Objective: To analyze the correlation between cerebral oxygenation and cerebral complications after aortic aneurysm operation and to evaluate the protective effects of DHCA and/or ASCP during aortic aneurysm operation.
Methods: Thirty patients with aortic aneurysm, 24 with Stanford type A dissection, 4 with Stanford type B dissection, 1 with degenerative aneurysm in ascending and arch aorta, and 1 with false aneurysm in thoraco-abdominal aorta, 23 males and 7 females, aged 44 +/- 12, underwent aorta operation with circulatory arrest were alternatively allocated to two groups: 22 patients underwent aortic arch replacement under deep hypothermic circulatory arrest (DHCA) plus antegrade selective cerebral perfusion (ASCP), and 8 patients underwent descending thoracic aorta replacement under DHCA only. There was no significant difference in the lowest core temperature, hematocrit at lowest core temperature, and velocity of rewarming between these 2 groups. Near-infrared spectroscopy (NIRS) was used to continuously monitor the cerebral tissue oxygenation index (TOI) percutaneously.
Results: The mean circulatory arrest time in the DHCA + ASCP group was 23.25 min, significantly longer than that of the DHCA group (16.67 min, P = 0.022). Cerebral complication occurred in 8 patients after aortic operation (complication group). The baseline TOI of the complication group was 70% +/- 5%, and the maximum decrease in TOI was 58% +/- 8%; and the baseline TOI of the non-complication group was 69% +/- 8%, and the maximum decrease in TOI was 55% +/- 8%; however, there were no significant differences between these 2 groups (both P > 0.05). The TOI decrease was more significant in the DHCA group than in the DHCA + ASCP group. During circulatory arrest, the levels of TOI were higher than the baseline level all along in the ASCP group and were lower than the baseline level 3 to 10 minutes after arrest in the DHCA group. The duration of TOI less than the baseline level in the DHCA group was significantly longer than that in the ASCP group.
Conclusion: Mild decrease of TOI is not significantly correlated to the occurrence of complication. DHCA + ASCP is more effective in brain protection compared with only DHCA.