Metabolic response of blood cells to synthetic graft-materials with special reference to a Fluoromer Passivated Dacron graft. An in vitro study using microcalorimetry.

Microcalorimetry was used to study in vitro the metabolic response from human platelets and leukocytes when incubated with three different synthetic graft-materials. The graft to be studied primarily was Fluoromer Passivated Dacron (FPD) which was compared with ePTFE and with a knitted Teflon graft. A rapid increase in the metabolic activity of platelets was observed, followed by a steady-state for more than one hour, while the platelet metabolism did not differ among the various graft-materials. Leukocytes incubated with FPD showed a high initial metabolism, with a peak after about 15 minutes. After 60 minutes the metabolic response had reached control values. ePTFE and Teflon grafts differed significantly from FPD, without causing any peak metabolic activity. It may be concluded that FPD and ePTFE grafts, as evaluated in vitro, activate platelets to the same extent, while FPD causes a more extensive leukocyte activation. Whether these findings can be interpreted as differences in thrombogenicity and inflammatory responses has not been proven, but seems probable. This in vitro method should make it possible to further study human responses to synthetic materials a method possibly more reliable than animal experiments.