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Following a heterotopic auxiliary liver transplantation, commonly used measurements are either invasive or non-indicative of individual viability of the coexisting engrafted and native livers. Magnetic resonance imaging (MRI) was therefore tested for its potential to monitor the post-transplant hepatic viability in a rat model. Thirteen Wistar rats were systematically evaluated with MRI and serum biochemical liver parameters. Post-transplant complications and the causes of animal death were identified by autopsy and histo-pathological examinations. The data of the healthy survivors were compared with those of the rats that developed complications. On MRI, the hepatic complications could be depicted in the individual livers. A specific pattern of signal evolution was found in the livers of the healthy survivors: the mean T1 relaxation times of the engrafted livers increased immediately after transplantation (476 +/- 64 ms, mean +/- standard deviation, pre-operative; 730 +/- 48 ms, week 1) and then declined steadily to a 3 month value of 489 +/- 246 ms, while, following a transient first rise (476 +/- 64 ms, pre-operative; 589 +/- 28 ms, week 1), the mean T1 value of the native livers increased again 4 weeks after surgery and reached a 3 month value of 859 +/- 43 ms. However, in the rats with various complications, the mean T1 relaxation times of the engrafted livers continued to increase throughout the first post-operative month (760 +/- 48 ms, week 1; 922 +/- 76 ms, week 4), while that of the native liver only varied mildly (546 +/- 25 ms, week 1; 473 +/- 25 ms, week 4). After the first post-transplant week, the healthy engrafted livers could already be distinguished from those with complications by a significant decrease in T1 relaxation times. These data suggest that, besides demonstrating major complications, MRI may allow one to monitor the viability of each liver by analysing the relative signal intensity and T1 relaxation times after a heterotopic auxiliary liver transplantation., (Copyright 2001 John Wiley & Sons, Ltd.)

In the rat model of heterotopic auxiliary liver transplantation, graft re-arterialization may influence the outcome of inter-liver competition. This was investigated in the current study using two transplanted groups with or without graft re-arterialization. Immediately after reperfusion, the re-arterialized grafts showed significantly higher bile flow rate and bilirubin excretion than the grafts without re-arterialization. DNA synthesis rate was also increased more drastically in the re-arterialized group following the transplantation. Without re-arterialization, the rats developed more pronounced cytolysis and cholestasis. Among the long-term survivors, all healthy re-arterialized grafts regenerated, whereas 5/6 non-re-arterialized grafts atrophied. These data demonstrate that the re-arterialization increases graft survival by improving early hepatic function, enhancing regenerative response and preventing post-transplant biliary complications in this rat model., (Copyright 2000 S. Karger AG, Basel)

In the rat model of heterotopic auxiliary liver transplantation, the coexistence of the engrafted liver and the recipient's native liver makes it difficult to evaluate the posttransplant graft viability. In this study, auxiliary liver transplantation was performed in Wistar rats, in which the recipient's native liver was handicapped with a 68% partial hepatectomy and a common bile duct ligation. Serum biochemistry of the liver was analyzed and compared with that of the selected control group. The surgical handicap of the liver showed severe damaging effects: the handicapped native livers appeared atrophic at autopsy, and no long-term animal survival could be achieved without an auxiliary liver transplantation. As the engrafted liver corrected the cholestasis of the handicapped native liver, significant differences of serum biochemistry were found between the transplanted group and the control group: for bilirubin concentration and gamma glutamyl transferase activity from postoperative day 3 to 28 (p < .05); for alkaline phosphatase on days 3, 7, 14, and 28 (p < .05); for alanine aminotransferase activity on days 3 and 14 (p < .05); and for aspartate aminotransferase activity on day 14 (p < .05). The efficiency to induce hepatic failure and to hamper its regeneration capacity in the native liver makes animal survival and liver biology as reliable parameters to evaluate the posttransplant graft viability in this rat model.

In the rat model of heterotopic auxiliary liver transplantation (HALTx), the opinion varies on whether and how the recipient's native liver should be handicapped. To avoid atrophy of the transplanted organ, in this study, two different handicaps were evaluated and their effects on post-operative animal survival and liver biology are described. With a sole portacaval shunt (group 1) all rats survived longer than 3 months. An additional handicap of the liver with either a 68% partial hepatectomy (68% PH) (group 2), or both a 68% PH and a common bile duct ligation (CBDL) (group 3) led to a 100% mortality within 2 days after surgery. When an auxiliary liver was transplanted to the rats handicapped with a 68% PH (group 4), serum Bilirubin and ALAT values were significantly lower than those handicapped with both a 68% PH and a CBDL (group 5). Autopsy and histology of the long-term survivors revealed the atrophy of the engrafted livers and the regeneration of the native livers in group 4, whereas it showed the opposite in group 5. Thus the various manipulations of the native liver do influence differently the post-transplant animal survival, serum liver biochemistry and the outcome of the engrafted liver in this rat model of HALTx.

Although arterialisation of the portal vein has long been used in various surgical situations including treating patients with liver cirrhosis, hepatobiliary malignancy, and more recently in liver transplantation, the venous nature of the portal supply is considered essential to preserve hepatic integrity. Ninety-six Lewis rats were randomly assigned to four groups of twenty-four rats each. A standard 68% partial hepatectomy was performed in the rats of all groups to induce liver groups of twenty-four rats each. A standard 68% partial hepatectomy was performed in the rats of all groups to induce liver regeneration. Group 1 served as the control.