A micro vascular model was developed to study the composite tissue allotransplantation in rats. A vascularized composite limb graft, composed of skin, subcutaneous fat, muscles, bone and neurovascular structures, was taken from Sprague-Dowley rats and transplandted orthotopically to Wistar rats. The femoral artery, vein, nerve and sciatic nerve were anastomosed microsurgically.
There were three experimental groups, one for control replantation(n = 5), one for control transplantation without treatment(n = 5), and one for allotransplantation with cyclosporin A treatment (n=25), in which 10mg/kg/day of cyclosporin A was injected intramuscularly, everyday for 4 weeks. Mean survival of transplanted limb without any treatment was 7±0.5 days, whereas, cyclosporin A-treated group showed increased survival of 42±2.2 days including 14±2.2 days of post-treatment immune-tolerance period. There were no remarkable difference between replantation control group and cyclosporin A-treated group in terms of gross and histological findings throughout the study. Cyclosporin A showed no significant toxic or untoward effects on rats except for a prolonged diarrhea in a small numbers of rats receiving cyclosporin A.
These studies represent an initial step in laying the experimental foundation for clinical allotransplantation of composite tissue using cyclosporin A-induced immunosuppression.
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