A technique for perfusion of an isolated working heart to investigate hyperacute discordant xenograft rejection.

We developed an isolated working heart preparation to investigate hyperacute rejection of discordant xenografts. It is possible to correlate organ failure with the rejection process, and end points of rejection are easily identified. This unique model permits easy sampling of perfusates and examination of the rejected organ. The perfusate may be modified in ways not possible in in vivo preparations. Investigation of the discordant rabbit-to-pig combination with the technique has confirmed that hyperacute xenograft rejection can be reproduced. Rejection appears to be a complement-mediated immunologic phenomenon rather than the consequence of a nonspecific physical incompatibility. Hyperacute xenograft rejection can be prevented by depletion of C3 from the perfusing blood by treatment with cobra venom factor.