Studies of the immediately vascularized skin allograft.

In order to evaluate the effect of the nature of revascularization on survival rates of skin allografts, a rat model was devised which provided simultaneous and immediate establishment of arterial and venous blood supply to a composite skin-renal allograft. For 5 days after transplantation the skin portion of the composite grafts appeared normal, with minimal inflammation in 11 recipients. From 6 to 11 days, in 6 rats, active rejection developed with a marked inflammatory reaction of the skin-kidney interface. In 10 rats in which the composite grafts remained in the secondary hosts for 12--21 days rejection of the skin was complete. The renal portion of all composite grafts appeared normal in all three panels and all recipients of composite grafts rejected subsequent orthotopic skin grafts in an accelerated manner, with median survival time of 8.2 +/- 0.3 days compared with 11.5 +/- 0.7 days in untreated Fisher leads to Lewis controls. These results demonstrate that the skin on the composite graft retained its immunogenicity, that immediately vascularized skin allografts between AgB compatible rats will be rejected in a normal time and that anatomical factors are not sufficient to account for the difference in survival times between skin and solid organs.