Edaravone is an agent developed as a free radical scavenger, and is useful in functional recovery of the brain after cerebral infarction. However, to the best of our knowledge no experimental studies have been made regarding the effect of edaravone on cerebral protection during aortic arch surgery. We investigated the pharmacological effect of edaravone experimentally, through selective cerebral perfusion under deep hypothermia. Twelve adult dogs (body weight 14.8±2.0 kg) were used, and selective cerebral perfusion was performed under hypothermic circulatory arrest of 20°C for 120 min at 5 mg/kg/min, which was half the usual flow volume of cerebral perfusion. Group E (n=6) received 3 mg/kg edaravone for 30 min at the start of both selective cerebral perfusion and rewarming of the body, while Group C (n=6) received no drugs. Somatosensory evoked potential (SEP) was measured, and so were blood pressure, body temperature, pH level, oxygen partial pressure, and blood flow in the cerebral tissue. Histopathological investigations were also performed. In Group E, complete SEP recovery was observed in all dogs, while in Group C, complete SEP recovery was observed in only 2 dogs (33%) (p=0.014). A statistically significant difference was also observed in cerebral tissue pressure (p=0.014), but not in pH level, oxygen partial pressure, or cerebral tissue blood flow. On histopathological investigation, Group C demonstrated reduced staining of Nissl granules in neurons of the cerebral cortex, and many of them presented the appearance of acute circulatory impairment while Group E demonstrated no reduction in staining of Nissl granules. In the present experimental study of selective cerebral perfusion under deep hypothermia below the safety threshold flow, edaravone was effective in cerebral protection.

The earlier the diagnosis of acute type A aortic dissection is made, the more frequent the complications of aortic root destruction and/or a compromised coronary artery are encountered. Only aortography is diagnostic in these lesions, however, recently this modality tends to be avoided in order to try to improve the survival rate of the patients by obtaining diagnosis by noninvasive modalities. Therefore, contrast-enhanced CT scans in 49 patients with aortic dissection were analyzed in order to detect the slightest signs suggesting aortic root lesions. In 4 of the 6 cases in which intimal flap was detected in the aortic root by CT and in 2 of the 14 cases with an aortic root more than 35mm in diameter, aortic root reconstruction and/or concomitant CABG were neccessary for the repair of the destroyed aortic root. The aortic root diameter was more than 40mm in 8 of 9 patients with aortic root destruction, with a mean value of 45.6±3.6mm (p<0.01). In summary, detection of a septum in the aortic root and/or an aortic root dilated more than 40mm on CT were important signs suggesting the dissection extending to the aortic sinus combined with aortic root destruction. In such cases aortic root reconstruction and/or concomitant CABG may be necessary.