糖胺聚糖在主动脉夹层发病机制中的作用

<正> 主动脉夹层是发生于主动脉的最常见灾难性疾病之一,致残率及致死率极高。目前其发病机制尚未阐明,可能是血流动力学和组织病理学等多种因素综合作用的结果,而通常认为主动脉壁本身结构异常是发病基础,血流动力学异常是促发因素。细胞外基质(ECM)是构成主动脉壁的主要成分,其异常是主动脉夹层的特征性改变之一。糖胺聚糖是重要的细胞外基质大分子,对维持主动脉壁结构和功能的正常起着重要作用,其异常改变可能是主动脉夹层发病和进展     

主动脉夹层61例诊断与治疗体会

主动脉夹层（Aortic dissection，AD）主要由于主动脉壁内膜撕裂，血流自裂口处进入主动脉中层，使动脉中层与外膜分离并沿主动脉长轴方向扩展，形成一假腔。主动脉夹层的年自然发病率约1／100000。作为一种极其凶险的疾病，主动脉夹层如不及时明确诊断并给予有效治疗，预后很差。近年来，     

急性主动脉夹层分离的外科治疗

主动脉夹层分离 (也称主动脉夹层动脉瘤 )是各种原因引起动脉内膜与中层的损伤 ,血液沿撕裂的内膜 ,在中层形成血肿 ,并将主动脉壁剥离成两层 ,在血流的冲击下 ,剥离部分逐渐向主动脉近端及远端延伸扩张 ,形成不同范围的中层分离。在夹层的顺行或逆行发展过程中 ,通常出现一个或几个夹层内壁破口。夹层常在继发破口处终止 ,从而形成具有原发和继发破口、假腔和假腔血流的典型临床动脉夹层。但也有可能不出现继发破口或出现继发破口后夹层仍向远处发展而形成盲袋样终止 ,盲袋内多有血栓形成。根据动脉夹层发生的时间分为三类 :1夹层发生 <14…     

基质金属蛋白酶与主动脉夹层发病关系的研究进展

主动脉夹层是一种严重威胁人类生命健康的心血管疾病,常伴有较高的死亡率及并发症率,但目前其发病原因仍不明确。文献报道主动脉夹层的发病与主动脉中层退行变有关,而基质金属蛋白酶（MatrixMetalloproteinase,MMP）在细胞外基质代谢过程中发挥重要作用,其活性或含量增加可引起主动脉中层结构蛋白的过度降解,参与主动脉中层退行变,初步表明基质金属蛋白酶在主动脉夹层发病过程中可能发挥重要作用。本文就近年来有关MMP与主动脉夹层发病关系的研究进行综述。     

主动脉夹层的临床诊断与治疗

主动脉夹层指主动脉腔内的血液通过内膜的破口进入主动脉壁中层而形成的血肿。笔者临床诊治8例，报告如下。     

炎性细胞和主动脉固有细胞在主动脉夹层中的研究现状

主动脉夹层是指主动脉内膜撕裂, 血液经内膜撕裂口进入主动脉壁造成正常主动脉壁分离, 形成真假腔的一种凶险的心血管疾病。常见于中老年人群, 尽管发病率低, 但发病突然, 且病死率极高。主动脉夹层的诱因错综复杂, 发病机制尚未完全明确, 主要与主动脉壁结构异常、血管壁炎症反应和血流动力学有关。该文重点整理了炎性细胞和主动脉固有细胞在主动脉夹层发生发展过程中的作用, 为该疾病的治疗提供新思路。     

主动脉夹层的治疗对策

主动脉夹层是指主动脉中层发生与主动脉腔平行的撕裂,血液经内膜破口进入撕裂的腔隙。原有的主动脉腔称为真腔,而主动脉中层裂开的腔为假腔．真假腔之间有一个或数个内膜破口交通。主动脉夹层是主动脉疾病中最常见的灾难性病变。主动脉夹层的预后极差。     

主动脉夹层血肿误诊1例

主动脉夹层（aortic dissection）是指主动脉腔内的血液通过内膜的破口进入主动脉壁中层而形成的血肿。现笔者将主动脉夹层血肿误诊1例分析如下。[第一段]     

主动脉夹层15例误诊分析

主动脉夹层（Aortic Dissection，AD）是主动脉腔内的血液从主动脉内膜撕裂口进入主动脉壁内，使主动脉壁中层形成夹层血肿，并沿主动脉轴扩展的一种严重心血管急症。由于本病受累部位与范围不同，临床表现多变，易导致误诊。我院2003年8月～2007年8月共收治主动脉夹层患者15例，现将其误诊原因分析如下：     

