INTERNATIONAL CIRCULATION:The coronary stent has been in clinical use for 10-15years. In your opinion, what characteristics should an ideal stent have?
问:冠状动脉支架已有10-15年的历史,您认为理想的支架应该具备那些特点?
PROF.JOHN.REILLY:Sure, the ideal stent would be a stent that could give good support and keep the artery open. It is very important initially to prevent abrupt occlusion of the artery, so that is the primary focus or characteristic of a good stent. Stents have been plagued by restenosis.The ideal stents would have zero restonosis, currently drug eluting stents(DES) have made tremendous progress toward that objective, cutting that risk restenosis in half, and now its single digit percentages, but not zero. So ideal stents should have no restenosis and will no consequences for having zero restenosis. Also there are some concerns now about thrombosis, for the DES ,there is very late thrombosis. So an ideal stent should have no thrombosis. And it may or may not have to be permamently implanted. There are some works going on the bio absorbable stents, they hold the artery open and fade away.And that maybe the solution that address the issue restonosis and thrombosis.
答:我认为理想的支架应该能提供很好的支撑并能保持血管的畅通,特别是能避免血管急性塌陷,这是支架最重要的特性。再狭窄是目前捆扰支架的主要问题,所以零再狭窄应该是理想支架的目标。目前药物涂层支架(DES)在此方面取得了很大的进步,将再狭窄率降低了一半,现在是一位数,但并没有达到零。所以理想的支架应无再狭窄,同时无须为零再狭窄的结局付任何的代价。目前对支架内血栓形成仍然存在一些顾虑,特别是在DES中存在晚期支架内血栓形成,所以理想的支架不应该发生血栓。此外,支架无须被永久的植入,我知道目前有一些有关可吸收支架的工作正在进行当中,可以保持血管畅通,而后逐渐被吸收最后消失。这也许是解决再狭窄和血栓问题的方法之一。
INTERNATIONAL CIRCULATION:What kind of preventive measures or strategies we should use to prevent restenosis, because although there is very low restenosis rate in DES, but there is still some?
问:虽然在DES时代再狭窄率很低,但它仍然存在。您认为我们应该采取怎样的方法和措施来预防再狭窄的发生?
PROF.JOHN.REILLY:That is another very good question. In fact about two dozens, 24or 25 different drugs or vitamin supplements have been investigated. In bare metal stents, we try to eliminate restenosis before we came up the planting the drug on the stent. Another strategy is radiation therapy to keep the restenosis from recurring. But in order to prevent the restenosis from happening completely, I think right now what we may be to do is to make some adjustment to DES. Maybe the elution time of the drug, how long the drug is present, over what time course the drug releases, may be it needs to be longer or needs to be shorter, maybe we need to change characteristics?maybe different drugs or maybe be more effective ones?We just came into the era of second generation drugs, we have been using Sirolimus, Palitaxel drugs. We will soon to see in US the Zotarolimus,Evirolimus, maybe here in China there are some other drugs as well, maybe the combination of drugs will be solution.
答:这是另外一个非常好的问题。实际上目前有24或25种药物或维生素替代品被研究。在裸支架时代,我们试图将药物植入到支架内来预防再狭窄。支架内照射预防再狭窄是另一种办法。我想为了彻底避免再狭窄发生,我们应该对DES作一些调整。也许是药物释放的时间?或短或长?也许需要改变药物特性或采用其他更有效的药物?我们已经进入第二代药物涂层支架时代,我们目前在使用雷帕霉素和紫杉醇等药物。目前在美国还出现了经过Zotarolimus,Biolimus等药物涂层的支架,我想中国也在研究一些新的药物,也许联合用药可能是解决办法之一。
INTERNATIONAL CIRCULATION:Dou you think distal protection device is effective in preventing embolism in PCI
问:您认为远端保护装置能在冠状动脉介入手术(PCI)中有效的预防栓塞事件的发生吗?
PROF.JOHN.REILLY:We use embolic protection devices in the carotid artery and we have spoken before about distal protection or getting proximal protection to prevent emboli from travelling into the brain from carotic intervention.We use embolic protective device in saphenous vein graft intervention.The one problem in the native circulation is side branches, although you work very carefully, you may prefentially push that emboli down into side-branches as blood flow and move it into distal coronary arteries.I think the proximal protection may solve that problem to some degree if not completely because of the collateral circulation too. The sapheous vein graft and carotic arteries are straight shot and no side branches for embolic material to run off into, so it is ideally suited for embolic protection. I don’t know how embolic protection will play a role for native coronary arteries, but with current technology it is not easy to accomplish that.
答:我们在颈动脉介入操作中使用远端保护装置,我们曾经谈论过在颈动脉介入手术时使用原远端或近端保护装置来避免脑栓塞发生。我们在处理桥血管再狭窄时使用远端保护。在冠状动脉自然循环中,由于存在侧支循环,虽然我们操作时非常注意,但栓子仍然可能通过侧支到达冠状动脉远端。我认为近端保护装置在这方面的作用也很有限。由于静脉桥血管和颈动脉非常直,且没有侧支循环,非常适合使用保护装置。我不知道栓塞保护在自然冠脉循环中能起到怎样的作用,但即使目前的技术条件下,这个问题仍然难以解决。
INTERNATIONAL CIRCULATION:You must have encountered no reflow or slow flow in intervention operation and what do you do to prevent or solve these problems in your lab?
问:您在介入操作中肯定遇到过无复流和慢血流现象,请问您在您的导管室中如何来处理或避免这种问题的发生?
PROF.JOHN.REILLY:The slow flow and no reflow occur after coronary intervention. We try to give vasodilator first, at the beginning, such as nitroprusside or calcium channel blockers like verapamil. Inject that through the guide catheter down the bypass graft to try to open up microcirculation as much as possible. I don’t have any good data to support that, but we try use it anecdotally, it seems that this helps. Once you get no reflow, that is very difficult to distal delivery of microcirculatory vasodilatories such as nitroprusside calcium or channel blockers, but that is matter of time. The dosage is 30-40ug/ one bolus and the con