Implantation of the irradiation stent system intoportal vein: studies on normal beagles

Abstract

Objective: To assess the feasibility and safety of the irradiation stent system in portal vein on normal beagles. Methods: A portal vein irradiation stent system was composed of an Iodine-125 seeds-carrier and a conventional stent.Twenty beagle dogs were randomly assigned to receive treatment with a conventional stent (5 beagle dogs) or an irradiation stent system (15 beagle dogs in three groups received 11.1, 22.2, 33.3 MBq radioactivity, n=5 in each dose group). Follow-up methods included blood biochemical test, color Doppler sonographyand CT scan at 0, 15, 30, 60, and 120 days after implantation of irradiation stent system.Pathological tissues were obtained from sacrificed beagle dogs on the 120th day. Results: The portal vein irradiation stent systems and the conventional stents were successfully deployed into the targeted portal vein segment in all beagles, none was dislodged during the deployment or the follow-up period.Differences of blood biochemical indexes and portal vein flow volume measured by color Doppler sonography were not significant (P>0.05). Stent systems were morphologically intact and patent.None of the peripheral organs had hemorrhage, necrosis or perforation.Pathological tissues revealed that the systems were surrounded by fibrous tissues and a few inflammatory cells, but with no significant differences in all groups. Conclusion: It indicates that portal veinirradiation stent system is safe in all dose groups, and it is feasible to design a special irradiation stent system for each patient according to the size of the portal vein tumor thrombus.