主动脉夹层患者的临床护理体会

主动脉夹层（aortic dissection）指主动脉腔内的血液通过内膜的破口进入主动脉壁中层而形成的血肿,并非主动脉壁的扩张,有别于主动脉瘤,过去此种情况被称为主动脉夹层动脉瘤（aortic dissecting aneurysm）,现多改称为主动脉夹层血肿（aortic dissecting hematoma）,或主动脉夹层分离,简称主动脉夹层。急起剧烈胸痛、血压高、突发主动脉瓣关闭不全、两侧脉搏不等或触及搏动性肿块应考虑此症。     

An experimental model of Stanford type B aortic dissection with intravenous epinephrine injection

The aim of this study was to create an experimental model of aortic dissection (AD) with a long-term patent false lumen to develop new treatments for Stanford type B aortic dissection. Sixteen adult beagle dogs (weight 14–18 kg) were used. After exposure and partially clamping, the descending aorta was cut through the adventitia to one-third of the depth of the tunica media. The aortic wall was divided into two layers by raspatory. Then half the circumference of the inner layer was cut transversely. All of the proximal layers and the distal outer layers were anastomosed together. Epinephrine was immediately used to expand the false lumen, and the effect was terminated using nitroglycerin when necessary. All dogs underwent both digital subtraction angiography (DSA) and computed tomography angiography (CTA) immediately after and 1 week and 1 month after surgery. The dogs were followed up at 1 day, 3 months, 1 year, and 2 years. The surgery was successful in 12 dogs. Dissection formation was observed immediately after epinephrine administration and confirmed by DSA and CTA. Our results showed typical characteristics of AD, such as a tear, septum, and true and false lumens. This is an easy and feasible way of developing a Stanford type B AD model by intravenous injection of epinephrine. In this canine model of AD, the false lumen has excellent long-term patency and the dissection plane is histologically similar to that in human AD. This model may contribute to the development of new treatments for Stanford type B AD.     

主动脉夹层54例16层螺旋CT表现特征及其解剖、病理基础

目的明确主动脉夹层的16层螺旋CT及其图像后处理（即三维重建）的影像表现特征与其解剖、病理基础的相关性。方法54例经临床影像证实的主动脉夹层患者（典型夹层42例,壁内血肿12例）行16层螺旋CT平扫、增强扫描及三维重建。重点观察和评价夹层真假腔、内膜片、内膜破口以及重要分支血管的受累情况。结果（1）42例夹层真假腔、内膜片、内膜破口的显示率分别为100％、100％、97．6％。夹层真假腔及内膜片呈螺旋形走行41例（97．6％）。左肾动脉及右髂总动脉最易受夹层累及,均为20例（47．6％）。（2）12例壁内血肿、无内膜撕裂,10例（83．3％）平扫表现为主动脉壁呈新月形或环形稍高密度影,2例（16．7％）呈低密度改变;增强扫描均无强化。12例壁内血肿合并穿通性溃疡9例（75％）。结论16层螺旋CT横断面及其三维图像,能快速、准确显示主动脉夹层的病理解剖改变,为临床提供精细信息,对治疗方案的选择具有重要临床实用价值。     

Increased carotid artery stiffness without atherosclerotic change in patients with aortic dissection

The arterial properties and pathogenesis of aortic dissection remain obscure. To examine the arterial properties of patients with aortic dissection, the authors studied the ultrasonographic characteristics of the carotid artery in patients with an aortic dissection (AD, n = 86), and compared these findings with data of patients suffering from arteriosclerosis obliterans (ASO, n = 151), coronary artery disease (CAD, n = 163), and with healthy controls (HC, n = 77). Atherosclerotic intimal changes, such as intima-media thickness (IMT) and plaque formation, were milder in AD than in ASO or CAD (IMT: 0.83 +/- 0.16 vs 0.93 +/- 0.20/0.86 +/- 0.17 mm, p < 0.05; plaque number: 0.6 +/- 1.1 vs 2.7 +/- 2.4/2.5 +/- 2.1, p <0.05). Luminal diameter in AD, ASO, and CAD was significantly higher than in HC. The luminal distensibility in AD was decreased compared with HC but was the same as in ASO and CAD. Intra-AD group analysis showed that in patients with an intramural hematoma (IMH) or a dissection with a thrombosed false lumen (TLF) the IMT was higher than in patients with a classic dissection. In addition, plaque formation was more severe in AD patients with a coexisting abdominal aortic aneurysm (AAA). Reduced distensibility without severe intimal disease was found in AD. These findings suggest that patients with AD may have several arterial alterations, including structural abnormalities. Patients with IMH, TFL, or coexisting AAA may differ from patients who have a classic type of dissection or who do not have AAA, in terms of arterial characteristics including intimal disease and wall elastic property, and the initiating cause of the dissection.     

