A simple scoring system to evaluate the effects of cold ischemia on marginal liver donors

Liver Transplantation for Primary Sclerosing Cholangitis (PSC) With or Without Inflammatory Bowel Disease (IBD)-A European Society of Organ Transplantation (ESOT) Consensus Statement

Primary sclerosing cholangitis (PSC) is the classical hepatobiliary manifestation of inflammatory bowel disease (IBD) and a lead indication for liver transplantation (LT) in the western world. In this article, we present a Consensus Statement on LT practice, developed by a dedicated Guidelines' Taskforce of the European Society of Organ Transplantation (ESOT). The overarching goal is to provide practical guidance on commonly debated topics, including indications and timing of LT, management of bile duct stenosis in patients on the transplant waiting list, technical aspects of transplantation, immunosuppressive strategies post-transplant, timing and extension of intestinal resection and futility criteria for re-transplantation.

Consequences of Changes in the Liver Allocation System for Transplantation in the Silesian Voivodeship and in the Transplantation Center in Katowice

BACKGROUND

For a number of years, the system of procured livers for transplantation by transplant centers in a fixed order, regardless of the location of the procurement site, was in force in Poland. In mid-2018, priority was introduced in the collection of livers by a team from a given province. The aim of the study was to evaluate the impact of changing the liver transplantation allocation system at the Katowice Transplant Center (KTW) on the number of transplanted livers and on the selected parameters of donors from which the liver was procured.

METHODS

The rates and cold ischemia time (CIT) of procured livers were analyzed.

RESULTS

The rate of livers procured by the KTW transplant team increased from 36.6% to 53.3%, and at the same time the rate of livers procured by this team and sent for transplantation in other transplant centers increased. The rate of livers transplanted in the KTW, which were procured in the Silesian Voivodeship, increased from 37.4% to 61.0%, and the rate of livers procured outside the Silesian Voivodeship decreased from 54.8% to 36.4%. The CIT of livers transplanted in the KTW was reduced from 407.5 to 360.0 minutes. The comparative analysis of donor parameters of livers procured by the KTW transplant team and transplanted in Katowice revealed no differences regarding analyzed clinical and biochemical parameters.

CONCLUSION

The change in the allocation system increased the number of livers procured by the local team and shortened CIT of livers transplanted at the KTW.

Combination of Early Allograft Dysfunction and Protein Expression Patterns Predicts Outcome of Liver Transplantation From Donation After Cardiac Death

Early allograft dysfunction (EAD) after liver transplantation (LT) accompanies poor prognosis. This study aims to explore the relationship between pretransplant intrahepatic proteins and the incidence of EAD, and the value of combined EAD and protein profiles for predicting recipient and graft survival prognosis. Liver biopsy specimens of 105 pretransplant grafts used for LT were collected and used for immunohistochemistry analysis of 5 proteins. And matched clinical data of donor, recipient, transplantation, and prognosis were analyzed. The incidence of EAD was 41.9% (44/105) in this cohort. Macrovesicular steatosis (P = 0.016), donor body mass index (P = 0.013), recipients' pretransplant serum creatinine (P = 0.036), and intrahepatic expression of heme oxygenase 1 (HO1) (P = 0.015) and tumor necrosis factor α (TNF-α) (P = 0.039) were independent predictors of EAD. Inferior graft and recipient prognosis were observed in patients who experienced EAD (P = 0.028 and 0.031) or received grafts with higher expression of sirtuin 1 (P = 0.005 and 0.013). The graft and recipient survival were worst in patients with both EAD and high expression of sirtuin 1 (P = 0.001 and 0.004). In conclusion, pretransplant intrahepatic expression of HO1 and TNF-α are associated with the incidence of EAD. The combination of EAD and EAD-unrelated proteins showed superiority in distinguishing recipients with worse prognosis.

How to Handle Arterial Conduits in Liver Transplantation? Evidence From the First Multicenter Risk Analysis

OBJECTIVE

The aims of the present study were to identify independent risk factors for conduit occlusion, compare outcomes of different AC placement sites, and investigate whether postoperative platelet antiaggregation is protective.

BACKGROUND

Arterial conduits (AC) in liver transplantation (LT) offer an effective rescue option when regular arterial graft revascularization is not feasible. However, the role of the conduit placement site and postoperative antiaggregation is insufficiently answered in the literature.

STUDY DESIGN

This is an international, multicenter cohort study of adult deceased donor LT requiring AC. The study included 14 LT centers and covered the period from January 2007 to December 2016. Primary endpoint was arterial occlusion/patency. Secondary endpoints included intra- and perioperative outcomes and graft and patient survival.

