Effect of preoperative inflammation of the wound bed on survival of skin flaps in rats.

Pedicled dorsal flaps were raised and resutured on the backs of 20 rats. Aseptic inflammation of the bed of the wound flap was induced one week before the operation in 10 rats by scratching with a needle; the other 10 acted as controls. A week after the operation the extent of necrosis was estimated by computer assisted planimetry. Blood flow in the four quarters of the flap and in normal skin was estimated using the microsphere technique. A larger mean area of the skin flaps survived in rats in which the wound bed had been scratched (71%) compared with the controls (61%) (p < 0.05); blood flow in the flaps was also higher (p < 0.0005). We conclude that the most likely explanation for these results was preoperative angiogenesis in the wound bed.