[Experimental study on mechanism of graft injury of small-for-size liver transplantation in miniature pigs].

OBJECTIVE

To elucidate the mechanisms of graft injury in small-for-size liver transplantation.

METHODS

Animal models were established with skeletonized and denervated anatomic parahepatic dissection, hepatectomy and perfusion in situ. Chinese Bama miniature pigs were divided into three groups (n = 5): Group A, liver transplantation; Group B, partial liver transplantation with right hemi-liver graft and Group C, liver transplantation with right median and caudate lobe graft. Animals were followed for 7 days with regards to survival, dynamical portal venous pressure (PVP), portal blood flow (PBF) and graft histopathological examination.

RESULTS

Animal survivals were as follows: Group A, 5/5, Group B, 5/5 and Group C, 1/5. PVP rose immediately after reperfusion. PVP in Group C peaked to 28.6 +/- 2.07 mm Hg. Portal blood flow (PBF) measured by CDFI showed that the index of PBF per gram liver tissue reached 3.56 +/- 0.11 ml x min(-1) x g(-1) at the first hour post-reperfusion in Group C. Hepatic morphological examination showed that severe pathological changes occurred in small-for-size grafts, including sinusoidal congestion, hemorrhage, hepatocytic ballooning change or necrosis, endothelial cell detachment, Disse's space widening or vanishing and significant apoptosis.

CONCLUSION

Portal over perfusion and acute portal hypertension are the primary etiological mechanisms of graft injury in small-for-size liver transplantation.