RESULTS

The cohort was composed of 565 LT. Infrarenal aortic placement was performed in 77% of ACs whereas supraceliac placement in 20%. Early occlusion (≤30 days) occurred in 8% of cases. Primary patency was equivalent for supraceliac, infrarenal, and iliac conduits. Multivariate analysis identified donor age >40 years, coronary artery bypass, and no aspirin after LT as independent risk factors for early occlusion. Postoperative antiaggregation regimen differed among centers and was given in 49% of cases. Graft survival was significantly superior for patients receiving aggregation inhibitors after LT.

CONCLUSION

When AC is required for rescue graft revascularization, the conduit placement site seems to be negligible and should follow the surgeon's preference. In this high-risk group, the study supports the concept of postoperative antiaggregation in LT requiring AC.

Double-lobectomy in a steatotic liver transplantation rat model

Establishing a steatotic liver transplantation animal model can be a challenging process, which requires complex microsurgical technologies. The present study established a novel rat model of stable steatotic liver transplantation for marginal liver graft research, which notably minimized the number of animals used for the experiment. Briefly, male Sprague-Dawley rats (n=90) were fed with a high-fat diet (HFD; 60%, kJ) or standard chow diet (SCD) for 8 weeks. The liver enzymes and lipid levels were assessed every week, and the degree of steatosis was determined via hematoxylin and eosin and Oil Red O staining. The results demonstrated that there were no significant differences in alanine aminotransaminase and aspartate aminotransferase levels between the SCD and HFD groups (P>0.05), whereas the level of plasma triglyceride (TG) increased by 1.76-fold in the HFD group at week 2, and progressively decreased to baseline levels by week 8. Significantly higher levels of TG were observed in the HFD group compared with the SCD group at week 2 (P<0.05). In addition, the levels of plasma glucose (P<0.05), portal insulin (P<0.05) and content of liver lipid (P<0.01) increased in the HFD group compared with the SCD group. After 6 weeks, the liver steatosis was successfully formed and stable. Consequently, a rat liver developed hepatic macrovesicular steatosis >60%, which was subsequently used for transplantation after double-lobectomy. Post-transplantation survival rates in the HFD and SCD groups were as follows: Week 1, 80 vs. 100% and 1 month, 20 vs. 100%. A total of 20 rats were not sacrificed by performing double-lobectomy for biopsy. Taken together, the results of the present study suggest that rat liver double-lobectomy may be safely applied in steatotic liver transplantation without the need to sacrifice a large number of animals.

Contrast-enhanced ultrasonography to evaluate risk factors for short-term and long-term outcomes after liver transplantation: A pilot prospective study

PURPOSE

To evaluate whether Doppler ultrasonography (DUS) and contrast-enhanced ultrasonography (CEUS) can identify liver donation after brain death (DBD) and cardiac death (DCD) with the risk of developing short-term primary graft dysfunction (PGD) or arterial and biliary complications within 1 year.

MATERIALS AND METHODS

Consecutive DBD and DCD donors who underwent DUS/CEUS examinations before surgical procurement from February 2016 to June 2018 at our institution were included. The US and CEUS images of each donor liver were analysed, and the parameters were recorded.

RESULTS

The mean time for US examination was 32 min (range, 20-59 min), and all donors tolerated the examination well. In terms of short-term outcomes, among the 52 eligible donor livers, 20 (38.5 %) of their recipients developed PGD. The multivariable analysis showed that decreased enhancement of donor livers on CEUS (OR = 15.976, 95 % CI: 1.652-154.628, P = 0.017) and high recipient model for end-stage liver disease (MELD) scores (OR = 1.050, 95 % CI: 1.004-1.099, P = 0.034) before liver transplantation (LT) were independent factors of PGD. In contrast, for long-term complications, among the 48 eligible donor livers, 16 (33.3 %) developed arterial or biliary complications within 1 year. The multivariable analysis did not show any independent factors of arterial or biliary complications within 1 year.

CONCLUSIONS

A decrease in enhancement on CEUS is an independent risk factor for poor short-term outcomes of LT. CEUS may be promising for predicting post-LT outcomes of critically ill donors effectively and safely by evaluating the haemodynamic changes in DBD and DCD donor livers.

