不同肝实质劈离方式对大鼠门静脉结扎术后预留肝脏增生的影响

Impact of split completeness and site on future liver remnant hypertrophy in a rat model following portal vein ligation

目的探讨肝实质劈离在促进门静脉部分结扎(PVL)大鼠预留肝脏(FLR)再生中的作用和机制。方法用随机数字表法将健康成年Sprague-Dawley(SD)大鼠分为PVL组、PVL+肝实质完全劈离(ALPPS)组、PVL+肝实质部分劈离(PVL+PLP)组、PVL+结扎侧肝叶劈离组(PVL+PLL)、PVL+脾脏射频消融组(PVL+RFA)和假手术组(Sham),术后按1、3、5、7 d共4个时相点分别处死动物采取标本,每一时相点4只大鼠,每组共16只大鼠。分别测定预留肝脏质量和门静脉压力,酶联免疫吸附试验(ELISA)检测血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、总胆红素(TBIL)、白蛋白(ALB)和肝再生相关细胞因子(HGF)、白细胞介素-6(IL-6)、肿瘤坏死因子α(TNF-α)水平,免疫组织化学检测细胞增殖核抗原(Ki-67)及磷酸化组蛋白H3(pH3)的表达并计算阳性率。计量资料以均数±标准差表示,多组均数间的比较采用One-way ANOVA分析,组间采用最小显著差异法(LSD法)行两两比较。结果PVL+PLP组的FLR质量与体重之比(RML/BW)明显低于ALPPS组[术后3 d,(1.7±0.1)%比(2.2±0.3)%,t=4.042,P<0.01],差异有统计学意义;但高于PVL组[术后3 d,(1.7±0.1)%比(1.5±0.2)%,t=2.740,P<0.05],差异有统计学意义。PVL+PLL组的RML/BW显著低于ALPPS组[术后3 d,(1.4±0.1)%比(2.2±0.3)%,t=4.969,P<0.01]和PVL+PLP组[术后3 d,(1.4±0.1)%比(1.7±0.1)%,t=2.064,P<0.05];PVL联合肝实质劈离及射频消融各组的细胞因子水平在术后7 d内均无显著性差异;肝实质劈离可以进一步增加PVL后预留肝脏的门静脉压力[劈离前:(16.2±4.3)cmH_(2)O比完全劈离后:(19.7±2.6)cmH_(2)O,t=4.282,P<0.01]。结论肝实质劈离可能通过增加预留侧肝脏门脉压力来加速FLR再生,生长因子释放可能并非其促进肝再生的主要机制。

Objective To investigate the role and mechanism of liver parenchyma splitting in accelerating the regeneration of future liver remnant(FLR)in rats with portal vein ligation(PVL).Methods Rats were randomly divided into PVL group,PVL+complete hepatic parenchyma splitting(ALPPS)group,PVL+partial liver parenchyma splitting(PVL+PLP)group,PVL+liver splitting in the portal vein ligated lobe(PVL+PLL)group,PVL+splenic radiofrequency ablation(PVL+RFA)group and sham operation(Sham)group.The animals were killed at 4 time points of postoperative 1,3,5 and 7 days,respectively.Four rats were killed at each time point,with 16 rats in each group.The weight of FLR and portal vein pressure were measured respectively.The major liver function enzymes[alanine aminotransferase(ALT),serum aspartate aminotransferase(AST),total bilirubin levels(TBIL),albumin(ALB)]and liver regeneration related cytokines(HGF,IL-6,TNF-ɑ)were detected by enzyme linked immunosorbent assay(ELISA).The expression of cell proliferating nuclear antigen(Ki-67)and phosphorylated histone H3(pH3)were detected by immunohistochemistry and the positive rate was calculated.Results The FLR weight to body weight(RML/BW)ratio of PVL+PLP group was significantly lower than that of ALPPS group[postoperative 3 d,(1.7±0.1)%vs.(2.2±0.3)%,t=4.042,P<0.01],but higher than that of PVL group[postoperative 3 d,(1.7±0.1)%vs.(1.5±0.2)%,t=2.740,P<0.05].The RML/BW ratio of PVL+PLL group was significantly lower than those in both of ALPPS[postoperative 3 d,(1.4±0.1)%vs.(2.2±0.3)%,t=4.969,P<0.01]and PVL+PLP group[postoperative 3 d,(1.4±0.1)%vs.(1.7±0.1)%,t=2.064,P<0.05].There was no significant difference in the cytokine levels among groups of PVL combined with liver parenchyma splitting and radiofrequency ablation in the first 7 days after operation.Liver split could further increase portal vein pressure of FLR after PVL[before splitting:(16.2±4.3)cmH_(2)O vs.after splitting:(19.7±2.6)cmH_(2)O,t=4.282,P<0.01].Conclusion Liver parenchyma splitting may accelerate liver regeneration by increasing the portal vein pressure of FLR in PVL rats,rather than by promoting the release of growth factors.