Evaluation and management of anterior urethral stricture disease

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.