Impact of donor sodium levels on clinical outcomes in liver transplant recipients: a systematic review

We performed a systematic review of the literature to examine the effects of donor sodium levels on liver graft function and recipient survival, as well as to identify the optimal serum sodium target in donors. We searched MEDLINE, Cochrane, and trial registries from 1946 to May 2019 for studies that evaluated the effect of serum sodium levels in neurologically deceased liver donors on transplant outcomes. We used a two-step review process with four independent reviewers to identify relevant articles based on inclusion/exclusion criteria. We summarize the results narratively, assess the risk of bias, and apply the Grading of Recommendations Assessment, Development, and Evaluation methods to evaluate the certainty in the evidence. We included 25 cohort studies were in our final analysis (total n = 19 389). Twenty-two reported on graft function and survival. Summary data suggest an association between donor serum sodium and recipient liver graft dysfunction, with very low certainty in evidence due to serious concerns with risk of bias, inconsistency, indirectness, and imprecision. Seven studies reported on recipient mortality, with results suggesting no association between donor sodium and recipient survival. The certainty in evidence for this outcome was also very low due to serious concerns with imprecision, indirectness, and risk of bias. Donor sodium dysregulation is associated with liver graft dysfunction, but not recipient mortality. Further research is needed to determine the effects of correcting donor sodium levels on transplant outcomes, quantify the dose-response curve, and identify liver recipients most vulnerable to sodium dysregulation.

Liver transplantation and aging

An increase in the average life expectancy, paralleled by a demographic shift in the population with end-stage liver disease lies behind the rising demand for liver transplantation (LT) among the elderly. Some of the most common indications for LT including hepatocellular carcinoma, alcohol-related liver disease, chronic hepatitis C and non-alcoholic fatty liver disease tend to affect older patients. Transplant professionals are faced with an increasing demand for LT among elderly patients in an age of organ shortage and it is important that risk and benefits are carefully weighed in order to achieve the optimum use of precious liver grafts.

The Role of Ischemia/Reperfusion Injury in Early Hepatic Allograft Dysfunction

Liver transplantation (LT) is the only available curative treatment for patients with end-stage liver disease. Early allograft dysfunction (EAD) is a life-threatening complication of LT and is thought to be mediated in large part through ischemia/reperfusion injury (IRI). However, the underlying mechanisms linking IRI and EAD after LT are poorly understood. Most previous studies focused on the clinical features of EAD, but basic research on the underlying mechanisms is insufficient, due, in part, to a lack of suitable animal models of EAD. There is still no consensus on definition of EAD, which hampers comparative analysis of data from different LT centers. IRI is considered as an important risk factor of EAD, which can induce both damage and adaptive responses in liver grafts. IRI and EAD are closely linked and share several common pathways. However, the underlying mechanisms remain largely unclear. Therapeutic interventions against EAD through the amelioration of IRI is a promising strategy, but most approaches are still in preclinical stages. To further study the mechanisms of EAD and promote collaborations between LT centers, optimized animal models and unified definitions of EAD are urgently needed. Because IRI and EAD are closely linked, more attention should be paid to the underlying mechanisms and the fundamental relationship between them. Ischemia/reperfusion-induced adaptive responses may play a crucial role in the prevention of EAD, and more preclinical studies and clinical trials are urgently needed to address the current limitation of available therapeutic interventions.

Implications of liver donor age on ischemia reperfusion injury and clinical outcomes

The aging process causes detrimental changes in a variety of organ systems. These changes include: lesser ability to cope with stress, impaired repair mechanisms and decreased cellular functional reserve capacity. Not surprisingly, aging has been associated with increased susceptibility of donor heart and kidneys grafts to ischemia reperfusion injury (IRI). In the context of liver transplantation, however, the effect of donor age seems to be less influential in predisposing the graft to IRI. In fact, a widely comprehensive understanding of IRI in the aged liver has yet to be agreed upon in the literature. Nevertheless, there have been many reported implications of increased liver donor age with poor clinical outcomes besides IRI. These other poor outcomes include: earlier HCV recurrence, increased rates of acute rejection and greater resistance to tolerance induction. While these other correlations have been identified, it is important to re-emphasize the fact that a unified consensus in regard to liver donor age and IRI has not yet been reached among researchers in this field. Many researchers have even demonstrated that the extent of IRI in aged livers can be ameliorated by careful donor selection, strict allocation or novel therapeutic modalities to decrease IRI. Thus, the goals of this review paper are twofold: 1) To delineate and summarize the conflicting data in regard to liver donor age and IRI. 2) Suggest that careful donor selection, appropriate allocation and strategic effort to minimize IRI can reduce the frequency of a variety of poor outcomes with aged liver donations.

