【作者】 刘振生；

【导师】 李晓强；

【作者基本信息】 苏州大学 ， 胸心血管外科（专业学位）， 2014， 博士

【摘要】 目的：研究新西兰大白兔脑动脉造影解剖及颅底动脉环（Willis环）的变异。方法：对50只新西兰大白兔行经股动脉途径选择性颈内动脉插管脑血管造影检查。具体方法如下：手术暴露右侧股动脉置入4F导管鞘，经鞘内送入4F单弯导管行主动脉弓造影后选择性进入右侧颈总动脉，经4F单弯导管插入3F微导管至颈内动脉造影。观察脑血管造影解剖及Willis环的常见变异。结果：由于对侧颈内动脉及椎动脉血流冲击，兔颈总动脉造影时颈内动脉及Willis环显影欠佳，只有选择性颈内动脉造影才能充分显示Willis环。50只兔中49只成功行选择性颈内动脉造影，其中2只由于血管痉挛导致右侧颈内动脉插管失败，但成功行对侧颈内动脉插管。选择性颈内动脉数字减影血管造影能清晰显示兔脑血管解剖细节。Willis环变异包括血管发育不良（22.4%），双大脑中动脉（20.4%），后循环不对称者（16.3%），完整对称的Willis环仅占41.9%。此外，枕动脉起源于颈内动脉者占30.1%。结论：经股动脉途径采用同轴导管技术对新西兰大白兔进行选择性颈内动血管造影可行，结果可靠。新西兰大白兔Willis环变异非常常见，熟悉其脑血管造影解剖及Willis环变异，有利于建立更加稳定脑缺血模型。目的：经股动脉途径行选择性颈内动脉插管注射血栓建立兔大脑中动脉（MCA）栓塞模型，并评价其技术可行性及模型的稳定性。方法：新西兰大白兔30只，不限雌雄，平均兔龄14个月，体重4.1kg。实验组20只，对照组10只。经股动脉途径行选择性颈内动脉插管、脑血管造影（DSA），实验组于颈内动脉内注射1~5枚血栓，对照组不注射血栓仅注射造影剂。以DSA检查明确脑血管闭塞情况，用改良Bederson评分法评价神经功能缺损，CT灌注成像观察脑血流动力学改变，磁共振扩散加权成像（DWI）、TTC染色明确脑梗死情况。结果：实验组20只兔16只（80%）成功栓塞右侧大脑中动脉主干，其中2只眼动脉代偿、3只大脑后动脉软脑膜支代偿使大脑中动脉显影，余大脑中动脉及分支不显影。4只兔右侧颈内动脉远端栓塞，其中3只大脑动脉环良好，大脑中动脉经大脑前动脉代偿显影良好，血流无明显影响。实验组16只兔表现为神经功能缺损，15只手术侧大脑中动脉供血区明显CT灌注异常，14只兔表现为不同程度DWI信号异常及TTC染色异常。对照组影像学及病理学均无异常。两组CT灌注参数差异明显（P<O.01）。结论：经股动脉途径行选择性颈内动脉插管建立兔大脑中动脉血栓栓塞模型具有创伤小、动物易存活、缺血效果可靠等优点。选择合适的血栓、熟悉兔颈内动脉系统解剖及变异，在脑血管造影指导及监视下能提高局灶性脑缺血模型的稳定性及可重复性。目的：研究Forgarty导管部分阻断腹主动脉对正常兔脑血流灌注的影响。方法：实验兔5只，暴露右侧股动置入4F导管鞘，经鞘置入4F Forgarty取栓导管，于肾动脉近端水平充盈球囊阻断腹主动脉约70%，维持1小时。以CT灌注扫描评估腹主动脉部分阻断前后兔脑血流量的变化。腹主动脉部分阻断前后不同时间点脑血流量（CBF）比较采用方差分析。结果：充盈球囊部分阻断腹主动脉后兔脑血流量明显增加，约29.4%～39.8%，抽瘪球囊解除阻断后脑血流量有下降趋势，但较基线比较仍明显增加，为23.4%。部分阻断腹主动脉前后不同时间点脑血流量差异有统计学意义（P＜0.05）。结论：部分阻断腹主动脉可显著增加兔脑血流灌注。尽管阻断解除后脑血流灌注有下降的趋势，但较高水平的脑血流仍能持续维持至12小时。目的：研究高位部分腹主动脉阻断对兔血流动力学及生存情况的影响。方法：实验兔5只，暴露右侧股动置入4F导管鞘，经鞘置入4F Forgarty取栓导管，于肾动脉近端水平充盈球囊阻断腹主动脉约70%，维持1小时。观察腹主动脉阻断前后血压、呼吸、中心静脉压的变化，及术后一周动物的生存情况。结果：实验兔腹主动脉部分阻断后BP、CVP均较阻断前有轻度升高；阻断解除后BP、CVP及HR则逐渐恢复至阻断前水平并趋于平稳。各观察指标于腹主动脉阻断前后及解除阻断后差异均无统计学意义。术后１周5只兔子均健康成活，下肢功能、饮食及大小便无异常表现。结论：部分阻断兔腹主动脉1小时安全，对血流动力学影响轻微。目的：研究部分阻断腹主动脉能否增加脑缺血模型脑血流灌注、降低脑梗死体积。方法：对20只兔经股动脉途径行选择性颈内动脉插管注射血栓建立大脑中动脉栓塞模型。模型成功建立1h后，对实验组模型兔行部分阻断腹主动脉治疗并维持1h，对照组不予任何特殊处理。两组模型兔分别于模型制作成功后30min、3h、6h、12h、24h行CT灌注扫描。24h后处死模型兔行TTC染色。实验组及对照组间同一时间点CBF比较及24h后脑梗死体积比较采用t检验。结果：大脑中动脉栓塞模型成功建立22只，对照组7只，实验组15只。对照组CBF动态变化主要表现为低灌注程度随时间延长逐渐加剧或在较低水平上波动。实验组CBF的动态变化主要表现为三种情况：（1）低灌注在3h呈不同程度恢复，然后轻度下降并维持在相对较高水平；（2）低灌注程度随时间延长逐渐加剧或在较低水平上波动；（3）低灌注在3h呈不同程度恢复，然后下一时间又逐渐降低并随着时间延长进一步加剧。实验组部分腹主动脉阻断前后各时间点CBF与对照组比较差异均有统计学意义（P＜0.05）。实验组平均脑梗死体积（263.2±36.2）mm3，明显小于对照组平均脑梗死体积（299.9±35.3）mm3，两组间差异有统计学意义（t=2.234，P＜0.05）。结论：部分阻断腹主动脉可增加脑缺血区侧支血流灌注，而随着腹主动脉阻断的解除，相对较高水平的脑血流灌注仍能在一定时间内持续维持，进而降低脑梗死体积。部分阻断腹主动脉增加脑缺血区血流灌注可能与兔侧支循环解剖基础密切相关，即此方法仅能增强现有的侧支循环，而无法有效建立新的侧支循环，所以，对那些侧支循环基础差的动物无效。更多还原

【Abstract】 Objective: To study the cerebral angiographic anatomy and variationsin the circle of Willis(COW) of the new zealand white rabbit. Methods: Subselectivetransfemoral internal carotid digital subtraction angiography was performed in50NewZealand White Rabbits. Specific methods are as follows: The right common femoral arterywas exposed and a4-F angiographic sheath was placed. A4-F angle-tip catheter wasadvanced to the aortic arch, and preliminary arch angiography and carotid artery selectionis performed. Then,3F microcatheter was employed through the4-F catheter to select theICA. Results: Common carotid artery injections provided poor filling of the COWbecause competitive flow from the opposite side and posterior circulation blocked fullCOW filling. Only with subselection of the ICA could the COW be fully displayed.49of50rabbits had subselective angiography with injections in the ICA and magnificationimaging. Two attempts at selecting the ICA on right side were not successful due to spasm,but the opposite side attempt in the same animal succeeded. Selective internal carotiddigital subtraction