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.
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 × 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.
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).
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.
From the Division of Plastic Surgery, University of Kentucky.
Received for publication August 12, 2009; accepted September 25, 2009.
Presented at the 54th Annual Meeting of the Plastic Surgery Research Council, in Pittsburgh, Pennsylvania, May 27 through 30, 2009.
Disclosure:The authors have no commercial associations that might pose or create a conflict of interest.
Brian Rinker, M.D., Division of Plastic Surgery, University of Kentucky, Kentucky Clinic, K454, Lexington, Ky. 40536-0284, firstname.lastname@example.org