Dose and time effects of nicotine treatment on the capillary blood flow and viability of random pattern skin flaps in the rat.

The deleterious effects of nicotine treatment on skin haemodynamics and survival of 4 X 10 cm acute random pattern skin flaps constructed on the dorsum of the rat were studied. Rats were injected subcutaneously with 0.2 ml of saline containing varying doses (0, 1, 2, 4 or 8 mg kg-1; bid) of nicotine for 5 weeks, starting 4 weeks before flap surgery. It was observed that nicotine treatment at the dose of 2 mg kg-1 (bid), or higher, significantly (p less than 0.05) decreased the length and area of skin flap survival compared with the control. This dose of nicotine treatment also significantly (p less than 0.05) decreased the capillary blood flow and distal perfusion in the skin flaps compared with the control. However, the detrimental effect of nicotine treatment on the survival of acute random pattern skin flaps was not seen if the treatment was started 2 instead of 4 weeks preoperatively. It is concluded that nicotine may cause hypoperfusion and necrosis in acute random pattern skin flap surgery, and the deleterious effects are time-dependent.