An alternative model of composite tissue allotransplantation: groin-thigh flap.

This study focuses on development of a simpler and nonfunctional model that includes all the same tissue components as the traditional hind limb allotransplantation in rats. Adult male inbred Wistar rats (WF, RT1u) weighing 250-300 g were used as syngeneic (n = 12) donors and recipients of a new experimental model for composite tissue allotransplantation. In the allogenic group (n = 4), adult male Brown Norway rats (BN, RT1n) weighing 200-250 g were used as donors. A groin-thigh osteo-myocutaneous flap, composed of skin (groin), muscle (thigh), and bone (2/3 femur), based on the femoral vessels and superficial epigastric vessels, was developed for composite tissue allotransplantation. All the flaps were successful except for two dying soon postoperatively. Histology confirmed vessel patency in the syngeneic group and acute rejection in the allogenic group. The total operative time was shortened compared with the standard and other modified models of rat hind limb allotransplantation. Advantages of this new model include its simplicity, relative purity, and the more humanistic fact that it does not cause claudication to the animals as does standard orthotopic hind limb transplantation, or extra-deformity to the recipients as does the heterotopic hind limb model.