Competition Between Native Liver and Graft in Auxiliary Liver Transplantation in a Rat Model

[Liver regeneration after resection in clinical and experimental conditions]

The researches devoted to postoperative liver regeneration and influence in this process were analyzed. Liver injury is followed by hypertrophy of residual liver parenchyma. The use of various cytokines is perspective for activation, acceleration and inhibition of liver recovery. Cellular technologies in the treatment of liver diseases can affect its repair. Moreover, these methods could make unnecessary resection and transplantation of liver in certain cases. It is generally accepted that the main effect of multipotent stromal cells (MSC) in liver failure is associated with their differentiation to the cellular elements of this organ. At the same time, recent reports revealed that MSC injection to the liver is followed by their quick death, dissemination to other organs and tissues or even elimination from the organism. Regeneration of non-parenchymal structures (vascular network and bile ducts) should be considered in addition to functional recovery of liver parenchyma after resection. Clarification of indications and contraindications for MSC therapy, as well as prevention of possible complications associated with cellular technologies are required.

Functional liver tissue engineering by an adult mouse liver-derived neuro-glia antigen 2-expressing stem/progenitor population

Deaths due to end-stage liver diseases are increasingly registered annually in the world. Liver transplantation is the ultimate treatment for end-stage liver diseases to date, which has been hampered by a critical shortage of organs. The potential of decellularized liver scaffolds (DLS) derived from solid organs as a three-dimensional platform has been evolved as a promising approach in liver tissue engineering for translating functional liver organ replacements, but questions still exist regarding the optimal cell population for seeding in DLS and the preparation of the DLS themselves. The aim of our study was to utilize a sodium dodecyl sulfate decellularization procedure in combination with a low concentration of trypsin (0.005%)-ethylenediaminetetraacetic acid (0.002%) process to manufacture DLS from whole mouse livers and recellularized with hepatic stem/progenitors for use in liver tissue engineering and injured liver treatment. Results showed that the DLS generated with all the necessary microstructure and the extracellular components to support seeded hepatic stem/progenitor cell attachment, functional hepatic cell differentiation. Hepatic differentiation from stem/progenitor cells loaded by DLS was more efficient than that of the stem/progenitor cells in the two-dimensional cell culture model. In summary, the method of DLS loaded by hepatic stem/progenitor cells provided by this study was effective in maintaining DLS extracellular matrix to introduce seeded stem/progenitor cell differentiation, hepatic-like tissue formation and functional hepatic protein production in vitro that promoted functional recovery and survival in a mouse model of dimethylnitrosamine-induced liver cirrhosis after auxiliary heterotopic liver transplantation. Copyright © 2016 John Wiley & Sons, Ltd.

Regeneration and Cell Recruitment in an Improved Heterotopic Auxiliary Partial Liver Transplantation Model in the Rat

BACKGROUND

Auxiliary partial liver transplantation (APLT) in humans is a therapeutic modality used especially to treat liver failure in children or congenital metabolic disease. Animal models of APLT have helped to explore therapeutic options. Though many groups have suggested improvements, standardizing the surgical procedure has been challenging. Additionally, the question of whether graft livers are reconstituted by recipient-derived cells after transplantation has been controversial. The aim of this study was to improve experimental APLT in rats and to assess cell recruitment in the liver grafts.

METHODS

To inhibit recipient liver regeneration and to promote graft regeneration, we treated recipients with retrorsine and added arterial anastomosis. Using green fluorescence protein transgenic rats as recipients, we examined liver resident cell recruitment within graft livers by immunofluorescence costaining.

RESULTS

In the improved APLT model, we achieved well-regenerated grafts that could maintain regeneration for at least 4 weeks. Regarding the cell recruitment, there was no evidence of recipient-derived hepatocyte, cholangiocyte, or hepatic stellate cell recruitment into the graft. Macrophages/monocytes, however, were consistently recruited into the graft and increased over time, which might be related to inflammatory responses. Very few endothelial cells showed colocalization of markers.

CONCLUSIONS

We have successfully established an improved rat APLT model with arterial anastomosis as a standard technique. Using this model, we have characterized cell recruitment into the regenerating grafts.