angiography can provide detailed images of cerebral vessels. TheVariations in the Circle of Willis include hypoplasia in22.4%, duplication of the middlecerebral artery in20.4%, asymmetries of the posterior region in16.3%. The completeclassical symmetric Circle of Willis without significant variation is present in only41.9%of animals. In addition, the occipital artery originated from the internal carotid artery in30.1%of all animals. Conclusion: Selective transfemoral internal carotid angiography ofthe rabbit is reliable. The variations of New Zealand White Rabbits are very common.With recognition of the cerebral angiography anatomy and variations of New ZealandWhite Rabbits, an improved model for embolic stroke could be obtained. Objective: To establish rabbit model of embolic middle cerebral artery（MCA） occlusion stroke with clots through selective transfemoral internal carotidchatheterization, and evaluate the technique feasibility and stability. Method:30NewZealand White rabbits of either gender, averaging14months old，weighing4.1kg onaverage， were divided into control group(n=10) and experimental group(n=20). Bothgroups received selective transfemoral internal carotid chatheterization and angiography.1-5clots were injected in experimental group and only the contrast media was injected incontrol group. DSA was used to observe the cerebral vascular obstruction, the modifiedBederson scoring was used to observe neurologic impairment, CT perfusion was used toobserve cerebral blood perfusion, and DWI and TTC staining were used to observecerebral infarction. Result: MCA were successfully embolized in16(80%) rabbits inexperimental group, in which MCA received compensation from ophthalmic artery in2rabbits and leptomeningeal collaterals of posterior cerebral artery in3rabbits. ICA wereembolized in4rabbits in experimental group, and because of good COW, the flow ofMCA is normal in3rabbits. There were neurologic deficits in16rabbits, abnomalities ofCT perfusion in15rabbits, and abnomalities of DWI and TTC staining in14rabbits. Noabnormal findings were found for control animals．There was obvious difference of CTPparameters between the two groups（P<0.01）. Conclusion: The established rabbit modelsof embolic middle cerebral arteries occlusion stroke with clots through selectivetransfemoral internal carotid chatheterization is simple, microinvasive and reliable. Tochoose appropriate clots and get familiar with the anatomy and variation of ICA canobviously improve the stability and reproducibility of focal cerebral ischemia model inrabbits.. Objective: To study the effect of partial aortic occlusion on cerebralperfusion in nonstroke rabbit model using the Forgarty catheter. Methods: Five rabbitswere studied. The right common femoral artery was exposed and a4-F angiographic sheathwas placed. A4-F Forgarty catheter was advanced to the abdominal aorta above renalartery, and the balloon was filled to occlude the abdominal aorta about70%. CT perfusionscanning was used to determine cerebral blood flow (CBF) before and after sequentialpartial aortic occlusion. CBF at different time before and after partial aortic occlusion wascompared using analysis of variance. Results: CBF increased significantly(29.4%～39.8%) with inflation of the balloon and remained elevated by23.4%12h after deflation.The difference of CBF before and after partial aortic occlusion was significant(P＜0.05).Conclusions: Partial aortic occlusion can increase cerebral perfusion significantly.Although there was a trend to return to baseline flows, the increased flows weremaintained to12after deflation. Objective: To investigate the changes