ABSTRACT
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 (<i>n</i>=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 (<i>n</i>=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%) (<i>p</i>=0.014). A statistically significant difference was also observed in cerebral tissue pressure (<i>p</i>=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.
ABSTRACT
Pre- and postoperative left ventricular (LV) function was assessed by Doppler echocardiography in 95 infants who underwent open heart surgery during the past two and half years. The patients were divided into three groups: 43 patients with ventricular septal defect (VSD group), 37 with atrial septal defect (ASD group) and 15 with the tetralogy of Fallot (TOF group). Echocardiography was performed before and at an early stage after surgery (average: 11.6 days) in all cases. The forward flow velocity pattern was evaluated by Doppler echocardiography, placing the sample volume at the pulmonary vein (PV) and the LV inflow portion. At the PV, the peak velocity of the S wave during systole (p-PV<sub>S</sub>) and the D wave during diastole (p-PV<sub>D</sub>) in patients with ASD were significantly lower (<i>p</i><0.01) postoperatively. In patients with VSD, only p-PV<sub>D</sub> was significantly lower (<i>p</i><0.05) postoperatively, showing a decrease of pulmonary blood flow. These results are thought to reflect a difference in the compliance of the left atrium between the two groups. At the LV inflow portion, the ratio of peak velocity of the wave during atrial systole to R wave on rapid inflow during diastole (A/R) was significantly lower in patients with VSD (<i>p</i> <0.01) postoperatively. At the same time, LV ejection fraction and fractional shortening were significantly lower (<i>p</i><0.01), but these values remained within the normal range. These results suggest that LV can maintain a sufficient systolic performance against the decrease in preload and the increase in afterload as well as the improvement of diastolic function during the early period after surgery in the VSD group. In patients with ASD or TOF, there were no significant differences in parameters of LV function between preoperative and postoperative periods.