猪肝脏体外劈离过程中常温机械灌注保存装置的建立及评价

Protective effect of normothermic machine perfusion preservation device for splitting in porcine livers

目的本研究拟利用体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)的原理,构建自己的常温机械灌注(normothermic machine perfusion,NMP)体系,通过对巴马小型猪肝脏灌注保存过程中进行劈离,验证其效果及稳定。方法健康巴马小型猪4只,常温下切取肝脏,连接NMP装置开始灌注。劈离过程中,监测门静脉、肝动脉流量、压力、肝脏保存温度。结果劈离过程中,门静脉压力控制在8.75~9.75 mmHg(1 mmHg=0.133 k Pa),肝动脉压力维持在92~92.75 mmHg;门静脉流量从劈离前(455.00±107.55)mmHg降至劈离后(392.50±125.27)mmHg,肝动脉流量则从(180.75±59.46)mmHg降至(126.25±6.99)mmHg。劈离前,保存液p H值(7.24±0.10)较基础值(7.50±0.08)降低,劈离结束后p H值(7.60±0.13)高于基础值;PO2在劈离过程维持在482.25~521.00 mmHg,较基础值(304.00±78.11)mmHg增高;HCO3-劈离前(10.10±5.04)mmol/L较基础值(24.05±0.31)mmol/L降低,随后HCO3-逐渐升高;Na+在劈离过程中维持在142.75~149.25 mmol/L;K+在劈离过程中从基础值(3.45±0.33)mmol/L升高至劈离后(4.98±1.12)mmol/L;乳酸在劈离前(2.86±1.77)mmol/L较基础值(3.85±2.58)mmol/L降低,劈离结束后,升高至(6.00±3.73)mmol/L。随着劈离的进行,胆汁分泌量减少,劈离前(16.75±3.30)ml/h,劈离中(10.55±1.83)ml/h,劈离后(6.53±1.33)ml/h。灌注保存开始,丙氨酸转氨酶(alanine aminotransferase,ALT)、乳酸脱氢酶(lactic dehydrogenase,LDH)、碱性磷酸酶(alkaline phosphatase,ALP)处于较基础值的低水平,随着劈离进行,ALT、LDH水平逐渐增高,ALP始终维持在一个较低的水平。天冬氨酸转氨酶(aspartate transaminase,AST)在保存开始时的水平和基础值接近,随着劈离的进行,AST水平逐渐增高。与保存前比较,NMP保存劈离后肝组织细胞结构无明显改变。结论自建NMP系统在供肝劈离过程中相对稳定,具有一定临床应用价值。

Objective We used the principle of extracorporeal membrane oxygenation（ECMO） to assemble our own normothermic machine perfusion（NMP） system, and to verify the effect and stability of NMP in the split liver process of perfusion and preservation of Bama miniature pig. Methods Four healthy Bama miniature pig were selected,the liver was quickly harvested and was connected to the NMP device for preservation and perfusion. In the process of split,portal vein,hepatic artery flow and pressure,the temperature of liver preservation were recorded. Results During the liver splitting procedure, the portal vein pressure was maintained between 8.75-9.75 mm Hg（1 mm Hg = 0.133 k Pa）. Meanwhile, the hepatic artery pressure was maintained in a range of 92.00-92.75 mm Hg. In the splitting process, portal venous flow reduced from（455.00±107.55）mm Hg before splitting to（392.50±125.27） mm Hg after splitting, while hepatic artery flow reduced from（180.75±59.46）mm Hg before splitting to（126.25±6.99） mm Hg after splitting. Before splitting, the p H value（7.24±0.10）was lower than the baseline value（7.50±0.08）, and it gradually increased with splitting and reached a value of（7.60±0.13） after splitting, which was slightly higher than the baseline value. The PO2 was maintained in a range of 482.25-521.00 mm Hg during splitting, which was significantly higher than the baseline value（304.00±78.11） mm Hg. HCO3-was（10.10± 5.04）mmol/L before splitting, which was significantly lower than the baseline value of（24.05±0.31）mmol/L, while it gradually increased. Na＋ was maintained in a range of 142.75-149.25mmol/L during splitting. During the preservation splitting,K＋ gradually increased from（3.45±0.33）mmol/L at baseline to（4.98±1.12）mmol/L at the end of splitting. Before splitting, the lactic acid was（2.86±1.77） mmol/L, which was lower than the baseline value of（3.85±2.58）mmol/L, and it gradually increased to（6.00±3.73） mmol/L at the end of splitting. The bile secretion was gradually reduced with splitting before splitting ：（16.75±3.30） ml/h, during splitting ：（10.55±1.83） ml/h, and after splitting ：（6.53±1.33） ml/h. At the beginning of perfusion preservation, the alanine aminotransferase（ALT）, lactate dehydrogenase（LDH）, and alkaline phosphatase（ALP）were lower than the baseline level. ALT and LDH gradually increased with splitting, whereas ALP was maintained in a lower level in the splitting. At the beginning of perfusion preservation, aspartate aminotransferase（AST） was comparable with the baseline value,and it was gradually increased with splitting. The cell structure in the liver did not show significant changes after splitting with NMP preservation compared with that before the preservation. Conclusion Our NMP system in the process of liver splitting is relatively stable,with a certain clinical value.