In Vitro Study On Co-flow Injection Of Embolic Glue Based On High Speed Photography

Vascular interventional embolization is a technique carried out under the guidance of medical imaging by injecting embolic agent into targeted vessels through microcatheters to occlude or interrupt blood supply,so as to achieve the desired therapeutic purpose.Cyanoacrylate embolic glues have the advantages of rapid polymerization,high fluidity,low viscosity and low tissue toxicity,which are preferred for the embolization of tortuous and intertwined vascular malformations.When the mixture of cyanoacrylate lipiodol is coaxially injected into blood via microcatheter,the effective control of the shape,size and polymerization rate of the gel droplets produced during the infusion process is the necessary prerequisite for the safe completion of embolization.In addition to the rapid polymerization and solidification of embolic glue,the changes of injection mode,injection rate,blood flow and vascular structure also directly affect the embolic effect.However,the regulation of mixing proportion and the injection method still depends on the clinical experience and operation habits of doctors.The quantitative relationship between injection mode,injection rate,blood flow,vascular structure and the shape and size of glue drops is not clear.How to control the injection conditions to achieve the desired embolization effect is still lack of systematic research.In this study,an in vitro modeling has been constructed to simulate the intravascular co-axial injection of embolic glues.The mixture of embolic glue and Lipiodol(dispersed phase)is injected into the blood substitute(continuous phase)through microcatheter under the control of peripheral pumps.The droplet formation process is recorded by high-speed image acquisition system.By changing the injection rate,concentration of embolic glue-lipiodol mixture,composition of blood simulant and flow rate of blood simulant,the droplet formation processes in the co-axial injection system under different infusion conditions have been recorded.Then,using the recorded images,the effects of different infusion conditions on the droplet morphology distribution,formation time and droplet size are quantitatively studied through image processing and data analysis.The results experimented demonstrate that,in the co-axial injection process of embolic glues,the droplet formation process is jointly influenced by the polymerization of embolic glues and the co-axial injection dynamics.When the injection rate of embolic glue is low or the infusion rate of blood simulant is low,the surface polymerization will be more intense,and the influence on the shape,time and size of the droplets will increase.With the increase of the injection rate of embolic glue and the infusion rate of blood simulant,the formation time and size of the droplets will decrease,However,the change of infusion rate of blood simulant has little effect on the formation of embolic glue;With the increase of embolic glue concentration in the mixture of embolic glue and Lipiodol,the effect of embolic glue polymerization is more severe,and the effect on the formation of rubber droplets is greater,resulting in the increase of time and volume required for the formation of rubber droplets,and vice versa;In addition,with the increase of protein concentration in blood simulation solution,the polymerization reaction of embolic glue is intensified,and the influence on the shape,time and size of the gel droplets is more significant.The results provide an important experimental basis for the effective control of the coaxial injection process of embolic agent,the optimization of the surgical scheme and the improvement of safety during embolization operation.