European experience with the urethral Wallstent for urethral strictures

Buccal mucosal graft urethroplasty in five male dogs with penile urethral stricture at the bulbus glandis

OBJECTIVES

To evaluate the feasibility of correcting penile urethral strictures at the bulbus glandis using buccal mucosal graft (BMG) urethroplasty in dogs.

STUDY DESIGN

Prospective clinical trial.

ANIMALS

Five male dogs with urethral strictures located at the bulbus glandis.

METHODS

Urethrotomy was performed throughout the entire length of the urethral stricture including ~0.5 cm healthy urethra proximal and distal. The scarred tissue and unhealthy mucosa of the strictured urethra were completely excised. The graft was harvested from the buccal mucosa and tubularized at the stricture site using a urethral catheter as the skeleton. The catheter was maintained for 14 days after surgery and removed when no urethral leakage was identified on a positive-contrast retrograde urethrogram. The dogs were discharged after spontaneous urination was confirmed. Six months postoperative follow-up was completed for all dogs with repeated positive contrast urethrogram and an owner questionnaire to score urinary function and quality of life.

RESULTS

The five dogs recovered well following surgery and only one dog experienced a minor complication. All dogs were able to urinate normally after catheter removal. No evidence of leakage was identified on a 14 day postoperative retrograde positive contrast urethrogram and clinically at a median follow-up time of 182 days (range, 182-186). All owners scored the urinary function as excellent and ranked their satisfaction very high 6 months after the procedure.

CONCLUSION

Buccal mucosal graft urethroplasty has positive outcomes for dogs with penile urethral strictures.

[Rational and selective management of patients with anterior urethral stricture disease]

INTRODUCTION

the management of anterior urethral stricture is controversial. A review article was written, which updates the current situation of the surgical treatment of anterior urethral stricture.

MATERIALS AND METHODS

the experience of the Hospital del Trabajador in Santiago de Chile regarding its different surgical approaches, as well as scientific literature on the topic, were reviewed.

RESULTS

traditionally, anterior urethral stricture has been treated using minimally invasive techniques (dilatation and internal urethrotomy), which are unable to cure more than 30-35% of patients. On the other hand, urethral reconstruction surgery (urethroplasty) is more complex and requires training, however it can cure a wide majority of patients in a single surgical procedure. Due to a lack of experience and training in reconstructive surgery, non-invasive methods are overused and abused, to the detriment of the patients' quality of life. There is substantial evidence that internal urethrotomy is an excellent method for treating stricture of up to 1cm in length, however its efficacy decreases drastically above 1.5cm. Notwithstanding, urethroplasty is directly indicated for larger strictures, especially if prior urethrotomy failed.

CONCLUSION

this procedure must be managed selectively, applying the appropriate treatment aimed at curing and not only palliating the disease. Urologists must be better trained in urethroplasty and/or centres of excellence must be established to be able to offer the best treatment in each case.

The Surgical Management of Obstructive Stents Used for Urethral Strictures

PURPOSE

We present our referral experience with patients who had extensive urethral obstruction following UroLume insertion and were treated with urethroplasty.

MATERIALS AND METHODS

We retrospectively analyzed the records of 13 men with urethral stricture who experienced recurrent obstruction following placement of a UroLume endoprosthesis. In all patients several attempts at urethral dilation and optical urethrotomy failed to overcome the obstruction. Complete excision of the obstructed urethra containing the stent with the surrounding periurethral fibrosis was done in all patients. In 12 patients a 1-stage bipedicled penile island tubularized flap was used to bridge the urethral defect. In 1 patient 1-stage urethroplasty was performed and he is awaiting stage 2. Followup assessment included urine flow, post-void residual urine measurement, retrograde urethrogram and urethroscopy at different intervals.

RESULTS

Of the 12 patients who underwent complete treatment 1 had a short segment stricture at the site of the distal anastomosis 3 months after catheter removal, which was successfully managed by internal urethrotomy. He was doing well at the 12-month followup. In 11 patients a successful outcome was noted immediately after catheter removal and it was maintained at a mean followup of 1.8 years (range 1 to 4).

