Mechanism of inhibiting neointimal proliferation with intra-arterial irradiation using rabbit iliac arteries

点击翻译按钮获取中文摘要

To evaluate effect of 192Ir-HDR intra-arterial irradiation for preventing neointimal proliferation percutaneous transluminal angioplasty (PTA) with cutting balloon catheter, experimental study was performed using rabbit iliac arteries. PTA was underwent in the both iliac arterial segments of rabbits. Intra-arterial irradiation with 6Gy or 12Gy was performed on one side of iliac artery segment and unirradiated side was studied as a control. Rabbits of 6Gy group survived until sacrifice at 1, 2, and 4 weeks. Rabbits of 12Gy group were euthanatized at 1, 2, 4, 8 and 12 weeks after PTA. Histopahologic, morphometric and immunohistochemical analyses were carried out. Histopathlogy showed repair of dissection by cellular accumulationand and a striking reduction in the amount of neointimal proliferation in irradiated arteries compared with control arteries. At one week, neointima area had markedly increased in control arteries. There was no evidence of neointimal proliferation in irradiated arterial segments. At 2-4 weeks, a marked and statistically significant decrease in neoientima area was observed in irradiated groups compared with control arteries(p<0.001). A significant difference was noted between irradiated arterial segments and control arteries at 8-12 weeks in 12Gy group. In 12Gy group, threre was a peak of PCNA-positive ratio in neointima of control arterial segments at one week. At 2-4 weeks, neointimal PCNA-positive ratio was still significantly increased in control arterial segments compared with irradiated arteries. After 8 weeks, PCNA-positive raio was below 1% in both irradiated and control arteries. From these results, 192Ir-HDR afterloading irradiation with a dose of 6-12Gy can be considered sufficient for inhibiting neointimal proliferation in angioplastic rabbit iliac arteries with cutting balloon catheter.