主动脉夹层动脉瘤实验动物模型的建立

发布时间：2018-04-08 17:50

本文选题：主动脉　切入点：夹层动脉瘤　出处：《同济大学》2005年硕士论文

【摘要】： 目的：探讨DebakeyⅢ型夹层动脉瘤实验动物模型建立的方法及注意事项，在较为接近病理生理条件下形成夹层动脉瘤，为夹层动脉瘤形成和发展的研究提供实验基础和实验手段，为临床探讨选择主动脉夹层动脉瘤治疗新途径提供可靠的动物模型和实验依据。材料与方法：5-7月龄、体重12-16kg的健康家猪(雌雄不限)12头，随机分为高脂饲料组(n=6)和普通饲料组(n=6)进行饲养，分别于饲养前、饲养后第4周、第8周测血脂水平，并记录体重。随后在气管插管全麻下建立夹层动脉瘤模型。术前测量正常主动脉直径，以距左锁骨下动脉远端2-3cm处为起始处，以0T针刺入降主动脉中膜，注入弹性蛋白酶200U分解弹力蛋白层，利用机械膨胀力使中膜与内膜分离，分离长度5-7cm左右，术中可见主动脉明显鼓起。在鼓起的主动脉上下两端分别用阻断钳阻断主动脉，尖头刀迅速切开主动脉管壁全层，用自制的动脉壁分离器分离主动脉中膜和内膜，并剪掉部分内膜，分离周径为主动脉周径的1／3-1／2。然后用无损伤侧壁钳钳夹切开处的主动脉，5-0prolene线缝合外膜和中层，开放主动脉，夹层模型建立成功。随后静脉注射肾上腺素0．5-1mg以升高血压，加速夹层的剥离，测量夹层形成处主动脉直径。术后采用抗凝等措施防止夹层内血栓形成，并行MRI检查证实夹层的存在。动物术后死亡者立即开胸，取降主动脉行大体观察和组织学检查。所得数据均以均数±标准差表示，应用SAS6．12软件进行统计分析，计量资料的比较采用t检验，检验水准设为以α=0．05。结果：①高脂饲料组动物4周后血总胆固醇、低密度脂蛋白、载脂蛋白B水平较喂饲前明显上升(P0．01)，8周后上升更显著(P0．001)；血甘油三脂水平4周后与喂饲前相比无显著性差异(P0．05)，8周后明显上升(P0．01)：高密度脂蛋白在第4周及8周虽有所上升(P0．01，P0．001)，但高密度脂蛋白／总胆固醇、高密度脂蛋白／低密度脂蛋白于第8周均显著下降(P0．01，P0．001)。普通饲料组动物在实验前及第4周和第8周的血脂水平基本接近，无显著性差异(P0．05)。两组动物体重差异无显著性(P0．05)。高脂饲料组动物的基础血压较普通饲料组动物高，分别为190-200／160-170mmHg，140-150／110-120mmHg。②高脂饲料组6只动物中，，3只动物死亡，检查发现2只动物有夹层形成；普通饲料组6只动物中，2只动物死亡，检查发现仅1只动物有夹层形成。③高脂饲料组和普通饲料组动物术前主动脉直径分别为1．0-1．4cm、0．9-1．3cm，夹层形成处主动脉直径分别为1．8-2．2cm、1．6-1．8cm，均较术前明显增粗，且高脂饲料组增大明显。④死亡动物立即取下降主动脉，标本肉眼可见内膜破口，中层与内膜分离，瘤壁变薄。光镜下高脂饲料组动物的主动脉壁可见内皮隆起、变形，管壁炎症反应明显，内膜下有泡沫细胞沉积等，Weigert弹力纤维染色可见夹层动脉瘤处弹力层断裂、溶解、破碎。普通饲料组主动脉切片在光镜下见内膜完整，管壁结构层次清晰，Weigert弹力纤维染色可见完整的波浪状弹力层。结论：①由于主动脉内膜损伤，形成破口，血液经内膜破孔进入主动脉中层，在高压下将主动脉分为双层，形成主动脉间血肿并进一步剥离、扩展，造成假腔，形成夹层动脉瘤。夹层的假腔可经第二处破口与真腔沟通。主动脉中层弹力纤维退变断裂、囊性坏死是本病的病理基础；高血压病、动脉粥样硬化是常见的病因。②该建模方法符合夹层动脉瘤形成的病变基础及病理生理过程，是科学的，可行的。③术前喂饲高脂饮食可造成一定程度高脂血症，基础血压升高，动脉处于早期硬化表现，符合夹层动脉瘤的病理基础，利于模型的建立；弹性蛋白酶可消融弹力纤维层，解除其弹力回缩作用，利于瘤壁的扩张。④该实验方法可为临床诊断疾病及探讨选择主动脉夹层动脉瘤治疗新途径提供可靠的动物模型和实验依据。
[Abstract]:Objective: to establish a method of Debakey type III dissection animal model and the matters needing attention, the formation of dissecting aneurysm in pathology is close to physiological conditions, and the development of the research provides the experimental basis and experimental methods for dissection, clinical study provides a reliable animal model and experimental basis for a new way of treatment for aortic dissection aneurysm.
Materials and methods: 5-7 months old, weighing 12-16kg healthy pigs (male or female) 12, were randomly divided into high-fat diet group (n=6) and normal diet group (n=6) were fed, respectively before breeding, fourth weeks after feeding for eighth weeks, measured serum lipid levels, and record the weight. Then in the air intubation under general anesthesia to establish model of dissecting aneurysm. Preoperative measurement of normal aortic diameter, distance to distal to the left subclavian artery at 2-3cm at the beginning, with 0T needle in the descending aorta in film, injection of elastase 200U decomposition of elastin layer, expansion force of membrane separation and membrane separation by using a mechanical length of about 5-7cm there were visible aortic obvious bulge in the muster of the aorta. The upper and lower ends are respectively clamped aorta, aortic wall incision knife tip rapidly with full thickness, intimal and arterial wall separating aortic homemade, and cut off part of the intima, the separation of week Diameter of aortic circumference 1 / 3-1 / 2. and no damage to wall incision aortic clamp, 5-0prolene suture outer and middle aortic dissection model was established successfully. Then, intravenous injection of epinephrine 0.5-1mg to increase blood pressure, accelerate the interlayer peeling, measuring the diameters of the aorta dissection. After the operation anticoagulation and other measures to prevent the interlayer of thrombosis, parallel MRI examination confirmed the existence of dissection of aorta. Death animal after surgery immediately, take the descending aorta for gross observation and histological examination. The data were expressed as the mean + SD., SAS6.12 software was used for statistical analysis, measurement data were analyzed by using t test, test set the standard for a =0.05.
