The histocompatibility of a new bovine pericard graft

An artificial defect of the umbilical area in ten calves was covered by a pericard graft whose new preparation method has been proved in bovine vessel grafts. Between 2 and 6 months postoperatively (p.o.) two animals at a time were euthanized to sample the graft and its surrounding tissue for histological investigations. On the one hand, there was an inflammatory foreign body type granulomatous reaction, but on the other hand this did not lead to rejection. Within the 6-month observation time the graft fibers were immigrated by the own young collagen fibers. We interpret this as a guide function of the graft fibers. Tiny focal calcifications appeared to be the effect of an intensive tissue irritation which may be caused by an incomplete edulcoration of the chemical substances used during preparation. We recommend a longer edulcoration time to prevent these reactions.