Evaluation and management of anterior urethral stricture disease

The use of amniotic membrane injection as an adjunct in endoscopic urethral stricture management

Introduction

Endoscopic urethral stricture treatment has high recurrence rates. Due to research supporting amniotic membrane's (AMs) anti-inflammatory and anti-fibrotic properties reducing scar tissue formation, AM has generated interest in reconstructive urethral surgery. To the best of our knowledge, we performed the first investigation of the success rate of urethral dilation when combined with micronized AM injection for the treatment of urethral stricture.

Methods

Eligible patients were adult males with anterior strictures meeting strict criteria for diameter, length, International Prostate Symptom Score (IPSS), and flow rate. Micronized AM was injected in the stricture region during urethral dilation. The primary study endpoint was an anatomical success (≥14Fr) at 6 months. Secondary endpoints were evaluated with the IPSS, urethral stricture surgery - patient-related outcome measure, International Index of Erectile Function, flow rate, and postvoid residual. Outcomes were assessed at baseline and multiple points postinjection. Injection safety was analyzed.

Results

Ten men with a mean age of 52 years were included in the study. At 6 months, 7 of 10 patients demonstrated recurrence of the urethral stricture on cystoscopy. Improvements in secondary endpoints were noted in 10 of 10 patients at 3 months and 3 of 10 patients at 6 months. No adverse events were observed.

Conclusions

To the best of our knowledge, this is the first study evaluating micronized AM injection as an adjunct treatment at the time of urethral dilation. The urethral stricture recurrence rate did not improve with the injection of AM despite the hypothesized benefits of anti-fibrotic and anti-inflammatory properties.

Current Potential Outcomes of Buccal Mucosal Graft Anterior Urethroplasty for Male Urethral Stricture: A Single-Centre Study in Nepal

Objective This study evaluates the efficacy and potential complications of Buccal Mucosal Graft (BMG) urethroplasty for anterior urethral stricture over a 48-month follow-up. Method A retrospective review was conducted on 130 patients who underwent various types of BMG urethroplasty between 2012 and 2019. Data on patient demographics, stricture etiology, and anatomic site were collected. Adverse outcomes such as complications like erectile dysfunction (ED) persisting for over 12 months, and post-micturition dribbling (PMD) were analyzed to determine success rates, recurrent stricture risk factors, complications, and the definition of failure as stricture recurrence during the 48-month follow-up period. Results Of the 130 patients, there was a recurrence in 15.4 % (20 males), yielding a success rate of 84.6% (n=110). ED was reported in 11% (n=14) and PMD in 14% (n=18). All instances of ED were non-organic, and patients were administered oral phosphodiesterase type 5 (PDE5) inhibitors. These complications were observed in 20 patients (15.4%); with urinary fistula (3.0%), graft contracture (2.3%), graft failure (3.8%), urinary tract infection (UTI) (3.0%), and wound infection (2.3%) being the most prevalent after penile urethroplasty. Univariate analysis indicated age (31-50 years, >50 = P<0.05) at surgery, etiology (Balanitis Xerotica Obliterans (BXO) = P<0.05), stricture length (4.1-8 cm, >8 cm = P<0.05), and location as significant predictors of stricture recurrence. However, multivariate analysis highlighted penile location (P<0.05) as the sole independent predictor for restricture during the follow-up period. Conclusion BMG urethroplasty demonstrates a substantial 84.6% success rate in treating anterior urethral stricture over a 48-month follow-up period. This outcome underscores the advancements in healthcare quality in resource-limited settings in countries like Nepal.

Analysis of the urethral stricture score and patient-related factors as predictors of outcomes following oral mucosal graft urethroplasty

Objective

The complexity of urethral strictures can predict outcomes following urethroplasty. The previously described urethral stricture score (U score) considered only stricture-related factors to grade the complexity of urethral strictures and to predict recurrence post urethroplasty, but not considered patient-related factors for the same. We aimed to study the correlation of both of these factors to the outcomes of oral mucosal graft urethroplasty.

Methods

We retrospectively reviewed data of 101 patients who underwent oral mucosal graft urethroplasty in our institute with a minimum follow-up of 6 months. Baseline patient characteristics and stricture-related parameters were noted. The U score was calculated for all patients which consisted of the length, location, number, and etiology of stricture. Univariate and multivariate Cox proportional hazard regression models were used to determine significant risk factors of recurrence.