CONCLUSIONS

Complete excision of the obstructed urethra containing the UroLume stent with the surrounding periurethral fibrosis is an important first step in reconstruction. Subsequent use of a 1-stage bipedicled penile island tubularized flap resulted in excellent long-term results. In a small subset of cases delayed stage 2 repair after skin inlay is a valuable option.

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.

11-Year Outcome Analysis of Endourethral Prosthesis for the Treatment of Recurrent Bulbar Urethral Stricture

PURPOSE

In a North American multicenter trial of endourethral prosthesis for the treatment of recurrent bulbar urethral stricture we reported 2-year followup results for patients treated with the UroLume endoprosthesis (American Medical Systems, Inc., Minnetonka, Minnesota) between 1989 and 1996. From that same study we report long-term effectiveness and safety results on 24 of 179 patients, all of whom have completed 11 years of followup.

MATERIALS AND METHODS

The North American Study Group enrolled 179 patients with recurrent bulbar urethral stricture between March 1989 and April 1996. Eleven-year post-implantation followup was obtained for 24 of these original patients in a post-approval study. Evaluation included uroflowmetry before versus after insertion, urinary symptom score, local tissue changes and percentage of stent covered by epithelium.

RESULTS

At 11 years mean flow rates before and after stenting were 9.5 and 20.8 ml per second, respectively, and mean urinary symptom scores were 11.3 before and 3.04 after stent. No demonstrable tissue changes were visualized at the site of the stent in 31.8%, while 40.9% had mild, 22.7% had moderate and 4.6% had marked changes. There were 8 patients who underwent 9 re-treatment procedures within the stented area during followup.

CONCLUSIONS

When used appropriately the UroLume Endoprosthesis is an effective treatment for recurrent bulbar urethral stricture. It has low morbidity, re-treatment and explantation rates, and local tissue change was mild or nonexistent in the majority of patients.

Covered, retrievable, expandable urethral nitinol stent: feasibility study in dogs

PURPOSE

To evaluate the feasibility of using a retrievable urethral stent and to evaluate whether granulation tissue resolves after stent removal in a canine urethra.

MATERIALS AND METHODS

Polyurethane-covered retrievable 0.10-mm-thick (n = 11) or 0.15-mm-thick (n = 10) nitinol wire stents were placed in the urethras of 20 dogs. In one dog, a second stent was placed in the urethra because of complete migration of the first stent into the urinary bladder. The stents were removed with retrieval hook wires 4 weeks (n = 10) and 8 weeks (n = 10) after placement. Fourteen dogs were sacrificed just after stent removal, and the other six dogs were sacrificed 2 weeks after stent removal. Information concerning procedure success, stent migration, and tissue response was obtained.

RESULTS

Stent placement was technically successful in all dogs. Follow-up urethrograms showed partial (n = 4) or complete (n = 1) stent migration. Stent removal failed in two dogs due to partial or complete migration. Granulation tissue was observed at both ends of the stent in 17 dogs. Urethrograms and urethral specimens obtained 2 weeks after stent removal showed diminished granulation tissue and decreased thickness of the papillary projections of the epithelium compared with results obtained immediately after stent removal.

CONCLUSION

Although some design modifications are necessary to reduce current complications, the polyurethane-covered retrievable nitinol stent seems feasible for use in the urethra. Stent-induced granulation tissue formation improved after stent removal.

Assessment of wrought ASTM F1058 cobalt alloy properties for permanent surgical implants

The behavior of the ASTM F1058 wrought cobalt-chromium-nickel-molybdenum-iron alloy (commonly referred to as Elgiloy or Phynox) is evaluated in terms of mechanical properties, magnetic resonance imaging, corrosion resistance, and biocompatibility. The data found in the literature, the experimental corrosion and biocompatibility results presented in this article, and its long track record as an implant material demonstrate that the cobalt superalloy is an appropriate material for permanent surgical implants that require high yield strength and fatigue resistance combined with high elastic modulus, and that it can be safely imaged with magnetic resonance.

Endoprosthesis implantation in the treatment of recurrent urethral stricture: a multicenter study. Sicilian-Calabrian Urology Society

PURPOSE

This study was conducted by nine urology departments in southern Italy to assess the efficacy of and tolerance to treatment of recurrent urethral stricture using a permanent prosthesis.

