Endoscopic Surveillance of Self-Expandable Metal Prostheses in Recurrent Urethral Strictures

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.

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.

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.

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.

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.