Results

The mean follow-up of patients was 15 months. Recurrence was seen in 28 patients and the mean time for detection of recurrence was 8 months of follow-up. The Charlson Comorbidity Index, history of previous intervention, length of strictures, location of strictures, number of strictures, history of smoking, and etiology were independent predictors of recurrence following urethroplasty. Based on these parameters, we formulated the modified U score (MU score). The scores ranged from 0 to 6 and a score of >2 was found to be predictive of recurrence. On comparing receiver operating characteristic curves for both scores by the DeLong test, the MU score had larger area under the curve than the U score.

Conclusion

The MU scoring system is the first of its kind attempt taking into consideration both patient- and stricture-related factors to predict recurrence following oral mucosal graft urethroplasty.

Is urethral stricture really so often idiopathic? Exploring the etiology of urethral strictures in males undergoing urethroplasty: a multicenter retrospective cohort study

Introduction

The aim of this study was to retrospectively evaluate the etiology of urethral stricture disease (USD) in a large series of patients undergoing urethroplasty.

Material and methods

The multicenter retrospective cohort study was conducted at two reconstructive urology referral centers in years 2015-2022. Prior to the surgical intervention, all patients underwent diagnostic procedures including retrograde urethrography and voiding cystourethrography. We collected comprehensive demographic and medical data including the length and location of the stricture. We paid particular attention to identifying the underlying causes of USD in the medical records.

Results

The study included 949 patients meeting criteria, with a mean age of 53. The primary cause of USD was identified as iatrogenic (404 cases, 42.6%), followed by trauma (210, 22.1%), previous hypospadias repair (122, 12.9%), lichen sclerosus (32, 3.4%), and infections (12, 1.3%). Notably, 169 patients (17.8%) did not have a discernible cause for their USD and were thus classified as idiopathic. Furthermore, it was observed that 66% of idiopathic USD cases were localized in the bulbar urethra. The etiology of USD varied significantly based on its localization (p <0.01). The mean stricture length differed among different causes, with the longest in patients with USD due to lichen sclerosus (41 mm), followed by previous hypospadias repair (35 mm), and iatrogenic causes (29 mm), p <0.001.

Conclusions

Careful medical history-taking can identify the etiology of urethral stricture in over 80% of patients undergoing urethroplasty. The etiology of the USD impacts its location and length and thus can affect surgical treatment strategy and outcomes.

Tissue Engineering for Penile Reconstruction

The penis is a complex organ with a development cycle from the fetal stage to puberty. In addition, it may suffer from either congenital or acquired anomalies. Penile surgical reconstruction has been the center of interest for many researchers but is still challenging due to the complexity of its anatomy and functionality. In this review, penile anatomy, pathologies, and current treatments are described, including surgical techniques and tissue engineering approaches. The self-assembly technique currently applied is emphasized since it is considered promising for an adequate tissue-engineered penile reconstructed substitute.

An innovative method for occluding the urethral meatus and accessing urethra strictures in retrograde urethrography in males

OBJECTIVES

To observe and evaluate the effectiveness and safety of using a sponge plug method to occlude the urethral meatus during retrograde urethrography (RUG) for accessing male urethral strictures.

METHODS

40 male patients with a mean age of 51.4 years and a history of urethral injury were primarily diagnosed with urethral stricture using a urethrocystoscope. RUG was performed using a ureteral catheter with a sponge plug inserted into the external meatus. Iodixanol, a contrast medium, was injected into the urethra or bladder for performing RUG and voiding cystourethrography (VCUG). The patients were positioned obliquely to obtain urethrograms.

RESULTS

All X-ray radiologic procedures for performing urethrography were successful without any overflow of contrast liquid observed. In all cases, the sponge plugs became visible in the resulting images. The external meatuses were directly visualized in all cases on the obtained images, allowing identification of the number, location, and length of strictures as well as coexistent pathologies such as fistulas. In one case, the plug slipped off the meatus immediately after completing the procedure. The pain Visual Analogue Scale (VAS) was 0 to 2, mean 0.35. No instances of complication or adverse reactions was observed.

CONCLUSIONS

The sponge plug effectively occludes the external urethral meatus for retrograde urethrography, enabling visualization of the actual caliber of the entire urethra, including the strictures and external meatus, by filling it with contrast liquid. This technique is safe and well-tolerated by patients.

Tissue Engineering for Gastrointestinal and Genitourinary Tracts

The gastrointestinal and genitourinary tracts share several similarities. Primarily, these tissues are composed of hollow structures lined by an epithelium through which materials need to flow with the help of peristalsis brought by muscle contraction. In the case of the gastrointestinal tract, solid or liquid food must circulate to be digested and absorbed and the waste products eliminated. In the case of the urinary tract, the urine produced by the kidneys must flow to the bladder, where it is stored until its elimination from the body. Finally, in the case of the vagina, it must allow the evacuation of blood during menstruation, accommodate the male sexual organ during coitus, and is the natural way to birth a child. The present review describes the anatomy, pathologies, and treatments of such organs, emphasizing tissue engineering strategies.

