Stanford A型主动脉夹层及升主动脉瘤样扩张血管组织结构的特点

 目的 观察正常升主动脉者、升主动脉瘤样扩张者及Stanford A型主动脉夹层分离（Stanford type A aortic dissection，TAAD）患者升主动脉血管组织结构特点，为探讨Stanford A型主动脉夹层分离的发生机制奠定结构基础。方法 收集34例升主动脉血管组织标本，其中TAAD 16例，升主动脉瘤样扩张10例，心脏移植供体心脏正常升主动脉8例。采用HE染色法、弹力和胶原纤维复染法及TUNEL法对升主动脉血管组织的结构特点进行研究。结果 HE染色与弹力和胶原纤维复染示正常升主动脉者与升主动脉瘤样扩张患者升主动脉结构相似，具有完整的血管结构即内膜、中层和外膜，但是瘤样扩张者血管弹力纤维变细甚至缺失，肌肉成分增生，靠近内膜处病变较重，靠近外膜处形态相对正常；TAAD患者升主动脉大体标本可见夹层撕裂破口的位置，光镜下可见弹力纤维变细、减少、断裂，大量的炎性细胞浸润及血细胞成分。TUNEL结果显示，TAAD升主动脉血管组织可见大量的细胞核呈棕褐色及固缩的凋亡细胞，升主动脉瘤样扩张及正常升主动脉中未见明显的细胞凋亡。结论 TAAD患者升主动脉血管组织中弹力纤维及胶原纤维稀疏、减少、断裂，结构紊乱，血管组织中细胞凋亡明显增加。

The vascular structural characteristics of Stanford type A aortic dissection and ascending aortic aneurysm

Objective To investigate the blood vessels structural characteristics of normal human ascending aorta, ascending aortic aneurysm and Stanford type A aortic dissection (TAAD) and to pave a way for advanced research of mechanisms of Stanford type A aortic dissection. Methods HE staining method, Vigesion staining method and TdT-mediated dUTP nick end labeling (TUNEL) were included to test the blood vessels structural characteristics of normal human aorta, ascending aortic aneurysm and TAAD. Sixteen TAAD tissues, 10 ascending aortic aneurysm tissues and 8 normal ascending aorta tissues were included in the study. Results The vascular walls of normal ascending aortae and ascending aortic aneurysms had similar structure. They consisted of intima, tunica media and adventitia. However, elastic fibers became more thinner or even absent in ascending aortic aneurysm tissue, while it is relatively normal in outer side. The conspicious hyperplasy of smooth muscle could also be observed in ascending aortic aneurysm tissue. TAAD ascending aortae showed conspicuous collapse of elastic and collagen fibers, thinner, inflammatory cells infiltration and blood cells. The results of TUNEL showed that there were many apoptosis cells in TAAD tissues and no obvious apoptosis in normal ascending aortae and ascending aortic aneurysm tissues. Conclusions Compared with ascending aortic aneurysm and normal ascending aortae, TAAD ascending aortae show conspicuous collapse of elastic and collagen fibers, thinner, inflammatory cells infiltration and apoptosis of smooth muscle cells.