The use of self-expanding metallic urethral stents in the treatment of recurrent bulbar urethral strictures: long-term results

Long-term results of permanent memotherm urethral stent in the treatment of recurrent bulbar urethral strictures

PURPOSE

To evaluate the long term outcomes of permanent Memotherm urethral stent in the treatment of recurrent bulbar urethral stricture.

MATERIALS AND METHODS

Twenty patients who underwent permanent Memotherm urethral stent implantation due to recurrent bulbar urethral stricture following previous unsuccessful surgical procedure from 1996 to 2002 were included in the study. Long-term outcomes of the patients were evaluated.

RESULTS

The overall success rate was 87.5% at the end of the tenth year. There was discomfort in implantation area in eight patients about 1 month following the procedure. These patients were treated with alpha-blocker and anti-inflammatory drugs. Stone formation was observed at the urethral stent implantation area in two patients. Post-void dripping has been observed in 15 patients up to the postoperative 3rd month. Stress urinary incontinence was observed in a patient with a 1-year follow-up. Partial stent migration was observed in two patients. None of the patients experienced pain during erection.

CONCLUSION

Memotherm urethral stent is a minimal invasive surgical procedure which can be safely and effectively used in patients with recurrent urethral stricture.

Polydioxanone biodegradable stent placement in a canine urethral model: analysis of inflammatory reaction and biodegradation

PURPOSE

To investigate the inflammatory reaction and perform quantitative analysis of biodegradation after placement of a polydioxanone (PDO) biodegradable stent in a canine urethral model.

MATERIALS AND METHODS

PDO biodegradable stents were placed in the proximal and distal urethra of nine male mongrel dogs. The dogs were euthanized 4 weeks (group A; n = 3), 8 weeks (group B; n = 3), or 12 weeks (group C; n = 3) after stent placement. The luminal diameter of the stent-implanted urethra was assessed by follow-up retrograde urethrography, and histologic findings were obtained after the dogs were killed. Stents were removed after euthanasia, and their surface morphology and molecular weight were evaluated. Hematologic examination was performed to evaluate inflammatory reaction.

RESULTS

Stent placement was technically successful in all dogs. The average luminal diameter gradually decreased. The average number of epithelial layers (2.93 vs 4.42; P < .001), the average thickness of papillary projection (0.80 mm vs 1.28 mm; P < .001), and the average thickness of submucosal fibrosis (0.34 mm vs 0.49 mm ; P < .001) were significantly increased in group B versus group A. There were no significant differences between group B and group C. The average inflammatory cell infiltration did not differ significantly in the three groups. Molecular weight losses were 54% in group A and 84% in group B. In group C, PDO stents were completely decomposed.

CONCLUSIONS

An experimental study in a canine urethral model has demonstrated acceptable inflammatory reaction with gradually increasing granulation tissue but no luminal obstruction within 12 weeks.

The stone formation in the Memotherm urethral stent implantation area: Is it a rare complication?

Recurrent urethral stricture is one of the biggest problems in urology. Urethral stents as an alternative treatment has been used since 1985. The stone formation in the Memotherm (Angiomed) urethral stent implantation area is a rare complication. We report the case of a 67-year-old man who had a stone in the Memotherm urethral stent implantation area 6 years after his urethral stent surgery.

Male urethral strictures and their management

Male urethral stricture disease is prevalent and has a substantial impact on quality of life and health-care costs. Management of urethral strictures is complex and depends on the characteristics of the stricture. Data show that there is no difference between urethral dilation and internal urethrotomy in terms of long-term outcomes; success rates range widely from 8-80%, with long-term success rates of 20-30%. For both of these procedures, the risk of recurrence is greater for men with longer strictures, penile urethral strictures, multiple strictures, presence of infection, or history of prior procedures. Analysis has shown that repeated use of urethrotomy is not clinically effective or cost-effective in these patients. Long-term success rates are higher for surgical reconstruction with urethroplasty, with most studies showing success rates of 85-90%. Many techniques have been utilized for urethroplasty, depending on the location, length, and character of the stricture. Successful management of urethral strictures requires detailed knowledge of anatomy, pathophysiology, proper patient selection, and reconstructive techniques.

Thermo-expandable metallic urethral stents for managing recurrent bulbar urethral strictures: To use or not?

Objectives

To assess the role of temporary thermally expandable urethral stents in maintaining urethral patency in patients with a recurrent bulbar urethral stricture.

Patients and methods

Twenty-three men with a recurrent bulbar urethral stricture after several attempts at direct visual internal urethrotomy (DVIU) and/or failed urethroplasty were managed with a thermally expandable, biocompatible nickel–titanium alloy urethral stent (Memokath® MK044, Pnn Medical, Kvistgaard, Denmark). The stents were applied by a special mounting device via a rigid urethroscope after DVIU. All patients were followed using plain radiography, uroflowmetry and urine analysis every 3 months for 1 year, and then every 6 months.

