Morphological evaluation of canine autogeneous vein grafts in the arterial circulation
Fonkalsrud, E.W.; Sanchez, M.; Zerubavel, R.
Surgery 84(2): 253-264
1978
ISSN/ISBN: 0039-6060 PMID: 684617 Document Number: 125894
The fate of unpreserved autogenous saphenous vein grafts placed into both femoral arteries of each of 12 dogs was evaluated serially over a 5 mo. period by light and scanning electron microscopy. Endothelial cell damage occurs within the first 48 h after grafting and appears to be related more to the techniques of harvesting and preservation than to arterial pressure. Thrombosis is uncommon when the endothelium is intact. The intimal surface is repopulated by endothelial cells within 2 wk, unless severe injury has occurred. New vein graft endothelial cells retain the morphological characteristics of venous endothelium (microvilli, etc.) and do not extend across the anastomosis from the adjacent artery. Vein graft media and adventitia develop congestion, hemorrhage, cell disruption and focal necrosis within the first 2 wk, followed by progressive fibrosis during the ensuing months, probably due to the effects of arterial pressure. Progressive subintimal proliferation begins within 2-4 wk after grafting beneath intact endothelium and is undoubtedly a major cause of late vein graft occulsion. This proliferation is believed to stem from arterial pressure. No evidence of an internal elastic membrane or other arterial contractile structures is present in vein grafts as long as 5 mo. after operation.