ABSTRACT
Objectives: To observe the radiological and pathological changes of flow diverting sent implanting into abdominal aortae of rabbits at 3 months and to evaluate the safety of stents for normal arteries of rabbits. Methods: The abdominal aorta beyond the left renal artery opening was showed via preoperative angiography. The flow diverting stents with metal coverage of 35% to 45% were implanted into the abdominal aortae of 20 New Zealand white rabbits. Intravenous digital subtraction angiography was performed at 4 weeks after the procedure. Arterial digital subtraction angiography was performed for all the animals at 3 months and they were sacrificed for histopathological examination. The angiography showed that the diameter changes of abdominal aortae on the stenting sites at different time points were measured and compared. The relationship between the neointima and the metal coverage of local stent were analyzed. Results: The mean diameter of the abdominal aortae before stenting, immediately after stenting, at 4 weeks, and at 3 months were 3.47 ± 0.44 mm, 3.65 ± 0.40 mm, 3.57 ± 0.36 mm, and 3.51 ± 0.30 mm, respectively. There were significant differences among the different time points (P=0.009). The neointima fully covered the stents with a mean thickness of 95 ± 42 μm. They were predominantly composed of smooth muscle cells, collagen fibers, and a small amount of macrophages. The neointimal thickness was positively correlated with the local coverage of the metal stents (r = 0.523; P = 0.001). Conclusion Three months after the implantation of flow diverting stents, the abdominal aorta intima thickened slightly, and the stents were safety for normal arteries of rabbits.