Prevalence of true vein graft aneurysms: Implications for aneurysm pathogenesis

Background: Circumstantial evidence suggests that arterial aneurysms have a different cause than atherosclerosis and may form part of a generalized di lating diathesis. The aim of this study was to compare the rates of spontan eous aneurysm formation in vein grafts performed either for popliteal aneur ysms or for occlusive disease. The hypothesis was that if arterial aneurysm s form a part of a systemic process, then the rates of vein graft aneurysms should be higher for patients with popliteal aneurysms than for patients w ith lower limb ischemia caused by atherosclerosis. Methods: Infrainguinal vein grafting procedures performed from 1990 to 1995 were entered into a prospective audit and graft surveillance program. Ancu rysmal change was defined as a focal increase in the graft diameter of 1.5 cm or greater, excluding false aneurysms and dilatations after graft angiop lasty. Results: During the study period, 221 grafting procedures were performed in 200 patients with occlusive disease and 24 grafting procedures were perfor med in 21 patients with popliteal aneurysms. Graft surveillance revealed sp ontaneous aneurysm formation in 10 of the 24 bypass grafts (42%) for poplit eal aneurysms but in only 4 of the 221 grafting procedures (2%) that were p erformed for chronic lower limb ischemia. Conclusion: This study provides further evidence that aneurysmal disease is a systemic process, and this finding has clinical implications for the tre atment of popliteal aneurysms.