PATIENTS AND METHODS

Since 1992, 99 prostheses have been implanted to treat inflammatory and iatrogenic (seven departments) or all types (two departments) of urethral strictures. The Urolume Wallstent was used in 94 cases. Three centers implanted more than one prosthesis when this was indicated. Local anesthesia was used by six centers, spinal anesthesia by two, and local or general by one. At three centers, urethrotomy was performed immediately prior to implantation; two centers used dilation to 30F, and two centers performed urethrotomy 24 or 36 hours before implantation. The median follow-up is 29.1 months (range 3-53 months).

RESULTS

The results were good in 52%, fair in 34%, and poor in 14% of patients. The maximum flow rate increased >75% in 82% of patients. All departments reported complete reepithelialization of the urethra by 6 months. The short-term complications (7-28 days) were perineal discomfort (86%) and dribbling (14%). The long-term complications were painful erection (44%), mucous hyperplasia (44%), recurring stricture (29%), and incontinence (14%). All departments performed resection for hyperplasia in many cases.

CONCLUSION

Permanent urethral endoprostheses can produce excellent results in patients with recurrent urethral strictures.

Interventional radiology and the use of metal stents in nonvascular clinical practice: a systematic overview

PURPOSE

The intent of this systematic overview was to describe the clinical role of metal stents in nonvascular health care interventions and the level of evidence supporting their use.

MATERIALS AND METHODS

Structured searches of Medline were conducted and limited to original peer-reviewed articles published in English.

RESULTS

Clinical practice involving metal stents was reported in more than 109 clinical series involving 4,753 patients. Stents were placed mainly for palliation of malignant biliary, esophageal, and airway obstruction in patients who were untreatable or had surgically unresectable lesions. Assessment of these interventions has so far centered on safety and technical success. Efficacy, quality of life, and costing factors were not routinely reported. Randomized trial evidence was available but limited; six randomized trials involving metal stents have been reported. Three trials involved biliary malignant obstruction, and all three reported metal stent (132 patients) palliation to be superior to plastic stent palliation (136 patients) based on longer patency and lower reintervention costs. Safety and complication differences between stents, however, were inconsistent across trials. In three trials involving esophageal malignant obstruction, metal stent (82 patients) palliation was reported to be superior to plastic stent (41 patients), based on lower complication and reintervention rates, and superior to laser therapy (18 patients), based on better dysphagia relief.

CONCLUSION

Use of metal stents has been reported for obstructed ducts and passageways of most body systems. There is, however, limited controlled trial evidence confirming the advantages of their use over plastic stents or other forms of treatment.

A study of the geometrical and mechanical properties of a self-expanding metallic stent--theory and experiment

Stents are tubular devices that are used in cylindrical passages of the body following trauma or disease in order to keep the cross section of these passages open. A mathematical model of a self-expanding metallic stent has been developed with the aim of predicting various geometrical and mechanical properties of the stent. The model was developed with the main assumptions that the stent acts as a combination of a number of independent open-coiled helical springs with ends fixed against rotation, and that the springs undergo elastic deformations only. A series of experiments has been carried out in order to assess the validity of the model. The experimental results show good agreement with theory for the tests involving stent diameter and longitudinal force as a function of stent length and fair agreement, limited by frictional effects, for the tests involving radial pressure as a function of stent diameter.

A bioabsorbable self-expandable, self-reinforced poly-l-lactic acid urethral stent for recurrent urethral strictures: a preliminary report

PURPOSE

We studied whether a new bioabsorbable self-expandable, self-retaining and self-reinforced poly-l-lactic acid double spiral stent is able to prevent the edges of a cut recurrent urethral stricture from adhering together and the scar from shrinking, thus obviating stricture recurrence.

MATERIALS AND METHODS

A bioabsorbable spiral stent was inserted into the stricture site in the urethra immediately after optical urethrotomy in 22 patients with recurrent urethral stricture. Uroflowmetry, measurement of residual urine volume, urine culture and urethroscopy were performed before and 1, 3, 6 and 12 months after optical urethrotomy.

