Lin P J, Chang C H, Tan P P, Chang C N, Lee S T, Wang C C, Chang J P, Liu D W, Chu J J, Tsai K T, Kao C L, Hsieh M J, Hua M S
Division of Thoracic and Cardiovascular Surgery, Chang Gung Memorial Hospital, Chang Gung Medical College, Taipei, Taiwan, Republic of China.
Circulation. 1996 Nov 1;94(9 Suppl):II169-72.
Circulatory arrest (CA), which provides a bloodless field and good visualization without the need of aortic cross-clamp, is commonly used to facilitate repair of aortic lesions. However, extended periods of CA may impair cerebral metabolism and cause ischemic injury. Studies were performed to evaluate the efficacy of retrograde cerebral perfusion (RCP) in protecting the brain from ischemic injury during a prolonged period of CA in moderate hypothermia.
Twenty-three patients (18 men and 5 women) were operated on for aortic lesions (17 acute type A aortic dissection and 6 chronic type A aortic dissection with Marfan's syndrome). The aortic operations were performed with CA (58 to 104 minutes; mean +/- SD, 75 +/- 12 minutes) at a rectal temperature of 23.3 +/- 0.5 degrees C (21 degrees C to 25 degrees C). For RCP, cold (14 degrees C to 18 degrees C) oxygenated blood (300 mL/min) was pumped to the superior vena cava with internal jugular venous pressure of 15 +/- 5 mm Hg. The cardiopulmonary bypass time was 157 +/- 18 minutes. Cortical blood flow during RCP detected by subdural laser Doppler probe was 10 +/- 5% of baseline. Percent oxygen extraction and pyruvate and lactate levels (26 +/- 2% and 0.43 +/- 0.17 and 45 +/- 16 mg/dI) were insignificantly different from those before CA (28 +/- 3% and 0.71 +/- 0.08 and 62 +/- 20 mg/dL, P > .05). Creatine kinase-BB isoenzyme was undetectable. All but 1 patient survived the operation (95.5%) and woke up without neurological deficit. Follow-up (mean, 13 months) was complete in all survivors. There were no late deaths. Cerebral functional studies performed 3 months after discharge showed results insignificantly different from those of the normal control subjects.
There is no evidence of ischemia of the brain during prolonged moderate hypothermic CA with the aid of RCP. Retrograde cerebral perfusion effectively extends the safe time of CA. Deep hypothermia during CA seems unnecessary.
循环骤停（CA）可提供无血视野且无需主动脉交叉钳夹即可实现良好的可视化，常用于促进主动脉病变的修复。然而，长时间的CA可能会损害脑代谢并导致缺血性损伤。本研究旨在评估在中度低温下长时间CA期间逆行脑灌注（RCP）保护大脑免受缺血性损伤的效果。
23例患者（18例男性和5例女性）接受了主动脉病变手术（17例急性A型主动脉夹层和6例合并马凡综合征的慢性A型主动脉夹层）。在直肠温度为23.3±0.5℃（21℃至25℃）的情况下，采用CA进行主动脉手术（58至104分钟；平均±标准差，75±12分钟）。对于RCP，将冷（14℃至18℃）氧合血（300 mL/分钟）泵入上腔静脉，颈内静脉压力为15±5 mmHg。体外循环时间为157±18分钟。硬膜下激光多普勒探头检测到的RCP期间皮质血流为基线的10±5%。氧摄取百分比以及丙酮酸和乳酸水平（26±2%、0.43±0.17和45±16 mg/dI）与CA前（28±3%、0.71±0.08和62±20 mg/dL）相比无显著差异（P>0.05）。肌酸激酶-BB同工酶未检测到。除1例患者外，所有患者均手术存活（95.5%），且苏醒后无神经功能缺损。所有幸存者均完成随访（平均13个月）。无晚期死亡病例。出院3个月后进行的脑功能研究结果与正常对照受试者相比无显著差异。
没有证据表明在借助RCP的长时间中度低温CA期间存在脑缺血。逆行脑灌注有效地延长了CA的安全时间。CA期间似乎无需深度低温。