Stenting of the aortic arch and the supra-aortic vessels,in a patient with DeBakey type I dissection

BackgroundAortic dissection (AD) is a medical condition which requires emergent surgical intervention for dissection type I and II DeBakey. Despite advances in diagnostic and therapeutic modalities, mortality is still high. Additional tears, critical true lumen compression and obliteration with end-organ ischemia can compromise acute and chronic clinical outcomes after surgical intervention of AD. Endovascular treatment with non-covered stent implantation can be the treatment of choice for these cases. Thus the purpose includes closure of the proximal entry tear, depressurization of the false lumen, leading to its thrombosis, redirection of the blood flow toward the true lumen and induction of “aortic remodeling” process.     

False lumen patency as a predictor of late outcome in aortic dissection

Aortic dissection (AD) is a disease with a high-risk of mortality. Late deaths are often related to complications in nonoperated aortic segments. Between 1984 and 1996, we retrospectively analyzed the data of 109 patients with acute AD (81 men and 28 women; average age 61 ± 14 years). All imaging examinations were reviewed, and a magnetic resonance imaging examination was performed at the time of the study. Aortic diameters were measured on each aortic segment. Predictive factors of mortality were determined by Cox’s proportional hazard model, in univariate and multivariate analyses, using BMDP statistical software. Follow-up was an average of 44 ± 46 months (range 24 to 164). Actuarial survival rates were 52%, 46%, and 37% at 1, 5, and 10 years, respectively, for type A AD versus 76%, 72%, and 46% for type B AD. Predictors of late mortality were age >70 years and postoperative false lumen patency of the thoracic descending aorta (RR 3.4, 95% confidence intervals 1.20 to 9.8). Descending aorta diameter was larger when false lumen was patent (31 vs 44 mm; P = 0.02) in type A AD. Furthermore, patency was less frequent in operated type A AD when surgery had been extended to the aortic arch. Thus, patency of descending aorta false lumen is responsible for progressive aortic dilation. In type A AD, open distal repair makes it possible to check the aortic arch and replace it when necessary, decreases the false lumen patency rate, and improves late survival.     

Follow-up of patients undergoing surgery for aortic dissection: evaluation with transesophageal echocardiography]

BACKGROUND. Transesophageal echocardiography (TEE) is a useful means in the diagnosis of acute aortic dissection (AD), owing to its very high sensibility and specificity. In this study, TEE was performed to assess post-surgical evolution. PATIENTS. Between 1982 and 1991, 119 pts. were operated on in our institution for AD (De Bakey I and II type): 87 pts. underwent replacement of the ascending aorta with a composite tubular graft bearing a mechanical valve; 26 had a simple tubular graft and 6 had aortic reconstruction. Sixty-eight of 72 discharged pts. were followed for up to 9.5 years (mean 4.5 +/- 2.6). Nine years after surgery actuarial survival of discharged pts. was 75%. Seven pts. died after a mean period of 3.4 years from surgery: only one died from postoperative complication (dehiscence of proximal anastomosis), none for aortic rupture distal to the graft. TEE was performed in 32 of these pts. and in other two operated on elsewhere, after 4.4 +/- 2.7 years from surgery; before the operation, type I AD was diagnosed in 23 pts. and type II in 11 pts. RESULTS. In 10/11 pts. with type II AD the aortic arch and the descending aorta looked normal; in one patient a localized intimal flap was found up to the arch. The descending aorta diameter was somewhat higher than in normal subjects (25.2 +/- 2.8 vs 21.9 +/- 3.7 mm), but in only one case was it beyond 2DS (32 mm). In all type I pts. an intimal flap persisted distal to the graft, along the whole thoracic aorta. Within the false lumen a flow was detected by color-Doppler in 14/23 pts. (61%), and spontaneous echo-contrast was noted in 14 pts. (61%). A thrombus was observed in 7 pts. (30%) and it was generally localized; in only one case it was extensive with total obliteration of the false lumen. In 16 pts. (70%) communications between the two lumina were found. The descending aorta diameter ranged from 25 to 53 mm, and mean value was higher than in normal subjects (34.2 +/- 6.2 vs 21.9 +/- 3.7 mm). CONCLUSIONS. In most pts. with type II AD, surgery can be a definitive treatment, as the remaining aorta keeps to normal size and appearance. In type I AD, operation is only palliative, as the dissection persists: the false lumen is often perfused through one or more communications with the true lumen and seldom its obliteration is noted. The persistence of dissection does not necessarily seem to be an ominous finding, as the survival of the study population was high and no patient died from aortic rupture. Nevertheless, long-term prognosis can be affected by aorta dilation that often (but not always) follows the persistence of wall dissection. For its high reliability, easy feasibility and low cost TEE is a very useful method for following up patients operated on for AD and for detecting those who are at higher risk of aortic rupture because of lumen dilation.     

