BackgroundTrigeminocardiac reflex (TCR) is a brainstem reflex that can lead to hemodynamic instability manifested as bradycardia, decrease/increase of mean arterial pressure (MAP) and, in the worst case scenario, asystole during surgery. The effective intraoperative management of recurrent and profound TCR has yet to be established. This randomized paired study was performed to identify the effect of a prophylactic intra-arterial injection of lidocaine to prevent TCR caused by Onyx embolization during cerebrovascular intervention surgery.MethodsA total of 136 patients who received Onyx embolization under general anesthesia were assigned to a control group pretreated with intra-arterial saline injection or a lidocaine group pretreated with an intra-arterial injection of 20 mg lidocaine. Heart rate (HR) and MAP were closely monitored during the embolization procedures and the incidence of TCR, mainly characterized by a decrease in HR of ≥20%, and perioperative adverse events was recorded.ResultsDuring dimethyl sulfoxide (DMSO)/Onyx injection, HR was much slower in the control group than in the lidocaine group (p<0.05). TCR occurred in 12 patients (17.6%) in the control group (cardiac arrest in 3 patients) with decreased (7 cases) or increased (5 cases) MAP, whereas no TCR was observed in the lidocaine group. Notably, most TCR episodes occurred in patients with dural arteriovenous fistula and middle meningeal artery being affected. The composite adverse events were significantly higher in the control group than in the lidocaine group (p<0.05).ConclusionThis prospective study shows that a prophylactic intra-arterial injection of 20 mg lidocaine could be recommended as a novel strategy to effectively and safely prevent TCR during endovascular embolization.