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对预防吻合口狭窄的作用，并评价低剂量放射对手术插入股动脉移植物吻合口的影响。采用8-0单丝连续缝合法建立股动脉-股动脉或股动脉-股静脉复合移植物。用10戈伊、20戈伊和30戈伊剂量的X射线照射复合移植物。移植后14天通过组织学分析评估辐射的效果。通过组织病理学研究阐明了这种作用的机制。与对照组相比，放射组的新生内膜形成程度和管腔面积狭窄百分比显著减少。对照组中抗α-actin和抗PCNA阳性细胞数量较多，且随照射剂量的增加而减少。抗PCNA阳性细胞在外膜较中膜密集。抗MCP-α抗体和抗AM-3抗体双重染色显示抗MCP-α抗体阳性细胞对抗AM-3抗体呈阳性反应。放射组抗血管性血友病抗体阳性细胞减少。照射组显示管腔表面的不完全内皮化，这导致血栓形成。本实验研究表明，低剂量照射可有效减少管腔狭窄和新生内膜形成。使用冠状动脉搭桥术进行进一步研究。需要在犬中建立模型，以确定该疗法预防冠状动脉搭桥术后吻合部位狭窄的临床潜力。

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.