Background: Empirical and experimental evidence abounds as to the negative effects of smoking on skin flaps. The ideal duration of preoperative smoking cessation is unclear. The present study evaluates the effect of various durations of smoking cessation on skin flap survival in a rat model.
Methods: Forty smoke-exposed and 10 non-smoke-exposed Sprague-Dawley rats were divided into five groups: controls and 0 days, 2 weeks, 4 weeks, and 8 weeks of smoking cessation. All animals had a dorsally based random pattern flap created and either bilateral pure axial superficial inferior epigastric (superficial inferior epigastric) flaps or a unilaterally superficial inferior epigastric axial with random component flap. The percentage of flap necrosis was assessed 2 weeks postoperatively.
Results: The mean amount of random skin flap necrosis was 16.6 +/- 13.0 percent, 30.3 +/- 8.4 percent, 27.6 +/- 7.9 percent, 27.1 +/- 6.1 percent, and 29.7 +/- 10.3 percent, respectively. There was significantly less flap necrosis in the controls than in all other groups (p < 0.03). There was no necrosis of any of the pure axial superficial inferior epigastric flaps. The mean amount of superficial inferior epigastric axial with random component skin flap necrosis was 11.1 +/- 6.2 percent, 31.1 +/- 6.0 percent, 36.0 +/- 8.4 percent, 21.7 +/- 4.0 percent, and 19.1 +/- 6.3 percent, respectively. All smoke-exposed groups had significantly greater flap necrosis than controls, with the exception of the 8-week group (p < 0.02).
Conclusions: Smoking irreversibly increases the risk of flap necrosis in a random pattern flap out to 2 months of preoperative cessation. Preoperative smoking does not result in any necrosis of pure axial flaps. In axial with random component flaps, significant decreases in skin flap necrosis are not seen until 4 weeks of preoperative cessation.