[Clinical application of cerebral oxygenation monitoring during aortic aneurysm operation]

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.

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.

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.

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.