| Objective:1.This study performed longitudinal linear ablation of normal blood vessels in rabbits by using temperature-controlled radiofrequency ablation balloon.We aimed to explore the damage of rabbit normal arteries at different temperatures,observe the damage of normal blood vessel intima,hyperplasia and fibers by radiofrequency temperature-controlled balloon and ordinary balloon and understand the optimal temperature of radiofrequency ablation of arterial blood vessels.2.Longitudinal linear ablation of atherosclerotic vessels was performed in rabbits with temperature-controlled radiofrequency balloon,to explore its effect on atherosclerotic plaque,and on the area of vascular lumen of atherosclerotic plaque.Besides,its effect on inflammatory factors,apoptotic factors and TGF-β pathway,the histological changes of blood vessels,the changes of pro-inflammatory cytokines,anti-inflammatory cytokines,apoptotic factors and TGF-β / Smad-2 inflammatory pathways were also investigate to provide new ideas for clinical treatment of atherosclerosis.Methods:1 The normal healthy rabbits were divided into 4 groups: ordinary balloon dilatation control group,45 ℃ radio frequency temperature controlled balloon dilation group,50 ℃ radio frequency temperature controlled balloon dilation group,55 ℃ radio frequency temperature controlled balloon dilation group.The temperature-controlled radiofrequency balloon was used to remove rabbit iliac artery specimens at 1h,3d,and 7d after expansion,and the specimens were fixed with formaldehyde,and performed HE and Masson staining to observe the vascular proliferation and collagen fiber changes and measure the vascular cavity area.2.Modeling of arteriosclerosis: the rabbit aorta intima was injuried by balloon,and the rabbits were feed with high-fat diet to establish an atherosclerosis model.At12 w,2 rabbits were randomly killed to test whether the atherosclerosis model was successfully established.3.The rabbits with successful modeling were randomly divided into 2 groups:55 °C radiofrequency ablation dilatation group and ordinary balloon dilatation group.Arterial specimens were retained at 1 hour,7 days,14 days,and 28 days.HE and MASSON staining were performed to observe the pathological histological changes.The methods of immunohistochemistry,western blot and real time quantitative PCR were used to detect the changes of pro-inflammatory,anti-inflammatory,apoptotic factors,TGF-β / Smad-2 pathway protein levels and m RNA levels in tissues.Results:1 Compared with the simple balloon dilatation group,there was no statistical difference in the vascular lumen area of the normal rabbit arterial vessels among 45 °C,50 ° C and 55 ° C groups.2 At the same time point of 55 ° C radiofrequency expansion of atherosclerotic blood vessels,the vascular lumen area of ??the temperature-controlled radiofrequency balloon group was larger than that of the simple balloon dilation group.However,the vascular lumen area did not change much both in temperature-controlled radiofrequency ablation balloon group and the balloon-expanded group.There was no statistical difference in tube wall thickness between the different time point groups of the temperature-controlled radio frequency balloon group.3 At the tissue level,the expressions of IL-1β,IL-17,Bax,INF-γ,TGF-β,Smad-2 and Caspase3 in the temperature-controlled radiofrequency balloon dilation group were significantly higher than those in the simple balloon dilation group.The expression level of IL-10 and Bcl-2 in the temperature-controlled radiofrequency ablation balloon dilation group was significantly lower than that in the simple balloon dilation group.4 At the time points of 1 hour,7 day,14 days,and 28 days,the overall expression of Bcl-2 in rabbit arterial blood vessels in the temperature-controlled balloon dilation group was significantly lower than that in the simple balloon dilation group.However,the overall expression levels of Bax,TGF-β,Smad-2 and Caspase3 in rabbit arterial blood vessels in the temperature-controlled radiofrequency balloon dilation group were significantly higher than those in the simple balloon dilation group alone.Conclusion:1 When using a temperature-controlled radiofrequency ablation balloon to ablate normal blood vessels in rabbits,normal blood vessels can be damaged at 45 ℃,50 ℃,and 55 ℃.The extent of damage to the vessel wall is correspondingly expanded,but it is still safe to ablate normal vessels for 30 seconds at 55 ° C.2 Using a 55 ° C radiofrequency ablation balloon to dilate rabbit atherosclerotic blood vessels can increase the lumen area of ??atherosclerotic blood vessels.This might because the plaque was squeezed by ballon and radio frequency energy lead to linear damage to blood vessels and increase blood vessel compliance.The atherosclerotic blood vessels were expanded under the effect of arterial blood pressure.3 atherosclerotic plaques at the ablation site can become fibrotic,which can help stabilize atherosclerotic plaques when performing radiofrequency ablation of atherosclerotic blood vessels.4 Radiofrequency ablation can increase the expression of pro-inflammatory cytokines,reduce the expression of anti-inflammatory cytokines,inhibit apoptosis,and activate the TGF-β / smad2 pathway.This also suggests that although radiofrequency ablation can increase blood vessel area,inflammatory pathways are also activated at the same time.If it is used clinically,drugs that inhibit inflammatory response should also be applied.The long-term effect of balloon ablation is maintained. |