Impact of nighttime procedures on outcomes after liver transplantation

Background

Sleep deprivation is a well-known risk factor for the performance of medical professionals. Solid organ transplantation (especially orthotopic liver transplantation (oLT)) appears to be vulnerable since it combines technically challenging operative procedures with an often unpredictable start time, frequently during the night. Aim of this study was to analyze whether night time oLT has an impact on one-year graft and patient survival.

Material and methods

Deceased donor oLTs between 2006 and 2017 were retrospectively analyzed and stratified for recipients with a start time at day (8 a.m. and 6 p.m.) or at night (6 p.m. to 8 a.m.). We examined donor as well as recipient demographics and primary outcome measure was one-year patient and graft survival.

Results

350 oLTs were conducted in the study period, 154 (44%) during daytime and 196 (56%) during nighttime. Donor and recipient variables were comparable. One-year patient survival (daytime 75.3% vs nighttime 76.5%, p = 0.85) as well as graft survival (daytime 69.5% vs nighttime 73.5%, p = 0.46) were similar between the two groups. Frequencies of reoperation (daytime 53.2% vs nighttime 55.1%, p = 0.74) were also not significantly different.

Conclusion

Our retrospective single center data derived from a German transplant center within the Eurotransplant region provides evidence that oLT is a safe procedure irrespective of the starting time. Our data demonstrate that compared to daytime surgery nighttime liver transplantation is not associated with a greater risk of surgical complications. In addition, one-year graft and patient survival do not display inferior results in patients undergoing nighttime transplantation.

The Impact of Steatosis on the Outcome of Liver Transplantation: A Meta-Analysis

Background and Aims

Liver transplantation is one of the most effective treatments for end-stage liver disease as well as for cases of acute liver failure. Facing organ donor shortage, liver transplant teams had to use marginal organs. Thus, increasing availability is a key concern of donor liver grafts including steatotic livers. However, the use of steatotic liver is still controversial. The aim of this systematic review and meta-analysis was to analyze the impact of steatosis on the outcome of liver transplantation.

Methods

We searched PubMed, Cochrane Library, Embase, Web of knowledge, and so on for studies published through May 31, 2018, in which patients experienced liver transplantation using fatty liver. All studies extracted outcome indicators, and we draw conclusions by contrasting outcome indicators in different groups of steatosis. Odds ratios and 95% confidence intervals were calculated. P<0.05 was considered as statistically significant difference.

Results

19 publications were included. There was no significant difference between the group of no steatosis and mild group in primary nonfunction rate (P=0.605) or early graft dysfunction rate (P=0.44). The PNF rate was significantly higher in moderate group (P=0.003) and severe group (P <0.001) compared with that in no steatosis group. The same results were seen in early graft dysfunction rate. However, graft survival rate and patient survival rate did not differ between groups.

Conclusions

Livers with mild steatosis, even with moderate or severe steatosis, could be suitable donor under strict control of transplant conditions.

Evaluation of Graft Effluent High Mobility Group Box-1 (HMGB-1) for Prediction of Outcome After Liver Transplantation

BACKGROUND Pre-transplant assessment of the graft for liver transplantation is crucial. Based on experimental data, this study was designed to assess both nuclear high mobility group box-1 (HMGB-1) protein and arginine-specific proteolytic activity (ASPA) in the graft effluent. MATERIAL AND METHODS In a non-interventional trial, both HMGB-1 and ASPA were measured in the effluent of 30 liver grafts after cold storage before transplantation. Values of HMGB-1 and ASPA levels were compared with established prognostic parameters such as the donor risk index, balance of risk score, and Donor-Model for End-Stage Liver Disease. RESULTS The early allograft dysfunction (EAD) was best predicted by recipient age (p=0.026) and HMGB-1 (p=0.031). HMGB -1 thresholds indicated the likelihood for initial non-function (1608 ng/ml, p=0.004) and EAD (580 ng/ml, p=0.017). The multivariate binary regression analysis showed a 21-fold higher (95% CI: 1.6-284.5, p=0.022) risk for EAD in cases with levels exceeding 580 ng/ml. The ASPA was lower in cases of initial non-function (p=0.028) but did not correlate with the rate of EAD (p=0.4). CONCLUSIONS This study demonstrates the feasibility of HMGB-1 detection in the graft effluent after cold storage. Along with conventional prognostic scores, it may be helpful to predict the early fate of a graft in human liver transplantation.

Hepatic artery occlusion in liver transplantation: What counts more, the type of reconstruction or the severity of the recipient's disease?

