Neointimal Hyperplasia: Basic Considerations

Vascular surgeons must understand neointimal hyperplasia, the body's response to vascular surgery and procedures. Neointimal hyperplasia is the pathology of vein graft, stent, and angioplasty failures, as well as vein graft adaptation to the stress of the arterial environment. Smooth muscle cell proliferation and migration as well as extracellular matrix deposition are critical processes, and research in this area has led to the PREVENT III trial, a randomized controlled trial testing the blockade of smooth muscle cell proliferation in order to prevent vein graft restenosis. However, the disappointing failure of the PREVENT III trial shows that our current understanding of neointimal hyperplasia remains incomplete, especially at the molecular level. As new molecular mechanisms of neointimal hyperplasia are continually discovered, new potential is enabled to prevent restenosis after angioplasty and stenting as well as bypass graft failure.