Hemodynamics and viability of acute neurovascular island skin flaps in rats.

Hemodynamics and skin survival were studied in acute 8 X 8 cm2 neurovascular island skin flaps in rats. Maximum blood flow and extent of fluorescein and 15 mu microsphere penetration in the skin flap occurred at about 24 hours after flap construction. However, maximum A-V shunt flow occurred at about 12 hours. It is concluded that ischemia in the acute skin flap, probably due to vasoconstriction, did occur in the early stage of the postoperative period. The opening of A-V shunts and vasodilation of the capillary bed in the later stage may be controlled by the same mechanism(s). It is also suggested that treatment which results in vasodilation in the skin flap in the early stages of the postoperative period may augment the extent of skin viability.