Buccal mucosal graft urethroplasty for anterior urethral stricture, experience from a low-income country

Background/purpose

This study was conducted to present our experience in urethral mucosal graft urethroplasty to repair urethral stricture, as the first experience in our context.

Methods

This is a prospective hospital-based study that had been designed to review management outcomes of buccal mucosal graft urethroplasty for anterior urethral stricture from January 2017 to January 2019.

Results

The total number of involved patients was 60. The success rate was found to be 90% (n = 54), while 6 (10%) had a recurrence of stricture. Pain and pain combined bleeding from internal suture lines were the only early complication encountered in 50 (83.3%) and 2 (3.3%) patients, respectively. late complications occurred as follows 14 (23.3%) patients had UTI, 12 (20%) had wound infections, 8 (13.3%) had changes in ejaculation, and decrease in intensity of orgasm, and 6 (10%) had erectile dysfunction. One of the long-term complications was graft diverticulum in one case and was treated conservatively (in ventral on lay BMG).

Conclusion

Improvement of the service in limited resources countries like Sudan and was reflected in the excellent outcome of BMG urethroplasty as treatment of anterior urethral stricture (success rate 90%).

Considerations for the clinical use of stem cells in genitourinary regenerative medicine

The genitourinary tract can be affected by several pathologies which require repair or replacement to recover biological functions. Current therapeutic strategies are challenged by a growing shortage of adequate tissues. Therefore, new options must be considered for the treatment of patients, with the use of stem cells (SCs) being attractive. Two different strategies can be derived from stem cell use: Cell therapy and tissue therapy, mainly through tissue engineering. The recent advances using these approaches are described in this review, with a focus on stromal/mesenchymal cells found in adipose tissue. Indeed, the accessibility, high yield at harvest as well as anti-fibrotic, immunomodulatory and proangiogenic properties make adipose-derived stromal/SCs promising alternatives to the therapies currently offered to patients. Finally, an innovative technique allowing tissue reconstruction without exogenous material, the self-assembly approach, will be presented. Despite advances, more studies are needed to translate such approaches from the bench to clinics in urology. For the 21^st century, cell and tissue therapies based on SCs are certainly the future of genitourinary regenerative medicine.

Genitourinary Tissue Engineering: Reconstruction and Research Models

Tissue engineering is an emerging field of research that initially aimed to produce 3D tissues to bypass the lack of adequate tissues for the repair or replacement of deficient organs. The basis of tissue engineering protocols is to create scaffolds, which can have a synthetic or natural origin, seeded or not with cells. At the same time, more and more studies have indicated the low clinic translation rate of research realised using standard cell culture conditions, i.e., cells on plastic surfaces or using animal models that are too different from humans. New models are needed to mimic the 3D organisation of tissue and the cells themselves and the interaction between cells and the extracellular matrix. In this regard, urology and gynaecology fields are of particular interest. The urethra and vagina can be sites suffering from many pathologies without currently adequate treatment options. Due to the specific organisation of the human urethral/bladder and vaginal epithelium, current research models remain poorly representative. In this review, the anatomy, the current pathologies, and the treatments will be described before focusing on producing tissues and research models using tissue engineering. An emphasis is made on the self-assembly approach, which allows tissue production without the need for biomaterials.

Reconstruction of Vascular and Urologic Tubular Grafts by Tissue Engineering

Tissue engineering is one of the most promising scientific breakthroughs of the late 20th century. Its objective is to produce in vitro tissues or organs to repair and replace damaged ones using various techniques, biomaterials, and cells. Tissue engineering emerged to substitute the use of native autologous tissues, whose quantities are sometimes insufficient to correct the most severe pathologies. Indeed, the patient’s health status, regulations, or fibrotic scars at the site of the initial biopsy limit their availability, especially to treat recurrence. This new technology relies on the use of biomaterials to create scaffolds on which the patient’s cells can be seeded. This review focuses on the reconstruction, by tissue engineering, of two types of tissue with tubular structures: vascular and urological grafts. The emphasis is on self-assembly methods which allow the production of tissue/organ substitute without the use of exogenous material, with the patient’s cells producing their own scaffold. These continuously improved techniques, which allow rapid graft integration without immune rejection in the treatment of severely burned patients, give hope that similar results will be observed in the vascular and urological fields.

