Histopathologic findings in synthetic and biologic explanted grafts used in peripheral arterial reconstruction.

Surgically explanted vascular grafts, including 47 autografts, 14 allografts, 103 chemically processed human umbilical vein (HUV) grafts, and 406 polytetrafluoroethylene (PTFE) grafts, were studied histopathologically. Autografts, HUV, and PTFE grafts were implanted mostly in the femoropopliteal position, whereas allografts were used as a blood access for hemodialysis. The main cause for explantation in autografts (53.6%), HUV (74.8%), and PTFE (61.3%) was thrombosis, whereas allograft failure was usually related to aneurysmal degeneration (72.7%). The infection rates of HUV (20.9%) and PTFE (25%) grafts were higher than those of autografts (4.8%) and allografts (9.1%). Furthermore, bacterial colonization occurred more frequently in HUV (63.9%) and PTFE (64.7%) than in autografts (6.7%) and allografts (0%). Leukocyte infiltration was detected mostly in HUV (39.4%) and PTFE (27%) explants. Autografts and allografts both showed a 7.1% rate of lipid uptake, whereas lipid retention was observed in 84.9% of HUV and 79.8% of PTFE grafts. These results suggest that biologic vascular grafts are to be used preferentially in small diameter arterial reconstruction because of their resistance to bacterial colonization and lipid uptake.