人体发育对肾动脉下腹主动脉的影响

Effects of body development on infra-renal aorta in human being

目的 从形态发育的角度探讨人类肾动脉下腹主动脉(IRA)容易形成粥样硬化和动脉瘤的原因。方法本组研究对象年龄均为0-30岁。超声测量55例正常人颈总动脉(CCA)和IRA的直径及管壁脉动幅度(PWM)。CT扫描测量50例胸降主动脉(TDA)直径,数字减影血管造影技术(DSA)测量35例非主动脉疾病患者TDA的PWM。结果在人发育过程中,IRA直径增加幅度最大,25-30岁组IRA直径平均值是0-5岁组的2.4倍,而CCA和TDA分别为1.5倍和1.6倍。IRA管壁PWM最大,IRA、CCA和TDA的PWM峰值分别为26.5％、13.5％和16.0％。结论 人体发育过程中IRA直径增加的幅度较大导致了成年人IRA中膜弹力板层数目与直径的比值低于其他部位和其他哺乳动物。中膜的这一结构缺陷可能通过管壁PWM增加来促进中膜硬化和内膜的增厚,进而促进管壁退化。

Objective To explore the underlying causes of infra-renal aorta (IRA) prone to suffering from arteriosclerosis and aneurysms by comparing the developmental difference among IRA, common carotid arteries (CCA) and thoracic descending aortas (TDA). Methods All data in this study were from persons aged from 0 to 30 years. The diameters and the pulsatile wall motion (PWM) of IRA and CCA in 55 healthy people were measured by ultrasonic echo-tracking scans. Diameters of TDA of 50 cases were measured by CT scan and PWM of TDA of 35 cases were determined by analyses of digital subtract angiographic data from patients without aortic lesions. Results With the body development of human being, diameter of IRA was increased in a larger proportion than that of CCA and TDA. Compared with persons aged from 0 to 5 years, the mean values of diameter of IRA, CCA and TDA in persons aged from 25 to 30 were 2.4 fold, 1.5 fold and 1.6 fold respectively. PWM in IRA was also larger than that of CCA and TDA during this period.The PWM of IRA, CCA and TDA peaked in 26.5%, 13. 5% and 16.0% respectively. Conclusion To adapt to the body development, diameter of IRA in human being was increased in a larger proportion than other part, which leads to the media deficiency, with a lowering ratio of laminar units to arterial diameter. Media deficiency of IRA resulted in enlarged amplitude of PWM, which may induce medial stiffness and intimal thickening and contribute to arterial wall degeneration.