RESULTS

All 22 patients voided freely on day 1 or 2 after urethrotomy. The stent slipped partially proximal to the stricture and had to be changed in only 1 patient. The stent was totally epithelialized in all but 1 patient at 6 months and had degraded in all at 12 months. The improvement in flow rate was maintained during followup except in 10 patients with stricture recurrence, which was outside the stent area usually close to the external sphincter in 7 and in the stent area in 3. All recurrences were treated with repeat optical urethrotomy and a new stent was inserted. Urinary infections developed in 2 patients and were successfully treated with oral antibiotics.

CONCLUSIONS

The self-expandable self-reinforced poly-l-lactic acid double spiral stent is a promising new method in the treatment of recurrent urethral strictures. There is no need to remove the device and no foreign material remains in the urethra. However, longer followup and controlled studies are needed to evaluate all benefits and side effects of this new treatment modality.

Role of permanent stents

The application of permanent stents in the urinary tract followed their success in the vascular system. Permanent metal stents have been used in the treatment of urethral stenosis, bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH), and detrusor-sphincter dyssynergia. In addition, stents are used in the ureter for ureteroileal strictures and malignant obstruction. Despite the favorable early results, concerns have been raised about their biocompatibility, hyperplastic tissue response, encrustation, and carcinogenicity. This paper reviews the long-term data on permanent stents, primarily the Urolume device, which has been studied extensively in multicenter trials in North America and was recently approved for use in the urethra and for the treatment of bladder outlet obstruction secondary to BPH.

Urolume double prosthesis in the treatment of complex urethral strictures: a 5-year follow-up case report

The 5-year follow-up of the implantation of a UroLume double urethral stent in 2 patients with recurrent, post-traumatic urethral strictures is presented. The double implantation for each patient was done by the long extension of the urethral lesion. Only 1 patient presented a single phosphatic concretion in the implantation area during the extended follow-up. Urinary flow rates remained absolutely normal. Sexual life was unaffected. This simple modification of the UroLume implantation may offer effective treatment for extended and recurrent posterior urethral strictures in young sexually active men, for almost 5 years without early or delayed complications of clinical relevance.

The wall stent in strictures of the lower urinary tract in inoperable patients

– A new therapeutic procedure originally used in angiological surgery has been used in the treatment of urethral strictures. A permanent stent (tubular in shape), called the “wall stent” is placed in the stricture by means of a specially designed urethroscope. The authors report their experience using the “wall stent” in 2 patients with recurrent urethral stenosis and in 1 patient with BPH. There was no recurrence at follow-up.

Heat-expansible permanent intraurethral stents for benign prostatic hyperplasia and urethral strictures

We report our experience with the insertion of a new thermoexpansible permanent intraurethral stent, the Memotherm. We treated 49 patients, 25 with benign prostic hyperplasia (BPH), 21 with recurrent urethral strictures (2 cervicourethral and 18 bulbar and 1 of a vescicourethral anastomosis after radical prostatectomy), and 3 with sphincterotomies (2 for dyssynergia and 1 with incontinence plus stenosis). The patients' ages ranged from 24 to 84 (mean 59.7) years. In all patients, stent insertion was achieved without any operative problem. In two patients, stents were removed (one in the BPH group and one in the urethral stricture group), and at long-term follow-up, we have seen two patients with severe mucosal hyperplasia.

Urethral prostheses. An overview

The first report in Literature dealing with an endourethral prosthesis in the treatment of recurrent bulbar strictures dates back to 1988. Since then other prostheses with different design and materials have been proposed. The Urolume by A.M.S., the first ever, is used worldwide and its indications are better known due to a longer follow-up time. In 6 months epithelium covers the prosthesis and it is generally well tolerated, but some Authors do not agree with its use in the treatment of traumatic strictures. Titanium prostheses have been used in few cases. A temporary steel alloy prosthesis, the Urocoil, has been proposed recently. Not enough follow-up data are available about this and the new “thermic memory” prosthesis. The bigdegradable prosthesis, used till now only on rabbits, actually represents the new frontier in the treatment of urethral strictures.

Urolume endourethral prosthesis for the treatment of urethral stricture disease: long-term results of the North American Multicenter UroLume Trial

OBJECTIVES

To evaluate the long-term results of the UroLume endourethral prosthesis for the treatment of recurrent bulbar urethral strictures.

