Comparative merits of autogenous arterial and venous bypass grafts as alternatives to direct arterial anastomosis

Abstract

As the number of patients referred for revascularization of the cerebral cortex increases, it is inevitable that some of them will be found to have neither a superficial temporal (STA) nor an occipital artery suitable for direct anastomosis to the cortical arteries. The same problem is presented if a patient who has had a successful extracranial-intracranial anastomosis develops an occlusion of the external carotid artery and is then found to need a second revascularization procedure. In both circumstances a bypass graft could be used as an alternative to direct arterial anastomosis as a means of conveying an extra supply of blood to the brain, but it must be kept in mind that the diameter of the graft at the point of anastomosis to the cortical artery will need to be in the region of 1 mm, and this limits the choice of tube that can be used. Tubes of synthetic materials with diameters of less than 3 mm fail to remain patent because of intraluminal coagulation, and immunologic reactions lead to the blockage of arterial and venous homografts.