大鼠边缘性体积供肝肝移植模型的实验研究

目的通过建立不同体积供肝的大鼠肝移植模型，探索边缘性体积供肝大小的适宜范围，为研究小肝综合征的发病机理及防治措施提供一种易于复制的小动物模型。方法将192只大鼠随机分为全肝移植组、半肝移植组、小体积供肝移植组及超小体积供肝移植组，每组48只，分别建立全肝、半肝、小体积供肝和超小体积供肝的大鼠肝移植模型。移植术后，4组各抽取24只大鼠用于观察存活率；抽取12只大鼠于移植术前，移植术后5、15、30、45及60min测定门静脉压力；另12只大鼠于术后24h测定谷丙转氨酶（ALT）水平。结果全肝移植组的7d累积生存率为100％（24／24），半肝移植组为87．5％（21／24），小体积供肝移植组为37．5％（9／24），超小体积供肝移植组均于术后48h内死亡。全肝移植组术中开放门静脉后，60min内其门静脉压力稳定；半肝移植组大鼠在开放门静脉后，其门脉压力虽有小幅升高，但仍保持相对稳定；而小体积供肝移植组和超小体积供肝移植组开放门静脉后，其门静脉压力均显著升高，15min时均达到高峰，之后该2组的门静脉压力开始回落，至45～60min时逐渐稳定。供肝的体积大小与开放门静脉后5（r=-0．942）、15（r=-0．947）、30（r=-0．900）、45（r=-0．825）和60min（r=-0．705）时的门静脉压力均呈负相关关系（P〈0．001）。肝移植术后24h，全肝移植组和半肝移植组ALT水平均低于小体积供肝移植组及超小体积供肝移植组（P〈0．05），且小体积供肝移植组ALT水平低于超小体积供肝移植组（P〈0．05）。供肝体积的大小与大鼠移植术后的ALT水平呈负相关关系（r=-0．685，P〈0．001）。结论大鼠部分肝移植模型中，供肝与受体标准肝脏体积比（Gv／sLV）的安全界限为50％，GV／SLV为30％～35％的供肝可视为边缘性体积供肝，小于30％的供肝可视为超小体积供肝。

The Study on Establishment of Liver Transplantation Model by Using Marginal Size Liver Graft in Rat

Objective To establish different kinds of reduced size liver transplantation model of rats, and to explore the optimal marginal size of liver graft in orthotopic liver transplantation, in purpose of providing a kind of animal model for the study about mechanism and prevention measures of small-for-size syndrome. Methods One hundred and ninety- two rats were randomly divided into whole liver graft transplantation group （underwent whole liver graft transplantation）, half liver graft transplantation group （the median lobe and right lobe of the liver were selected to be the graft）, small size liver graft transplantation group （the median lobe of the liver was selected to be the graft）, and extra-small size liver graft transplantation group （the median lobe and left lobe of the liver were reduced, and remained lobes were selected to be the graft）, each group enrolled 48 rats. After liver graft transplantation, 24 rats of each group were selected to observe the survival situation, 12 rats of each group were selected to measure portal venous pressure at time point of before operation,and 5, 15, 30, 45, and 60 minutes after transplantation. The other 12 rats of each group were test the level of alanine aminotransferase （ALT）. Results Seven-day survival rate of the whole liver graft transplantation group, half liver graft transplantation group, small size liver graft transplantation group, and extra-small size liver graft transplantation group was 100% （24/24）, 87. 5% （21/24）, 37. 5% （9/24）, and 0 respectively. Portal venous pressure of whole liver graft trans- plantation group was stable after opening the portal vein, although there was slight increase at prophase in half liver graft transplantation group, and then the portal venous pressure would let down, keeping stable at the later stage. But in small size liver graft transplantation group and extra-small size liver graft transplantation group, the portal venous pressure incr- eased and got the top at 15 minutes after opening the portal vein, and then induced, keeping stable during the 45-60 minutes. Portal venous pressure at the point of 5 （r=-0. 942）, 15 （r=-0. 947）, 30 （r=-0. 900）, 45 （r=-0. 825）, and 60 （r=--0. 705） minutes after opening the portal vein were significantly related to liver graft size （P〈0. 001）. The levels of ALT in whole liver graft transplantation group and half liver graft transplantation group were both lower than those of small size liver graft transplantation group and extra-small size liver graft transplantation group （P 〈 0. 05）, and levels of ALT in small size liver graft transplantation group was lower than extra-small size liver graft transplantation group too （P〈0. 05）. Level of ALT at 24 hours after transplantation were significantly related to liver graft size （r=-0. 685, P〈 0. 001）. Conclusions The minimum graft volume/standard liver volume （GV/SLV） in reduced size liver transplantation in rat is 50%. The liver graft whose GV/SLV is 30%-35% should be considered as marginal size liver graft, and the liver graft whose GV/SLV less than 30% should be considered as extra-small size liver graft in the rat.