Wholey Mark H, Barbato Joel E, Al-Khoury Georges E
Pittsburgh Vascular Institute, University of Pittsburgh Medical Center, Shadyside Hospital, Pittsburgh, PA 15232, USA.
Semin Vasc Surg. 2008 Jun;21(2):95-9. doi: 10.1053/j.semvascsurg.2008.03.005.
The assumptions upon which the decisions to treat asymptomatic patients are founded on landmark studies, such as the Asymptomatic Carotid Atherosclerotic Study (ACAS), the Veterans Affairs Cooperative Study (VA), and the Asymptomatic Carotid Surgical Trial (ACST). In total, these trials randomized more than 5,000 patients to surgical vs. medical therapy. These trials were based on 60% stenosis and basically "no-risk" entry criteria. The carotid stent trials and registries, however, were based on 80% stenosis and all high-risk entry criteria. With a wide range of operator experience, and patient enrollment based on surgical risk criteria, Carotid ACCULINK/ACCUNET Post Approval Trial to Uncover Rare Events II (CAPTURE) II, Emboshield and Xact Post Approval Carotid Stent Trial (EXACT), and the Carotid Artery Revascularization Using the Boston Scientific EPI FilterWire EX/EZ and the EndoTex NexStent (CABERNET) trials were able to meet the American Heart Association guidelines of 3% procedural events in the asymptomatic subset. Carotid stenting is presently in the first and second generation of devices, and as the technology improves, procedural event rates should also improve. An understanding of the plaque composition and presence or absence of plaque vulnerability will separate those patients best suited for stenting versus endarterectomy. Asymptomatic patients cannot be grouped, but rather require individualization. Those patients with anatomical risks, preocclusive stenosis, and an incomplete Circle of Willis with a poorly collateralized hemisphere, are best managed with stenting versus endarterectomy or best medical management. Those patients, however, with <or=80% stenosis, and without comorbidities or anatomical risk, can be offered best medical management.
对无症状患者进行治疗的决策所依据的假设，是基于一些具有里程碑意义的研究，如无症状颈动脉粥样硬化研究（ACAS）、退伍军人事务部合作研究（VA）以及无症状颈动脉外科试验（ACST）。这些试验总共将超过5000名患者随机分为手术治疗组和药物治疗组。这些试验基于60%狭窄率和基本“无风险”的入选标准。然而，颈动脉支架试验和登记研究则基于80%狭窄率和所有高风险入选标准。凭借广泛的术者经验，以及基于手术风险标准的患者入组，颈动脉ACCULINK/ACCUNET批准后试验以发现罕见事件II（CAPTURE）II、Emboshield和Xact批准后颈动脉支架试验（EXACT），以及使用波士顿科学公司EPI FilterWire EX/EZ和EndoTex NexStent进行颈动脉血管重建（CABERNET）试验，能够达到美国心脏协会针对无症状亚组3%手术事件发生率的指南要求。目前颈动脉支架置入术处于第一代和第二代设备阶段，随着技术的改进，手术事件发生率也应会提高。了解斑块成分以及斑块是否具有易损性，将区分出最适合支架置入术与内膜切除术的患者。无症状患者不能一概而论，而需要个体化评估。那些具有解剖学风险、闭塞前狭窄以及Willis环不完整且半球侧支循环不良的患者，相比于内膜切除术或最佳药物治疗，采用支架置入术治疗效果更佳。然而，那些狭窄率≤80%且无合并症或解剖学风险的患者，可以采用最佳药物治疗。
