Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large am...Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer's solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.展开更多
Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study ex...Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study examined cortical blood flow (CBF), cerebral oxygenation, and brain oxygen consumption in relation to deep hypothermic CPB with alpha-stat or pH-stat management. Methods: Twenty-two pigs were cooled with alpha-stat or pH-stat during CPB to 15℃ esophageal temperature. CBF and cerebral oxygenation were measured continuously with a laser flowmeter and near-infrared spec-troscopy, respectively. Brain oxygen consumption was measured with standard laboratory techniques. Results: During CPB cooling, CBF was significantly decreased, about 52,2%±6.3% (P<0.01 vs 92.6%±6.5% of pH-stat) at 15℃ in alpha-stat, whereas there were no significant changes in CBF in pH-stat. While cooling down, brain oxygen extraction (OER) progressively decreased, about 9.5%±0.9% and 10.9%±1.5% at 15℃ in alpha-stat and pH-stat, respectively. At 31℃ the decreased value in pH-stat was lower than in alpha-stat (29.9%±2.7% vs 22.5%±1.9%; P<0.05). The ratio of CBF/OER were 2.0±0.3 in alpha-stat and pH-stat, respectively; it was kept in constant level in alpha-stat, and significantly increased by 19 ℃ to 15℃ in pH-stat (4.9±0.9 vs 2.3±0.4; P<0.01). In mild hypothermia, cerebral oxyhemoglobin and oxygen saturation in alpha-stat were greater than that in pH-stat (102.5%±1.4% vs 99.1%±0.7%; P<0.05). In deep hypothermia, brain oxygen saturation in pH-stat was greater than that in alpha-stat (99.2%±1.0% vs 93.8%±1.0%; P<0.01), and deoxyhemoglobin in pH-stat decreased more greatly than that in alpha-stat (28.7%±6.8% vs 54.1%±4.7%; P<0.05). Conclusions: In mild hypothermic CPB, brain tissue oxygen saturation was greater in alpha-stat than in pH-stat. However, cerebral oxygenation and brain tissue oxygen saturation were better in pH-stat than in alpha-stat during profound hypothermia. PH-stat strategy provided much more oxygen to brain tissue before deep hypothermic circulatory arrest.展开更多
Background: In clinical and basic science medicine, we often isolate ourselves in silos, unaware of developments in other related disciplines. Our team has had substantial experience, both in the operating room and in...Background: In clinical and basic science medicine, we often isolate ourselves in silos, unaware of developments in other related disciplines. Our team has had substantial experience, both in the operating room and in the laboratory, with protecting the brain and the spinal cord via hypothermia. Herein, we briefly share this experience with our colleagues in Neurology, eager for comments and advice from the neurologic perspective. Methods: 1) Clinical brain protection via deep hypothermic circulatory arrest (DHCA) for surgery of the aortic arch. For aortic arch replacement (performed for aortic arch aneurysm or aortic dissection), the aortic arch must be opened and native perfusion stopped. We have decades of experience in many hundreds of patients with this technique. This experience is reviewed. 2) Experimental protection of the spinal cord via cooling. We review our laboratory experience with a novel, recirculating cooling catheter for the vulnerable spinal cord. 3) Experimental protection of the brain via an intraventricular cooling catheter. We review our laboratory experience cooling the brain with a balloon-tipped catheter residing the lateral ventricles. Results: 1) Deep hypothermic circulatory arrest for aortic arch surgery provides superb brain protection for periods up to 45 minutes or longer. Clinical neurologic function, and quantitative neurologic tests, show excellent brain preservation. 2) The novel spinal cooling catheter provides excellent cooling of the spinal cord in a large animal model, without apparent injury of any type. 3) The intraventricular brain cooling catheter provides excellent cooling of the brain, documented by both direct temperature probe and high-tech brain imaging. Conclusions: We wish herein (in this article) to share this experience across our disciplines (Cardiac Surgery and Neurology). We welcome advice from the Neurology community on these surgically-directed methods for cooling and protection of neurological tissue in both the brain and the spinal cord.展开更多
目的:评价急性复杂型Stanford A 型主动脉夹层手术中改良双侧选择性顺行脑保护的效果及升主动脉插管、左锁骨下动脉(LSA)“开窗”技术对手术风险的影响。方法122例急性复杂型Stanford A 型主动脉夹层患者行改良全主动脉弓置换加降主...目的:评价急性复杂型Stanford A 型主动脉夹层手术中改良双侧选择性顺行脑保护的效果及升主动脉插管、左锁骨下动脉(LSA)“开窗”技术对手术风险的影响。方法122例急性复杂型Stanford A 型主动脉夹层患者行改良全主动脉弓置换加降主动脉内支架象鼻植入术,按照脑保护及动脉供血管插管方式分为单侧脑保护组与改良双侧脑保护组及右锁骨下动脉(RSA)插管组与主动脉插管组,比较各组的手术方式、死亡率及并发症率。部分患者采用左锁骨下动脉“开窗”技术重建血运。结果单侧脑保护组与改良双侧脑保护组总的院内死亡率分别为5.77%、2.86%,差异无统计学意义(P值为0.650);神经系统总并发症率分别为26.92%、10.00%,差异有统计学意义(P值为0.014)。右锁骨下动脉插管组与升主动脉插管组总的院内死亡率均为4.55%,总并发症率分别为15.9%、15.2%,差异均无统计学意义(P值分别为1、0.914)。左锁骨下动脉“开窗”者术后多次复查CTA左锁骨下动脉均通畅,无左锁骨下盗血综合征发生,1例出现无需处理的少量内漏。结论改良双侧选择性顺行脑保护安全、可行、可靠;选择升主动脉插管符合生理、操作简捷,不增加手术风险;左锁骨下动脉“开窗术”简化了手术,缩短了深低温停循环时间,增加了手术安全性。展开更多
基金supported by the National Natural Science Foundation of China, No. 30960398the 47th Post-doctoral Scientific Foundation of China, No. 20100470376the Natural Science Foundation of Yunnan Province, No.2009CD178
文摘Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer's solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.
