Objective To establish an animal model of subintimal angioplasty(SIA),and observe the pathologic changes of the components in the treated arteries.Methods 16 Bama mini-pigs were used in this study.Atherosclerotic occlusion model was created in 7 swine.SIA was performed in normal common carotid artery(9 swine)and atherosclerotic common carotid artery(7 swine).The patency rate and vascular pathologic changes were surveyed and examined.Results Technical success rate of SIA performed on swine common carotid arteries was 93.8%(15/16).The total patency rate after SIA was 53.3%(8/15).There was no significant difference in the patency rates after SIA between the groups of normal artery and ASO artery(P=0.43).Comparing to the normal artery,the media of the artery wall was thicker after SIA,and more collagen fibers as well as elastic fibers were present.Smooth muscle cells(SMC)in the media were observed in both contractile and synthesizing appearance.Conclusions(1)An animal model of subintimal angioplasty in Bama swine has been successfully designed and established.The following factors are of great importance to ensure the success:choosing swine as the experimental animal,performing SIA on the common carotid artery,closing the true luminal of the artery with suture,and using anticoagulation drugs after the operation.(2)The pathologic changes after SIA was similar with that after PTA,such as recovered endothelium,SMCs phenotype changed from contracted to synthesis,and increased amount of some extracellular matrix(collagen and elastic fibers).