Arrangement pattern of new-lining endothelial cells.

New-lining endothelial cells in the neointimae of two types of synthetic vascular prostheses were examined by light- and electron microscopy. Examination was carried out at one to 846 days post implantation of the prostheses in the thoracic aortae of 57 canines. The surfaces of both types of prostheses were covered by a continuous layer of endothelial cells. The long axes of the cells were found to be parallel to the blood stream. This observation indicates that the arrangement pattern of endothelial cells in the neointimae is largely dependent on the direction of the blood stream rather than on the direction of the tension exerted on the vascular prostheses.