文摘Objective: There is a remarkable lack of scientific evidence to support the option to use alpha-stat or pH-stat management, as to which is more beneficial to brain protection during deep hypothermic CPB. This study examined cortical blood flow (CBF), cerebral oxygenation, and brain oxygen consumption in relation to deep hypothermic CPB with alpha-stat or pH-stat management. Methods: Twenty-two pigs were cooled with alpha-stat or pH-stat during CPB to 15℃ esophageal temperature. CBF and cerebral oxygenation were measured continuously with a laser flowmeter and near-infrared spec-troscopy, respectively. Brain oxygen consumption was measured with standard laboratory techniques. Results: During CPB cooling, CBF was significantly decreased, about 52,2%±6.3% (P<0.01 vs 92.6%±6.5% of pH-stat) at 15℃ in alpha-stat, whereas there were no significant changes in CBF in pH-stat. While cooling down, brain oxygen extraction (OER) progressively decreased, about 9.5%±0.9% and 10.9%±1.5% at 15℃ in alpha-stat and pH-stat, respectively. At 31℃ the decreased value in pH-stat was lower than in alpha-stat (29.9%±2.7% vs 22.5%±1.9%; P<0.05). The ratio of CBF/OER were 2.0±0.3 in alpha-stat and pH-stat, respectively; it was kept in constant level in alpha-stat, and significantly increased by 19 ℃ to 15℃ in pH-stat (4.9±0.9 vs 2.3±0.4; P<0.01). In mild hypothermia, cerebral oxyhemoglobin and oxygen saturation in alpha-stat were greater than that in pH-stat (102.5%±1.4% vs 99.1%±0.7%; P<0.05). In deep hypothermia, brain oxygen saturation in pH-stat was greater than that in alpha-stat (99.2%±1.0% vs 93.8%±1.0%; P<0.01), and deoxyhemoglobin in pH-stat decreased more greatly than that in alpha-stat (28.7%±6.8% vs 54.1%±4.7%; P<0.05). Conclusions: In mild hypothermic CPB, brain tissue oxygen saturation was greater in alpha-stat than in pH-stat. However, cerebral oxygenation and brain tissue oxygen saturation were better in pH-stat than in alpha-stat during profound hypothermia. PH-stat strategy provided much more oxygen to brain tissue before deep hypothermic circulatory arrest.
文摘Background: In clinical and basic science medicine, we often isolate ourselves in silos, unaware of developments in other related disciplines. Our team has had substantial experience, both in the operating room and in the laboratory, with protecting the brain and the spinal cord via hypothermia. Herein, we briefly share this experience with our colleagues in Neurology, eager for comments and advice from the neurologic perspective. Methods: 1) Clinical brain protection via deep hypothermic circulatory arrest (DHCA) for surgery of the aortic arch. For aortic arch replacement (performed for aortic arch aneurysm or aortic dissection), the aortic arch must be opened and native perfusion stopped. We have decades of experience in many hundreds of patients with this technique. This experience is reviewed. 2) Experimental protection of the spinal cord via cooling. We review our laboratory experience with a novel, recirculating cooling catheter for the vulnerable spinal cord. 3) Experimental protection of the brain via an intraventricular cooling catheter. We review our laboratory experience cooling the brain with a balloon-tipped catheter residing the lateral ventricles. Results: 1) Deep hypothermic circulatory arrest for aortic arch surgery provides superb brain protection for periods up to 45 minutes or longer. Clinical neurologic function, and quantitative neurologic tests, show excellent brain preservation. 2) The novel spinal cooling catheter provides excellent cooling of the spinal cord in a large animal model, without apparent injury of any type. 3) The intraventricular brain cooling catheter provides excellent cooling of the brain, documented by both direct temperature probe and high-tech brain imaging. Conclusions: We wish herein (in this article) to share this experience across our disciplines (Cardiac Surgery and Neurology). We welcome advice from the Neurology community on these surgically-directed methods for cooling and protection of neurological tissue in both the brain and the spinal cord.
文摘目的:评价急性复杂型Stanford A 型主动脉夹层手术中改良双侧选择性顺行脑保护的效果及升主动脉插管、左锁骨下动脉(LSA)“开窗”技术对手术风险的影响。方法122例急性复杂型Stanford A 型主动脉夹层患者行改良全主动脉弓置换加降主动脉内支架象鼻植入术,按照脑保护及动脉供血管插管方式分为单侧脑保护组与改良双侧脑保护组及右锁骨下动脉(RSA)插管组与主动脉插管组,比较各组的手术方式、死亡率及并发症率。部分患者采用左锁骨下动脉“开窗”技术重建血运。结果单侧脑保护组与改良双侧脑保护组总的院内死亡率分别为5.77%、2.86%,差异无统计学意义(P值为0.650);神经系统总并发症率分别为26.92%、10.00%,差异有统计学意义(P值为0.014)。右锁骨下动脉插管组与升主动脉插管组总的院内死亡率均为4.55%,总并发症率分别为15.9%、15.2%,差异均无统计学意义(P值分别为1、0.914)。左锁骨下动脉“开窗”者术后多次复查CTA左锁骨下动脉均通畅,无左锁骨下盗血综合征发生,1例出现无需处理的少量内漏。结论改良双侧选择性顺行脑保护安全、可行、可靠;选择升主动脉插管符合生理、操作简捷,不增加手术风险;左锁骨下动脉“开窗术”简化了手术,缩短了深低温停循环时间,增加了手术安全性。