《国际循环》:本次ISC年会上,您对“急性卒中干预中的7件事”专题进行了主持,这一话题也是临床中关乎患者利益的问题,您能简要介绍哪7件事吗?
International Circulation: There is a session titled “Problems with Interventions in Acute Stroke: 7 Little Things” on this meeting, which is closely related to patients’ interests. As its moderator, could you introduce these 7 little things?
Jovin教授:这个专题上提及的7件小事是目前该领域面临的最重要问题,包括如何使患者获益最大化、如何选择最合适患者、如何改善护理系统、如何使治疗相关并发症降至最低、患者转运问题以及卒中治疗经济学问题。随着越来越多的患者接受此类治疗,这些问题显得愈发重要。这一专题涵盖了急性卒中干预的广泛话题,我希望能够对澄清卒中血管内治疗中存在的问题有所裨益。
Dr. Jovin: Yes, so the seven little things are pretty much the most important things that come from the field nowadays. Some have to do with who derives benefit, how to best select patients, how to improve the systems of care, how to minimize complications from these procedures, what the logistical problems are, and what the economical aspects of stroke and vascular stroke care, are which are increasingly playing a more important role as many more patients are getting treated. This session covered a broad spectrum of topics relevant to acute stroke interventions and I hope it did help clarify some of the most stringent problems facing in the field of endovascular stroke.
《国际循环》:目前,针对缺血性卒中急性期血管内治疗策略的重点是什么?
International Circulation: Currently, what is the point of endovascular treatment strategies for ischemic stroke in acute stage?
Jovin教授:这种治疗策略一直用于挽救大血管阻塞患者可挽救的脑组织。目前,我们发现,通过使用有效器械,可在最快时间内改善再灌注率,从而挽救缺血脑组织。这种技术已为患者带来良好效果,可打通闭塞血管,且操作迅速。
Dr. Jovin: Well, the strategy is and has always been to, with patients with large vessel occlusion, to salvage the brain that is still salvageable, and we realize now that can be done with effective devices that improve the rates of reperfusion that have to be done in the fastest possible time. As the technology now allows us to get the excellent results that we have all been waiting for in terms of opening up these blocked vessels, it is very clear that what needs to happen is for us to do this in the most expeditious way possible.
《国际循环》:缺血性卒中急性期血管内治疗策略的应用优势体现在哪些方面?
International Circulation: So what is the advantage to do this procedure?
Jovin教授:与静脉tPA溶栓相比,这种技术的优势在于大血管闭塞方面。静脉tPA对脑再灌注效果欠佳,因此需更激进的治疗方法。较小的血管如大脑中动脉(MCA)的M2分支是否仍会从血管内治疗中获益尚不明确,因此需开展相关研究。我们知道,越靠近端且有大量血栓的血管阻塞,tPA效果越差,虽然治疗比不治疗好一些。近期试验已告诉我们,采用现代器械行血管内治疗有潜在优势。
Dr. Jovin: The advantage of doing this procedure as opposed to intravenous tPA is that in large vessel occlusions, IV tPA is not effective enough in reperfusion the brain, and so more radical measures are needed. We do not have the answers as to whether a smaller vessel like the M2 division of the MCA still benefits from endovascular therapy. It may not benefit or it may benefit, we do not know, we need trials for that, but we know that in the more proximal vessel occlusions where there is a lot of clot, and where there is a lot of clot burden, tPA is not effective enough. It is better than no treatment, but these recent trials have taught us that there are substantial advantages derived from endovascular approaches with the modern devices.
《国际循环》:侧支循环的代偿作用不仅影响脑梗死早期临床症状改善,且益于远期预后。侧支循环功能评估的常用方法有哪些?
International Circulation: Thank you very much. So in this kind of scenario, the compensation of the collateral circulation is very important. What kind of method is commonly used for evaluation of the collateral circulation function?