Results

The mean (SD) age of the patients was 55.4 (7.3) years and the mean (SD) stricture length was 3.6 (1.2) cm. All patients tolerated the stent, with minimal discomfort in some patients. Four patients (17%) had urinary tract infections, three (13%) had haematuria, three (13%) had obstructed stents due to encrustation, in five (22%) the stent migrated, and two patients had no delayed complications. The mean (SD) follow-up was 17.4 (6.1) months.

Conclusion

Urethral stenting with nickel–titanium alloy thermally expandable stents can be an acceptable temporary procedure for patients with recurrent bulbar urethral strictures who are unfit for or who refuse urethroplasty. However, they have limitations; the search for an ideal urethral stent continues.

Management of restenosis after urethral stent placement

PURPOSE

We describe our experience with the management of restricture after urethral stent placement, including endoscopic and open surgical treatment.

MATERIALS AND METHODS

We surveyed our prospectively collected database for patients with restenosis after urethral stent insertion. We reviewed patient age, comorbidities, indications for stent placement, restricture length, management of restricture, postoperative complications and the further restenosis rate.

RESULTS

Overall we have treated 22 patients with failed urethral stents with a median followup of 30 months (range 1 to 96). All stents were initially placed for urethral stricture management. Stricture etiology included prostate cancer therapy in 9 cases, idiopathic causes in 6, urethral instrumentation in 2, trauma in 2, simple prostatectomy in 2 and gender reassignment/phalloplasty in 1. Ten patients had anterior urethral stricture, 11 had posterior stricture and 1 patient had each type. Of the 22 patients with stenosis after stent placement 13 underwent urethroplasty. Of the 18 patients with indwelling stents at treatment the stent was removed in 8 intraoperatively and in 10 the stent was left in situ. Ten of the 11 anterior strictures were treated with urethroplasty. Only 4 of the 12 posterior strictures were treated with urethroplasty, while 8 were managed endoscopically. Our overall success rate for treatment after stent failure was 67% (8 of 12 cases) for posterior urethral strictures and 82% (9 of 11) for anterior strictures.

CONCLUSIONS

Urethral stent failure requires complex intervention. A failed posterior urethral stent can often be managed endoscopically. Conversely we have managed failed anterior urethral stents by urethroplasty.

Management of recurrent urethral strictures with covered retrievable expandable nitinol stents: long-term results

OBJECTIVE

The purpose of this study was to evaluate the long-term clinical efficacy of temporary placement of covered retrievable stents in the management of recurrent urethral strictures.

MATERIALS AND METHODS

During the period December 1998-December 2005, 32 men and one adolescent boy (mean age, 48.6 years; range, 16-73 years) with recurrent urethral strictures underwent fluoroscopically guided insertion of a total of 68 stents. Patients without complications underwent elective stent removal 2 or 4 months after stent insertion. Rates of clinical success (long-term clinical and radiographic resolution of urethral strictures) were assessed. The Mann-Whitney U test was used to compare the duration of stent placement in patients with long-term clinical resolution with that in patients with stricture relapse.

RESULTS

Clinical success was achieved in 18 (55%) of the 33 patients. The mean duration of stent placement in patients with clinical success was significantly different from that in patients who had recurrences (p < 0.0001). Stricture relapse did not occur in only four (20%) of 20 cases of stent placement for 2 months. All 14 stent placements lasting at least 4 months resulted in long-term resolution after a mean follow-up period of 3.6 years. The most common complications necessitating early stent removal were stent migration (33.8% of stents) and tissue hyperplasia (20.6% of stents).

CONCLUSION

Placement of a covered retrievable stent for a minimum of 4 months is effective in inducing long-term resolution of refractory urethral strictures. Stent migration remains the largest obstacle in achieving adequate duration of stent placement.

Endourethral prostheses for urethral stricture

A number of urethral stents made of different materials, with different time of indwelling and different designs, primarily based on the vascular stent concept, have been applied in the clinical practice so far. According to the published studies, urethral stents have justified their clinical application, however with certain limitations. Within an attempt to overcome the limitations, a covered, temporary urethral stent was initially designed by Daniel Yachie and Zeljko Markovic in Allium corporation from Israel. With its triangular shape, the stent is a replica of the obstructive urethral lumen. The follow-up of results was done according to a priori established protocol including the following:UCG, uroflowmetry and interview with patients. Due to stent migration, the stent over stent technique was applied in two case, while reposition by balloon-catheter outward traction was performed in two cases of caudal migration. No irritative discomforts were reported in the first 6 months after stent dwelling. Uroflowmetric controls verified at least four times better results than before the insertion. Given it is the question of covered stent, there is no possibility of proliferative secondary lumen obstruction. On account of soft structure and conic shape of posterior part of stent, no lesions of the external urethral sphincter were manifested. The stent is simply withdrawn after 12 months by outward traction using the forceps at the time when the stent construction turns into soft and straight wire. After 12-16 months in all cases we removel stent and in all patients we find complete rekanalisation without any disuric problem. In 5 cases we find new "contact" stricture on anterior part of stent and treated succeed with balloon recanalisation.

One-stage urethral reconstruction for stricture recurrence after urethral stent placement

PURPOSE

We report our 8-year experience with 1-stage open urethral reconstruction in 10 patients with recurrent bulbar and/or membranous strictures after UroLume urethral stent placement.

