in diverse urethral reconstructions. Buccal grafts are now preferred for penile, bulbar, and panurethral strictures, demonstrating high perceived success rates in the reconstructive community.

Refining Bacteriuria as a Risk Factor for Complications After Urethroplasty: Identifying the Culprit

OBJECTIVE

To determine which bacteria are associated with an increased risk of 90-day complications after urethroplasty. Preoperative bacteriuria is associated with an increased risk of complications after urethroplasty. However, it remains unclear which specific micro-organisms are the primary drivers of this morbidity.

METHODS

A single-institution, 2-surgeon retrospective review was performed on patients undergoing urethroplasty from 08/2003 to 06/2021. Preoperative bacteriuria was considered significant when the patient had a mixed culture with ≥108 CFU/L or an identifiable micro-organism with ≥106 CFU/L. Descriptive statistics were used to summarize the results and chi-square was used to determine the association between 90-day complications (Clavien ≥2) and clinical characteristics/bacteria.

RESULTS

Out of 1611 patients, 23.2% (373) had significant preoperative bacteriuria. The most common pathogens included coagulase-negative staphylococcus 18.5% (69), mixed growth 15.8% (59), Escherichia coli 10.7% (40), and Enterococcus 14.2% (53). 7.9% (128/1611) experienced a significant 90-day complication (Clavien-Dindo ≥2). Gram-negative bacilli including E coli, Pseudomonas sp, Klebsiella sp, Serratia sp, Citrobacter sp, Achromobacter sp, Stenotrophomonas sp, and Morganella sp were associated with higher rates of postoperative complications (14.2%; P = .01) as well as Enterococcus sp (15.1%; P = .03). However, gram-positive cocci (7.9%; P = .97), gram-positive bacilli (11.8%; P = .47), mixed growth (5.1%; P = .54) and Candida (16.7%; P = .27) were not. Neither escalating concentrations of bacteria (P = .44) or number of strains (P = .08) were associated with increased risk of complications.

CONCLUSION

The main driver of bacteriuria-related complications after urethroplasty are gram-negative bacilli and Enterococcus sp. Patients with bacteriuria related to other micro-organisms can likely proceed with urethroplasty without increased risk of postoperative complications.

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.

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.

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.

Recent Trends and Advances in Anterior Urethroplasty

While patient preference often helps guide treatment decisions, poor long-term success combined with cumulative risk of repeat endoscopic treatments and the complications innately associated with urethral stricture emphasize that urethroplasty is most often the best choice for successful treatment in the long-term. This has led to the need to better refine urethroplasty techniques and optimize patient outcomes. Urethroplasty has now largely transitioned to a day-surgery procedure in the majority of centers. Some evidence suggests that avoiding urethral transection and/or avoiding overzealous urethral mobilization may lead to a reduction in post-operative sexual dysfunction. The trend toward single stage penile urethroplasty with buccal mucosal grafts likely minimizes patient morbidity without compromising urethroplasty success. For urethroplasty success to further improve particularly in patients at high risk for stricture recurrence, the synergistic potential of combining wound healing enhancing agents with evolving tissue-engineering represents an exciting future opportunity in the quest to perfect urethroplasty outcomes.

Simplified urethral score system for predicting complex anterior urethroplasty

OBJECTIVE

To assess U-score individual values as urethral complex surgery predictors.

METHODS

Cross-sectional study including patients who received anterior urethroplasty from 2011 to 2019. U-score (etiology (1-2 points), number of strictures (1-2 points), anatomic location (1-2 points) and length (1-3 points)) was measured individually and globally. Surgical complexity was defined as low (anastomotic, buccal mucosal graft, and augmented anterior urethroplasty), and high complexity (double buccal mucosal graft, flap, and graft/flap combination). U-score components were included as complex surgery predictor and as main variable with individual probability values estimations and comparisons. Risk complex surgery probability groups were established.

