脑动脉瘤模型制作及高血压对其影响的实验研究

目的 建立脑动脉瘤动物模型并初步探讨高血压对脑动脉瘤的影响.方法 45只雄性SD大鼠按随机数字表法分为高血压组、正常血压组和正常对照组.高血压组行脑动脉瘤模型制作+双侧肾动脉狭窄术:正常血压组只建立脑动脉瘤模型:正常对照组不予任何处理.各组在术前,术后6周、12周三个时间点分别测量各组大鼠动脉收缩压.术后12周测量脑动脉瘤大小,并灌注固定,取脑动脉瘤部位血管组织,应用HE染色、Van Geson染色和Verhoeff染色进行病理检查.结果 高血压组在处死前血压明显升高[(197.48±15.44)mm Hg],与手术前的血压[(104.40±14.70)mm Hg]相比差异有统计学意义(P<0.05);处死前脑动脉瘤的长度[(2.38±0.31)mm]和宽度[(1.89±0.35)mm]与脑动脉瘤制作完成时的长度[(1.62±0.18)mm]和宽度[(1.36±0.09)mm]相比差异有统计学意义(P<0.05);正常血压组和正常对照组无明显变化.病理检查显示高血压组血管内膜消失,弹力层完全断裂;正常血压组尚存部分弹性纤维;正常对照组血管组织无改变.结论本实验采用的脑动脉瘤模型稳定性好,制作方便,具有与人类脑动脉瘤相似的形态和病理结构.高血压对脑动脉瘤的弹力蛋白和胶原蛋白有明显影响,是影响脑动脉瘤增大的重要因素之一.

Effect of hypertension on cerebral aneurysms and model production of cerebral aneurysm in a rat

Objective To establish a rat model of cerebral aneurysms and explore the impact of hypertension on it. Methods Forty-five rats were randomly divided into hypertensive, normotensive, and normal control groups (n=15). The origin of the right external carotid artery was digested with porcine pancreatic elastase, ligated and cut at 1.5 mm from the carotid bifurcation. Cerebral aneurysm models were established in this stump in the hypertensive and normotensive groups, and then, stenosis of the bilateral renal artery was induced surgically in the hypertensive group. The systolic blood pressures in the 3 groups were measured before and at 6 and 12 weeks after the operation. At 12 weeks after the operation, the aneurysms, after measurement of the size, were fixed by formalin perfusion. The vascular tissues in the aneurysms were isolated for pathological examination using HE staining, Van-Geson staining and Verhoeff staining. Results A significant increase in the blood pressure occurred in the hypertensive group to the level of 197.48±15.44 mm Hg, and the aneurysm was obviously enlarged measuring 2.38±0.31 mm in length and 1.89±0.35 mm in width;no significant changes occurred in the normotensive and normal control groups. Pathological examinations demonstrated the absence of the intima and rupture of the elastin layer in the hypertensive group;the normotensive group retained part of the elastic fibers, and no vascular damage was found in the normal control group. Conclusion This aneurysm model can be prepared conveniently with good stability, and can well simulate the structure and pathology of human cerebral aneurysm. Hypertension significantly affects the elastin and collagen in the blood vessels to contribute to aneurysm enlargement.