Jovin教授:任何组织存活成像均可评估侧支循环功能;若大部分脑组织仍处于存活状态,侧支循环可正常运转;当发现较大梗死或梗死核心区,说明失去侧支循环。一般来说,CAT平扫及神经功能均可说明是否存在侧支循环,若CAT扫描显示正常,但神经功能障碍严重,可能患者仍有较好的侧支循环可保证大脑存活。另外,使用CT血管造影,正如本届ISC上展示的ESCAPE试验中采用的创新方法,大脑成像稍微延迟可允许侧支循环出现;MRI 技术也可用于侧支成像,所有的灌注研究如CT或MRI灌注,实际上均可评估侧支功能。第三是采用血管造影评估。我们可以在血管造影时直接观察侧支情况并进行分级,较高级别的侧支与患者对再灌注治疗反应佳有关。
Dr. Jovin: Any kind of tissue viability image is a function of the collateral flow, because if there is a large area of brain that is still viable, then we know that the collaterals are working. When we see a large infarct or a large core, we know that collaterals are not working. So at the most basic level, even a plain CAT scan in conjunction with a severe neurological deficit can tell us a lot about whether or not there is collateral there, because if the CAT scan is normal and the patient has a severe neurological deficit, then probably they have good collaterals that keep the brain alive. At the more sophisticated levels, there are either CT angiography methods, we have heard about a very innovative method used in the ESCAPE trial, where the brain is filmed a bit later than usual to allow time for collaterals to appear. There are MRI techniques that allow us to image collaterals, and all the perfusion studies, CT perfusion or MRI perfusions, are in fact the function of collaterals. The third level is angiographic collaterals. We can also visualize the collaterals on angiography and we know now that when we do that, when we grade the collaterals on angiography, good collateral grades are associated to good response to reperfusion therapy.
《国际循环》:匹兹堡侧支比评估方法的效用如何?
International Circulation: How about the effectiveness of Pittsburgh Collateral Ratio?
Jovin教授:目前这方面的研究数据仍很初级,但这种评估方法确实有应用前景,因为它可预测患者是否有较好的侧支循环。这种评估方法基于血管大小的检测,需要在进一步的影像学检查中进行验证。
Dr. Jovin: Well, it is a very preliminary data set, but it is promising in the sense that it does predict whether the patient has good collaterals. It is based on measurement of vessel sizes and we need to validate it with further imaging tests.
《国际循环》:如何选择性促进侧支循环生成?
International Circulation: How to selectively promote collateral circulation formation?
Jovin教授:这是很重要且及时的话题,我们已发现采用器械手段恢复灌注是可行的,现在需要做的是探索可能增强血管内治疗效果的其他方法,其中一种即为增加侧支循环并维持其存活功能,以使血管内治疗打通闭塞血管前,大脑仍存活。这些策略包括神经保护方法,如非常重要的即刻低温疗法。另一种重要且非常有潜力的方法,即神经保护策略联合应用,虽然其有效性尚不清楚,但我相信这是血管内治疗和急性卒中干预的下一个前沿,有助于延长患者治疗时间窗,允许其在开通阻塞血管前维持侧支循环以维持大脑存活。
Dr. Jovin: That is a very important topic and it becomes even more timely now, because I think we answered the question whether reperfusion with mechanical means works. We know now it works. Now what we need to do is move on to other forms of treatment that may enhance the effect of endovascular therapy. One of these types of treatments is exactly the augmentation of collaterals and the allowing of collaterals to still maintain viability so that the brain can sustain viability until the vessel is opened up with endovascular treatment. These kinds of approaches include neuroprotecting strategies such as hypothermia for instance, that is a very important approach. Other important and promising approaches, we of course do not know if it works, but there is no doubt in my mind that the next frontier in endovascular therapy and acute stroke interventions is to combine neuroprotecting strategies that would allow us to extend the time window for patients that will allow the brain to stay viable by preserving collaterals until the occluded vessel is opened up.