Preventive effect of botulinum toxin A in microanastomotic thrombosis: A rabbit model

Background: Microvascular free tissue transfers play an important role in the reconstruction of body defects. Various aetiologies lead to vascular thrombosis and free-flap failure. In this study, the effects of botulinum toxin A on vessel diameters and prevention of anastomotic thrombosis were studied in a blinded vasospasm model in rabbits. Methods: One side of 16 adult rabbit ears was pre-treated with botulinum toxin type A, and normal saline injections were performed as control in the contralateral side. Seven days later, vessel diameters were measured in both the groups; the vessels were then cut and reanastomosed after vasospastic challenge and vessel patencies were evaluated. Results: Both artery and vein diameters were significantly larger in the botulinum toxin A group (P = 0.002 and < 0.001, respectively). The patency rate of arterial and venous anastomosis was significantly higher in the neurotoxin pre-treated group (P = 0.038 and 0.003, respectively). Conclusion: This study shows that pre-treatment with botulinum toxin type A is associated with a lower rate of arterial and venous thrombosis in rabbit-model microanastomosis. Further studies are necessary to evaluate its ability to decrease vasospasm and thrombosis in free-flap survival of humans.