METHODS

In a multicenter, prospective study 175 patients with recurrent bulbar urethral strictures were enrolled in a Food and Drug Administration (FDA) trial of the UroLume endourethral prosthesis. One hundred thirty-nine patients were available for follow-up at 1 year, and 81 patients were available for follow-up at 2 years.

RESULTS

Clinically and statistically significant results were seen at 1 year and sustained at 2 years. Re-treatment rate was down from 75.2% preinsertion to 14.3% 1 year postinsertion of the prosthesis. Explantation was required in only 3% of patients.

CONCLUSIONS

Based on these and European data, the UroLume endourethral prosthesis offers a significant advantage over the currently available treatments for recurrent bulbar urethral strictures.

Treatment of recurrent posterior and bulbar urethral strictures with expandable metallic stents

PURPOSE

The role of expandable metallic Z stents (non-mesh) in the treatment of recurrent posterior and bulbar urethral strictures was evaluated.

PATIENTS AND METHODS

Seven men with recurrent posterior/bulbar urethral strictures underwent balloon angioplasty followed by insertion of two stents in tandem. Retrograde urethrography, micturating cystourethrography, and urodynamic evaluation of these patients was done initially.

RESULTS

Successful dilation and placement of stents was possible in all cases. In one patient slight proximal migration of the stent occurred; terminal dysuria in this patient necessitated stent extraction. In two other patients near total occlusion of the stent by an exuberant fibrous reaction occurred and this open urethroplasty in the other. Immediate postprocedure urethrography and urodynamic evaluation showed significant improvement. Five patients continue to show a satisfactory clinical urodynamic response. The follow-up period in this patient group ranged from 5 months to 1 year.

CONCLUSION

Short-term response (5 months to 1 year) in patients with posterior/bulbar urethral strictures treated with Z stents appears promising. However, the efficacy of the procedure on a long-term basis requires further follow-up and evaluation.

Alternative endoscopic management in the treatment of urethral strictures

Advances in endoscopic instrumentation and techniques have expanded our armamentarium for safe and effective treatment of urethral strictures. Endoscopic incision or dilation should remain the preferred treatment for uncomplicated primary strictures. Balloon dilation can be useful in the treatment of dense strictures. Incision using laser energy has yet to provide better results than procedures employing a cold knife. As such, it would be difficult to justify the added expense of laser urethrotomy. Endoscopic placement of free skin grafts into the bed of the urethra after transurethral resection or deep incision of the stricture is a novel approach that has shown a great deal of promise. Endourethroplasty is a reasonable alternative to open urethroplasty when treating long strictures, as more than 90% of the reported patients have had a successful outcome with no recurrence. However, larger experience with this procedure is necessary to verify its efficacy and for greater acceptance. The placement of indwelling stents is another new promising treatment option. Overall short-term success rates range from 75% to 100%, but the follow-up period is short, and little is known about the long-term risks of an indwelling foreign body in the urethra. Endoscopic incision via "cut-to-the-light" or "core-through" procedures is an excellent alternative in patients with obliterative strictures. Data from several centers reveal that the majority of patients gain relief of obstruction while maintaining continence and erectile potency. However, at least 25% of these patients will need further endoscopic management to maintain urethral patency.

Long-term experience utilizing a new balloon expandable prostatic endoprosthesis: the Titan stent. North American Titan Stent Study Group

OBJECTIVES

To determine the long-term safety and efficacy of the Titan endoprosthesis as a therapeutic alternative in the management of men with bladder outlet obstruction.

METHODS

One hundred forty-four patients (mean age, 73.5 years +/- 4.2) had placement of the Titan stent. The stents were inserted under direct vision and expanded to 33 F using a balloon catheter. Of the 144 patients, 59 (41%) were in urinary retention and 85 (59%) presented with moderate to severe symptoms of prostatism. Patients were assessed at baseline and in follow-up at 1, 3, 6, 12, 18, and 24 months. Parameters of evaluation included the Madsen-Iversen symptom questionnaire, peak flow rate (Qmax), postvoid residual urine volume (PVR), and incidence of adverse events.

