The Development of Collateral Arteries

Abstract

Collateral development in the lower extremity of the rabbit was studied by arteriographic techniques after occlusion of the femoral artery. Characteristic collateral patterns developed, depending on the level and extent of arterial occlusion. Early after the occlusion some pathways were found to conduct the flow rapidly to the distal stem. In subsequent arteriograms on the same animals these arterial channels were later seen to dominate the collateral circulation, while other pathways seemed to regress. In most cases the definitive appearance of the collateral pattern could be anticipated at an early time after the occlusion. During the development histological study showed a pronounced increase in the smooth muscle mass of the collateral arterial wall, which permitted further dilatation of the vessel. This increase was most pronounced in the intermediate zone of the collateral pathway, but was also clearly evident in the proximal and distal zones. A critical investigation of the arteriographic method of estimating changes in diameter of collateral vessels showed that this method can give no reliable measurements of the changes in the initial stage of development.