The usefulness of contrast-enhanced echocardiography in the diagnosis and management of intramural hematoma and aortic dissection: A case report

Contrast-enhanced transthoracic echocardiography (cTTE) plays an important role in the diagnosis of intramural hematoma (IMH) and aortic dissection (AD), and is also necessary for the adequate management from the assessment of findings. We hereby present an interesting case in which cTTE provides additional value over contrast-enhanced computed tomography (CT) in the diagnosis and the morphological characterization of IMH and AD. A 58-year-old man presented to the emergency department with intermittent chest pain. After emergency consultation, an enhanced CT scan showed an acute aortic intramural hematoma involving aortic arch and descending aorta. Nevertheless, the entry tear and false lumen flow direction were identified by cTTE, which suggested an acute type B AD.     

Quantitative Erfassung von Ver?nderungen der thorakalen Aorta bei Patienten mit chronischer Aortendissektion mittels trans?sophagealer Echokardiographie

The aim of this serial 3 year follow-up study in 42 clinically stable patients with chronic aortic dissection was to assess quantitatively morphologic changes of the descending thoracic aorta (AD) using transesophageal echocardiography (TEE). Communicating dissections (ca) were present in 16/19 patients with operated type I and in 11/23 patients with type III AD whereas 12/23 type III AD according to De Bakey were non-communicating (nc). Diametral enlargement of the disc. thoracic aorta was 4 mm (mean value) at 1 year in all patients, 5.9 mm in type I ca, 7.2 mm in type III ca but only 3.1 mm in type III nc at 3 years. The ratio between true lumen and false lumen (FL) changed in ca AD from 1:2 to 1:3 over the period of 3 years but remained constant at 1:1 in ncAD. Progressive thrombosis of the false lumen (FL) occurred in 76% of patients but complete thrombosis of the FL occurred in only 6% of type I ca, 18% type III ca but in 84% of type III nc patients. Our results confirm observations that non-communicating dissections seem to have a more favorable outcome and less aneurysmal dilatation compared to ca dissection.     

Different remodeling of descending thoracic aorta after acute event in aortic intramural hemorrhage versus aortic dissection

The natural healing process of medically treated aortic dissection (AD) and aortic intramural hemorrhage (AIH) developed in the descending thoracic aorta was compared to test the hypothesis that absence of intimal tear and flow communication in AIH may have different impact on the remodeling of the affected aorta after the acute event. In 25 patients with AD and 20 with AIH involving distal descending thoracic aorta stabilized with medical treatment, follow-up (mean 9 months) transesophageal echocardiography was performed to measure the maximal dimensions of aorta, true lumen, false lumen in AD, and abnormal wall thickening in AIH. The sex ratio, prevalence of hypertension, baseline maximal dimension, and longitudinal extent of the affected aorta did not show any significant difference in both groups. Patients with AIH were older than those with AD (63 +/- 10 vs 50 +/- 9, p <0.01). Disappearance of abnormal wall thickening with complete restoration of the aorta occurred in 70% (14 of 20) patients with AIH, which was significantly more frequent than in AD (8%, p <0.01). In AD, progressive dilatation of the aorta with continuous flow communication in the false lumen resulted in larger dimension of the aorta than in AIH (44 +/- 13 vs 35 +/- 7 mm, p <0.01). Absence of persistent flow communication resulted in a favorable remodeling process in AIH affecting distal descending aorta. This finding, along with different mean age in AIH and AD, may suggest that AIH is not just a precursor of overt AD but a distinct disease entity with different pathophysiology.     

大动脉炎并发主动脉夹层临床特点分析

目的:探讨大动脉炎并发主动脉夹层的临床特点,为临床诊治提供参考.方法:回顾分析阜外心血管病医院2002-10至2011-08收治的5例大动脉炎并发主动脉夹层患者的临床资料,对其临床特征、影像特点及治疗情况进行总结.结果:5例患者均为女性,年龄中位数为39岁(18 ～46岁).1例患者降主动脉内置人两枚支架,4例内科保守治疗.中位数随访时间2年(3个月～8.8年),所有患者夹层无进展,无肢体灌注不足及缺血性疼痛等临床症状.1例假腔减小,支架内血流通畅,无再发狭窄.1例因血压不能控制于2009年行腹主动脉人工血管置换术.2例假腔无明显变化.1例夹层愈合,假腔消失.结论:大动脉炎可并发主动脉夹层,病程隐匿,临床应予重视.