Effect of Simvastatin Use in Free Tissue Transfer: An Experimental Study in a Rat Epigastric Free Flap Model.

Background:  Statins are traditionally used in lowering cholesterol and low-density lipoprotein biosynthesis, but recent reports show their beneficial effect on microcirculation. The aim of this study was to investigate the effect of simvastatin on the microcirculation and in conjunction with aspirin in a rat free epigastric flap model.

Methods:  Thirty-six Sprague-Dawley rats were divided into group A (control,  = 12), group B (simvastatin treated,  = 12), and group C (simvastatin and aspirin,  = 12). Bilateral free epigastric skin flap was used to evaluate the effect. At 48 hours, flaps biopsies were evaluated for inflammatory activity, nitric oxide content, and thrombomodulin regulation in the endothelial lining of microvessels. Flap survival was evaluated on day 7.

Results:  The diameter of microvessels and nitric oxide activity in groups B and C were significantly higher than in group A ( < 0.005 and 0.015, respectively). The perivascular inflammatory cell infiltrates and intravascular adhesions were predominant in group A compared with groups B and C ( < 0.005). Groups B and C demonstrated significant higher degree of thrombomodulin expression. The flap survival rate on day 7 was 70.8% for group A, and 87.5% and 91.7%, respectively, for groups B and C without significance between the two ( = 0.675).

Conclusion:  Simvastatin significantly improves the free flap survival by effective anti-inflammatory, vasodilator, and anticoagulant activities. Combined therapy did not have an antagonistic effect and further study is needed to see synergistic action through different mechanisms.