Carr S, Farb A, Pearce W H, Virmani R, Yao J S
Department of Surgery, Northwestern University Medical School, Chicago, USA.
J Vasc Surg. 1996 May;23(5):755-65; discussion 765-6. doi: 10.1016/s0741-5214(96)70237-9.
Plaque rupture is often the precipitating event in acute coronary syndromes. We hypothesized that a similar process occurs in stenotic carotid plaques in association with ischemic neurologic symptoms. Our purpose was to examine several morphologic features of stenotic carotid plaques and to determine which characteristics are more commonly associated with plaques obtained from patients with symptomatic carotid artery disease than with those from patients with asymptomatic carotid artery disease.
Forty-four carotid endarterectomy specimens (from 25 asymptomatic and 19 symptomatic patients) were analyzed with pentachrome staining and light microscopy. The asymptomatic patients and symptomatic patients had similar mean percent stenosis (77% vs 74%). Other risk factors, including hypertension, diabetes mellitus, coronary artery disease, smoking history, serum cholesterol, and triglyceride levels, were similar between groups.
Patients with symptomatic carotid artery disease were found to have more frequent plaque rupture, fibrous cap thinning, and fibrous cap foam-cell infiltration when compared with the asymptomatic group. Plaque rupture was seen in 74% of symptomatic plaques and in only 32% of plaques from asymptomatic patients (p = 0.004). Fibrous cap thinning was noted in 95% of symptomatic plaques and in 48% of asymptomatic plaques (p = 0.003). Infiltration of the fibrous cap with foam cells was also significantly more common in the symptomatic plaques (84% vs 44% of asymptomatic plaques; p = 0.006). In addition, intraplaque fibrin was more common in symptomatic plaques than in asymptomatic (100% vs 68%; p = 0.008). No significant differences were found between the two groups with respect to plaque hemorrhage, the presence of a necrotic core, luminal thrombus, smooth muscle cell infiltration, eccentric shape, and plaque type (fibrous, necrotic, or calcified).
As in the coronary artery system, rupture of the atherosclerotic plaque may play an important role in the pathogenesis of ischemic stroke caused by carotid artery stenosis. The process of inflammation, involving foam-cell infiltration of the fibrous cap, may contribute to rupture of the atherosclerotic plaque.
斑块破裂常为急性冠脉综合征的促发事件。我们推测，在伴有缺血性神经症状的颈动脉狭窄斑块中会发生类似过程。我们的目的是研究颈动脉狭窄斑块的几种形态学特征，并确定哪些特征与有症状颈动脉疾病患者的斑块更相关，而非与无症状颈动脉疾病患者的斑块相关。
对44例颈动脉内膜切除术标本（来自25例无症状患者和19例有症状患者）进行丽春红染色和光学显微镜分析。无症状患者和有症状患者的平均狭窄百分比相似（分别为77%和74%）。两组间其他危险因素，包括高血压、糖尿病、冠状动脉疾病、吸烟史、血清胆固醇和甘油三酯水平相似。
与无症状组相比，有症状颈动脉疾病患者的斑块破裂、纤维帽变薄和纤维帽泡沫细胞浸润更为常见。74%的有症状斑块出现斑块破裂，而无症状患者的斑块中仅32%出现斑块破裂（p = 0.004）。95%的有症状斑块出现纤维帽变薄，48%的无症状斑块出现纤维帽变薄（p = 0.003）。有症状斑块中纤维帽泡沫细胞浸润也显著更常见（84%对比无症状斑块的44%；p = 0.006）。此外，斑块内纤维蛋白在有症状斑块中比在无症状斑块中更常见（100%对比68%；p = 0.008）。两组在斑块出血、坏死核心的存在、腔内血栓、平滑肌细胞浸润、偏心形状和斑块类型（纤维性、坏死性或钙化性）方面未发现显著差异。
与冠状动脉系统一样，动脉粥样硬化斑块破裂可能在颈动脉狭窄所致缺血性卒中的发病机制中起重要作用。涉及纤维帽泡沫细胞浸润的炎症过程可能促使动脉粥样硬化斑块破裂。
