Abstract: Objective To investigate the effect of argon-helium knife cryoablation on the microvessels of rabbit VX2 liver transplantation tumors. Methods Fifteen rabbit VX2 liver transplantation tumor models were constructed by VX2 tumor tissue intrahepatic injection, and randomly divided into a control group and an argon-helium knife cryoablation group (including a 3 d group, a 7 d group, a 15 d group, and a 30 d group), with 3 rabbits in each group. The morphological changes of tumors in the treated area were observed by 320-row CT enhanced scanning and histological HE staining. The expression of tumor microvascular density(MVD)-CD31 and MVD-VEGF was detected by immunohistochemistry. Results Fifteen rabit VX2 liver transplantation tumor models were constructed successfully. The results of CT showed that the tumors in the control group were divided into a peripheral ring enhancement area and a middle necrotic area. In the cryoablation group, the blood flow defect of the treated site showed a low-density cavity, and the low-density range gradually narrowed with time; if the cryoablation area was incomplete, the residual lesions could be enhanced. The histological results showed that a necrotic area without cell structure was formed after treatment, accompanied by an inflammatory cell response zone, and inflammatory cells gradually decreased with time, and a fibrous hyperplasia zone appeared. If the cryoablation area was incomplete, residual tumor cells could be seen around the treatment area. The results of immunohistochemistry showed that compared with the control group, the expressions of MVD-CD31 and MVD-VEGF increased significantly in the cryoablation 3 d group and 7 d group (all P<0.05), but significantly decreased in the cryoablation 15 d group and 30 d group (all P<0.05). Conclusions The cryoablation with argon-helium knife can inhibit the microangiogenesis of rabbit VX2 liver transplantation tumors, and may provide an effective treatment for liver tumor.

Key words: Liver transplantation tumor, Babbit VX2 tumor, Cryoablation, Microvascular density, 320-row CT, Immunohistochemical staining