Experimental study on the effect of antegrade cerebral perfusion on brainswith old cerebral infarction

Objective: Patients with old cerebral infarction who undergo aortic arch op erations are susceptible to postoperative neurologic dysfunction. To verify such susceptibility, we performed this experimental study. Methods: A cerebral infarct model was created in mongrel dogs by means of i njection of cylindrical silicone embolus through the internal carotid arter y. The dogs that had obvious neurologic deficits 1 day later and survived f or 4 weeks or more were included in the cerebral infarct model. One month a fter cerebral infarction was induced, deep hypothermia and selective cerebr al perfusion were used in 14 mongrel dogs (infarct group, n = 7; control gr oup, n = 7). During this procedure, serum glutamate concentration and venou s-arterial lactate difference were measured. Histopathologic study of the b rain was also performed. Results: Changes in venous-arterial lactate difference in both groups were almost similar, except in the rewarming phase. At 32 degreesC during rewarm ing, the venous-arterial lactate difference in the infarct group was signif icantly higher than that in the control group (P =.006). Although precoolin g concentrations of serum glutamate were similar in both groups, the values in the infarct group at the end of rewarming were significantly higher tha n those in the control group (P =.046). Oil histologic examination, the pre sence of old cerebral infarction with gliosis was confirmed in the infarct group, but neither new cerebral infarction nor destruction of the blood-bra in barrier was found. Conclusion: We observed an accelerated anaerobic metabolism and an increase d extracellular glutamate release in the infarct group. The brain with old cerebral infarction is more susceptible to ischemia during arch operation t han noninfarcted brain.