MATERIALS AND METHODS

Ten consecutive referral patients underwent preoperative contrast imaging and urethroscopy followed by primary anastomotic repair or substitution urethroplasty, with concomitant open UroLume removal (when the stent was still present). Postoperative evaluation included contrast imaging 3 weeks after surgery, urethroscopy 4 months after surgery, uroflowmetry, and American Urological Association symptom score assessment.

RESULTS

At a medium followup of 51.2 months all patients remain free of bulbar or membranous stricture recurrence. No patient has required dilation or any other intervention.

CONCLUSIONS

One-stage open reconstruction with stent extraction offers a definitive treatment option with a high success rate for patients with recurrent bulbar and/or membranous strictures following urethral stent placement.

Traitement endoscopique des sténoses de l'urètre

The present article reviews the literature regarding the endoscopic treatment of urethral strictures. Only few prospective randomised clinical trials with sufficient power have been performed and most of the literature provides evidence of only level 3 and 4. Since length, location, extent and calibre of the urethral stricture have an important impact on prognosis, diagnosis and the role of ultrasonography are discussed. Pathophysiology of wound healing is discussed in relation to urethrotomy, as it explains the outcomes of the procedure. Operative techniques using cold knife and laser, use of endoprostheses, indications, complications, results and postoperative management are described. The possible role of urethral catheters, hydraulic dilatations and corticosteroid applications are discussed.

Extraction of UroLume endoprostheses with one-stage urethral reconstruction

We describe a technique for transperineal excision of UroLume endoprostheses with one-stage urethral reconstruction. We have used this technique in 3 patients with occluded urethral stents placed for bulbar stricture disease. All patients experienced acceptable outcomes.

Repeat urethrotomy and dilation for the treatment of urethral stricture are neither clinically effective nor cost-effective

PURPOSE

We developed an algorithm for the management of urethral stricture based on cost-effectiveness.

MATERIALS AND METHODS

United Kingdom medical and hospital costs associated with the current management of urethral stricture were calculated using private medical insurance schedules of reimbursement and clean intermittent self-catheterization supply costs. These costs were applied to 126 new patients treated endoscopically for urethral stricture in a general urological setting between January 1, 1991 and December 31, 1999. Treatment failure was defined as recurrent symptomatic stricture requiring further operative intervention following initial intervention. Mean followup available was 25 months (range 1 to 132).

RESULTS

The costs were urethrotomy/urethral dilation 2,250.00 pounds sterling (3,375.00 dollars, ratio 1.00), simple 1-stage urethroplasty 5,015.00 pounds sterling (7,522.50 dollars, ratio 2.23), complex 1-stage urethroplasty 5,335.00 pounds sterling (8,002.50 dollars, ratio 2.37) and 2-stage urethroplasty 10,370 pounds sterling (15,555.00 dollars, ratio 4.61). Of the 126 patients assessed 60 (47.6%) required more than 1 endoscopic retreatments (mean 3.13 each), 50 performed biweekly clean intermittent self-catheterization and 7 underwent urethroplasty during followup. The total cost per patient for all 126 patients for stricture treatment during followup was 6,113 pounds sterling (9,170 dollars). This cost was calculated by multiplying procedure cost by the number of procedures performed. A strategy of urethrotomy or urethral dilation as first line treatment, followed by urethroplasty for recurrence yielded a total cost per patient of 5,866 pounds sterling (8,799 dollars).

CONCLUSIONS

A strategy of initial urethrotomy or urethral dilation followed by urethroplasty in patients with recurrent stricture proves to be the most cost-effective strategy. This financially based strategy concurs with evidence based best practice for urethral stricture management.

Are stents still a useful therapy for benign prostatic hyperplasia?

PURPOSE OF REVIEW

The use of an endoprosthesis to maintain lumenal patency is a well-established concept used in a variety of surgical settings, including cardiovascular and gastrointestinal pathologies. However, the utility of self-retaining endoprosthetics and their application in prostatic pathology and benign prostatic hyperplasia is not as clear. This report reviews recent developments in the management of symptomatic benign prostatic hyperplasia, particularly the current role of intraprostatic stenting in the advent of other minimally invasive therapies such as laser prostatectomy.

RECENT FINDINGS

Over the past 5 years, urology has witnessed the proliferation of minimally invasive surgical therapies for benign prostatic hyperplasia. These interventions have enabled the urologist to treat a problem whose management was once limited to medical therapy, transurethral resection of the prostate, or open, relatively morbid surgery. The role of stents as an intermediary in cases of treatment failure, or as definitive therapy for benign prostatic hyperplasia and its associated problems is still not clear, when compared with newer, minimally invasive options. Current literature on stents is relatively sparse. However recent studies demonstrate that permanent and temporary prostatic urethral stenting are effective in relieving obstruction and urinary retention. Nevertheless larger controlled clinical studies are needed to demonstrate the real value of this intervention.

SUMMARY

Prostatic stenting has a definite role in the management of benign prostatic hypertrophy, but stents must be used with caution because complications are still relatively common, and their true efficacy and utility in the urological setting has not been determined.