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Concept: Urethral stricture

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PURPOSE: The long-term success rate of dilation and/or internal urethrotomy is low in cases of recurrent urethral stricture disease. This study investigated the Memokath™044TW stent’s ability to maintain urethral patency after dilation or internal urethrotomy of recurrent urethral stricture. MATERIALS AND METHODS: Ninety-two patients with recurrent bulbar urethral strictures (mean length 2.7 cm) were treated with dilation or internal urethrotomy and randomized to short-term urethral catheter diversion (N=29) or insertion of a Memokath™044 stent (N=63). The primary endpoint was urethral patency as assessed by the passage of a calibrated endoscope. Secondary endpoints included urinary symptoms and uroflowmetry parameters. Stents were scheduled to remain in situ 12 months. RESULTS: The rate of successful stent insertion was 93.6% (59/63). The stented patients maintained patency significantly longer than controls (292 days vs. 84 days (median), p<0.001). The patency was reflected in significantly improved uroflowmetry and symptom scores. The stent was removed in 100% of patients. The most frequently noted side-effects in the stented patients were bacteriuria, hematuria, and penile pain - all usually mild and transient. There were no differences in sexual function between the Memokath and control patients. Stent dislocation and occlusion were observed in eight and three patients, respectively. CONCLUSIONS: Patients with recurrent bulbar urethral strictures treated with dilation or urethrotomy and a Memokath™044 stent maintained urethral patency significantly longer than those treated with dilation or urethrotomy alone. The stent's side-effect profile was favorable. The stent was straightforward to insert and was removed without difficulty - even after long-term placement.

Concepts: Time, Medical terms, Urethra, Stent, Restenosis, Urethral stricture, Urethrotomy, Insertion

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The field of tissue engineering is rapidly progressing. Much work has gone into developing a tissue engineered urethral graft. Current grafts, when long, can create initial donor site morbidity. In this article, we evaluate the progress made in finding a tissue engineered substitute for the human urethra. Researchers have investigated cell-free and cell-seeded grafts. We discuss different approaches to developing these grafts and review their reported successes in human studies. With further work, tissue engineered grafts may facilitate the management of lengthy urethral strictures requiring oral mucosa substitution urethroplasty.

Concepts: Science, Urethral stricture, Chemical engineering, Biomedical engineering

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Strictures of the urethra are the most common cause of obstructed micturition in younger men and frequently recur after initial treatment. Standard treatment comprises internal widening of the strictured area by simple dilatation or by telescope-guided internal cutting (optical urethrotomy), but these interventions are associated with a high failure rate requiring repeated treatment. The alternative option of open urethroplasty whereby the urethral lumen is permanently widened by removal or grafting of the strictured segment is less likely to fail but requires greater expertise. Findings of Improved choice of graft material and shortened hospital stay suggest that urethroplasty may be under utilised. The extent and quality of evidence guiding treatment choice for this condition are uncertain.  

Concepts: Urethra, Urination, Failure, Urethral stricture, Failure rate, Urethrotomy, Reliability engineering, Cystoscopy

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OBJECTIVE: To compare lingual and buccal mucosa graft urethroplasty for anterior urethral stricture with respect to intraoperative, postoperative parameters and urethroplasty outcome. METHODS: From January 2011 to December 2011, a total of 30 patients with anterior urethral stricture whereas group 2 underwent dorsal onlay buccal mucosa graft urethroplasty. Patients were evaluated for postoperative, tongue protrusion, oral opening, and difficulty in speech and swallowing pain score. Surgical outcome was evaluated with pre- and postoperative work-up involving retrograde urethrogram, uroflow and urethroscopy. RESULTS: Mean age, stricture length and overall pain score were comparable in two groups. All the patients were mostly pain free by postoperative day 7. Group 1 patients had significant difficulty in speech and delayed return to normal diet as compared with group 2. The group 2 patients had a significant reduction in oral opening for the first week after surgery. In group 1, approximately 20% patients (with bilateral lingual grafts and stricture length >7 cm) complained of a change in speech character with restricted tongue movement in the long term, whereas there was no significant long-term morbidity in group 2. At mean follow up of 14.5 months, urethroplasty outcome was comparable in the two groups with one failure in group 1, and two failures in group 2. CONCLUSION: Lingual mucosa graft urethroplasty provides outcomes equivalent to those of buccal mucosa graft urethroplasty. Postoperative morbidity and long-term change in speech make it a second choice for strictures >7 cm, only for cases where buccal mucosa graft is unavailable.

Concepts: Mouth, Term, Urethral stricture, Tongue, Lingual nerve, Buccal mucosa, Urethroplasty

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Background: To evaluate the effects of hyaluronic acid (HA) and carboxymethylcellulose (CMC) on the recurrence of urethral stricture after a treatment with endoscopic internal urethrotomy (EIU). Methods: A total of 120 patients who underwent EIU for urethral stricture. Recruited patients were randomly divided into 2 groups: group A and B. Patients in group A (60 patients, experimental group) received HA/CMC instillation and patients in the group B (60 patients, control group) received lubricant instillation after internal urethrotomy. Each patient was evaluated at 4 weeks (V1), 12 weeks (V2) and 24 weeks (V3) after the surgery. The effectiveness of HA/CMC instillation was evaluated based on the International Prostate Symptom Score (IPSS)/ Quality of Life (QoL), peak urine flow rate (Qmax), voided volume and post-voiding residual urine volume (PVR). The visual analogue scale (VAS) pain score and degree of satisfaction were also determined for each participant. Results: Among 120 initial participants, 53 patients in group A and 48 patients in group B had completed the experiment. VAS pain scores were 0.67±0.76 and 3.60±1.52 (p<0.001), and degrees of satisfaction were 0.28±0.50 and 0.80±0.81 in group A and group B at 1 month after surgery (p=0.001). The recurrence of urethral stricture was observed in 5 cases (9.4%) in group A and 11 (22.9%) in group B (p=0.029). Conclusions: HA/CMC instillation during EIU may decrease the incidence of urethral stricture recurrence. In addition, the use of HA/CMC was effective in reducing pain during the early post-operative period without an adverse effect.

