The effect of botulinum toxin B pretreatment to the blood flow in the microvascular anastomosis

BACKGROUND: Although multiple factors can lead to free flap failure, vessel-related accidents are the most important. Many methods have been developed (both intraoperative and postoperative) to prevent vessel-related complications. In this article, we study the effects of a "preoperative treatment" using botulinum toxin B that could enhance the velocity and blood flow of vascular pedicles and decrease vascular accidents. METHODS: Ten Sprague-Dawley rats were pretreated with botulinum toxin type B at the perivascular area of the femoral vessel. Ten other rats were injected with saline as a control group. After 3 days, pedicle diameter and the peak mean frequency of blood in the pedicle were measured using laser Doppler flowmetry, and the peak mean blood velocity was calculated. We performed a "pedicle division and reanastomosis" operation to compare changes in vessel diameter and peak mean blood velocity. RESULTS: Vessel diameter was significantly increased in the botox-pretreated group for both veins and arteries. A comparison of the deep femoral vein and artery blood velocities showed that the peak mean velocity was significantly higher in the botox group. The average increase in blood velocity was significantly larger in the botox group. CONCLUSIONS: Botulinum toxin B is helpful by influencing the microvascular environment through an increase in the blood velocity of the pedicle.