Expression of vascular endothelial growth factor in aortocoronary saphenous vein bypass grafts.
Cardiovasc Surg
; 9(5): 492-8, 2001 Oct.
Article
em En
| MEDLINE
| ID: mdl-11489656
ABSTRACT
Neovascularisation is a prominent feature of long-term aortocoronary saphenous vein bypass grafts but mechanisms involved in the formation of neovessels have not been previously studied. Vascular Endothelial Growth Factor (VEGF) is an important angiogenic factor that induces migration and proliferation of endothelial cells, enhances permeability and modulates thrombogenecity. This study investigated the expression of VEGF in aortocoronary saphenous vein bypass grafts. Aortocoronary saphenous vein bypass grafts with angiographic luminal stenosis of >75% were explanted from 14 patients at redo coronary artery bypass grafting. The grafts demonstrated two distinct forms of graft occlusion four out of the 14 graft occlusions (29%) resulted from severe hyperplastic transformation of the intima complicated by thrombi attached to the degenerating liminal endothelium; the remaining graft occlusions (71%) were due to the development of atherosclerotic lesions associated with mural thrombosis. Hiperplastically altered intimal segments were practically free of neovascularisation while atherosclerotic-like lesions contained neovessels irregularly distributed throughout. Intimal neovessels were located exclusively in microzones enriched with VEGF-expressing cells and, furthermore, neovascular endothelial cells themselves also displayed VEGF immunopositivity. Double-immunostaining revealed that in areas of neovascularisation, the vast majority macrophages (CD68+) expressed VEGF. Some CD68+ foam cells that surrounded branches of neovascularisation were also VEGF-positive. These findings suggest that VEGF expressed by neovascular endothelial cells and by macrophages may act as a local regulator of endothelial cells functions and may induce intimal neovascularisation in aortocoronary saphenous vein bypass grafts affected by atherosclerosis.
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Base de dados:
MEDLINE
Assunto principal:
Veia Safena
/
Ponte de Artéria Coronária
/
Fatores de Crescimento Endotelial
/
Linfocinas
Tipo de estudo:
Etiology_studies
Limite:
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
2001
Tipo de documento:
Article