Although the type of hepatic artery revascularization technique is known to have an impact on patency rates, independent perioperative risk factors on patient outcomes are poorly defined. All consecutive adult patients undergoing cadaveric liver transplantation (n = 361) from July 2007 to June 2016 in a single institution were analyzed. Primary outcomes were early (<30 days) hepatic artery occlusion and primary hepatic artery patency rate. A multivariate model was used to identify independent risk factors for occlusion and the need of arterial conduit, as well as their impact on graft and patient survival. Arterial revascularization without additional reconstruction (end-to-end arterial anastomosis [AA]) was performed in 77% (n = 279), arterial reconstruction (AR) in 15% (n = 53), and aortohepatic conduit (AHC) in 8% (n = 29) of patients. AHC had the highest mean intraoperative flow (275 mL/minute; P = 0.02) compared with AA (250 mL/minute) and AR (200 mL/minute; P = 0.02). There were 43 recipients (12%) who had an occlusive event with successful revascularization in 20 (47%) recipients. One-year primary patency rates of AA, AR, and AHC were 97%, 88%, and 74%, respectively. Aortic calcification had an impact on early occlusion. AR (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.26-10.75; P = 0.02) and AHC (OR, 6.21; 95% CI, 2.02-18.87; P = 0.001) were independent risk factors for early occlusion. Dyslipidemia additionally independently contributed to early occlusion (OR, 2.74; 95% CI, 0.96-7.87; P = 0.06). The 1- and 5-year graft survival rates were 83% and 70% for AA, 75% and 69% for AR, and 59% and 50% for AHC (P = 0.004), respectively. In conclusion, arterial patency is primarily determined by the type of vascular reconstruction rather than patient or disease characteristics. The preoperative lipid status is an independent risk factor for early occlusion, whereas overall occlusion is only based on the performed vascular reconstruction, which is also associated with reduced graft and patient survival. Liver Transplantation 24 790-802 2018 AASLD.

The weekend effect in liver transplantation

Background

The weekend effect describes a phenomenon whereby patients admitted to hospitals on weekends are at higher risk of complications compared to those admitted during weekdays. However, if a weekend effect exists in orthotopic liver transplantation (oLT).

Methods

We analyzed oLT between 2006 and 2016 and stratified patients into weekday (Monday to Friday) and weekend (Saturday, Sunday) groups. Primary outcome measures were one-year patient and graft survival.

Results

364 deceased donor livers were transplanted into 329 patients with 246 weekday (74.77%) and 83 weekend (25.23%) patients. Potential confounders (e.g. age, ischemia time, MELD score) were comparable. One-year patient and graft survival were similar. Frequencies of rejections, primary-non function or re-transplantation were not different. The day of transplantation was not associated with one-year patient and graft survival in multivariate analysis.

Conclusions

We provide the first data for the Eurotransplant region on oLT stratified for weekend and weekday procedures and our findings suggest there was no weekend effect on oLT. While we hypothesize that the absent weekend effect is due to standardized transplant procedures and specialized multidisciplinary transplant teams, our results are encouraging showing oLT is a safe and successful procedure, independent from the day of the week.

The impact of serum cytokines in the development of early allograft dysfunction in living donor liver transplantation

Early allograft dysfunction (EAD) is considered a precursor to graft loss in liver transplantation. To date, the use of preoperative serum cytokine profiles to predict EAD development has not been systematically investigated in living donor liver transplantation (LDLT). Here, we investigated the association between preoperative serum cytokine profiles and EAD development in LDLT patients.Serum cytokine profiles collected preoperatively and on postoperative day 7 were retrospectively reviewed. The specific serum cytokines analyzed included interleukin (IL)-2, IL-6, IL-10, IL-12, IL-17, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. The cytokine levels of patients with EAD were compared with those of patients without EAD and the impact of cytokine levels on the occurrence of EAD was evaluated.Preoperatively, the serum levels of IL-6, 10, 17, and TNF-α were significantly higher in the EAD group than in the non-EAD group. In univariate logistic analysis, the preoperative levels of IL-6, IL-10, IL-17, IFN-γ, and TNF-α were potentially associated with EAD development. After multivariate logistic analysis, higher preoperative serum levels of IL-6 and 17 were significantly associated with EAD development. In addition, the incidence of EAD increased as the preoperative serum levels of IL-6 and IL-17 increased.Preoperative serum levels of IL-6 and IL-17 were significantly associated with EAD development in LDLT.

Octogenarian donors in liver transplantation grant an equivalent perioperative course to ideal young donors

BACKGROUND

Use of grafts from very old donors for liver transplantation is controversial.

