[Stents in therapy of urethral strictures]

The human urethra seems remarkably tolerant of foreign material within its lumen. Providing that a stricture has been adequately cut by means of urethrotomy, or dilated with bougies, the majority of urethras will tolerate both permanent and temporary stents with few problems. Temporary stents have the obvious advantage over permanent stents that no foreign material is left in the urethra but before these can be recommended it is essential that more clinical experience is gained and that long term results up to ten years after removal of the stent are published. Great care is also needed in the use of any sort of permanent device, either the Urolume stent, or varieties of the Strecker such as the Memotherm device. These should not be used in children and should be probably be avoided in young adults. The majority of strictures in this age group are in any case treated more easily by single stage urethroplasty procedures. The use of permanent epithelial covering stents should be limited to the bulbo-membranous urethra, with the possible exception of carefully selected sphincters strictures used in combination with an artificial urinary sphincter. Better results will be obtained by using these stents in strictures with a short history before multiple urethrotomies and dilatations have been carried out and before extensive urethral and periurethral fibrosis has occurred. This means that urethral rupture strictures are unsuitable, and in any case these are simple to deal with be means of stricture excision and primary end to end anastomosis of the urethra particularly when the stricture is in the bulbar urethra. Care must also be taken in using these devices in post-urethroplasty strictures if extensive periurethral fibrosis exists, although it has to be admitted that these stents may be very successful in some of these patients. The difficulty at the present time is our inability to define exactly which traumatic stricture or post-urethroplasty stricture will succeed and which will fail. Metal urethral stents should not be used for the first treatment of a urethral stricture. Depending on the aetiology, the site and the length of the stricture there is always a 40-50% chance that the stricture may be cured by means of a simple urethrotomy or dilatation and this should always be tried at least once before resorting to urethral stenting. There is no doubt that permanent urethral stents have an important role to play in the treatment of recurrent urethral strictures. Careful patient selection is essential in order to achieve the best results and we need more long term results before the final role of these devices in the treatment of urethral strictures can be determined. Temporary stenting of the urethra with non-epithelial covering stents is a simpler and safer treatment but at this point in time we cannot be sure how effective this treatment is and for which patients it is most successful. Long term results must be awaited before the place of these temporary devices can be defined.