Development Of Primary And Secondary Level Copper Coil And Vascula Embolization Test

Objective:The purpose of research is to improve the physical and chemical stability of first and second level copper coil by using new technology and materials.The self-made copper coils will be tested in vivo and vitro to explore its characteristics of the controllability,memorability,embolic effectiveness and ability to pass catheter.Materials and Methods:1,First level of pure copper micro-coil(Φ:0.48～0.74mm): made from 0.1～0.23mm diameter pure copper wire.The prepared coil had been delivered through 3F catheter by guide wire or sodium chloride injection.Its controllability and flexibility was observed.The coagulative ability was compared with first level platinum micro-coil.Renal artery embolization with first level pure copper coil was performed through 3F catheter in rabbits.10min,30min,3d,1w,2w, 4w,6w,and 12w after embolization,angiography was respectively processed to observe thrombus extent.After the embolization 3 days,1w,2w,4w,6w and 12w,the rabbits were killed to observe the histopathological changes in kidneys.2,second level pure copper micro-coil(Φ:1.96～5.96mm):made from prepared first level copper micro-coil.Its controllability and flexibility was observed after delivering coil through 3F～5F catheter by guide wire or sodium chloride injection.3,Second level of copper plated micro-coil(Φ:1.98～5.98mm):The second level platinum micro-coil is made from 0.28mm diameter platinum guide wire manufactured by Cook Company, from which the internal mandril had been removed.Second-level platinum micro-coil was made from the guide wire by heat-treatment.Then the second level platinum coil was coated with copper.Plated copper thickness was measured and stability of copper layer was tested.In vitro tests,the coil had been pushed through 3F～5F catheter by guide wire or sodium chloride injection.The second level copper coated micro-coil; platinum micro-coil and pure copper micro-coil were putted at random into three containers with artery blood to observe their coagulative ability.In animal experiments,one common carotid artery or subclavian artery was embolized by second level copper coated micro-coils through 3F～4F catheter,and the other common carotid artery or subclavian artery was embolized by second level platinum micro-coils as control,10min,30min,3d,1w,2w,4w,6w,and 12w after embolization,angiography was respectively processed to observe thrombus extent. After the embolization 3 days,1w,2w,4w,6w and 12w,the rabbits were killed to observe the histopathological changes in the embolic-artery.Results:1,First level of pure copper micro-coil:the coil pushed through 3F micro-catheter by guide wire or sodium chloride injection,there is no change in coil between pre and post-releases;In vitro experiments show that pure copper coils have stronger role in promoting blood coagulation,the experiment results indicate that copper coil can be released through the 3F micro-catheter to embolize renal artery of rabbit and the embolization was effective.2,second level pure copper micro-coil: memorability and controllability of the coil is poor because it is difficult to pushed the coil through below the 5F catheter(not including 5F) by guide wire or sodium chloride injection.3,Second level of copper plated micro-coil:With the heat treatment and copper plating process on the second level platinum coil,the coil have showed good copper layer fixedness,memorability,flexibility and controllability.It could restore after through the 3F and 4F catheter.In vitro experiments showed that second level copper plated coil have a stronger role in promoting blood coagulation; animals embolization experimental results show that the second level copper plated micro-coil can be released through the 3F micro-catheter to embolize subclavian artery of rabbit.The embolization was superior to second level platinum coil(P＜0.05 =0.001). Conclusion:The purpose of research is to improve the physical and chemical stability of first and second level copper coil by using new technology and materials.It is easy to prepare the first level pure copper micro-coil and release it through 3F catheter to embolize below lmm diameter blood vessel.It showed advanced controllability and stability.Second level copper plated coil have good physical property,rememorability, flexibility and controllability.Pure cooper wries is only used to make first level coil.