Abdo Emilio Elias, Figueira Estela Regina Ramos, Rocha-Filho Joel Avancini, Chaib Eleazar, D'Albuquerque Luiz Augusto Carneiro, Bacchella Telesforo
Hospital das Clínicas, Universidade de São Paulo, Faculdade de Medicina, Departamento de Gastroenterologia, Divisão de Cirurgia Digestiva, São Paulo, SP, Brasil.
Hospital das Clínicas, Universidade de São Paulo, Faculdade de Medicina, Departamento de Gastroenterologia, Laboratório de Investigação Médica LIM37, São Paulo, SP, Brasil.
Arq Gastroenterol. 2017 Jul-Sept;54(3):246-249. doi: 10.1590/S0004-2803.201700000-30. Epub 2017 Jul 6.
Ischemia/reperfusion causes organ damage but it is mandatory in hepatic transplantation, trauma and other complex liver surgeries, when Pringle maneuver is applied to minimize bleeding during these procedures. It is well known that liver ischemia/reperfusion leads to microcirculatory disturbance and cellular injury. In this setting hypothermia is known to reduce oxygen demand, lowering intracellular metabolism.
: To evaluate the effects of hypothermia in liver ischemia/reperfusion injury, using a new model of topic isolated liver hypothermia.
We used male Wistar rats weighting about 250 grams, kept in ad libitum feeding regime and randomly divided into two groups of nine animals: 1) Normothermic group, rats were submitted to normothermic ischemia of the median and left hepatic lobes, with subsequent resection of right and caudate lobes during liver reperfusion; and 2) Hypothermic group, rats were submitted to liver ischemia under hypothermia at 10°C. Liver ischemia was performed for 45 minutes. The animals were euthanized 48 hours after liver reperfusion for blood and liver tissue sampling.
The transaminases analyses showed a significant decrease of AST and ALT in Hypothermic group (P<0.01) compared to Normothermic group (1403±1234 x 454±213 and 730±680 x 271±211 U/L, respectively). Histology showed severe necrosis in 50% and mild necrosis in 50% of cases in Normothermic group, but severe necrosis in 10% and mild or absent necrosis 90% of the cases in hypothermic group.
: A simplified model of liver ischemia/reperfusion that simulates orthotopic liver autotransplantion was demonstrated. Topical hypothermia of isolated hepatic lobules showed liver protection, being a viable and practical method for any kind of in vivo liver preservation study.
缺血/再灌注会导致器官损伤，但在肝移植、创伤及其他复杂肝脏手术中，当应用普林格尔手法以尽量减少这些手术过程中的出血时，缺血/再灌注是必要的。众所周知，肝脏缺血/再灌注会导致微循环紊乱和细胞损伤。在这种情况下，低温已知可降低氧需求，降低细胞内代谢。
使用一种新的局部隔离肝脏低温模型，评估低温对肝脏缺血/再灌注损伤的影响。
我们使用体重约250克的雄性Wistar大鼠，自由采食，随机分为两组，每组9只动物：1）常温组，大鼠接受肝中叶和左肝叶的常温缺血，随后在肝脏再灌注期间切除右叶和尾状叶；2）低温组，大鼠在10°C低温下接受肝脏缺血。肝脏缺血持续45分钟。在肝脏再灌注48小时后对动物实施安乐死以采集血液和肝脏组织样本。
转氨酶分析显示，与常温组相比，低温组的AST和ALT显著降低（P<0.01）（分别为1403±1234×454±213和730±680×271±211 U/L）。组织学检查显示，常温组50%的病例出现严重坏死，50%的病例出现轻度坏死，而低温组10%的病例出现严重坏死，90%的病例出现轻度或无坏死。
展示了一种模拟原位肝脏自体移植的简化肝脏缺血/再灌注模型。局部隔离肝小叶低温显示出肝脏保护作用，是任何类型体内肝脏保存研究的一种可行且实用的方法。