AIM

To compare the perioperative course of patients receiving liver grafts from young ideal vs octogenarian donors.

METHODS

Analysis of the perioperative course of patients receiving liver grafts from young, ideal (18-39 years) vs octogenarian (≥80years) deceased donors between 2001 and 2014.

RESULTS

346 patients were studied: 179 (51.7%) received grafts aged 18-39 years whereas 167 (48.3%) received a graft from a donor aged ≥80years. Intra-operative cardiovascular (p=0.2), coagulopathy (p=0.5) and respiratory (p=1.0) complications and incidence of reperfusion syndrome (p=0.3) were similar. Patients receiving a young graft required more fresh frozen plasma units (p≤0.03) but did not differ for the need of packed red cells (p=0.2) and platelet (p=0.3) transfusions. Median ICU stay was identical (p=0.4). Patients receiving octogenarian vs young grafts did not differ in terms of death or re-transplant (p=1.0) during the ICU stay. Similar cardiovascular, respiratory, renal, infectious and neurological postoperative complication rates were observed in the two groups.

CONCLUSIONS

Octogenarian donors in liver transplantation grant an equivalent perioperative course to ideal young donors.

Application of hyperbaric oxygen in liver transplantation

In recent years, hyperbaric oxygen (HBO) has been used in the treatment of a lot of diseases such as decompression sickness, arterial gas embolism, carbon dioxide poisoning, soft tissue infection, refractory osteomyelitis, and problematic wound, but little is known about its application in liver transplantation. Although several studies have been conducted to investigate the protective effects of HBO on liver transplantation and liver preservation, there are still some controversies on this issue, especially its immunomodulatory effect. In this short review, we briefly summarize the findings supporting the application of HBO during liver transplantation (including donors and recipients).

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1^th and the 5^th day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

Overextended Criteria Donors: Experience of an Italian Transplantation Center

The increasing gap between the number of patients who could benefit from liver transplantation and the number of available donors has fueled efforts to maximize the donor pool using marginal grafts that usually were discarded for transplantation. This study included data of all patients who received decreased donor liver grafts between January 2004 and January 2013 (n = 218) with the use of a prospectively collected database. Patients with acute liver failure, retransplantation, pediatric transplantation, and split liver transplantation were excluded. Donors were classified as standard donor (SD), extended criteria donor (ECD), and overextended criteria donor (OECD). The primary endpoints of the study were early allograft primary dysfunction (PDF), primary nonfunction (PNF), and patient survival (PS), whereas incidence of major postoperative complications was the secondary endpoint. In our series we demonstrated that OECD have similar outcome in terms of survival and incidence of complication after liver transplantation as ideal grafts.

Effects of Donor Age and Cold Ischemia on Liver Transplantation Outcomes According to the Severity of Recipient Status

BackgroundProlonged cold ischemic time (CIT) and increased donor age are well-known factors negatively influencing outcomes after liver transplantation (LT).

AIMS

The aim of this study was to evaluate whether the magnitude of their negative effects is related to recipient model for end-stage liver disease (MELD) score.

METHODS

This retrospective study was based on a cohort of 1402 LTs, divided into those performed in low-MELD (<10), moderate-MELD (10–20), and high-MELD (>20) recipients.

RESULTS

While neither donor age (p = 0.775) nor CIT (p = 0.561) was a significant risk factor for worse 5-year graft survival in low-MELD recipients, both were found to yield independent effects (p = 0.003 and p = 0.012, respectively) in moderate-MELD recipients, and only CIT (p = 0.004) in high-MELD recipients. However, increased donor age only triggered the negative effect of CIT in moderate-MELD recipients, which was limited to grafts recovered from donors aged ≥46 years (p = 0.019). Notably, utilization of grafts from donors aged ≥46 years with CIT ≥9 h in moderate-MELD recipients (p = 0.003) and those with CIT ≥9 h irrespective of donor age in high-MELD recipients (p = 0.031) was associated with particularly compromised outcomes.

CONCLUSIONS

In conclusion, the negative effects of prolonged CIT seem to be limited to patients with moderate MELD receiving organs procured from older donors and to high-MELD recipients, irrespective of donor age. Varying effects of donor age and CIT according to recipient MELD score should be considered during the allocation process in order to avoid high-risk matches.

