Objective To introduce the mechanisms of graft injuries after small-for-size liver transplantation and protective measures. Methods Recently relevant literatures were reviewed and summarized. Results Portal hypertension after small-for-size liver transplantation induces mechanical injuries as well as hepatic sinusoidal microcirculation disturbance and cytokines release, which worsened the injuries. Decrease portal pressure by surgery or drug could improve grafts function. ConclusionComprehending the mechanisms of graft injuries will contribute a lot for the living donor liver transplantation.
Objective To investigate the effects of adenosine 2A receptor (A2AR) activation on oxidative stress in small-forsize liver transplantation. Methods A rat orthotopic liver transplantation model was performed using 40% graft, 18 recipients were given intravenously saline (control group), CGS21680 (A2AR agonist, CGS21680 group) or ZM241385 (A2AR antagonist, CGS21680+ZM241385 group) randomly. Aspartate aminotransferase (AST), enzymatic antioxidants 〔superoxide dismutase (SOD); catalase (CAT); glutathione peroxidase (GSH-Px)〕, non-enzymatic antioxidants 〔ascorbic acid (AA); glutathione (GSH); α-tocopherol (TOC)〕 and lipid oxidant metabolites malondialdehyde (MDA) were measured and analyzed at 6 h after reperfusion. Results Compared with the control group and CGS21680+ZM241385 group, A2AR activation increased the activities of SOD and GSHPx (Plt;0.05), reduced the productions of AST and MDA (Plt;0.05), increased the levels of AA, GSH and TOC (Plt;0.05) in CGS21680 group. But there was no significant change in CAT activity (Pgt;0.05) among 3 groups. Conclusions A2AR activation improves the antioxidant enzyme activities, promotes the production of antioxidants, and slowes down the increase in MDA level, depresses of the increase in AST activity. A2AR activation suppresses oxidative damage and increases the antioxidant capacity which in turn minimizes their harmful effects of ischemia-reperfusion in small-for-size liver transplantation.
Objective To establish and modify a rat model of arterialized small-for-size orthotopic liver transplantation and investigate the histopathologic changes of the grafts after transplantation. Methods Modified two-cuff technique was applied to establish a rat model of 40% small-for-size orthotopic liver transplantation with a modified microvascular “sleeve” anastomosis between the celiac trunk of donors and the stump of right kidney artery of recipients. Seven days survival rate was observed, main indices of liver function, histopathologic changes of the grafts were detected on the 1st, 2nd, 4th and 7th day after transplantation, respectively. Results The successful rate of operation was 93.3%. Seven days survival rate was 60.0%. The mean time of nonhepatic time was (12.0±2.5) min. Alanine aminotransferase (ALT) and total bilirubin (TB) began to elevate on the first day and peaked on the second day after operation. Histological findings indicated that hepatic sinusoidal and central vein dilation, monocytes infiltration in partial area were found on the 1st day after operation, more diploid and polyploid hepatocytes could be observed on the 4th day after operation. Conclusion The model is easily available and highly reproducible, and the stability of the model is improved by modifying the technique. The histological changes of the grafts are mainly caused by ischemia-reperfusion injury.
Objective To investigate the significance of hepatic arterial reconstruction on the model of 40% small-for-size orthotopic liver transplantation in rats. Methods Modified two-cuff technique was applied to establish a rat model of 40% orthotopic liver transplantation. A total of 240 Sprague Dawley (SD) rats were randomly divided into 2 groups: reconstructive artery group and non-reconstructive artery group. One week survival rate was observed. Main indexes of liver function, histology and the expression of proliferative cell nuclear antigen (PCNA) of liver graft （by immunohistochemical method） were detected on day 1, 2, 4 and 7 after transplantation, respectively. Results One week survival rates of reconstructive artery group and non-reconstructive artery group were 65.0% (13/20) and 50.0% (10/20) respectively (Pgt;0.05). Alanine aminotransferase (ALT) and total bilirubin (TB) began to elevate from day 1 and peaked on day 2 after surgery in two groups. ALT in non-reconstructive artery group on day 2 and 4 were significantly higher than that in reconstructive artery group (P＜0.05). TB in non-reconstructive artery group on day 2 and 7 were significantly higher than that in reconstructive artery group (P＜0.05). Histological findings indicated that more diploid and polyploid hepatocytes and more gently dilation of central veins and hepatic sinusoids could be seen postoperatively in reconstructive artery group. The expression of PCNA of liver graft peaked on day 2 after surgery. The expression of PCNA of reconstructive artery group was higher on day 1 (P＜0.01) and lower on day 7 than that of non-reconstructive artery group after operation (P＜0.05). Conclusions Arterial reconstruction can improve liver function of liver grafts after small-for-size orthotopic liver transplantation, alleviate the histological changes and promote the regeneration of liver grafts quickly.