摘要：目的为主动脉弓生物力学和血流动力学研究提供形态学基础。方法应用组织学和计算机图像分析方法，对5例正常成人升主动脉-主动脉弓进行计量形态学研究。结果获得了人升主动脉-主动脉弓几何形态和显微结构成分含量沿轴向和周向连续变化的完整数据。升主动脉根部结构成分以胶原纤维为主，左、右、后瓣环、窦壁的厚度和结构成分含量在血管周向无显著差异。结论人主动脉弓几何形态与显微结构存在血管轴向和周向非均匀性，提示主动脉弓应力应变的不均匀状况。主动脉弓胶原纤维的周向非均匀性不如弹性纤维和平滑肌显著，与其力学性质相符合。

分类号：R322.1+21文献标识码：A

文章编号：0529-1356(2000)01-82

GEOMETRICAL MORPHOLOGY AND MICROSTRUCTURE OF THE

HUMAN AORTIC ARCH

CAI Guo-jun

(Department of Anatomy,Institute of Biomedical Engineering,The Second Military Medical University,

Shanghai 200433,China)

JIANG Zong-lai

(Department of Anatomy,Institute of Biomedical Engineering,The Second Military Medical University,

Shanghai 200433,China)

JI Rong-ming

(Department of Anatomy,Institute of Biomedical Engineering,The Second Military Medical University,

Shanghai 200433,China)

Abstract：ObjectiveThe aim of the present study is to provide essential morphological data for research concerning biomechanics and hemodynamics of the vessel.MethodsA quantitative study was conducted on 5 ascending aorta and aortic arch specimens of normal adult human cadaver by continuous vascular sections and computer image analysis.ResultsA series of data were gained of geometrical morphology and relative area(Aa%) of smooth muscle cells,elastin and collagen in axial and circumferential directions of the ascending aorta and aortic arch.At the site of aortic root collagen is the main component.The difference of wall thickness and Aa% of the microstructural components among aortic rings and walls of aortic sinuses are all not significant.ConclusionThe geometrical morphology and microstructure alter unequally in axial and circumferential directions of the aortic arch,which reflects the inequality of the vascular stress and strain.The inequality of collagen in circumferential directions is not as significant as that of elastin and smooth muscle cells,according with whose mechanical properties of high elastic modulus.

Key words：Aortic arch; Geometrical morphology; Smooth muscle cells; Elastin; Collagen; Biomechanics▲

升主动脉-主动脉弓是一段弯曲、分支的血管，其形态结构和血流动力学复杂。Wasano^［1］和Sans^［2］等对其做过不同侧重的研究，但有关升主动脉-主动脉弓几何形态和显微结构的定量资料尚不完整，对其结构的血管周向和轴向非均匀性未见报道。我们对正常成人升主动脉-主动脉弓进行了系统定量的形态学研究，为其生物力学和血流动力学研究提供必要的形态学基础，为主动脉瘤、动脉粥样硬化等主动脉常见疾病的临床诊治提供形态学依据。

材料和方法

1.取材方法和组织切片

主动脉(包括升主动脉、主动脉弓和部分胸主动脉)新鲜标本5例，均为青年男性，生前无心血管相关疾病史。120mmHg压力下灌注固定后，自主动脉瓣环基底平面起，沿血管轴线量取升主动脉-主动脉弓全长150mm。垂直血管长轴，于A、B、C、D、E各平面处切断血管取材(图1)，其余自主动脉瓣环基底平面至平面A血管段和平面E远段血管，分别按血管轴线长度平均7等分和4等分切断取材。标记血管段方位，以血管弓凸缘为上，凹缘为下，与上、下相垂直的方向，近腹侧为前，近背侧为后。常规石蜡切片，厚4μm。自主动脉瓣环基底平面起，各段切面分别标记为01、02……16。根据Han^［3］的方法，将升主动脉-主动脉弓全长记为L，各切面距瓣环基底平面沿血管轴线的长度记为x，这样，主动脉上任一切面的位置可以用x/L表示。

图1人升主动脉-主动脉弓模式图。示取材部位：

01：主动脉瓣环基底平面

A：头臂动脉起始处近端(08)

B：左颈总动脉起始处近端(09)

C：左锁骨下动脉起始处近端(10)

D：主动脉狭部中点(11)

E：动脉韧带附着处近端(12)

Fig.1Diagram of the human ascending aorta and aortic arch,

showing the special sections where measurements were taken:

01，Base attachment of the aortic root.

A，Proximal to the origin of the innominate artery(08).

B，Proximal to the origin of the left common carotid

artery (09).

C，Proximal to the origin of the left subclavian artery(10).

D，Middle point of the aortic isthmus(11).

E，Proximal to the anastomosis of the arterial ligament with

the aorta(12).

2.切片染色和图像分析

各血管段连续3张切片分别用Neubert酸性茜素蓝法、Weigert间苯二酚复红法和苯胺蓝法染血管平滑肌、弹性纤维和胶原纤维。光镜下用计算机图像分析测定血管的形态学指标。结果经统计学处理，两组资料比较用t检验，多组资料比较用方差分析。

结果

1.升主动脉根部的几何形态与显微结构

在主动脉瓣环基底平面(切面01)，胶原纤维与弹性纤维含量的比值(C/E值)显著大于主动脉其他部位(图2)，血管平滑肌、弹性纤维和胶原纤维的相对含量在3个瓣环间均无显著差异，左、右、后3个瓣环的壁厚分别为497.0±22.7μm、508.1±26.3μm和499.9±25.7μm，三者无显著差异(图3)。

图2人升主动脉-主动脉弓的C/E值。主动脉根部(切面01，02)的C/E值显著大于主动脉其他部位(P＜0.01)

Fig.2The C/E of the human ascending aorta and aortic arch.The C/E of the aortic root(section 01,02) is significantly larger than that of the other part of the aorta (P＜0.01)

图3主动脉瓣环基底平面(切面01)切片。L：左瓣环，R：右瓣环，P：后瓣环。

Fig.3Cross-sectional view of the base attachment of the aortic root(section 01).L,left aortic ring;R,right aortic ring; P,posterior aortic ring.The difference of wall thickness among three aortic rings is not significant.

在主动脉窦平面(切面02)，左、右、后窦壁厚度分别为624.6±29.7μm、631.2±33.4μm和627.5±30.6μm，三者无显著差异。窦壁为瓣环向主动脉壁的延续部分，其显微结构成分含量也界于两者之间，仍以胶原纤维为主，各显微结构成分的相对含量在3个窦壁间也无显著差异。

2.升主动脉-主动脉弓的几何形态学

升主动脉-主动脉弓的管径、壁厚、管壁和管腔横截面积在血管轴向连续变化(图4)。

轴向位置（x-L）

Axial location

4升主动脉-主动脉弓的几何形态在血管轴向的变化。

Fig.4Line graphs show