<International Circulation>: Your team published a paper on the characteristics of ischemic brain lesions after stenting or endarterectomy for symptomatic carotid artery stenosis on diffusion-weighted magnetic resonance imaging (MRI) in Stroke this year The results showed that， compared with patients undergoing CEA， patients treated with CAS had higher numbers of periprocedural ischemic brain lesions and that lesions were smaller and more likely to occur in cortical areas and subjacent white matter. How do you interpret these results? Has this once again proved that treatment with CAS is inferior to CEA?

　　Prof. Brown: I believe it has confirmed the main results of an excess of results with stenting. It was an important study to do because one of the advantages of MRI imaging is that it allows for blinded analysis. You can analyze results without knowing what treatment the patient had. Whereas the patient follow-up is not really blind because you cannot really blind the patient or the doctor. That could have led to some bias， not that I think I did. The MRI imaging confirmed the results. The other thing it shows the excess of stents appears to be minor areas of damage， due to small emboli dislodged during the stenting procedure. That isthe same as what we found in the main study (that the excess events were minor in effect). I think it does show that CAS does cause more minor embolization to the brain during treatment than does CEA.

　　What we really don’t know is whether those small lesions lead to permanent problems. Our long-term study suggests that it doesn’t lead to any major differences in disability despite the fact that there were more minor lesions and more scars on the brain. Again， when interpreted with a long-term data， yes there are certainly more minor events， which are not desirable， but they did not lead to long-term disability.

　　《国际循环》：您的团队在今年的《卒中》杂志中曾发表了一篇有关症状性颈动脉狭窄患者行CAS或CEA后缺血性脑损伤临床特点的文章。其结果显示，与CEA相比，接受CAS治疗的患者围术期缺血性脑损伤的发生率更高，病变更小，更易发生与皮质区及下方的大脑白质。您对这些结果是如何解释的？这是不是再次证明CAS不如CEA？

　　Brown教授：我认为，这已经证实了支架置入术存在更多不良结局。该研究的重要性在于其采用了MRI影响分析，其优点在于能够进行盲态分析。研究者能在不知道患者接受了哪种治疗的情况下，对患者的结果进行分析。而之前的随访研究因为无法真正的使患者或医生处于盲态，所以并不是在真正的盲态下进行的。这就存在一定的偏倚。MRI成像证实了这一结果。此外，其显示，支架置入术组增多的脑损伤似乎面积较小，可能是由支架植入过程中小栓子的脱落所导致的。这与我们ICSS研究的结果（增多的结局事件对后续日常生活影响较小）相一致。我认为，研究已经明确表明，与CEA相比，CAS治疗容易造成更多的轻微脑栓塞。但目前尚不清楚这些小的病变是否会导致永久性问题。我们长期研究的结果提示，虽然CAS治疗组患者存在更多脑损伤，大脑中存在更多的疤痕，但这并不会对患者的日常生活能力产生太大的影响。同样，长期数据提示，虽然，CAS组肯定会出现更多的轻微事件，但并不会影响患者的日常生活能力。

　　<International Circulation>: Finally， how do we select patients for carotid intervention? What are some of the common complications and how can they be prevented?

　　Prof. Brown: I think that’s a very important question because based on what our study has shown is， if everything is equal， CEA is probably the treatment of choice; otherwise， there are definite advantages to CAS in that it does avoid MI and the scar on the neck which can damage cranial nerves， and in a small number of patients cause long-term disability as well as more blood clots in the neck for surgery patients than with stenting. Therefore， if you could chose a patient in whom CAS is equivalent in risk for stroke to CAE， there would be good reason to recommend CAS as a better treatment for that patient.

　　I think the evidence says that we’re beginning to acquire some good ways of selecting patients. One of the most important analyses we’ve done since publishing the interim analysis was with some small data from three European trials (3S). That showed rather convincingly that age was an important factor in choosing between risks for the two procedures. In fact， for patients over the age of 70， CAS had a much higher risk of stroke， whereas patients under the age of 70 there was no difference in stroke risk for CAS or CAE. Indeed， the younger the patient， the more likely that CAS was to be superior to CAE. The first thing is that now that we’ve shown in our long-term study the difference in disability， we’ve also shown that it’s durable (there’s no difference in the risk of restenosis. That being said， I think one can recommend CAS as an appropriate alternative to CAE in patients in younger age groups (70 years of age or less).

　　The second thing we’ve just published， and I can send you the press release， is a paper showing the degree of white matter damage on the brain scan. These patients had a much higher risk from CAS than if they had a lower amount of white matter damage. In the patients with lower amounts of white matter damage， there was no difference in risks between CAE and CAS in terms of stroke. Again， we should be using brain scans to select patients for these two treatments.

　　《国际循环》：在进行颈动脉干预时我们应如何进行患者的选择？其常见的并发症有哪些？我们应如何预防？

　　Brown教授：我认为患者的选择是个非常重要的问题，因为我们的研究结果显示，在同等条件下，CEA是更为合适的治疗选择；但CAS也有自己独特的优势，那就是能够避免心肌梗死的发生，且不会产生可损伤脑神经的颈部疤痕。与支架置入术患者相比，少数接受CEA手术的患者颈部会出现更多血块，并影响其颈部活动能力。对应用CAS及CAE时存在同等卒中风险的患者而言，CAS是一种更好的治疗之选。我们正在开始探寻能够进行更好的患者选择的方式。在发布中期分析结果后，我们对三项欧洲研究的一部分数据进行了分析。结果发现，年龄是两种治疗方式风险的重要评估因素。在年龄大于70岁的患者中，行CAS存在更高的卒中风险；在年龄小于70岁的患者中，CAS及CAE的卒中风险则并无差异。实际上，患者越年轻，与CAE相比，CAS的优势越明显。其一，虽然我们的长期研究已经发现生活能力及再狭窄的风险并无差异，但我仍然推荐年龄≤70岁的年轻患者采用CAS替代CAE。我们刚刚发表的一篇文章探讨了大脑白质损伤的程度。结果显示，大脑白质损伤程度越高，CAS治疗相关的风险越大。而在大脑白质损伤较少的患者中，CAE与CAS的卒中风险并无差异。因此，我们可以采用脑部扫描进行两种治疗方式的患者选择。