RESULTS

654 patients were included. Mean age was 57.2 years. Low complexity surgery was performed in 464 patients (259 anastomotic, 144 graft, 61 augmented anterior urethroplasty) and high complexity was done in 190 (53 double buccal mucosa graft, 27 flap, 110 graft/flap comb.). In multivariate analysis length, number of strictures and location were predictors of complexity. Introducing U-Score as only variable in univariate model predicted an OR 8.52 (95%CI 6.1-11). Simplified U-score grouping set obtained by complex probability was: low risk (4-5 points), medium risk (6 points) and high risk of complexity (7-9 points) Predicted risk of complex surgery probability (95%CI) for low, median and high risk group were 1.6 (0-2.9), 19.1 (13.8-25.9) and 77.9 (61.6-88.7), respectively.

CONCLUSIONS

U-score can be used as a tool to predict complex urethral surgery. We present a simplified U-score risk tool to assess individual complex anterior urethroplasty probability.

Multi-institutional review of non-hypospadiac penile urethral stricture management and outcomes

OBJECTIVES

Penile urethral stricture disease not associated with hypospadias is rare, and there is a wide range of commonly used surgical repair techniques for this disease. We sought to compile a multi-institutional database of patients who had surgical correction of strictures in the penile urethra not limited to the meatus, and who had no history of hypospadias, for analysis using the Trauma and Urologic Reconstructive Network of Surgeons length, urethral segment and etiology classification system.

METHODS

A retrospective database from 13 institutions was compiled of patients who had undergone surgical correction of Trauma and Urologic Reconstructive Network of Surgeons length, urethral segment and etiology urethral stricture segments S2b/S2c and excluding E5, with a minimum follow-up time of 4 months. Failure was defined as cystoscopically confirmed recurrence of a stricture measuring less than 16-Fr.

RESULTS

We analyzed 222 patients with a median age of 57 years and a follow-up of 49 months. The overall surgical success rate was 80.2%. On multivariate analysis, the two variables identified that were predictive of surgical success were stricture length ≤2 cm as well as use of a buccal mucosa graft as compared to use of a fasciocutaneous flap, which had success rates of 83% and 52%, respectively (P = 0.0004). No statistically significant differences were found based on incisional approach or surgical technique, nor were outcomes different based on etiology or preoperative patient demographics.

CONCLUSIONS

Surgical repair of penile urethral strictures of non-hypospadiac origin have a favorable overall success rate, at 80.2%. Regardless of incisional approach or surgical technique, all operations appear to have similar outcomes other than repairs using fasciocutaneous flap, which were statistically less successful than those using buccal mucosa graft.

Extensive perineal Actinomadura pelletieri actinomycetoma-induced urethral stricture: a rare complication

Mycetoma is a neglected tropical disease that causes tremendous suffering and misery to affected patients. In Sudanese rural communities, many patients hide their lesions, especially those located in the perineal, scrotal, inguinal and genital regions, and they regard them as sources of social stigma. We report the case of a 45-year-old male from northern Kordofan State, Sudan, who presented with multiple discharging sinuses in the perineal region. Clinical diagnosis was actinomycetoma and fine-needle aspiration cytology was consistent with Actinomadura pelletieri, confirmed by culture and biochemical analysis. To our knowledge, this is the first case of A. pelletieri with urethral complications and subsequent implications for management.

Effects of Anti-Inflammatory Nanofibers on Urethral Healing

Protracted postsurgical inflammation leading to postoperative complications remains a persistent problem in urethral reconstruction. Nanofibers in the form of peptide amphiphiles expressing anti-inflammatory peptides (AIF-PA) have positively modulated local inflammatory responses. Urethroplasty is performed to repair 5 mm ventral urethral defects with: uncoated small intestinal submucosa (SIS); SIS dip-coated with AIF-PA1 (anti-inflammatory treatment), or SIS dip-coated with AIF-PA6 (control) on 12-week-old male Sprague Dawley rats (n = 6/group/timepoint). Animals are euthanized at 14 and 28 d postsurgery. Hematoxylin-eosin, Masson's Trichrome, and immunohistochemistry with primary antibodies against myeloperoxidase (MPO; neutrophils), CD68, CD86, CD206 (macrophages), and proinflammatory cytokines TNFα and IL-1β are performed. Complete urethral healing occurs in 3/6 uncoated SIS (50%), 2/6 SIS+AIF-PA6 (33.3%), and 5/6 SIS+AIF-PA1 (83.3%) animals at 14 d and all at 28 d. Application of AIF-PA1 to SIS substitution urethroplasty decreases MPO⁺ neutrophils, CD86⁺ M1 proinflammatory macrophages, TNFα, and IL-1β levels while concurrently increasing levels of CD206⁺ M2 proregenerative/anti-inflammatory macrophages at the anastomoses and the regenerated tissue at the wound bed (REGEN). AIF-PA1 treatment enhances the healing process, contributing to earlier, complete urethral healing, and increased angiogenesis. Further studies are needed to elucidate the specific mechanism of inflammatory response modulation on angiogenesis and overall urethral healing.