RESULTS

At 24 months, for the retention cohort, symptoms, Qmax, and PVR were 5.21 +/- 0.81, 11.34 +/- 1.12 mL/s, and 31.00 +/- 12.8 mL, respectively (P < 0.002). For patients with symptoms of bladder outlet obstruction, the results were as follows at 24 months: (1) symptoms decreased from 15.89 +/- 0.47 to 9.33 +/- 0.86 (P < 0.001); (2) Qmax increased from 8.59 +/- 0.41 mL/s to 11.43 +/- 1.12 mL/s (P < 0.001); and (3) PVR decreased from 116.94 +/- 19.95 mL to 74.4 +/- 36.2 mL (P < 0.03). There were minimal complications; stents were removed from 28 patients (19%) because of migration, 10 of which were placed by one investigator.

CONCLUSIONS

When properly placed, the Titan stent was an effective therapeutic alternative to prostatectomy or long-term catheterization in high-risk obstructed patients or those in urinary retention.

Antegrade-retrograde urethrotomy for treatment of severe strictures of the urethra: experience and literature review

In cases of urethral stricture that are nonpassable when using conventional internal urethrotomy, open urethroplasty can be avoided by performing combined antegrade-retrograde urethrotomy (ARUT). A rigid cystoscope is guided through a dilated suprapubic cystostomy channel toward the stricture in the membranous or bulbar urethra. A urethrotome is inserted in retrograde fashion, and the "cut to the light" procedure is performed. Using the ARUT method, realignment was achieved in nine patients; four of whom had strictures induced by trauma or urethritis and five of which were the result of previous transurethral management. Recurrent stricture in four of seven cases necessitated further urethrotomy. There was no recurrence in five of seven patients for at least 5 months subsequent to the last treatment. All patients were spared open surgery. The antegrade-retrograde technique was described in 1978, but to date, only 70 cases have been reported in the literature. The primary success rate is 25%. Successful retreatment following recurrence was observed in 65%. We recommend ARUT as a first-choice treatment for severe strictures of the bulbar and membranous urethra.

Nitinol urethral stents: long-term results in dogs

No information has been available to date on the long-term behavior of nitinol (nickel-titanium alloy) urethral stents. In the present study, prostheses of this type were implanted in 18 German shepherd dogs in order to evaluate the reaction of the mucosa, muscles and periurethral tissue. Follow-up examinations performed after 1 week, and 1, 3, 6, 12 and 18 months included urine, macroscopic, radiologic, histologic and scanning electron microscopic analyses. Despite the excellent biocompatibility of the material, with no evidence of foreign body reactions or corrosion, there were no complete incorporations of the stent by epithelialization. Clinical application therefore appears to be problematic.

Urolume in urethral stenosis: Italian Club of Minimally Invasive Urology experience

A multicenter study of the patients in whom the Urolume has been implanted has been among the actions undertaken by the Italian Club of Minimally Invasive Urology (UMICLUB). For each patient, a computer information format has been prepared containing evaluation data related to the preoperative period, the endoscopic procedure, and follow-up. The collected data were computerized through unifunctional and multifunctional analysis. Of the 82 patients recruited, 76 were followed for a period ranging from 1 to 40 months. Urinoflow results dramatically improved after implantation of the endoprosthesis: peak flow rates increased by 310%, while mean flow rates increased by 294%. Incontinence and dribbling were found in 4% and 20% of the patients, respectively, and were independent of the distance between the external sphincter and the Urolume prosthesis and of the stent number and length. The cross-data elaboration seems to indicate a statistically significant relation between urethral preparation before Urolume implantation and stricture recurrence, with recurrence being more frequent after dilation. Significant correlations have not been noticed between stenosis etiology, urinary infection, type of anesthesia, and recurrence; between the type of anesthesia, stent length, and duration of hospitalization; or between stent number and position and pain. The impact of the Urolume prosthesis on sexual activity was marginal by all three measures considered (pain during erection, coitus, and ejaculation).

