Plasminogen activators, matrix metalloproteinases, and their inhibitors inimplanted vascular prostheses

Objectives: to examine the role of plasminogen activators (PAs) and matrix metalloproteinases (MMPs) in the healing of prosthetic grafts. Methods: thirty explanted grafts (26 Dacron and 24 DTFE) were studied immun ohistochemically using antibodies to PAs, MMPs, and their inhibitors. The p ercentages of immunostain-positive multinucleated giant cells (MGC) were re lated to duration of implantation (early vs late), type of lesion (stenosis vs false aneurysm), graft material (Dacron vs PTFE), and graft status (occ luded vs patent). Results: all specimens were positive for PAs and MMPs, There were no signif icant differences; in the percentages of MGCs positive for PAs, MMPs, or ti ssue inhibitor type 2 of MMP (TIMP-2) between the groups. The percentage of TIMP-1 in the aneurysm group (mean, 26%) was significantly lower than that of the stenosis group (mean, 46%) (p<0.05). Conclusion: after the implantation of a vascular prosthesis, PAs and MMPs a re expressed in cell migration, proliferation and matrix construction. Unde r-expression of TIMP-1 may be related to the formulation of an anastomotic aneurysm.