Prophylactic Intra-Arterial Injection of Lidocaine Prevents Trigeminocardiac Reflex During Endovascular Embolization for Dural Arteriovenous Fistula: A Report of 2 Cases

Case series Patients: Male, 56-year-old • Male, 57-year-old Final Diagnosis: Trigeminocardiac reflex Symptoms: Bradycardia • severe hemodynamic fluctuation Medication: — Clinical Procedure: — Specialty: Anesthesiology • Neurosurgery OBJECTIVE: Unusual clinical course BACKGROUND: Trigeminocardiac reflex (TCR) is a unique brain stem reflex that manifests as the sudden onset of hemodynamic perturbation in heart rate and blood pressure as a result of stimulation of any branches of the trigeminal nerve. Onyx™ embolization in cerebrovascular interventional surgery can trigger TCR, leading to severe hemo-dynamic fluctuations and even cardiac arrest. Appropriate prophylactic approaches to prevent Onyx™ embolization-induced TCR are still lacking. CASE REPORTS: We report the cases of 2 patients with recurrent and profound bradycardia due to TCR during endovascular Onyx™ embolization for a dural arteriovenous fistula. Prophylactic intra-arterial injection of lidocaine (10–20 mg) effectively and safely blocked the recurrence and potential occurrence of TCR. These 2 patients had reduced heart rate with either hypotension or hypertension during their TCR episodes, suggesting that stimulating a distinct cerebral artery (occipital artery versus vertebral artery branch) can initiate TCR by provoking the vagus nerve via the common neuronal pathway while simultaneously inhibiting or exciting the sympathetic pathway. CONCLUSIONS: Intra-arterial injection of lidocaine during endovascular procedures can be recommended as an effective prophylactic approach for use in the treatment of the cerebrovascular disorder where there is high risk of embolization-induced TCR.