Research On Dextran Microspheres Embolization In Rabbit VX2Liver Tumor

Objective: To compare with the survival time of the rabbits, liverfunction and the change of CT perfusion parameter, through the establishmentof the rabbit VX₂liver tumor animal model, interventional embolizationtreatment on New Zealand white rabbits using dextran microspheres andiodized oil embolization agent, and to explore which treatment effects arebetter between dextran microspheres and iodized oil embolization.Methods: VX₂tumor cells were implanted in the liver of rabbits toestablish the liver tumor animal model. New Zealand white rabbits in whichanimal model established successfully were divided into two groups randomly.Lipiodol group:25rabbits were performed with hepatic arterial embolizationusing lipiodol;Dextran microspheres group: there are25rabbits implantedsuccessfully to perform interventional embolization with dextranmicrospheres; Blank contrast group: there are6rabbits implantedsuccessfully were observed and compared without any treatment.The survivaltime of rabbits were observed from implanting tumor to death afterintervention.The changes of the rabbit liver function were observed1daybefore operation,7days after operation and14days after operation, theparameters of CT perfusion scan were analysed7days after operation. Thereare19rabbits implanted successfully and survived more than14days inlipiodol group, there are22rabbits implanted successfully and survived morethan14days in dextran microspheres group.Results:1There are59New Zealand white rabbits in which VX₂tumor cells wereimplanted,including56rabbits established successfully,2rabbits diedbecause of anesthesia accident,1rabbits died of unexplained reason, the lesions of all rabbits implanted were detected.2Comparison of survival time of rabbits among3groups after interventionaltherapy: the average survival time of dextran microspheres group was46days, the average survival time of lipiodol group was40days, and theaverage survival time of blank contrast group was33days, the differencewere statistically significant; And the average survival time of dextranmicrosphere group was longer than the lipiodol group,the difference werestatistically significant.3Changes of ALT and AST in rabbits: The difference of the index between3groups had no statistically significance on1day before interventionalembolization; the index of dextran microspheres and iodized oil groupwere significantly increased than that of the blank contrast group, but thedifference of index between dextran microspheres and iodized oil grouphad no significant on7days and14days after interventional treatment.4The rabbits were examined by CT perfusion scan after interventionaltherapy, the HAF of liver tumor in dextran microspheres group and iodizedoil group were less than that of contrast group, and the HAF of rabbitVX₂liver tumor in dextran microsphere was less than lipiodol group, thedifference was statistically significant （P<0.05）.5The tumor fibrous tissue capsule was thickening clearly（H-E staining） indextran microspheres and iodized oil groups, large necrotic areas wereobserved in the center of the cancer nests, the distribution of cancer cellswas relatively loose, nuclear was pyknosis obviously, and pathologicalkaryokinesis was significantly reduced, but the necrosis area of lipiodolgroup was less than that of dextran microsphere group.6The manifestations of Angiography: the peritumoral stain7days afterinterventional therapy by dextran microspheres was less than that by iodineoil, and there was no significant collateral blood supply developing, andthe reexamined angiography showed that deposition time of dextranmicrospheres group was more longer than lipiodol group. Conclusions:1The implanting success rate is high in the establishment of rabbit VX₂livertumor animal model,we can build the ideal animal model of interventionaltreatment, and thus help to study the effect after interventional treatment ofliver tumor with microspheres.2On survival time of experimental rabbit between groups, the averagesurvival time of dextran microspheres group is longer than lipiodol group,this shows the intervention effect of dextran microspheres group was betterthan that of lipiodol group; two treatment groups compared with the blankcontrol group, the average survival time is significantly prolonged, thisshows interventional therapy for tumor has obvious curative effect.3ALT and AST of Rabbits in the short term after interventional treatment hassignificantly increased, this shows there is certain damage for liver functionby interventional embolization treatment, and short-term can not return tonormal levels. ALT and AST have no significant difference betweenDextran microspheres and iodized oil two groups, but the blank controlgroup, the changes of ALT and AST with time is not obvious.4The HAF by CT perfusion scan of Dextran microspheres group is less thanthat of lipiodol group and blank control group. This shows that artery bloodflow in liver tumor decreased significantly after interventional therapy withdextran microspheres.5The focal necrosis area in lipiodol group is smaller than that in the dextranmicrosphere group in H-E staining, this shows that dextran microspheres ininterventional treatment is more accurate, more effective.6Through the contrast of DSA image7days after intervention surgery,dextran microspheres embolization has no significant collateral bloodsupply developing, and the deposition time of embolic agents was morelonger.