主动脉瘤手术中脑氧饱和度监测的临床应用

Clinical application of cerebral oxygenation monitoring during aortic aneurysm operation

目的探讨主动脉瘤手术患者术中脑氧饱和度的变化与脑部并发症发生的相关性,评价两种脑保护方法的效果。方法 30例主动脉瘤手术患者中主动脉夹层 Stanford A 型24例,StanfordB 型4例,升主动脉及主动脉弓部瘤1例,假性胸腹主动脉瘤1例。在深低温停循环(DHCA)合并选择性顺行脑灌注(ASCP)下行主动脉弓部替换22例(ASCP组);在单纯 DHCA 下行胸降主动脉替换8例(DHCA 组)。于术中应用近红外光谱分析技术(NIRS)进行持续脑氧饱和度(TOI)监测。结果出现脑部并发症患者8例。并发症组与非并发症组术中转机前 TOI 分别为70%±5%和69%±8%,分别降至58%±8%和55%±8%,两组间差异无统计学意义(P>0.05)。停循环期间 DHCA 组 TOI 从77%±6%降至52%±7%,ASCP 组 TOI 从75%±6%降至71%±7%;两组间 TOI 的下降程度差异有统计学意义(P<0.05)。结论轻度的 TOI 降低与脑部并发症的发生无明显相关性。DHCA 合并ASCP 与单纯的 DHCA 相比,具有更好的脑保护效果。

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.