A Rho kinase inhibitor (Fasudil) suppresses TGF-β mediated autophagy in urethra fibroblasts to attenuate traumatic urethral stricture (TUS) through re-activating Akt/mTOR pathway: An in vitro study

AIMS

Transforming growth factor-β (TGF-β) mediated super-activation of urethra fibroblasts contributes to the progression of traumatic urethral stricture (TUS), and the Rho-associated kinase inhibitors, Fasudil, might be a novel therapeutic agent for TUS, but the underlying mechanisms had not been studied.

MATERIALS AND METHODS

The primary urethral fibroblasts (PUFs) were isolated from rabbit urethral scar tissues and cultured in vitro, and the PUFs were subsequently treated with TGF-β (10 μg/L) to simulate the realistic conditions of TUS pathogenesis. Next, the PUFs were exposed to Fasudil (50 μM) and autophagy inhibitor 3-methyladenine (3-MA) treatment. Genes expression was examined by Western Blot and immunofluorescence staining, and cellular functions were determined by MTT assay and Transwell assay.

KEY FINDINGS

TGF-β promoted cell proliferation, migration, autophagy, and secretion of extracellular matrix (ECM), including collagen I and collagen III, which were reversed by co-treating cells with both Fasudil and 3-MA. In addition, TGF-β treatment decreased the expression levels of phosphorylated Akt (p-Akt) and mTOR (p-mTOR) to inactivate the Akt/mTOR pathway in the PUFs, which could be re-activated by Fasudil. Then, the fibroblasts were treated with the Pan-Akt inhibitor (GDC-0068), and we surprisingly found that GDC-0068 abrogated the inhibiting effects of Fasudil on cell autophagy and proliferation in the PUFs treated with TGF-β.

SIGNIFICANCE

Fasudil regulated Akt/mTOR pathway mediated autophagy to hamper TGF-β-mediated super-activation in PUFs, which supported that Fasudil might be an ideal candidate therapeutic agent for TUS treatment for clinical utilization.

Canadian Urological Association guideline on male urethral stricture

Urethral stricture is fundamentally a fibrosis of the urethral epithelial and associated corpus spongiosum, which in turn, causes obstruction of the urethral lumen. Patients with urethral stricture most commonly present with lower urinary tract symptoms, urinary retention or urinary tract infection but may also experience a broad spectrum of other signs and symptoms, including genitourinary pain, hematuria, abscess, ejaculatory dysfunction, or renal failure. When urethral stricture is initially suspected based on clinical assessment, cystoscopy is suggested as the modality that most accurately establishes the diagnosis. This recommendation is based on several factors, including the accuracy of cystoscopy, as well as its wide availability, lesser overall cost, and comfort of urologists with this technique. When recurrent urethral stricture is suspected, we suggest performing retrograde urethrography to further stage the length and location of the stricture or referring the patient to a physician with expertise in reconstructive urology. Ultimately, the treatment decision depends on several factors, including the type and acuity of patient symptoms, the presence of complications, prior interventions, and the overall impact of the urethral stricture on the patient's quality of life. Endoscopic treatment, either as dilation or internal urethrotomy, is suggested rather than urethroplasty for the initial treatment of urethral stricture. This recommendation applies to men with undifferentiated urethral stricture and does not apply to trauma-related urethral injuries, penile urethral strictures (hypospadias, lichen sclerosus), or suspected urethral malignancy. In the setting of recurrent urethral stricture, urethroplasty is suggested rather than repeat endoscopic management but this may vary depending on patient preference and impact of the symptoms on the patient.The purpose of this guideline is to provide a practical summary outlining the diagnosis and treatment of urethral stricture in the Canadian setting.