Development of Luminally Originating Vasa Vasorum in Arterially Implanted Autogenous Vein Graft and Related Anastomosis in Dogs

Abstract

Using light and scanning electron microscopes, the authors examined the development of luminally originating vasa vasorum in the course of intimal hyperplasia of vein grafts implanted to the canine femoral artery under conditions of abnormal blood flow with a high peripheral resistance. Five days after the implantation, the luminally originating vasa vasorum in the autogenous vein grafts developed dominantly near the anastomosis and often at the site of the area of valvular sinus. This vasa vasorum took the form of numerous small holes on the luminal surface of the graft and along the suture materials at the site of the anastomosis. These holes were lined with endothelial-like cells two weeks after the implantation, and four weeks later these cells were distributed in the thickened neointima connecting the vasa vasorum in the media and adventitia. This vasa vasorum observed on the thickened neointima at the area of the valvular sinus of the vein graft at more than five days after the implantation was considered to have developed in the course of organization of the mural thrombi deposited on the suture line at and on the area of the valvular sinus. Thus, numerous interstices of the vessel wall, formed along the suture materials at the anastomosis, and some clefts, formed with shrinkage of the deposited mural thrombi at the area of the valvular sinus, are the source of the luminally originating vasa vasorum.