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

Yueyong QI; Liguang ZOU; Shuhua DAI; Ping LIANG; Xiaobing HUANG

ABSTRACT

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.