Longterm outcomes of auxiliary partial orthotopic liver transplantation in preadolescent children with fulminant hepatic failure

By preserving part of the native liver, auxiliary partial orthotopic liver transplantation (APOLT) provides the advantage of potential immunosuppression (ISP) withdrawal if the native liver recovers but has had limited acceptance, especially in the United States, due to technical complications and low rates of native liver regeneration. No previous study has evaluated APOLT specifically for preadolescent children with fulminant hepatic failure (FHF). This population might benefit especially based on greater capacity for liver regeneration. Data from 13 preadolescent children who underwent APOLT were compared to 13 matched controls who underwent orthotopic liver transplantation (OLT) for FHF from 1996 to 2013. There were no significant differences in patient demographics or survival between the 2 groups. However, all surviving OLT recipients (10/13) remain on ISP, while all but 1 surviving APOLT recipient (12/13) showed native liver regeneration, and the first 10 recipients (76.9%) are currently off ISP with 2 additional patients currently weaning. In our experience, APOLT produced excellent survival and high rates of native liver regeneration in preadolescent children with FHF. This represents the largest series to date to report such outcomes. Liberating these children from lifelong ISP without the downside of increased surgical morbidity makes APOLT an attractive alternative. In conclusion, we therefore propose that, with the availability of technical expertise and with the technical modifications above, APOLT for FHF should be strongly considered for preteenage children with FHF.

Effects of dual arterial blood supply on liver regeneration in the graft and the host following heterotopic auxiliary liver transplantation

This study aimed to investigate the effect of the dual arterial blood supply method used in auxiliary liver transplantation on the regeneration of grafted and host liver. A total of 72 male Sprague-Dawley rats were randomly assigned to three experimental groups, namely the 68% hepatectomy group (group A), the 68% hepatectomy with dual arterial blood supply group (group B) and the auxiliary liver transplantation with dual arterial blood supply group (group C). Group C was further divided into the host liver subgroup (group Ca) and the transplanted liver subgroup (group Cb). Six animals from each group were sacrificed at 1, 2 and 7 days after surgery. The calculation of the liver regeneration rate (LRR) was based on measuring liver weight. Liver function was assessed by measuring serum alanine aminotransferase (ALT) levels. Immunohistochemistry was employed to detect the expression of proliferating cell nuclear antigen (PCNA). Apoptotic changes in the grafts and host livers were evaluated using TUNEL staining. The LRR in each group exhibited a tendency to increase over time. At each time point, the LRR of transplanted livers in group C exhibited no significant difference from that of host livers in group C (P>0.05). The ALT levels for each group exhibited a time-dependent decreasing tendency. The ALT level in group C was significantly higher compared to that in groups A and B at each time point (P<0.05). The expression of PCNA in transplanted and host livers in group C was significantly lower compared to that in groups A and B at the same time point (P<0.001). Although the number of apoptotic cells in each group varied at different time points, there was no statistically significant difference (P>0.05). In auxiliary liver transplantation with the dual arterial blood supply method, the capacity of the liver regeneration in the grafts was similar to that of the host livers. Therefore, this technique may reduce the potential risk of graft liver atrophy caused by functional competition.

A modified heterotopic auxiliary living donor liver transplantation: report of a case

Liver transplantation is regarded as an effective treatment for Wilson's disease (WD), and recently has been shown to improve not only hepatic but also neurologic manifestations. Conventional auxiliary liver transplantation for WD is orthotopic liver transplantation and heterotopic liver transplantation. But the conventional procedure could not avoid the problem of space, functional competition, hemodynamic variation. Here we report a case of heterotopic auxiliary living-donor liver transplantation (HALDLT) to treat WD. We modified the operation to have a splenectomy, implant graft into the splenic fossa. The patient recovered well after the transplantation and has been symptom-free during a 5-year follow-up. This modified operation is more safe and simple. HALDLT might be an effective treatment for WD patients with splenomegaly.