of hemodynamics and thesurvival conditions after partial abdominal aortic occlusion and then provide referencematerials for clinical abdominal aorta interruption in rabbits. Methods: Five rabbits werestudied. The right common femoral artery was exposed and a4-F angiographic sheath wasplaced. A4-F Forgarty catheter was advanced to the abdominal aorta above renal artery,and the balloon was filled to occlude the abdominal aorta about70%for one hour. Heartrate(HR)，blood pressure(BP) and central venous pressure(CVP) before and after partialabdominal aortic occlusion were measured, and the survival condition in the followingweek was observed. Results: The results of hemodynamic changes in the group show that BP and CVP increased and HR slowed down slightly after the partial abdominal aorticocclusion. When the occlusion was removed, BP, CVP and HR were gradually restored tothe former level. The difference among the main outcome measures before and after partialabdominal aortic occlusion and after withdrawal was not significant. All rabbits survived,and the posterior limbs function, stool and urine and feed situation was normal in thefollowing week. Conclusions: Partial abdominal aortic occlusion for one hour is safeand has minor effect on hemodynamics. Objective: To investigate wether partial aortic occlusion can increaseCBF and reduce cerebral infarction volume in a rabbit focal embolic stroke model.Methods: To establish the model of embolic MCA occlusion stroke with clots throughselective transfemoral internal carotid chatheterization in20rabbits. One hour after theembolic rabbit stroke models were established successfully, the models in experimentalgroup received the treatment of partial aortic occlusion for one hour and the models incontrol group did not received any treatment. All the rabbit models underwent CTperfusion imaging(CTPI) at0.5h,3h,6h,12h, and24h respectively after the embolic rabbitstroke models were established successfully. TTC staining were used to observe cerebralinfarction24h after stroke models were established. The CBF at the same point in time andcerebral infarction volume between two groups were compared using t test. Results: Theembolic rabbit stroke models were established successfully in22, which were grouped intoexperimental group(15) and control group(7) randomly. The changes of CBF in controlgroup were mainly characterized by an increasingly and sustained reduction over time. Thechanges of CBF in experimental group were manifested as three kinds of status.(1)Thelower cerebral perfusion recovered to some extent at3h and maintained relatively highlevel.(2) The lower cerebral perfusion reduced increasingly over time.(3) The lowercerebral perfusion recovered to some extent at3h and followed by increasingly andsustained reduction over time. The mean CBF at different points in experimental group were higher than those in control group, and the differences were significant(P＜0.05). Themean cerebral infarction volume in experimental group(263.2±36.2mm3) was less thanthat of control group(299.9±35.3mm3), and the difference was significant(t=2.234, P＜0.05). Conclusions: Partial aortic occlusion can increase cerebral collateral circulationperfusion significantly in the rabbit stroke models and the increased flows were maintainedfor some time, which resulted in the reduction of cerebral infarction volume. The increasedcerebral perfusion by partial aortic occlusion might be closely related to the existence ofcollateral circulation. In other words, partial aortic occlusion could not increase cerebralperfusion for the stroke model without collateral circulation..更多还原