Arterial graft maturation: the duration of thrombotic activity in Dacron aortobifemoral grafts measured by platelet and fibrinogen kinetics.

Dacron is thrombogenic, hence small arterial grafts of this material frequently thrombose in the period prior to graft maturation. Anti-thrombotic therapy may therefore be indicated to preserve patency during this risk period. To evaluate the thrombogencity of immature Dacron grafts, platelet and fibrinogen kinetics using 51Cr and 125I respectively were measured before operation and at 3, 6 and 9 months in 10 patients following aortobifemoral bypass and in 6 age-matched volunteers. Platelet survival was reduced from 8.8 +/- 0.2 d before surgery to 7.4 +/- 0.24 d at 3 months. This was accompanied by an increase in platelet turnover from 39 +/- 2.4 X 10(9)l-1d-1 to 46.9 +/- 2.9 X 10(9)l-1d-1. Fibrinogen t1/2 fell from 3.72 +/- 0.13 d preoperatively to 3.36 +/- 0.11 d at 3 months, while fibrinogen fractional catabolic rate rose from 0.27 +/- 0.014 to 0.34 +/- 0.014. These changes were all significant (P less than 0.01). Fibrinogen consumption had returned to normal by 6 months following surgery but platelet kinetics only equated to preoperative levels at 9 months. We suggest that Dacron grafts are thrombogenically active for about 9 months. When anti-thrombotic therapy is indicated it should be continued throughout this period.