Cerebral Pial Vascular Changes Under Propofol or Sevoflurane Anesthesia During Global Cerebral Ischemia and Reperfusion in Rabbits

Abstract

Propofol and sevoflurane are commonly used anesthetics for neurosurgery. The aim of the study was to compare the effects of propofol with sevoflurane on cerebral pial arteriolar and venular diameters during global brain ischemia and reperfusion. Japanese white rabbits were anesthetized with propofol (n=11), sevoflurane (n=9), or the combination of sevoflurane and intralipid (n=10). Global brain ischemia was induced by clamping the brachiocephalic, left common carotid, and left subclavian arteries for 15 minutes. Pial microcirculation was observed microscopically through closed cranial windows and measured using a digital-video analyzer. Measurements were recorded before clamping and afterward for 120 minutes. Plasma glucose and mean arterial blood pressure increased significantly during ischemia in the propofol-anesthetized rabbits. During ischemia, pial arteriolar and venular diameters decreased significantly in all groups. After unclamping, large and small, pial arteriolar and venular diameters increased temporarily and significant dilation was observed in both sevoflurane groups. From 10 minutes after unclamping until the end of the study, large and small arterioles returned to baseline diameters in the sevoflurane groups, but decreased significantly by 10% to 20% in the propofol rabbits. Ischemia-induced adverse effects such as pulmonary edema and acute brain swelling were observed primarily in propofol-anesthetized rabbits. Propofol and sevoflurane acted differently on pial vessels during reperfusion after ischemic insult. Pial arterioles and venules did not dilate immediately after reperfusion, and subsequently constricted throughout the reperfusion period in propofol-anesthetized rabbits. In contrast, pial arterioles and venules dilated temporarily and returned to baseline in sevoflurane-anesthetized rabbits.