Genomic profiles and predictors of early allograft dysfunction after human liver transplantation

Early hepatic allograft dysfunction (EAD) manifests posttransplantation with high serum transaminases, persistent cholestasis, and coagulopathy. The biological mechanisms are poorly understood. This study investigates the molecular mechanisms involved in EAD and defines a gene expression signature revealing different biological pathways in subjects with EAD from those without EAD, a potential first step in developing a molecular classifier as a potential clinical diagnostic. Global gene expression profiles of 30 liver transplant recipients of deceased donor grafts with EAD and 26 recipients without graft dysfunction were investigated using microarrays of liver biopsies performed at the end of cold storage and after graft reperfusion prior to closure. Results reveal a shift in inflammatory and metabolic responses between the two time points and differences between EAD and non-EAD. We identified relevant pathways (PPARα and NF-κB) and targets (such as CXCL1, IL1, TRAF6, TIPARP, and TNFRSF1B) associated with the phenotype of EAD. Preliminary proof of concept gene expression classifiers that distinguish EAD from non-EAD patients, with Area Under the Curve (AUC) >0.80 were also identified. This data may have mechanistic and diagnostic implications for EAD.

Use of octogenarian donors for liver transplantation: a survival analysis

Use of very old donors in liver transplantation (LT) is controversial because advanced donor age is associated with a higher risk for graft dysfunction and worse long-term results, especially for hepatitis C virus (HCV)-positive recipients. This was a retrospective, single-center review of primary, ABO-compatible LT performed between 2001 and 2010. Recipients were stratified in four groups based on donor age (<60 years; 60-69 years; 70-79 years and ≥80 years) and their outcomes were compared. A total of 842 patients were included: 348 (41.3%) with donors <60 years; 176 (20.9%) with donors 60-69 years; 233 (27.7%) with donors 70-79 years and 85 (10.1%) with donors ≥80 years. There was no difference across groups in terms of early (≤30 days) graft loss, and graft survival at 1 and 5 years was 90.5% and 78.6% for grafts <60 years; 88.6% and 81.3% for grafts 60-69 years; 87.6% and 75.1% for grafts 70-79 years and 84.7% and 77.1% for grafts ≥80 years (p = 0.065). In the group ≥80 years, the 5-year graft survival was lower for HCV-positive versus HCV-negative recipients (62.4% vs. 85.6%, p = 0.034). Based on our experience, grafts from donors ≥80 years may provide favorable results but require appropriate selection and allocation policies.

Critical care of the potential organ donor

Organ transplantation represents one of the great success stories of 20th century medicine. However, its continued success is greatly limited by the shortage of donor organs. This has led to an increased focus within the critical care community on optimal identification and management of the potential organ donor. The multi-organ donor can represent one of the most complex intensive care patients, with numerous competing physiological priorities. However, appropriate management of the donor not only increases the number of organs that can be successfully donated but has long-term implications for the outcomes of multiple recipients. This review outlines current understandings of the physiological derangements seen in the organ donor and evaluates the available evidence for management strategies designed to optimize donation potential and organ recovery. Finally, emerging management strategies for the potential donor are discussed within the current ethical and legal frameworks permitting donation after both brain and circulatory death.

Evaluation of the updated definition of early allograft dysfunction in donation after brain death and donation after cardiac death liver allografts

BACKGROUND

An updated definition of early allograft dysfunction (EAD) was recently validated in a multicenter study of 300 deceased donor liver transplant recipients. This analysis did not differentiate between donation after brain death (DBD) and donation after cardiac death (DCD) allograft recipients.

METHODS

We reviewed our prospectively entered database for all DBD (n=377) and DCD (n=38) liver transplantations between January 1, 2006 and October 30, 2011. The incidence of EAD as well as its ability to predict graft failure and survival was compared between DBD and DCD groups.

RESULTS

EAD was a valid predictor of both graft and patient survival at six months in DBD allograft recipients, but in DCD allograft recipients there was no significant difference in the rate of graft failure in those with EAD (11.5%) compared with those without EAD (16.7%) (P=0.664) or in the rate of death in recipients with EAD (3.8%) compared with those without EAD (8.3%) (P=0.565). The graft failure rate in the first 6 months in those with international normalized ratio ≥1.6 on day 7 who received a DCD allograft was 37.5% compared with 6.7% for those with international normalized ratio <1.6 on day 7 (P=0.022).

CONCLUSIONS

The recently validated definition of EAD is a valid predictor of patient and graft survival in recipients of DBD allografts. On initial assessment, it does not appear to be a useful predictor of patient and graft survival in recipients of DCD allografts, however a study with a larger sample size of DCD allografts is needed to confirm these findings. The high ALT/AST levels in most recipients of DCD livers as well as the predisposition to biliary complications and early cholestasis make these parameters as poor predictors of graft failure. An alternative definition of EAD that gives greater weight to the INR on day 7 may be more relevant in this population.

