The Establishment Of A Rabbit Carotid Aneurismal Model And The Fundamental Research About The Aneurysm

Part1.The establishment and validation of the rabbit carotidaneurismal model induced by elastaseObjective:1.To made a elastase-induced rabbit carotid aneurismal model for the researchabout the new interventional material;2.To confirm the method ’ s feasibility with digitalsubtraction angiography (DSA).Methods:40New Zealand white rabbits were supplied from the center of animalexperiments of The Fourth Military Medical University, weighing about3kg, male orfemale was half.they were randomly divided into4groups,A group(control group);Bgroup(2weeks group);C group(3weeks group);D group(4weeks group), each of thegroup was10New Zealand white rabbits.2. Experimental group(B group、C group、Dgroup) were maded by the surgical operation method, carefully separating andexposuring the initial segment of carotid artery under microscope, carefully stripping theadventitial connective tissue, operation silk threaded a ligation of the carotid artery fromstarting of the right carotid artery about2.0cm in rabbits, with the micro vascularclamping of the right initating carotid artery, a closed tube was formed. Physiologicalsaline was absorbed by syringe(1ml) to rinse until the closed tube wasclean.Elastase(70U/0.1ml) was injected in to the closed tube,20minutes later,the microvascular was unclasped.The method of control group wase equal to experimentalgroup,only the elastase was replaced with physiological saline;3.All animal aneurismalmodel was observed for the the size, morphology and the relationship with parent arteryunder the DSA. According to the aneurismal flow, to determine whether aneurismalmodel was successful.Results: After2weeks，7rabbit survived in the control group，27rabbit survived in theexperimental group.In the control group,there were caecum in the starting of the rightcarotid artery, there were no normal vascular/anatomy/structure/shape. In the experimental group,6aneurysm were closed up,21aneurysm were successful，the heightwas about0.3～1.3(cm), the neck width was about0.3～1.2(cm). Comparing the rate ofaneurysm,p＞0.05,there was no significant differences.Conclusion: Elastase could induce a perfect rabbit carotid aneurismal model,wich wasmade simply, existing chronically for the research of new interventional material; Wecould use DSA for confirming whether the method was successful.DSA was the firstlychosen for the treatment and examination. Part2The expression of VEGF、TGF-β in the the rabbit carotidaneurismal modelObjective:1.To observe the histopathology of vascular remodeling with HE staining;2. toobserve expression of VEGF、TGF-β in the the rabbit carotid aneurismal model, To studythe mechanism of aneurysm.Methods:1.we could let the experimental group leaving the right carotid aneurysm alongunder microscope. To observe the growth and size of aneurysms, Remove the specimenof the aneurysm for a frozen section. to observe the histopathology of vascularremodeling with HE staining; also we could let the control group leaving the right carotidcaecum along under microscope and observe the histopathology of vascular remodelingwith HE staining;To observe the change between the experimental group and controlgroup;2.Immunohistochemical determination of VEGF、TGF-β in the the rabbit carotidaneurismal model.Results:1.There were no obvious change in the vascular wall structure of the controlgroup.There were obvious change in the vascular wall structure of the experimentalgroup,Lumen enlarging,Vascular wall thinning,layer of vascular elastic disappearing,cellsarranged in disorder,vessel normal wall structure of vessel disappeared;2.There were noexpression of VEGF、TGF-β in the vascular wall structure of the control group,butobvious expression of VEGF、TGF-β in the experimental group,about2weeks, theexpression of VEGF was on the peak and kept a long time, about3weeks, the expressionof TGF-β was on the peak and decreasing in the future. expression of VEGF、TGF-β inthe experimental group was obvious higher than control group(p<0.05).Conclusion:1.The aneurysmal wall remodeling was similar between the aneurismalmodel and the human. Lumen enlarging,Vascular wall thinning,layer of vascular elasticdisappearing,cells arranged in disorder, vessel normal wall structure of vesseldisappeared and so on.2.There were obvious expression of VEGF、TGF-β in theaneurismal model,they were involved in the inflammatory response of aneurysmalwall,VEGF could promote the formation of new blood vessels, TGF-β play regulatoryroles for VEGF in the Structural remodeling of aneurysmal wall.