论文标题:冠脉血流显像评价猪慢性冠脉闭塞后侧支循环状态及VEGF基因治疗效果的实验研究
Study of Coronary Collateral Circulation and VEGF165 Gene Therapy in Swine Chronic Myocardial Ischemia by Color Doppler Coronary Flow Imaging
论文作者
论文导师 李治安,论文学位 博士,论文专业 影像医学与核医学
论文单位 华中科技大学,点击次数 276,论文页数 102页File Size3079K
2002-05-01论文网 http://www.lw23.com/lunwen_1049897/
Color Doppler Coronary Flow Imaging ;Myocardial Contrast Echocardiography ;Chronic myocardial ischemia ;Coronary collateral circulation; Vascular endothelium growth factor (VEGF) ;Angiogenesis ;Myocardial perfusion
研究表明,冠状动脉逐渐狭窄或闭塞可以刺激冠脉侧支循环的建立,对维持静息状态下缺血区心肌细胞的结构和功能有重要意义。近年来,随着分子生物技术的飞速发展,人们发现通过不同途径导入含有血管生长因子的重组蛋白或基因有促进缺血组织血管新生、加速侧支循环形成的作用。基因治疗性血管新生有可能通过直接增加缺血区血供来改善心肌缺血,为冠心病心肌血运重建开辟了新的方向。然而目前尚缺乏直观检测侧支循环的有效手段,对基因治疗后心肌内是否有稳定的新生血管系统形成以及心肌灌注能否改善仍存有争议。本课题应用超声彩色多普勒冠脉血流显像和心肌声学造影在观察心肌内血流信号和心肌微循环灌注方面的优越性,通过建立猪的慢性心肌缺血模型,研究了慢性冠脉闭塞后的侧支循环状态,以及心肌内直接注射VEGF165基因治疗后的新生血管形成情况。本研究分为三个部分: 第一部分冠脉血流显像无创性检测正常猪心外膜和心肌内冠脉血流的实验研究 本部分应用冠脉血流显像技术,经胸检测正常猪不同节段心外膜冠脉和心肌内冠脉的血流信号及其特征,分析右冠脉、左前降支以及心肌内冠脉的不同时相灌注特点,观察静脉注射潘生丁后冠脉血流信号及其频谱的变化。结果显示:冠脉血流显像技术可以无创性检测心外膜和心肌内冠脉血流,并显示其血流信号的分布特点及频谱特征;心外膜冠脉为全心动周期前向灌注,右冠脉的收缩期血流速度明显高于前降支;心肌内冠脉的时相灌注特点为收
The coronary collateral circulation may be beneficial in protecting against myocardial ischemia or necrosis and sustaining contractile function when flow is impaired as a result of progressive coronary artery stenosis or occlusion. So it is important to assess the development of the collateral vessels. Lately, with the rapid development of the molecular biological technique, many angiogenic peptide growth factors have been used to enhance collateral development to ischemic myocardium and the therapeutic angiogenesis may offer an alternative therapy in patients with intractable myocardial ischemia not amenable to percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass graft (CABG). However, it is currently controversial whether gene therapy could induce formation of stable new collateral system and improve myocardial perfusion because of the lack of motheds to examine intramyocardial collateral circulation. Color Doppler Coronary Flow Imaging (CDCFI) and Myocardial Contrast Echocardiography (MCE) are new developed ultrasonic techniques to study coronary flow and myocardial microcirculation. In this series of experimental studies, we evaluate the values of CDCFI in observation of the coronay collateral circulation and assessment of the angiogenesis induced by direct intramyocardial
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