“一肝三受”动物实验的可行性

目的:研究1个肝脏劈离成3个供肝单位的动物实验可行性.方法:普通级健康犬分成供体组(n=30,体质量20-25 kg)和受体组(n=30,体质量8-15kg),供受体随机配对.供体手术断离右外叶和右中叶、左中叶和方叶之间的2处肝组织桥,原位灌注后将左侧区、中央区和右侧区供肝各自的一级肝蒂在近主干处切断,移植物受体体质量比(graft-to-recipient weight ratio,GRWR)>1.0%且最接近1.5%的供肝入选为移植物,植入左侧区、中央区和右侧区供肝的受体分别分入A组、B组和C组.供肝背驮式植入受体,流出口和腔静脉壁端侧吻合,供肝一级肝蒂分别和受体门管三联的主干端端吻合.术后观察受体腹腔及胆汁引流,死亡后进行尸检,移植物取标本进行病理检查.结果:犬肝外观呈分叶状,深陷的叶间裂将各叶分隔开来,各叶间由较少的肝组织桥相连接,右外叶和右中叶间的肝桥组织较左中叶和方叶间的肝桥组织更薄更少,2处肝桥离断时均未发现有大的血管及胆管.门静脉主要分成左支、中支和右支;胆总管也由左、中及右肝管三支肝管汇合而成;肝动脉可存在变异;肝血液经由肝左、中、右3支静脉回流.3组供体的平均体质量、手术时间及失血量差异的比较无统计学意义.体内劈离技术全部得以完成,供肝无热缺血损伤.3组受体体质量、供肝质量和GRWR之间的差异均存在显著的统计学意义(P<0.01),但手术时间、无肝期、失血量及输血量间的差异无统计学意义(P>0.05).3组受体中无术中死亡者,30个供肝均成功植入,所有血管及胆道的吻合均不需要移植物间置,门静脉和动脉重建后均能排泌胆汁,各组新肝均无淤血、缺血区.3组受体存活时间分别为128.3 h±48.5 h、102.7 h±59.8 h和98.7 h±36.8 h,各组之间的差异无统计学意义(P=0.234).死亡后尸检均未发现有吻合口出血、血栓等外科技术性并发症者,移植物标本病理检查肝细胞无淤血肿胀和缺血坏死者.结论:此项动物实验证明:一个大受体的肝脏能劈离成3个部分,且每一部分都能作为独立完整的供肝移植给不同体质量的小受体.

An experimental study of triple split-liver transplantation in dogs

AIM: To explore the feasibility of a strategy of tripartition of a whole deceased liver graft for use in 3 recipients in dogs to ultimately maximize donor organ use.METHODS: Adult healthy mongrel dogs were selected to be donors(n = 30,weighing between 20-25 kg) and recipients(n = 30,weighing between 8-15 kg).Donor/recipient pairs were randomly matched.For donor operation,transection of the parenchymal bridge was performed between the right lateral lobe and right middle lobe,and between the left middle lobe and the quadrate lobe.After in vivo perfusion,the left,middle and right liver grafts were procured,and their primary branches were cut near the main stem.Among the three liver grafts,the one was chosen to be implanted if it’s GRWR(graft-torecipient weight ratio) was more than 1.0% and was nearest to 1.5%.Recipients entered Groups A,B and C if the left,middle and right grafts were chosen,respectively.With the piggyback technique,the outflow orifice of liver graft was anastomosed to the anterolateral wall of the recipient vena cava.The graft was revascularized via reconstructed hepatic vein and portal vein,and then the hepatic artery and bile duct were anastomosed both in an end-to-end manner.Biliary and abdominal drainage was inspected postoperatively.Autopsies were performed promptly after recipients’ death to investigate the possibility of technical complications.RESULTS: By prominent fissures,the canine liver was divided into 7 lobes,among which the parenchymal bridges were thin.The parenchymal bridge connecting the right lateral lobe to the right middle lobe was much thinner than that connecting the left middle lobe to the quadrate lobe.No major conduit was found during transection of these two parenchymal bridges.The portal vein was split into three branches.The common bile duct was formed by the union of three hepatic ducts-the left,middle and right hepatic ducts.The hepatic vein consisted of the left,median and right hepatic veins.Anatomical variations in the hepatic arteries could be found.Among three recipient groups,the operation time,anhepatic time and blood loss did not show significant differences(P > 0.05),but the mean recipient weight,liver graft weight,and GRWR differed significantly(all P < 0.01).In the three groups,none of the recipients died during surgery.Once the hepatic vein and the portal vein were anastomosed and declamped,the implanted liver regained its color soon and its appearance returned to normal following arterial revascularization.There was no statistical difference in survival duration among the three groups(128.3 h ± 48.5 h vs 102.7 h ± 59.8 h vs 98.7 h ± 46.8 h,P = 0.234).Ascites and liver necrosis were not found at autopsy.Bile was present in the bile duct and all anastomoses were patent.CONCLUSION: Our experimental results indicate that the whole liver of a big dog can be split into three parts,every one of which can be transplanted to a small recipient as an independent allograft.