Roerick Olaf, Seitz Timo, Mauser-Weber Petra, Palmaers Thomas, Weyand Michael, Cesnjevar Robert
Department of Cardiothoracic Surgery, University Hospital Erlangen, University of Erlangen-Nuremberg, Krankenhausstrasse 12, 91054 Erlangen, Germany.
Eur J Cardiothorac Surg. 2006 Apr;29(4):517-24. doi: 10.1016/j.ejcts.2005.12.048. Epub 2006 Feb 28.
Aortic arch operations in pediatric patients using low-flow perfusion techniques have been standardized to a certain degree, but some of the often-stated beneficial effects have never been proven. Especially, the existence or efficacy of any subdiaphragmal perfusion still remains unclear.
Twenty-six newborn male piglets (10-15 kg) underwent aortic arch surgery under general anesthesia using either low-flow perfusion via the innominate artery (LF, 30 ml/(kg min), 25 degrees C, n=12) or conventional deep hypothermic circulatory arrest (DHCA, 20 degrees C, n=14). Cortical somatosensory-evoked potentials (SSEPs), carotid, and subdiaphragmal blood flows were measured. The animals of both groups have been randomized to either pH-stat or alpha-stat management on cardiopulmonary bypass (CPB).
During low-flow perfusion via the innominate artery only negligible flows of maximum 1-3 ml/min in the femoral arteries were detected, whereas the right carotid artery flow doubled. During reperfusion, serum-lactate and aspartate amino-transferase (AST) levels were significantly higher compared to the circulatory arrest group, whereas alanine amino-transferase (ALT), gamma-glutamyl transpeptidase (gamma-GT), AP, and creatinine did not show any significant differences. Cortical SSEP returned to preoperative values in all but two low-flow animals. There was no return of SSEP in all piglets operated under deep hypothermic circulatory arrest (p<0.01).
Compared to DHCA, low-flow perfusion via the innominate artery provides superior neuroprotection despite higher tissue temperatures. Although collateral blood flow via the subclavian artery and the circulus arteriosus willisii has often been presumed, only 'trickle-flow' with some protective potential was detectable in the femoral arteries during low-flow perfusion. Origin of elevated lactate and AST levels seems to be the lower limbs.
小儿患者使用低流量灌注技术进行主动脉弓手术已在一定程度上实现标准化，但一些常提到的有益效果从未得到证实。特别是，膈下灌注的存在或效果仍不明确。
26只新生雄性仔猪（10 - 15千克）在全身麻醉下接受主动脉弓手术，采用经无名动脉低流量灌注（LF，30毫升/（千克·分钟），25摄氏度，n = 12）或传统的深低温循环停搏（DHCA，20摄氏度，n = 14）。测量皮质体感诱发电位（SSEP）、颈动脉和膈下血流量。两组动物在体外循环（CPB）期间随机采用pH稳态或α稳态管理。
在经无名动脉低流量灌注期间，仅在股动脉中检测到最大1 - 3毫升/分钟的可忽略不计的血流，而右颈动脉血流增加了一倍。再灌注期间，与循环停搏组相比，血清乳酸和天冬氨酸氨基转移酶（AST）水平显著更高，而丙氨酸氨基转移酶（ALT）、γ-谷氨酰转肽酶（γ-GT）、碱性磷酸酶（AP）和肌酐没有显示出任何显著差异。除两只低流量动物外，所有低流量动物的皮质SSEP均恢复到术前值。在深低温循环停搏下手术的所有仔猪中，SSEP均未恢复（p < 0.01）。
与DHCA相比，经无名动脉低流量灌注尽管组织温度较高，但能提供更好的神经保护。尽管通常推测有通过锁骨下动脉和Willis环的侧支血流，但在低流量灌注期间，股动脉中仅检测到具有一定保护潜力的“涓流”。乳酸和AST水平升高的来源似乎是下肢。
