Intimal hyperplasia and secondary changes in vein grafts

Intimal hyperplasia is of greatest prognostic importance for autologous vein grafts. The mechanism of this process is largely unknown, although a combination of traumatic, hemodynamic and metabolic factors are probably involved. In addition, secondary atherosclerosis may be responsible for diffuse graft obstruction. Fibrotic valves, traumatic stenosis and suture stenosis, probably due to improper handling during harvesting of the saphenous vein, give rise to segmental narrowing of the grafts. Changes in flow characteristics in addition to compliance mismatch may be responsible for the occurrence of anastomotic hyperplasia seen following implantation of synthetic vascular grafts and vein grafts. The prophylaxis and treatment of these conditions is discussed.