An immunohistochemical analysis of implanted woven Dacron and expanded polytetrafluoroethylene grafts in humans.

Abstract

An immunohistochemical analysis was performed to clarify the healing process in implanted vascular grafts in human. Eight woven Dacron grafts and 6 expanded polytetrafluoroethylene grafts were obtained following redo surgery, limb amputation, and autopsy. The implantation periods ranged from 5 days to 148 months. The antibodies used for the analysis were specific to alpha-actin (smooth muscle cells), macrophages, von Willebrand factor (endothelial cells), fibrin, elastin, collagen types 1-5, CD3 (T cells), and CD20 (B cells). At 5 and 24 days after implantation, thrombi containing red blood cells and fibrin covered the anastomotic lines and some of the luminal surfaces of the grafts. Macrophages were scattered throughout the thrombi. At 11-148 months after implantation, either a single layer of endothelial cells or a thin layer of fibrin covered the anastomotic segments of the grafts, and smooth muscle cells and collagen fiber were seen forming anastomotic intimal hyperplasia (AIH). The AIH in the grafts at 94 and 148 months after implantation was almost the same thickness and length a that in the grafts at 11-36 months after implantation Apart from the anastomotic segments, a connective tissue matrix containing collagen fibers covered the luminal surfaces, and some thrombi were noted. Most of the collagen present was type 3, in addition to some type 1, 4, and 5 collagen. No type 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.