AN IMMUNOHISTOCHEMICAL ANALYSIS OF IMPLANTED WOVEN DACRON AND EXPANDED POLYTETRAFLUOROETHYLENE GRAFTS IN HUMANS

An immunohistochemical analysis was performed to clarify the healing p rocess in implanted vascular grafts in human. Eight woven Dacron graft s and 6 expanded polytetrafluoroethylene grafts were obtained followin g redo surgery, limb amputation, and autopsy. The implantation periods ranged from 5 days to 148 months. The antibodies used for the analysi s were specific to a-actin (smooth muscle cells), macrophages, von Wil lebrand factor (endothelial cells), fibrin, elastin, collagen types 1- 5, CD3 (T cells), and CD20 (B cells). At 5 and 24 days after implantat ion, thrombi containing red blood cells and fibrin covered the anastom otic lines and some of the luminal surfaces of the grafts. Macrophages were scattered throughout the thrombi. At 11-148 months after implant ation, either a single layer of endothelial cells or a thin layer of f ibrin covered the anastomotic segments of the grafts, and smooth muscl e cells and collagen fibers were seen forming anastomotic intimal hype rplasia (AIH). The AIH in the grafts at 94 and 148 months after implan tation was almost the same thickness and length as that in the grafts at 11-36 months after implantation. Apart from the anastomotic segment s, a connective tissue matrix containing collagen fibers covered the l uminal surfaces, and some thrombi were noted. Most of the collagen pre sent was type 3, in addition to some type 1, 4, and 5 collagen. No typ e 2 collagen was noted. Some elastin was also detected in the AIH but not in the midportion of the grafts. Some macrophages and T cells were noted in the perigraft tissues.