Development of a new auxiliary heterotopic partial liver transplantation technique using a liver cirrhosis model in minipigs: Preliminary report of eight transplants

This study aimed to develop a new auxiliary heterotopic partial liver transplantation (AHPLT) technique in minipigs using a model of liver cirrhosis. Based on our previous study, 14 minipigs were induced to cirrhosis by administration of carbon tetrachloride (CCl(4)) through intraperitoneal injection. All of the cirrhotic animals were utilized as recipients. The donor's liver was placed on the recipient's splenic bed, and the anastomosis was performed as follows: end-to-end anastomosis between the donor's portal vein and the recipient's splenic vein, end-to-side anastomosis between the donor's suprahepatic vena cava and the recipient's suprahepatic vena cava, and end-to-end anastomosis between the donor's hepatic artery and the recipient's splenic artery. The common bile duct of the donor was intubated and bile was collected with an extracorporeal bag. Vital signs, portal vein pressure (PVP), hepatic venous pressure (HVP) and portal vein pressure gradient (PVPG) were monitored throughout the transplantation. All 8 minipigs that developed liver cirrhosis were utilized to establish the new AHPLT; 7 cases survived. Following the surgical intervention, the PVP and PVPG of the recipients were lower than those prior to the operation (P<0.05), whereas the PVP and PVPG of the donors increased significantly compared to those of the normal animals (P<0.05). A new operative technique for AHPLT has been successfully described herein using a model of liver cirrhosis.

Feasibility of orthotopic fetal liver transplantation: an experimental study

BACKGROUND

The use of livers from nonviable fetuses is particularly attractive for its potential to solve the current limitations of organ availability for the pediatric recipient. Therefore, it is essential to study the feasibility of orthotopic fetal liver transplantation.

METHOD

We measured the hepatic and extra-hepatic anatomical structures of fetal and neonatal lambs and established an orthotopic liver transplantation model of the fetal lamb.

RESULTS

Mean weight of the liver of fetal lambs at 142 to 145 days gestation was 34.75 g and the mean diameter of the portal vein was 3.03 mm, the supra-hepatic vena cava was 5.88 mm, and the infra-hepatic vena cava was 4.00 mm, which matched the corresponding sizes in neonatal lambs aged up to 2 weeks. Using standard surgical procedures we completed the vascular inosculation of fetal liver. However, all the newborn lamb recipients survived less than 24 hours.

CONCLUSIONS

Orthotopic transplantation of the fetal liver is anatomically and technically feasible. However, perioperative issues need to be resolved prior to clinical application.

A better way to do small-for-size liver transplantation in rats

Establishing a model for small-for-size liver transplantation is the basis for this study of partial and living donor graft liver transplantation. This study aims to explore a simpler and more effective way of establishing a 30% small-for-size liver transplantation in rats. Sprague-Dawley rats were selected as the donors and recipients. Small-for-size orthotopic liver transplantation was performed using Kamada's two-cuff method. The donor's liver was flushed via the abdominal aorta and hepatectomy was performed in situ. The animals were divided into three groups depending on the graft selected, with 40 pairs of rats in each group. In group I, the median lobe of the liver was used as graft; in group II, the right half of the median lobe and the right lobe were used as graft; and in group III, the median and right lobes were used as graft. In groups I and II, the bodyweights of donors were the same as those of recipients; however, in group III the bodyweights of donors were 100-120 g less than those of the recipients. The duration needed for transplantation, the 7-day survival rates, and the technical complication rates were compared among these three groups. The time required for hepatectomy was shorter in group III compared with groups I and II (8.8±0.7 min vs. 11.5±1.1 min and 10.1±1.0 min, P = 0.001). The cold ischemia time for the grafts, the anhepatic times, and the transplantation times for the recipients were not significantly different among the three groups. Compared with groups I and II, the incidence of bleeding, bile leakage, and inferior vena caval strictures were significantly decreased in group III (P<0.05). No significant differences between the three groups were found based on other complications after the operation (P>0.05). Group III had better 7-day survival rates and longer median survival times but the differences were not statistically significant. The method of small for donor bodyweight using the median and right lobes for grafting may be a more effective and simpler way of establishing a 30% small-for-size liver transplantation in rats, as shown by the shorter hepatectomy time and the occurrence of fewer complications after the operation.