Effectiveness of radiation therapy in the prevention of anastomotic site steriosis after-copinary cortery bypass grafts

本研究的目的是探讨冠状动脉放射治疗预防吻合口消毒的作用，并评价低剂量辐射对手术间置入的股动脉移植物吻合口的影响。采用8-0单丝连续缝合建立股动脉-股动脉或股动脉-股静脉复合移植物。复合移植物分别接受10Gy20Gy30GyX射线照射。移植后14天进行组织学观察，评价放射治疗效果。通过组织病理学研究，阐明了其作用机制。与对照组相比，放射组新生内膜形成程度和管腔面积狭窄率明显减少。对照组中抗α-肌动蛋白阳性细胞和抗增殖细胞核抗原阳性细胞较多，其密度随照射剂量的增加而降低。与中膜相比，抗增殖细胞核抗原阳性细胞在外膜的分布更为密集。抗MCP-a抗体和抗AM-3抗体双重染色显示抗MCP-a抗体阳性细胞对抗AM-3抗体呈阳性反应。照射组小鼠抗von Willebrand抗体阳性细胞减少。照射组显示管腔表面不完全皮化，导致血栓形成。本实验研究表明，低剂量照射能有效地减少管腔狭窄和新生内膜形成。冠状动脉搭桥术的进一步研究。需要建立犬模型，以确定该疗法预防冠状动脉搭桥术后吻合口狭窄的临床潜力。

The purpose of this study is to investigate the coronary radiation therapy for the prevention of anastomotic site steriosis, and we evaluated the effect of low dose radiation on the anastomotic site of surgically interposed femoral artery graft. Composite graft of femoral artery -femoral artery or femoral artery -femoral vein was created using 8-0 monofilament Continuous suture. The composite graft was irradiated with x-ray at the dose of 10 Gy,20 Gy, and 30 Gy. Effect of radiation was assessed by histological analysis 14 days after the grafting. Mechanism of this effect was elucidated by histopathological study. Extent of neointimal formation and percent luminal area stenosis were significantly less in radiation groups as compared with control group. Anti alpha-actin positive cells and anti PCNA positive cells were more abundant in control group and density of these cells was reduced in proportion to the dose of irradiation. The anti PCNA positive cells were more densely distributed in adventitia as compared with media. Double staining with anti MCP-a antibody and anti AM-3 antibody showed that anti MCP-a antibody positive cells were positive to anti AM-3 antibody. Anti von Willebrand antibody positive cells were decreased in radiation groups. The irradiation groups showed incomplete eridothelialization of the luminal surface, which caused thrombi formation. This experimental study demonstrated that low dose irradiation was effective in reducing luminal narrowing and neointimal formation. Further study using coronary bypass. model in dog is required to determine the clinical potential for this therapy to prevent stenosis of the anastomotic site after coronary bypass operation.