The effect of cigarette smoking on functional recovery following peripheral nerve ischemia/reperfusion injury.

This study was designed to determine if cigarette smoking adversely affects functional recovery following ischemia/reperfusion (I/R) injury in peripheral nerves. Forty Wistar rats were divided evenly among four groups. Animals in groups A and B were exposed to cigarette smoke via a controlled smoking chamber for 20 minutes daily. On study day 14, all animals underwent a controlled I/R injury to one sciatic nerve. Recovery was assessed with walking track assessments, malondialdehyde (MDA) assay, and histology. Walking track results on study day 21 did not differ significantly between the smoking and nonsmoking animals. However, by study day 28, the nonsmoking animals showed a greater degree of functional recovery (SFI = -18.0 and -22.8, respectively, P = 0.03). MDA concentration in the smoking group was significantly higher than the nonsmoking group at the 28 day time point (P = 0.04). Exposure to cigarette smoke was associated with a slower functional recovery following peripheral nerve I/R injury.

The effect of calcium channel blockers on smoking-induced skin flap necrosis.

BACKGROUND: Calcium channel blockers have been shown experimentally to reverse many of the effects of nicotine. The purpose of this study was to assess the effect of calcium channel blockers on smoking-induced skin flap necrosis. METHODS: Forty male albino Wistar rats were divided into four groups. Groups A, B, and C were treated in a controlled smoking chamber for 20 minutes daily for 21 days. On day 14, caudally based dorsal skin flaps (3 x 10 cm) were created. On days 14 through 21, group B animals received verapamil (20 mg/kg/day) by gavage. Group C received nifedipine (10 mg/kg/day). On day 21, standardized photographs were taken and flap survival areas determined. Urine cotinine concentrations were measured on days 14 and 21. RESULTS: The mean cotinine level at surgery was 161 ng/ml in group A (smoking), 149 ng/ml in group B (verapamil), and 168 ng/ml in group C (nifedipine). These differences were not statistically significant. Cotinine concentration at surgery for group D (no smoking) was less than 10 ng/ml. The mean flap survival in group D was 79.1 percent, compared with 63.7 percent in group A (p = 0.003). The mean flap survival in group B (verapamil) was 72.8 percent, compared with 73.7 percent in group C (nifedipine). Both values were significantly greater than in group A (p = 0.04 and p = 0.008, respectively). CONCLUSIONS: In this study, enteral calcium channel blockers were associated with a statistically significant improvement in flap survival compared with untreated animals with an equivalent smoke exposure. Calcium channel blockers may reduce perioperative risk in active smokers who require skin flap surgery.