Analysis of factors contributing to success or failure of 1-stage urethroplasty for urethral stricture disease

We reviewed charts with adequate documentation and followup (mean 24.6 months) between 1970 and 1987 of 110 patients who had undergone 1-stage urethroplasty for urethral stricture disease at our institutions. Two age peaks were observed, 1 in the younger population (21 to 30 years old) with traumatic strictures (50% of all strictures) and 1 in elderly men (61 to 70 years old) with mainly post-inflammatory strictures (28.2% of all strictures). The majority of all strictures (63.6%) were in the bulbous urethra. Only strictures induced by trauma were located in the membranous urethra (total 28.2%). A patch graft repair was used in 49.1% of all cases, an end-to-end technique in 29.1% and a transpubic repair in 21.8%. Overall, a 57% rate of excellent results was observed with 24% failures. The results were best for patch graft repairs (65% excellent), followed by end-to-end repairs (56% excellent) and transpubic repairs (42% excellent). The choice of the surgical approach in urethral stricture surgery is dictated by the location of the stricture. The location in turn is dependent on the etiology of the stricture. Consequently, the cause of the stricture affects the location and character of the stricture and, therefore, has an immediate impact on the choice of the surgical approach and, thus, the outcome of the patient. The failure rate doubled overall when the patients had a previous manipulation for the stricture disease or if the urine was infected preoperatively despite antibiotic coverage. While our patient population may not be representative for other institutions, some general conclusions regarding proper management and treatment selection can be drawn from our experience.

Treatment of a recurrent penobulbar urethral stricture after wallstent implantation with a second inner wallstent

The wallstent has been proved to be effective for the treatment of bulbar urethral strictures. Only a few failures are reported in the literature. We present a case of a patient with a recurrent stricture after wallstent implantation. The recurrence has been managed successfully with gradual dilation and with the insertion of an inner stent inside the first one, with a twenty-nine-month follow-up.

Treatment of sphincter strictures using permanent UroLume stent

The success of the permanent UroLume urethral stent in the treatment of recurrent bulbar urethral strictures led to its use in cases of recurrent strictures in the sphincter active membranous urethra. Among 6 patients treated 3 traumatic strictures have recurred despite the urethral stent but 3 post-prostatectomy strictures have been treated successfully in conjunction with an artificial sphincter to restore continence.

The titanium intraprostatic stent: the United States experience

This multicenter, cooperative study represents the initial United States experience using an expandable, titanium intraprostatic stent in 68 patients (60 to 93 years old). The stents were inserted under direct vision and expanded to 33F using a balloon catheter. All patients had a symptom score analysis, and underwent measurement of peak urine flow and rate and post-void residual urine volume as part of the initial evaluation. Patients were seen at approximately 1, 3, 6 and 18 months after stent insertion (mean followup 16 months). Of the 68 patients 38 presented in urinary retention. The type of anesthesia used included general anesthesia in 6 patients, spinal or epidural anesthesia in 24, intravenous sedation in 20 and intraurethral lidocaine only in 18. All patients were able to void spontaneously within 36 hours after stent insertion. Symptom scores decreased from 16.8 to 3.9, 6.3, 5.0, 5.7 and 3.2 at approximately 1, 3, 6, 12 and 18 months, respectively. Peak urine flow rate increased from 3.9 to 13.8, 11.5, 11.2, 12.4 and 14.4 ml. per second at approximately 1, 3, 6, 12 and 18 months, respectively. Post-void residual urine volume decreased from 74.4 to 30.1, 29.2, 19.8 and 40.2 ml. at approximately 1, 3, 6 and 12 months, respectively. Of the initial 68 patients 5 died of the underlying disorder (all voiding satisfactorily with the stent in place) and 17 underwent uneventful stent removal (10 for technical failure and 7 for treatment failure). Technical failures were secondary to either inaccurate positioning or improper stent sizing. Of the 58 patients with proper placement of the stent and no technical failures 46 (79%) had improvement in symptom scores and urine flow rate. Transient hematuria was noted in 43 patients (63%) and usually resolved within 48 hours. None of the 6 urinary tract infections (9%) was recurrent. In conclusion, the titanium intraprostatic stent, when properly placed, is a promising therapeutic alternative to prostatectomy or long-term catheterization in high risk obstructed patients or those in urinary retention. Studies are currently in progress to determine the long-term efficacy of this therapeutic modality.

