Aortic arch reconstruction: safety of moderate hypothermia and antegrade cerebral perfusion during systemic circulatory arrest.

Background And Aim: The ideal strategy for cerebral protection during aortic arch (AA) reconstructive surgery remains undefined. Antegrade cerebral perfusion (ACP) during systemic circulatory arrest (SCA) may provide superior results; however, optimal systemic temperature is undetermined. Our objective was to determine whether "deep" hypothermia is necessary during ACP with SCA, and whether the degree of hypothermia is associated with neurologic outcomes postoperatively.

Methods: Retrospective series of 72 consecutive patients (aged 65.9 +/- 3.2 years) who underwent AA reconstructive surgery at Vancouver General Hospital using a cerebral protection strategy of ACP with SCA between December 1995 and December 2002. Patients were divided into two groups according to lowest systemic temperature: <22 degrees C (n = 52) and > or =22 degrees C (n = 20).

Results: ACP was via right axillary or innominate artery, +/- left common carotid cannulation. Median SCA time with ACP was not different between groups. There were four hospital deaths (5.6%) (three from the <22 degrees C group). Eight patients (11.2%) had major neurologic injuries (seven from the <22 degrees C group): 4 (5.6%) permanent (1 fatal) and 4 (5.6%) temporary. There was a trend toward a significantly higher incidence of delirium in the <22 degrees C group than the > or =22 degrees C group (30.8 vs 10.0%, respectively, p = 0.07).

Conclusions: In our experience, SCA with ACP was a safe technique for AA reconstructive surgery. The observation of a larger number of major neurologic injuries, and a trend toward a higher incidence of delirium in the <22 degrees C group, suggests that systemic temperatures below 22 degrees C may not be necessary and may be associated with a higher incidence of neurologic injury when using ACP during SCA.