Effects of use of Thiopental + Mannitol or Etomidate + Mannitol on Cerebral Ischemia During Temporary Occlusion of Middle Cerebral Artery in Intracranial Aneurysm Surgery

Abstract

Temporary vessel occlusion is an effective technique used by microvascular surgeons to facilitate dissection and permanent clipping of cerebral aneurysms. Prolonged temporary occlusion carries the risk of infarction in the territory distal to the point of occlusion. The risk of infarction can be reduced by reducing the oxygen requirements of the brain and by maintaining collateral circulation by means of blood pressure control. We studied the effects in 90 patients of etomidate + mannitol or thiopental + mannitol usage during temporary clipping in aneurysm surgery on SjVO2. group 1 received thiopental + mannitol and group 2 received etomidate + mannitol for protection before temporary clipping. After normalization of blood pressure (mild hypertension, mean arterial pressure 90-110 mm Hg) a temporary clip was used. Blood samples were taken from the jugular venous bulb catheter to assess SjVO2 at intervals during the procedure. Postoperative radiologic and clinical ischemia were evaluated with a CT scan and neurologic examination. In group 1, 6 patients were given inotropic agent infusion to maintain mean arterial pressure. However, in group 2, the inotropic agent was not required. SjVO2 values increased more than 80% in 1 patient in group 1 and in 2 patients in group 2. A new radiographic stroke was observed in 2 patients in group 2. When etomidate + mannitol was used for protection before temporary clipping, cerebral infaction appeared to be permanent as a result of the prolonged occlusion time. The results of this clinical study need further investigation.