Use of multiple Wallstents in treatment of bladder outlet obstruction

Of 23 patients being treated with the Urolume Wallstent for bladder outlet obstruction, 4--3 with anterior urethral strictures and 1 with benign prostatic hyperplasia--required two to four stents. When placing multiple stents, there should be enough overlap to prevent the opening of a gap as the stents expand and shorten over the ensuing weeks. Use of more than 1 stent is indicated when the stricture or the prostatic urethra is longer than 3 cm or when stricture recurs beyond the end of a previously placed stent.

Outcomes of non-self-expandable metal prostheses in strictured human ureter: suggestions for future developments

The success of metal stents in the urethra led us to implant flexible metal stents unilaterally in the ureter in four patients. Radiographic and endoscopic controls during follow-up showed an obstruction in three cases. We describe the different aspects of these unfavorable outcomes and propose changes to be made in metal stents for use in the upper urinary tract.

A bioresorbable urethral stent. An experimental study

The aim of the present study was to examine the suitability of biodegradable polymers as materials for a urethral stent. A new urethral stent made of biodegradable self-reinforced poly-L-lactide (SR-PLLA) was implanted in 16 male rabbits after urethrotomy. Seven stents of stainless steel served as controls. The dimensions of the two types of stents were identical: length 15 mm, diameter 8.2 mm. The mechanical construction was a helical spiral. The SR-PLLA spiral was sustained with three microspirals, and the whole device was coated with DL-lactide to achieve an active initial tissue reaction and better tissue penetration. The SR-PLLA stent showed more favourable implantation properties than the steel one. Within 6 months all PLLA stents had implanted, and the tissue reaction around the stent material was minimal. The helical spiral of stainless steel induced a remarkable inflammatory reaction due to poor implantation properties. We suggest that biodegradable SR-PLLA is a promising material for a urethral stent to prevent re-stenosis of urethral strictures.

Endoluminal urethral stents: a review

Although Fabian first introduced the concept of an endourethral stent in 1980, recent developments in biomedical technology and the treatment philosophy of urethral obstruction has led to a resurgence of this concept. We review the past and current literature with regard to both temporary and permanent stents. Available stents are described, clinical results summarized, and indications discussed.

Urologic applications of a permanent, epithelializing urethral endoprosthesis

Recently, a flexible, self-expanding, permanent endoprosthesis has been developed to maintain patency of stenotic arteries after balloon angioplasty. This device, known as the UroLume Wallstent, is now under active investigation in both Europe and the United States as a treatment for: (1) recurrent bulbar urethral strictures, (2) benign prostatic hyperplasia, and (3) detrusor-external sphincter dyssynergia. Preliminary data demonstrate this device to be an effective treatment for all three indications in select patients and to be associated with minimal untoward effects. If the long-term results are equally encouraging, this unique endoprosthesis will represent a significant advancement for the field of urology.

The "Wallstent": a new stent for the treatment of urethral strictures

Ten patients have been reviewed in whom urethral stents were implanted for treatment of urethral stricture. Their urethral strictures had been treated with a median of 4.2 endoscopic urethrotomies under direct vision without success. The patients were first treated with optical urethrotomy, and dilatation to 30 F--after which the stents were inserted under direct endoscopic control. A total of 12 stents were inserted. All patients had a 30 mm stent inserted first, and two patients had an additional 20 mm stent inserted because of recurrent stricture at the distal or proximal end of the first stent. One patient had a urethrotomy 12 months after insertion of the stent because of a short recurrent stricture at its distal end. The median length of follow up was 24 months. The median preoperative maximum flow rate was 6.5 ml/s, and the median postoperative maximum flow rate was 20.3 ml/s. Half the patients had postmicturition dribbling postoperatively. The stents were covered with epithelium after 6-18 months, most between 12 and 18 months.

Significant obliteration of the urethral lumen after Wallstent implantation

The permanently implanted self-expandable urethral stent (Wallstent) has found increased use in patients with recurrent urethral strictures because of its simple implantation technique. To date there have been no reports of serious complications. At 6 weeks after stent implantation our patient had complete luminal obstruction. This complication demonstrates the need for short-term controls after implantation of a urethral stent.