Convulsive seizures following subdural application of fibrin sealant containing tranexamic acid in a rat model

OBJECTIVES: Tranexamic acid (t-AMCA) has been shown to cause severe convuls ions in humans and cats when applied topically to the central nervous syste m. We wanted to determine whether pure t-AMCA or fibrin sealant (FS) contai ning t-AMCA would induce similar effects when applied to the spinal cord in a rat model. METHODS: Following low-thoracic laminectomy, Be dura was incised to expose the dorsal surface of the lumbar enlargement. Rats were allocated to one of the following treatments: 1) t-AMCA (10 mg/ml), 2) vehicle (phosphate buff ered saline), 3) FS containing tAMCA, 4) FS containing aprotinin. The respo nse of the rats was evaluated based on neurological and behavioral observat ions. Additionally, motor function was scored in the rats that had received FS. RESULTS: Application of either 10 mg/ml t-AMCA or FS containing t-AMCA caus ed severe hind limb spasms that developed into spontaneous generalized conv ulsions. Two of the three rats that had received FS containing tAMCA died o f respiratory failure. In contrast, application of vehicle or FS containing aprotinin did not cause any abnormal conditions of the animals. CONCLUSION: Tranexamic acid may cause severe complications when used in the central nervous system. Thus, fibrin sealants containing t-AMCA should not be used in neurosurgery.