Glasgow Coma Score and Tumor Necrosis Factor α as Predictive Criteria for Initial Poor Graft Function

Intensive care management of liver transplant recipients

PURPOSE OF REVIEW

Liver transplantation remains the only definitive treatment for advanced liver disease and liver failure. Current allocation schemes utilized for liver transplantation mandate a 'sickest first' approach, thus most liver transplants occur in patients with severe systemic illness. For intensive care providers who care for liver transplant recipients, a foundation of knowledge of technical considerations of orthotopic liver transplantation, basic management considerations, and common complications is essential. This review highlights the authors' approach to intensive care management of the postoperative liver transplant recipient with a review of common issues, which arise in this patient population.

RECENT FINDINGS

The number of centers offering liver transplantation continues to increase globally and the number of patients receiving liver transplantation also continues to increase. The number of patients with advanced liver disease far outpaces organ availability and, therefore, patients undergoing liver transplant are sicker at the time of transplant. Outcomes for liver transplant patients continue to improve owing to advancements in surgical technique, immunosuppression management, and intensive care management of liver disease both pretransplant and posttransplant.

SUMMARY

Given a global increase in liver transplantation, an increasing number of intensive care professionals are likely to care for this patient population. For these providers, a foundational knowledge of the common complications and key management considerations is essential.

Transplantation of Extended Criteria Donor Livers Following Continuous Normothermic Machine Perfusion Without Recooling

BACKGROUND

Traditional liver transplant strategies with cold preservation usually result in ischemia-reperfusion injury (IRI) to the donor liver. Regular normothermic machine perfusion (NMP) donor livers suffer IRI twice. Here, we aimed to introduce a novel technique called continuous NMP without recooling to avoid a second IRI and its application in livers from extended criteria donors.

METHODS

Seven donor livers transplanted following continuous NMP without recooling, 7 donor livers transplanted following standard NMP, and 14 livers under static cold storage (SCS) were included in this study. Perioperative outcomes were recorded and analyzed between groups.

RESULTS

During the NMP without a recooling procedure, all livers cleared lactate quickly to normal levels in a median time of 100 min (interquartile range, 60-180) and remained stable until the end of perfusion. In the NMP without recooling and standard NMP groups, posttransplant peak aspartate aminotransferase and alanine aminotransferase levels were both significantly lower than those in the SCS group (P = 0.0015 and 0.016, respectively). The occurrence rate of early allograft dysfunction was significantly lower in the NMP without recooling group than in the SCS group (P = 0.022), whereas there was no difference in the NMP group with or without recooling (P = 0.462).

CONCLUSIONS

Our pilot study revealed a novel technique designed to avoid secondary IRI. This novel technique is shown to have at least a comparable effect on the standard NMP, although more data are needed to show its superiority in the future.

Graft Dysfunction and Management in Liver Transplantation

Graft dysfunction of the liver allograft manifests across a spectrum in both timing posttransplantation and clinical presentation. This can range from mild transient abnormalities of liver tests to acute liver failure potentially leading to graft failure. The causes of graft dysfunction can be divided into those resulting in early and late graft dysfunction. Although nonspecific, liver biochemistry abnormalities are still the mainstay investigation used in monitoring for dysfunction. This article provides a summary of the main causes and management strategies for liver graft dysfunction in the early through late posttransplant stages.

Concentration of Tumor Necrosis Factor-α and Interleukin-1β in Isolated Porcine Liver Depending on Type of Transgenesis

BACKGROUND

Transgenic animals may serve as organ donors in human organ transplantation. However, the number of the studies addressing all doubts related to this issue is currently insufficient for the clinical application of this approach. The aim of this study was to analyze the hepatic tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) synthesis during a 24-hour cold preservation of the transgenic pig liver, depending on the type of transgenesis.

MATERIALS AND METHODS

The study was carried out on wild-type and transgenic pig livers with transferred human α1,2-fucosyltransferase (FUT) and/or α-galactosidase (GAL) gene (four groups; n = 6). Harvested livers were perfused for 30 minutes and stored for 24 hours in Biolasol (Biochefa) solution at 4°C with a subsequent 30-minute reperfusion (reflush). TNF-α and IL-1β concentrations were analyzed with an enzyme-linked immunosorbent assay. Perfusates were collected during the initial perfusion as well as after 24 hours of preservation and during the reperfusion. Tissue samples were harvested just after animal sacrifice, and after organ perfusion and reperfusion.

RESULTS

A decrease in TNF-α concentration in homogenates was noted after both perfusion and reperfusion in all experimental groups. In contrast, there was a significant decrease in IL-1β concentration in the group with combined human FUT and GAL transgenes. Concurrently, increases in TNF-α and IL-1β concentrations were observed in the reperfusion perfusates in all groups.

CONCLUSION

This study shows that IL-1β is synthesized in the ischemic livers of the transgenic animals with both human α1,2-fucosyltransferase and α-galactosidase transgenes. Further analysis is required to determine the importance of this observation.

Primary graft dysfunction after liver transplantation

BACKGROUND

Primary graft dysfunction (PGD) causes complications in liver transplantation, which result in poor prognosis. Recipients who develop PGD usually experience a longer intensive care unit and hospital stay and have higher mortality and graft loss rates compared with those without graft dysfunction. However, because of the lack of universally accepted definition, early diagnosis of graft dysfunction is difficult. Additionally, numerous factors affect the allograft function after transplantation, making the prediction of PGD more difficult. The present review was to analyze the literature available on PGD and to propose a definition.

DATA SOURCE

A search of PubMed (up to the end of 2012) for English-language articles relevant to PGD was performed to clarify the characteristics, risk factors, and possible treatments or interventions for PGD.

RESULTS

There is no pathological diagnostic standard; many documented definitions of PGD are different. Many factors, such as donor status, procurement and transplant process and recipient illness may affect the function of graft, and ischemia-reperfusion injury is considered the direct cause. Potential managements which are helpful to improve graft function were investigated. Some of them are promising.

CONCLUSIONS

Our analyses suggested that the definition of PGD should include one or more of the following variables: (1) bilirubin ≥ 10 mg/dL on postoperative day 7; (2) international normalized ratio ≥ 1.6 on postoperative day 7; and (3) alanine aminotransferase or aspartate aminotransferase >2000 IU/L within 7 postoperative days. Reducing risk factors may decrease the incidence of PGD. A majority of the recipients could recover from PGD; however, when the graft progresses into primary non-function, the patients need to be treated with re-transplantation.