Results: the high fat diet group animal after 4 weeks, serum total cholesterol, low density lipoprotein, apolipoprotein B levels were fed with significantly increased (P0.01), after 8 weeks rose more significantly (P0.001); blood lipid level of three glycerol after 4 weeks and the Fed had no statistically significant difference (P0.05), after 8 weeks was significantly increased (P0.01), high density lipoprotein in fourth weeks and 8 weeks has increased (P0.01, P0.001), but the high density lipoprotein and total cholesterol, high density lipoprotein and low density lipoprotein in eighth weeks were significantly decreased (P0.01, P0.001). Normal diet group animal close to the lipid level in the experiment before and 4 weeks and eighth weeks, there was no significant difference (P0.05). Two groups of animal weight had no significant difference (P0.05). The blood pressure of high fat diet group than that of the normal animal feed group animal, respectively, 190-200 / 160-170mmHg, 140-150 / 110-120mmHg. in high fat diet group 6 Animal, 3 animal deaths, found in 2 animal dissection; normal diet group 6 animal, 2 animal deaths, inspection found only 1 animal dissection. The high fat diet group and normal diet group animal preoperative aortic diameter were 1.0-1.4cm, 0.9-1.3cm, dissection at aortic diameters were 1.8-2.2cm, 1.6-1.8cm, were significant thickening, and high fat diet group increased significantly. The dead animal immediately take down aortic specimens, visible intimal tear, separating the middle and inner membrane, aneurysm wall thinning. Light microscopy of aortic wall under high fat diet group animal shows endothelial uplift and deformation the tube wall, inflammation, intimal foam cell deposition, staining of dissecting aneurysm at the elastic layer fracture, Weigert elastic fibers dissolved and broken. The normal diet group aortic sections in the light microscope to see intimal end The structure of the tube wall is clear and the Weigert elastic fiber can be dyed with a complete wave elastic layer.
Conclusion: the aortic intimal injury, the formation of breach, the blood by the hole into the medial aortic intima, under high pressure will be divided into double aortic, aortic hematoma between and further stripping, expansion, resulting in false lumen formation of dissecting aneurysm. Dissection false lumen through second break communication with the true lumen of aortic media. The degeneration of elastic fibers fracture, cystic necrosis is the pathological basis of this disease; hypertension, atherosclerosis is a common cause. The modeling method is consistent with the pathological basis and pathophysiology of dissection, is scientific, feasible. The preoperative feeding high fat diet can cause a certain degree of hyperlipidemia the foundation, elevated blood pressure, artery in early stage of sclerosis, with the pathological basis of dissecting aneurysm, to establish model; elastase ablation elastic fibers and lift its elastic recovery effects, and The experimental method can provide reliable animal models and experimental evidence for clinical diagnosis of disease and the new way to select aortic dissection aneurysm.

【学位授予单位】：同济大学
【学位级别】：硕士
【学位授予年份】：2005
【分类号】：R-332;R654.3

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