Establishment Of Aneurysm Animal Model In Vasospasm Stage

Background: Intracranial aneurysms (AN) is the most common cause of spontaneoussubarachnoid hemorrhage（SAH）, accounting for25%of intracranial hemorrhage, andserious harm to the safety of human life. Cerebral vasospasm (CVS) after SAH is themost common complication, can cause secondary cerebral ischemic injury, is one of themain cause of subarachnoid hemorrhage high residual death rate and prognostic a majorfactor.CVS can lead to secondary cerebral ischemia and reduce blood flow velocity in theaneurysm at the same time, which in turn reduces the rate of aneurysm rupture again.How to choose the timing of surgery, cerebral vasospasm relief, both to ensure thepatient can tolerate surgery, but also effectively avoid aneurysm rupture again, is theunsolved problem of neurosurgery.All of research will base on the reliable model of theAN. As of today, there is no a way to fully simulate the biological characteristics of humanintracranial aneurysms. Therefore, how to design and production aneurysm consistentwith animal models of aneurysm is the basis of further research and the crux.The idealAN animal model should have the following characteristics:（1）Aneurysm morphology,pathological structural changes, hemodynamic and other aspects of nature identical orsimilar aneurysm;（2）Create a simple, low-cost, short cycle;（3）Stability aneurysmmorphology, shape and size can be controlled and good repeatability（;4）appropriate sizeof AN to make observation and operation easier;（5）thrombosis does not occur in AN andparent artery during the experiment and AN is not easy to rupture. The adoption themicrosurgical suture law to establish a vasospasm aneurysm model established in thisstudy provide help for the study of the aneurysmal vasospasm around its parent arteryhemodynamic changes.Materials and methods:(1)Preoperative preparation： nineteen adult healthy NewZealand white rabbits, male or female, weight2.3~3.1kg.Small dose of diazepamintravenous,3%pentobarbital solution,30mg/kg by ear vein once slow bolusanesthesia.(2)Free and cut into small pieces right external jugular vein:The rabbit supineposition fixed extremities and incisors were fixed on the the easy operating table side, theright side of the surgery free for a period of about1.5cm right external jugular vein,ligation of both ends, cut a section of about0.5cm venous segment, with heparinized salinerinse, trim free at one end, the other end ligation into the blind-side, placed inheparinized saline spare.(3)Free right common carotid artery:Blunt dissection of theanterior muscles, locate and confirm the right common carotid artery, carefully free themiddle of the bifurcated portion latex sheet placed at its next.(4)The intravenous bag-arterial anastomosis:Exfoliative vascular adventitia under a microscope, and then use thetemporary vascular clipping the right common carotid artery proximal end and telecentricend, for a length of about2-3mm longitudinal elliptical incision in the carotid artery centralfree, intravenous bags mouth with carotid arterial line end-sideanastomosis.Postoperative observation for a few minutes notice any leakage, no leakageafter skin and muscle, step by step a sterile gauze bandage.(5)Postoperative done incolor doppler and CT angiography:Go after two vascular color dopplar ultrasoundinspection measuring load tumor artery aneurysm and the diameter and blood flowvelocity, and then applied to vasospasm drugs (adrenaline) in ultrasound-guided localinjection so as to produce similar to rupture caused by vascular spasm,colour to exceedmeasure again, respectively, and vessels of aneurysm and its parent artery diameter andblood flow velocity. Vascular colour to exceed to check again after1week, CTangiography measurement before and after medication changes of parent artery diameterand the size of the aneurysm.All after the check1weeks under general anesthesia thedividing of rabbit neck, find and remove aneurysm observation.Results: Successfully produced16side aneurysm models.Color Doppler ultrasoundStatistics found to significantly narrow the medication after the parent artery diameter thanbefore treatment than before slowing down blood flow velocity within the statisticalanalysis are significant differences(p＜0.01).The blood flow of AN velocity after treatmentthan before also slowed down compared with a significant difference(p＜0.01).Nosignificant difference in the length and width diameter of the aneurysm before and aftertreatment(p>0.05).CT angiography data in statistical analysis shows the parent arterydiameter medication than before narrowing contrast significant（p＜0.05）.No significantdifference in the length and width diameter of the aneurysm before and after treatment(p>0.05).Conclusion:1.Vein cystic aneurysm model cause spasm drug combination to thesuccessful establishment of rabbit vasospasm AN model.2.Vasospasm AN modelestablished through the vascular color Doppler ultrasound and CT Angiography confirmedmorphologically similar human intracranial aneurysms. Color Doppler ultrasound and CTangiography successfully applied to the evaluation of aneurysmal vasospasm modelcontains vasospasm aneurysm before and after the new hemodynamic studyaids.3.Established through this experimental rabbit vasospasm aneurysm model is simple,molded short time, good repeatability better simulate the effect of the human aneurysmrupture vasospasm, and for blood flow dynamics within the aneurysm before and after thevasospasm the study provides a solid foundation.