Re-endothelialization of microvascular carotid end-to-side anastomosis in the rat

Abstract

A carotid end-to-side anastomosis was performed on 25 male and female Wistar rats (mean weight 197.8 gm). The animals were sacrificed at time intervals varying from 0-21 days after the operation. The anastomosis was exposed, the aorta cannulated and the animals perfused with a 2.5% buffered glutaraldehyde solution at a constant pressure of 80 mm Hg. The anastomoses were removed for scanning electron microscopic (SEM) and light microscopic stuides. The SEM results indicate that after the acute platelet-fibrin reaction in the first 48 h, the suture line itself becomes re-endothelialized after 4 days. On the stitches, a cellular population consisting of leukocytes transforming into flattened cells was seen after 2 days. The morphology of these cells and their role in the regeneration of endothelium is discussed. Evidence supporting a blood-borne genesis of endothelial cells in vivo is presented.