John D. Denstedt, MD, discusses the indications for stents, their potential drawbacks, and research aimed at developing safer, more comfortable stents.
Q. Please review for us some of the latest innovations in ureteral stents.
Specific innovations generally fall into two areas. One is mechanical or design changes in the stents and in their materials to improve comfort.
The other is the possible incorporation of pharmaceuticals; that is, drug-eluting types of stents designed to improve patient comfort or perhaps decrease infections. So drug delivery and mechanical/design changes are the two main innovations.
Q. What do you think practicing urologists should know about ureteral stents?
A. They need to know the technical aspects of how to insert them and the fundamental aspects of the procedure. They need to be able to counsel patients about the potential side effects of stents and the accompanying symptoms that patients will experience. They need to be aware, of course, if the stent needs to be taken out in a timely fashion so it doesn't develop encrustation, infection, or associated problems.
Also of importance is the monitoring of patients with stents for complications and problems and ensuring that they don't disappear from your practice and end up with what we call a neglected stent, which can be very complicated to remove. I think those are most of the fundamental things that a urologist would need to know.
Q. Tell us more about the neglected stent.
A. Unfortunately, there seems to be a population of patients who will have a stent put in, many of whom are under general anesthesia when their stent is placed, and may not even be aware that they have the stent, especially if they do not experience a lot of symptoms. A stent typically should only be left in for about 3 to 4 months and then either should be replaced or removed if it has served its purpose.
Stents that are in for longer periods of time can develop encrustation, which is a very similar process to kidney stone formation. Deposition of encrustation material on the stent, in the worst-case scenario, can often result in multiple surgical procedures to break off the encrustations, remove the stent, and salvage the kidney. It can actually threaten and jeopardize kidney function, and sepsis may result from obstruction caused by neglected stents that have been left in for too long.