van Wagensveld B A, van Gulik T M, Gabeler E E, van der Kleij A J, Obertop H, Gouma D J
Department of Surgery, Academical Medical Center, Amsterdam, The Netherlands.
Eur Surg Res. 1998;30(1):13-25. doi: 10.1159/000008553.
Temporary vascular inflow occlusion of the liver (clamping of the hepatic pedicle) can prevent massive blood loss during liver resections. In this study, intrahepatic tissue pO2 was assessed as parameter of microcirculatory disturbances induced by ischemia and reperfusion (I/R) in the liver following continuous (Cnt) or intermittent (Int) clamping in a hemihepatectomy model in the pig.
Pigs (20-34 kg) were divided into 2 groups: I/R without hemihepatectomy (-HH; n = 10) and I/R with hemihepatectomy (+HH; n = 8). Ischemia during 90 min was Cnt or Int (6 sequential periods of 12 min of ischemia and 3 min of reperfusion), followed by 120 min of reperfusion. Intrahepatic pO2 histograms (polarographic pO2 needle electrode) were constructed before ischemia, at the end of 90 min of ischemia and after 120 min of reperfusion, along with assessment of plasma AST, ALT and LDH. Bile production was monitored continuously.
Cumulative frequency distribution curves (CFDC) after 120 min of reperfusion in the Cnt-HH group were not different from preischemic CFDC (means +/- SEM), whereas in the Int-HH group a left shift occurred indicating more hypo(non)perfused liver areas (pO2 < 10 mm Hg: 2.6 +/- 1.2 and 41.0 +/- 17.5% in Cnt-HH and Int-HH; p < 0.01). In the Cnt+HH group, a left shift in the CFDC occurred. In the Int+HH group, a left and a right shift occurred simultaneously, indicating both hypo(non)- and hyperperfused (shunting) liver areas (pO2 < 10 mm Hg: 4.0 +/- 2.7 and 9.6 +/- 8.5%, n.s., and pO2 > 60 mm Hg: 2.0 +/- 2.0 and 17.3 +/- 6.4%, p = 0.015, in Cnt+HH and Int+HH). Plasma AST, ALT and LDH levels were not increased after 120 min of reperfusion, except for AST in Cnt+HH and Int+HH (from 54.6 +/- 14.0 to 270.4 +/- 42.8 U/l, p < 0.01, and from 47.8 +/- 9.4 to 176.5 +/- 55.9 U/l, n.s.). Bile production (percentage of mean preischemic value) during 120 min of reperfusion was significantly reduced in the Int-HH group, as compared to the Cnt-HH group (57.0 and 117.0% after 120 min of reperfusion, p = 0.002). In Cnt+HH and Int+HH, bile production was significantly reduced (33.3 +/- 20.0%, p = 0.05, and 38.5 +/- 7.9%, p = 0.007); however it was not different between the two groups.
(1) Intrahepatic tissue pO2 as indicator of microvascular perfusion is a parameter of early I/R injury; (2) continuous vascular inflow occlusion resulted in less microcirculatory disturbances, when compared to intermittent occlusion.
肝脏临时血管流入阻断（肝蒂钳夹）可防止肝切除术中大量失血。在本研究中，在猪的半肝切除模型中，通过连续（Cnt）或间歇性（Int）钳夹后，将肝内组织pO₂作为肝缺血再灌注（I/R）诱导的微循环障碍的参数进行评估。
将猪（20 - 34 kg）分为2组：无半肝切除的I/R组（-HH；n = 10）和有半肝切除的I/R组（+HH；n = 8）。90分钟的缺血为连续或间歇性（6个连续的12分钟缺血期和3分钟再灌注期），随后进行120分钟的再灌注。在缺血前、90分钟缺血结束时和120分钟再灌注后构建肝内pO₂直方图（极谱pO₂针电极），同时评估血浆AST、ALT和LDH。持续监测胆汁生成。
Cnt-HH组再灌注120分钟后的累积频率分布曲线（CFDC）与缺血前的CFDC无差异（均值±标准误），而Int-HH组出现左移，表明肝低（无）灌注区域增多（pO₂ < 10 mmHg：Cnt-HH组为2.6±1.2%，Int-HH组为41.0±17.5%；p < 0.01）。Cnt+HH组CFDC出现左移。在Int+HH组，同时出现左移和右移，表明存在肝低（无）灌注和高灌注（分流）区域（pO₂ < 10 mmHg：Cnt+HH组为4.0±2.7%，Int+HH组为9.6±8.5%，无显著性差异；pO₂ > 60 mmHg：Cnt+HH组为2.0±2.0%，Int+HH组为17.3±6.4%，p = 0.015）。再灌注120分钟后，除Cnt+HH组和Int+HH组的AST外，血浆AST、ALT和LDH水平均未升高（Cnt+HH组和Int+HH组的AST分别从54.6±14.0 U/L升至270.4±42.8 U/L，p < 0.01，以及从47.8±9.4 U/L升至176.5±55.9 U/L，无显著性差异）。与Cnt-HH组相比，Int-HH组再灌注期间120分钟的胆汁生成（缺血前平均值的百分比）显著降低（再灌注120分钟后分别为57.0%和117.0%，p = 0.002）。在Cnt+HH组和Int+HH组中，胆汁生成显著降低（分别为33.3±20.0%，p = 0.05，和38.5±7.9%，p = 0.007）；然而两组之间无差异。
（1）肝内组织pO₂作为微血管灌注的指标是早期I/R损伤的一个参数；（2）与间歇性阻断相比，连续血管流入阻断导致的微循环障碍更少。
