The effect of botulinum toxin A on skin flap survival in rats

This study examines the role of botulinum toxin type A (BoTA) in preventing the collapse of the peripheral vessels in the cutaneous flap and in increasing the survival of the flap. Because BoTA cleaves the SNAP-25 protein, the release of vasoconstriction cotransmitters as well as acetylcholine would be blocked. Dorsal skin flaps in rats were elevated and returned to the original position. In the BoTA and the control group, either BoTA or saline was injected into the entire flap. The flap survival rate measurement and a histopathological examination were performed 1 week after flap elevation. The cutaneous blood flow was measured in three different areas of each flap, serially. In BoTA group, there was a significant increase in the survival rate (93.79 +/- 6.06%, p=0.042). In the control group, the blood flow was decreased significantly immediately after flap elevation. The blood flow was high in all areas in the BoTA group in a week, and also most of the vessels maintained their shape without collapsing. In conclusion, pretreatment with BoTA increases the dorsal skin flap survival in rats by increased perfusion, and further studies should be performed to determine the possible mechanism by which BoTA attenuates the sympathetic vasoconstriction effect in skin flaps.