Concepts: Urine, Effect, Effectiveness, Urology, Urethra, Experiment, Urethral stricture, International Prostate Symptom Score

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Objective: To establish an experimental rabbit model of urethral stricture using holmium laser under direct urethroscopic visualization. Methods: Sixteen adult male New Zealand rabbits were divided into equally-sized control and experimental groups. All rabbits underwent retrograde urethrography and transurethral endoscopy with a 7.5 F urethroscope after intramuscular anesthetic injection. We used a holmium:YAG laser to injure the distal urethra in all rabbits in the experimental group under direct visualization. Thirty days after surgery, all animals were evaluated with retrograde urethrography and urethroscopy. The flow rate of the isolated urethras was measured to evaluate urethral stricture formation. Results: One rabbit in the experimental group (12.5%) died of infection 4 days after surgery. Thirty days after surgery, retrograde urethrography and urethroscopy revealed strictures in all seven surviving rabbits (87.5%) in the experimental group. The mean flow rate of the isolated urethras was significantly lower in the experimental group than in the control group. Conclusion: A rabbit model of urethral stricture can be successfully established using holmium laser under direct urethroscopic visualization, providing an ideal object for research concerning the pathogenesis and molecular biology of urethral strictures. © 2014 S. Karger AG, Basel.

Concepts: Biology, Surgery, Chemistry, Urethra, Abstract algebra, Urethral stricture, Urethrotomy, New Zealand white rabbit

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Bulbar urethroplasty outcomes studies have shown low, but significant, rates of post- void dribbling (PVD) and ejaculatory dysfunction. The bulbospongiosus muscle is involved with expulsion of seminal fluid and urine from the bulbar urethra, and thus we hypothesized that performing urethroplasty utilizing a technique that does not split the muscle may result in better post-operative patient reported ejaculatory function (EF) and less PVD.

Concepts: Urinary bladder, Semen, Urethral stricture, Ejaculation, Functionalism, Masturbation, Pudendal nerve, Bulbospongiosus muscle

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Radiation-induced urethral stricture occurs most often due to radiation for prostate cancer. It is one of the most common side effects of radiotherapy. Stricture rates are lowest in patients undergoing external beam radiation therapy, occur more frequently in those who require brachytherapy and show highest stricture rates in patients receiving a combination of external beam radiation and brachytherapy. Strictures are mostly located at the bulbomembranous part of the urethra. Diagnostic work-up should include basic urologic work-up, ultrasound, uroflowmetric assessment, urethroscopy, retrograde urethrogram and voiding cystourethrography. Endoscopic management such as dilatation and internal urethrotomy has been proposed in short strictures. However these therapies have a high risk for recurrence. The success rate of urethroplasty is higher. Success rates of primary end-to-end anastomosis (EPA) have been reported to be 70-95 %; rates of incontinence are 7-40 %. While success rates of buccal mucosa graft urethroplasty (BMGU) range from 71-78 %, postoperative incontinence occurs in 10.5-44 %. Usually, postoperative incontinence can successfully be treated with an artificial urinary sphincter. It seems like EPA is the treatment of choice for short urethral strictures, whereas BMGU is indicated in longer, more complex strictures. Patients should be counselled with regard to length and location of strictures as well as with regard to postoperative incontinence.

Concepts: Cancer, Proton therapy, Prostate cancer, Radiation therapy, Urethra, Urethral stricture, Hormonal therapy, External beam radiotherapy

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Meatal stenosis is markedly more common in circumcised than genitally intact males, affecting 5-20 per cent of circumcised boys. However, no population-based study has estimated the relative risk of meatal stenosis and other urethral stricture diseases (USDs) or the population attributable fraction (AFp) associated with non-therapeutic circumcision.

Concepts: Cohort study, Epidemiology, Demography, Actuarial science, Relative risk, Urethral stricture, Circumcision, Meatal stenosis

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Substitution urethroplasty for the treatment of male stricture disease is often accompanied by subsequent tissue fibrosis and secondary stricture formation. Patients with pre-existing morbidities are often at increased risk of urethral stricture recurrence brought upon in-part by delayed vascularization accompanied by overactive inflammatory responses following surgery. Within the context of this study, we demonstrate the functional utility of a cell/scaffold composite graft comprised of human bone marrow-derived mesenchymal stem cells (MSC) combined with CD34+ hematopoietic stem/progenitor cells (HSPC) to modulate inflammation and wound healing in a rodent model of substitution urethroplasty. Composite grafts demonstrated potent anti-inflammatory effects with regards to tissue macrophage and neutrophil density following urethral tissue analyses. This was accompanied by a significant reduction in pro-inflammatory cytokines TNFα and IL-1β and further resulted in an earlier transition to tissue remodeling and maturation with a shift in collagen type III to I. Grafted animals demonstrated a progressive maturation and increase in vessel size compared to control animals. Overall, MSC/CD34+ HSPC composite grafts reduce inflammation, enhance an earlier transition to wound remodeling and maturation concurrently increasing neovascularization in the periurethral tissue. We demonstrate the feasibility and efficacy of a stem cell-seeded synthetic graft in a rodent substitution urethroplasty model.

Concepts: Inflammation, Collagen, Extracellular matrix, Stem cell, Mesenchymal stem cell, Bone marrow, Anti-inflammatory, Urethral stricture