兔肝VX2移植瘤门静脉阻断模型的建立及其多层螺旋CT评价

背景:临床研究发现肝癌门静脉阻断有利于抑制肝癌的生长,促进未阻断肝组织的代偿性增生,并降低经门静脉途径的转移,目前尚需动物实验进一步验证。目的:探讨兔肝VX2移植瘤门静脉阻断模型的建立方法,及其多层螺旋CT评价价值。)设计:随机分组设计、动物实验。单位:解放军第三军医大学新桥医院放射科。材料:实验于2002-07/2005-01在第三军医大学新桥医院影像学实验室完成。选择新西兰大白兔40只,随机数字表法分为4组,每组10只,门静脉阻断即刻移植瘤体组、瘤体移植3周后门静脉阻断组、阴性对照组、阳性对照组。方法:采用开腹包埋接种法移植兔肝VX2肿瘤,分别进行门静脉阻断后即刻移植瘤体和移植瘤体生长3周后行门静脉阻断,同时设立阴性对照组(门静脉左外支行假手术阻断,兔肝左外叶假性包埋接种)、阳性对照组(移植瘤体未行门静脉阻断)。所有实验兔均行兔多层螺旋CT检查。主要观察指标:门静脉阻断后肝大体变化、瘤体变化、肿瘤转移情况,肝动脉、门静脉各级分支的多层螺旋CT血管成像显示率,肝血流量、血容量、平均通过时间、血管表面通透性和肝动脉灌注分数。结果:纳入动物40只,均进入结果分析。①门静脉阻断即刻移植瘤体组于门静脉分支结扎术3周后均未见瘤体生长。瘤体移植3周后门静脉阻断组动物左内叶明显萎缩,肿瘤的生长明显受抑制,其瘤体最大径明显小于阳性对照组[分别为(2.55±0.46),(3.59±0.37)cm,t=5.57,P<0.001]。瘤体移植3周后门静脉阻断组肝内转移及肺转移发生率也明显少于阳性对照组(分别为10%,40%和100%,90%);但两者的邻近转移率差异却无显著性意义。②多层螺旋CT血管成像检查对Ⅲ级以上肝动脉分支的显示率明显低于Ⅰ、Ⅱ级肝动脉分支的显示率(分别为40%,100%,70%,P<0.05)。门静脉各级分支的显示率差异无显著性意义(P>0.05)。③门静脉阻断即刻移植瘤体组、瘤体移植3周后门静脉阻断组肝血流量、血容量、平均通过时间和血管表面通透性值均较相应对照组降低,但肝动脉灌注分数值均明显增高。结论:门静脉左外支结扎是兔肝VX2移植瘤门静脉阻断的理想模型。多层螺旋CT在兔肝门静脉阻断效果的评价中起着重要作用。

Establishing models of portal vein occlusion and value of multi-slice CT in the evaluation of hepatic VX2 tumor in rabbits

BACKGROUND: Clinical researches found that portal vein occlusion was beneficial to inhibit growth of hepatocarcinoma, promote compensatory hyperplasia of un-blocking hepatic tissue and decrease metastasis of portal vein occlusion; however, it should be fu~her proved by animal experiments.OBJECTIVE: To investigate models of portal vein occlusion of hepatic VX2 tumor in rabbits and evaluate value of multi-slice CT.DESIGN: Randomized grouping design and animal study.SETTING: Department of Radiology, Xinqiao Hospital of the Third Military Medical University of Chinese PLA.MATERIALS: The experiment was carried out in the Imaging Department of Xinqiao Hospital of the Third Military Medical University of Chinese PLA from July 2002 to January 2005. Forty New Zealand rabbits were divided according to digital table into 4 groups: immediate group (transplantation of tumor after immediate portal vein occlusion), 3-week group (transplantation of tumor at 3 weeks after portal vein occlusion), negative control group and positive control group, 10 in each group.METHODS: Hepatic VX2 tumor was transplanted with abdominal-embedding innoculation at immediate portal vein occlusion and 3 weeks after portal vein occlusion. Meanwhile, they were divided into negative control group (Left external branch of portal vein was done sham-operative block,and left exite was embedded and inoculated pseudoly) and positive control group (Transplanted tumor did not suffer from portal vein occlusion). All rabbits were scanned with multi-slice CT.MAIN OUTCOME MEASURES: General changes of liver, changes of tumor, metastasis of tumor, vascular-imaging displaying rate of multi-slice CT of hepatic artery and portal vein, blood flow of liver, blood volume,mean transit time, permeability of vascular surface and fraction of hepatic arterial infusion (HAI).RESULTS: All 40 animals were involved in the final analysis. ① Tumor did not grow in both immediate group and 3-week group. In 3-week group,left endite was atrophied and growth of tumor was inhibited. The maximal diameter of tumor was smaller than that in positive control group [(2.55 ±0.46), (3.59±0.37) cm, t=5.57, P ＜ 0.001]. Incidences of metastasis in liver and lung were lower in 3-week group than those in positive control group (10%, 40%; 100%, 90%); however, there was no significant difference. ② Scanning with multi-slice CT, displaying rate of branches hepatic artery was lower in grade Ⅲ than that in grade Ⅰ and Ⅱ (40%, 70%,100%, P ＜ 0.05); but there was no significant difference of displaying rate of portal vein at various grades (P ＞ 0.05). ③ Values of blood flow of liver,blood volume, mean transit time and permeability of vascular surface were lower in immediate group and 3-week group than those in control groups,but values of HAI were increased.CONCLUSION: Ligating left external branch of portal vein is an ideal way to establish models of portal vein occlusion of hepatic VX2 tumor in rabbits; furthermore, multi-slice CT plays a key role in evaluating effect of portal vein occlusion.