Neointimal hyperplasia causes vascular graft failure as a result of hyperophy of

Vascular injury leading to endothelial cell loss or dysfunction stimulates smooth muscle cell growth and associated matrix synthesis. Healing of injured vessels involves the migration of smooth muscle cells or smooth muscle cell precursor cells into the intima. Here these cells proliferate, and synthesize ECM in much the same way that fibroblasts fill in a wound, forming a neointima that typically is covered by an intact endothelial cell layer. This neointimal response occurs with any form of vascular damage or dysfunction, including infection, inflammation, immune injury, physical trauma (e.g., from a balloon catheter or hypeension), or toxic exposure (e.g. oxidized lipids or cigarette smoke). Thus, intimal thickening is a stereotypical response of the vessel wall to any insult ( Robbins Basic Pathology, 9 th edition, page 334 )