Animal Experimental Study On Safety And Effectiveness Of Domestic Stent Thrombectomy System

Objective:To explore the safety and effectiveness of domestic stent thrombectomy system.Methods:A total of 12 experimental animals were used in this experiment.They were divided into 0,30 and 90 days animal model groups.There were 4 animals in each model,3 in the experimental group and 1 in the control group.Three target blood vessels were selected for each animal.The standard thrombectomy was performed in the 0-day animal model group after each blood vessel was successfully established.The simulation thrombectomy was performed in the 30-day and 90-day animal model group three times in each blood vessel.The animals survived to the end of 0,30 and 90 days,respectively.For the 0-day group,GE Innova 2010-IQ system was used to evaluate the recanalization rate,vascular dissection and spasm during thrombectomy.Finally,the animals were executed and the experimental vessels were taken out to observe their pathological changes.Eight animals at the end of the experiment(30 days,90 days)were evaluated by DSA system for the presence or absence of restenosis and dissection.The stent was deployed and its 1 cm artery fragments at both ends and the main organs(brain,heart,liver,spleen,lung and kidney)of animals were evaluated by gross and histopathological methods.Results:Twelve thromboembolic models were successfully established in the animal model group on day 0.All the blood vessels in the experimental group and the control group(12 vessels)were successfully removed(P>0.05).The successful recanalization rate of the main therapeutic indicators was 100%(P>0.05).All the blood vessels in the experimental group(9 vessels)were successfully removed once.In the control group(3 vessels),the thrombus was removed twice in the right side artery.At mTICI level 3,the average number of thrombectomy was 1.3 times.All the 12 assessed vessels had no-mild/moderate degree of vasospasm,and no dissection occurred.On the 0 day group,the 11/12(91.6%)roots were assessed with no mild to moderate thrombotic(p=0.55).On the 30 day group,angiography revealed that 10/12(83.3%)blood vessels did not induce vasospasm on zeroth days(P=0.37).2 severe vessels spasm were resolved successfully after a intra-arterial infusion of Verapamil.No dissection occurred in all the assessed vessels(12/12).The 30-day model animals remained healthy throughout the survival period without significant clinical changes.The experimental animals survived to the end of 30 days as planned.Pathological observation at 30 days after operation showed that all the blood vessels in the two groups were basically endothelialized and formed thin neointima.There was no evidence of damage to the blood vessel wall and no thrombosis in all the blood vessels.10/12(83.3%)of the 90-day group had no induced vasospasm(P=0.37),while the other two vessels in the control group had mild vasospasm.No dissection was found in all the assessed vessels(12/12).All animals remained healthy throughout the survival period without significant clinical changes.The experimental animals survived to the end of 90 days as planned Pathological observation at 90 days after operation showed that all the blood vessels in the two groups were basically endothelialized and formed thin neointima.No thrombosis was found in all the blood vessels in the experimental group.Conclusion:The safety and effectiveness of domestic stent thrombectomy system in animal experiments were similar to those of the control group.