Management of In-Stent Restenosis——Live Interview with Dr. Ron Waksman
Yes it is true that restenosis has been significantly reduced by the use of drug eluting stents but we still see about 5% of target lesion revascularization with simple lesions and with complex lesions we see them up to 10%. It is multi-factorial; there is not one single cause. For example, it could be mechanical as we have seen some stent fractures.
International Circulation: What is your view of the latest generation of stents?
Dr. Waksman: In terms of the next generation (I don’t want to call it first, second or third), we are seeing those with biodegradable polymer. Some of these are available in China such as BioMatrix. The polymer is biodegradable and at the end of the day you are stenting with a bare metal stent. On its own, this has not shown to reduce restenosis. Then you have the option of the complete elimination of the stent; this is the BVS program from Abbott which is not approved or available commercially anywhere in the world right now. The data is based on about 120 patients so we have to be careful, but it is very promising. We are not ever going to be free of restenosis but I have to admit that the latest generation of DES have shown acceptable results of recurrences. Five percent is acceptable as we cannot expect to reach zero restenosis rates. It is still a challenge to treat those patients. One of the issues, however, is when you look at the number of patients you see, it does not amount to many. If you lab does a thousand patients for example, 5% of these across the time span of a year is not a lot of patients in which to see that phenomenon and then to study and follow-up on. It is something we need to deal with and unfortunately at this time we have not identified a “winning” therapy right now. I think over time we will find that one therapy is better than another but for the most part, it is better to eliminate the problem at its outset by using better stent technology and also focusing on implantation because if you don’t expand a stent well, you will have restenosis. So, good stent deployment technique and selecting stents that have reported lower rates of TLR in the first place are factors that have to be taken into account and consideration when you want to eliminate this problem.