Multimodality imaging of the male urethra: trauma, infection, neoplasm, and common surgical repairs

OBJECTIVE

The aim of this article is to describe the indications and proper technique for RUG and MRI, their respective image findings in various disease states, and the common surgical techniques and imaging strategies employed for stricture correction.

RESULTS

Because of its length and passage through numerous anatomic structures, the adult male urethra can undergo a wide array of acquired maladies, including traumatic injury, infection, and neoplasm. For the urologist, imaging plays a crucial role in the diagnosis of these conditions, as well as complications such as stricture and fistula formation. While retrograde urethrography (RUG) and voiding cystourethrography (VCUG) have traditionally been the cornerstone of urethral imaging, MRI has become a useful adjunct particularly for the staging of suspected urethral neoplasm, visualization of complex posterior urethral fistulas, and problem solving for indeterminate findings at RUG.

CONCLUSIONS

Familiarity with common urethral pathology, as well as its appearance on conventional urethrography and MRI, is crucial for the radiologist in order to guide the treating urologist in patient management.

Penile urethral stricture disease

Patients affected by a urethral stricture account for a considerable cost to all healthcare systems. The estimated prevalence of all urethral stricture in the UK is 10/100,000 men during youth, increasing to about 40/100,000 by age 65 years and to more than 100/100,000 thereafter. A penile urethral stricture is a narrowing of the lumen of the urethra due to ischaemic fibrosis of the urethral epithelium and/or spongiofibrosis of the corpus spongiosum occurring within the penile urethra. Its aetiology is largely idiopathic but other important causes are failed hypospadias repair and lichen sclerosus, which account for 60% of all cases. Strictures of the anterior urethra account for 92% of cases: bulbar strictures are more frequent (46.9%), followed by penile (30.5%) and combined bulbar/penile (9.9%), that is, 40.4% of all men presenting with stricture will have a penile urethral stricture alone or in combination with a bulbar urethral stricture. There are several options for the treatment of penile urethral strictures ranging from less invasive treatments, including urethral dilatation and direct vision internal urethrotomy, to more complex augmentation graft and flap urethroplasty. The aim of the present review is to describe the aetiology and epidemiology of anterior urethral strictures and the available options reported in literature for their treatment.

Level of evidence: 1a

Lingual mucosal graft urethroplasty 12 years later: Systematic review and meta-analysis

Objective

To evaluate the functional results and complications of the lingual mucosal graft (LMG) urethroplasty and to sum up the current state of the art of this surgical technique.

Methods

A systematic search of PubMed and Scopus electronic databases was performed, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies involving male patients treated with LMG urethroplasty for urethral stricture were included. Complete protocol is available at http://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42017080121. A meta-analysis comparing functional and long-term oral complication outcomes of LMG and buccal mucosal graft (BMG) was performed, calculating the odds ratio (OR) and 95% confidence interval (CI).

Results

Twenty original articles were included in the qualitative analysis. Strictures of 1.5-16.5 cm have been treated with LMG urethroplasty, due to the improvement of harvesting technique and very low rate of long-term oral complications. Very good functional results have been reported by different authors for LMG urethroplasty, with lower rate of oral complications than BMG. The meta-analysis included six comparative studies involving 187 and 178 patients treated with LMG and BMG urethroplasty, respectively. An OR of 1.65 (95% CI [0.95-2.87], I ² = 0%) and 0.18 (95% CI [0.03-1.26], I ² = 68%) were found for LMG vs. BMG urethroplasty, in terms of success and oral complication rate, respectively.

Conclusion

LMG urethroplasty can be reasonably considered a first choice technique for urethral stricture with very good results. Oral complications are temporary and minimally disabling, basically less than those for BMG, and depend mainly on the graft extent.

Three-Dimensional Imaging of Urethral Stricture Disease and Urethral Pathology for Operative Planning

Diagnosing urethral pathology can prove difficult, as clinically, the presentation is often nonspecific and may be suggestive of multiple etiologies. Therefore, detailed and accurate urethral imaging in both males and females is critical. Since the early 1900s, conventional imaging studies including RUG and VCUG, with adjunct cystourethroscopy, have remained the gold standard diagnostic techniques to evaluate urethral pathology. However, limitations of conventional imaging have generated interest in finding alternative imaging modalities with comparable, if not superior, diagnostic accuracy, the goal being a more complete assessment of urethral pathology and anatomy that would allow for appropriate surgical planning. Imaging modalities with three-dimensional (3D) capabilities may provide more comprehensive information regarding urethral diseases through a more detailed illustration of periurethral soft tissue structures. Whether or not these imaging modalities will replace conventional studies is unclear, though there is an increasing body of literature that support their use.