Selecting valid in vitro biocompatibility tests that predict the in vivo healing response of synthetic vascular prostheses.

We have investigated the usefulness of six in vitro biocompatibility tests in predicting the healing performance of polyester vascular prostheses as observed in previous canine in vivo trials. Vascular grafts were evaluated by using (i) a direct contact (DC) assay, (ii) an extract dilution (ED) assay on murine fibroblast cells, (iii) a DC assay on endothelial cells, (iv) a complement activation study, (v) a leucocyte activation study of CD18 integrin subunit expression on human polymorphonuclear cells (PMNs) and (vi) interleukin-2 receptor expression on lymphocytes. Uncleaned polyester grafts had previously been associated with poor healing and gelatin-impregnated polyester grafts with delayed but satisfactory healing, whereas commercially cleaned polyester grafts had demonstrated excellent healing.