Molecular Imaging of Aortic Aneurysms
Molecular Imaging of Aortic Aneurysms
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DOI：
10.1161/circimaging.112.973727
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发表时间：
2012-05-01
影响因子：
7.5
通讯作者：
Buxton, Denis B.
中科院分区：
文献类型：
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作者：
Buxton, Denis B.
主动脉瘤 (AA) 是危及生命的主动脉永久性扩张，其直径通常为正常直径的 1.5 倍。 1 它们在解剖学上分为胸主动脉瘤 (TAAs) 和腹主动脉瘤 (AAA)。这两个解剖部位的潜在发病机制不同；对于 TAA，组织学异常是内侧变性，其特征是平滑肌细胞损失、弹性纤维破碎和减少以及蛋白聚糖积聚。 2, 3 基因突变是许多年轻或中年患者发生 TAA 的根本原因。 4 相反，AAA 的组织病理学主要是严重的内膜动脉粥样硬化、慢性透壁炎症和弹性介质重塑。 2, 3 基因表达分析表明，AAA 和 TAA 表现出不同的模式，其中大多数变化相对于每种疾病所特有的正常主动脉。 3 然而，TAA 和 AAA 之间存在一些共有的危险因素，包括吸烟、高血压、男性和衰老。 2 直径 2.9 至 4.9 厘米的 AAA 患病率说明了年龄和性别依赖性，范围从 45 岁男性的 1.3% 到 75 至 84 岁男性的 54% 至 12.5%。对于女性来说，同一年龄组的患病率分别为 0% 和 5.2%。 5 TAA 的患病率也随着年龄的增长而增加，其中男性更高。 6如果不治疗，AA 会扩张并最终破裂，导致死亡率高达 90%； 2009 年，美国因 AA 和夹层而死亡的人数为 10 500 人。7 AA 的扩张率和破裂率均随动脉瘤大小的增加而增加。 AA 的诊断通常涉及解剖成像，通常是超声或 CT 血管造影，一旦诊断，风险分层涉及通过 CT 血管造影测量直径。 8 关于 AAA 人群筛查的价值一直存在争议，但多中心动脉瘤筛查研究 (MASS) 9 和其他几项试验 10 提供了支持筛查计划的证据。美国预防服务工作组建议对 65 至 75 岁曾经吸烟的男性进行筛查。 11 目前，手术治疗 AA 的阈值取决于动脉瘤直径；对于 TAA，升主动脉常用的阈值为 5.5 至 6 cm，降主动脉常用阈值为 6.0 至 6.5，6 而 AAA 的阈值为 5.0 至 5.5 cm。然而，一些AA
Aortic aneurysms (AAs) are life-threatening permanent dilations of the aorta, frequently defined by a diameter of 1.5 times normal. 1 They are subdivided anatomically into thoracic aortic aneurysms (TAAs) and abdominal aortic aneurysms (AAAs). The underlying pathogenesis differs between the 2 anatomic sites; for TAAs, the histological abnormality is medial degeneration characterized by loss of smooth muscle cells, fragmented and diminished elastic fibers, and accumulation of proteoglycans. 2, 3 Genetic mutations are the underlying cause of TAAs in many young or middle-aged patients. 4 In contrast, the histopathology of AAAs is dominated by severe intimal atherosclerosis, chronic transmural inflammation, and remodeling of the elastic media. 2, 3 Analysis of gene expression demonstrated that AAAs and TAAs exhibit distinct patterns with most changes relative to normal aortas unique to each disease. 3 However, several risk factors are shared between TAAs and AAAs, including smoking, hypertension, male sex, and aging. 2 The age and sex dependence is illustrated by the prevalence of AAAs 2.9 to 4.9 cm in diameter, ranging from 1.3% in men aged 45 years to 54% to 12.5% at ages 75 to 84 years. For women the prevalence for the same age groups is 0% and 5.2%, respectively. 5 The prevalence of TAAs also increases with age and is higher in men. 6If untreated, AAs can expand and eventually rupture, resulting in death rates as high as 90%; in 2009, mortality in the United States from AAs and dissections was 10 500. 7 Both expansion rates and rupture rates of AAs increase with aneurysm size. Diagnosis of AAs generally involves anatomic imaging, typically ultrasound or CT angiography, and once diagnosed, risk stratification involves measurement of diameter by CT angiography. 8 There has been controversy concerning the value of population screening for AAAs, but the Multicenter Aneurysm Screening Study (MASS) 9 and several other trials10 have provided evidence in support of screening programs. The US Preventive Services Task Force recommends screening for men aged 65 to 75 years who have ever smoked. 11 Currently, the threshold for surgical treatment of AAs is predicated on the aneurysm diameter; for TAAs, thresholds of 5.5 to 6 cm for the ascending aorta and 6.0 to 6.5 for the descending aorta are commonly used, 6 whereas for AAAs, the threshold is 5.0 to 5.5 cm. However, some AAs