An innovative hyperbaric hypothermic machine perfusion protects the liver from experimental preservation injury

Purpose. Hypothermic machine perfusion systems seem more effective than the current static storage to prevent cold ischemic liver injury. Thus, we test an innovative hyperbaric hypothermic machine perfusion (HHMP), which combines hyperbaric oxygenation of the preservation solution and continuous perfusion of the graft. Methods. Rat livers were preserved with Celsior solution according to 4 different modalities: normobaric static preservation; hyperbaric static preservation at 2 atmosphere absolute (ATA); normobaric dynamic preservation, with continuous perfusion; hyperbaric dynamic preservation, with continuous perfusion at 2 ATA. After 24 h cold preservation, we assessed different parameters. Results. Compared to baseline, livers preserved with the current static storage showed severe ultrastructural damage, glycogen depletion and an increased oxidative stress. Normobaric perfused livers showed improved hepatocyte ultrastructure and ameliorated glycogen stores, but they still suffered a significant oxidative damage. The addition of hyperbaric oxygen produces an extra benefit by improving oxidative injury and by inducing endothelial NO synthase (eNOS) gene expression. Conclusions. Preservation by means of the present innovative HHMP reduced the liver injury occurring after the current static cold storage by lowering glycogen depletion and oxidative damage. Interestingly, only the use of hyperbaric oxygen was associated to a blunted oxidative stress and an increased eNOS gene expression.

Grade of deceased donor liver macrovesicular steatosis impacts graft and recipient outcomes more than the Donor Risk Index

BACKGROUND AND AIM

Donor liver steatosis can impact on liver allograft outcomes. The aim of the present study was to comprehensively report on the impact of type and grade of donor steatosis, as well as donor and recipient factors, including the reported Donor Risk Index (DRI), on liver allograft outcomes.

METHODS

A review of unit data for all adult liver transplant procedures from 2001 to 2007, as well as donor offers. Donor liver biopsies were regraded for steatosis by an experienced histopathologist.

RESULTS

Steatosis was detected in 184/255 (72%) of biopsies, of which 114 (62%) had microvesicular steatosis (MiS; 68 mild, 22 moderate, 24 severe) and 70 (38%) macrovesicular steatosis (MaS; 59 mild, 7 moderate, 4 severe). The majority (66/70, 94%) of biopsies with MaS also contained MiS. Allograft steatosis was associated with increasing donor body mass index (P = 0.000), plus donor male sex (P < 0.05). Primary non function (P = 0.002), early renal failure (P = 0.040), and requirement for retransplantation (P = 0.012) were associated only with severe MaS. Early biliary complications were associated with moderate MaS (P = 0.039). Only severe MaS was significantly associated with inferior allograft survival at 3 months (relative risk = 12.09 [8.75-19.05], P = 0.000) and 1 year (P = 0.000).

CONCLUSIONS

MiS is a common finding and frequently coexists with MaS on liver allograft biopsy, while isolated MaS is uncommon. Only the presence of moderate to severe MaS is associated with inferior early allograft outcomes. The impact of severe MaS on allograft survival appears greater than other donor factors, including the calculated DRI.

Liver transplantation with donors over the expected lifespan in the model for end-staged liver disease era: is Mother Nature punishing us?

BACKGROUND

The lack of sufficient donors to satisfy the waiting list requirements has prompted many to expand the acceptance criteria. The purpose of this study was to evaluate our liver transplantation (LT) experience with donors beyond the average lifespan.

PATIENTS AND METHODS

From January 2008 to December 2009, we received 75 liver offers involving donors ≥ 75 years of age. Donor and recipient data were analysed by both uni- and multivariate Cox proportional hazard model analyses.

RESULTS

We performed 32 adult liver transplants (43%). Half of the patients received organs through rescue allocations. Seven recipients (22%) developed initial poor function. Two had primary graft non-function (PNF). Four recipients were re-transplanted (two PNF and two ischaemic-type bile lesions). One- and 3-year cumulative survival was 62 and 51% respectively. PNF, lab model for end-staged liver disease (MELD), post-LT haemodialysis, post-LT re-operations and post-LT sepsis were significant predictors by univariate analysis. Only PNF reached multivariate significance (P = 0.0307). Rescue offer allocation reached significance as a predictor of PNF by general linear model forward analysis. One- and 3-year 'MELD based allocation' (n = 16) vs 'rescue allocation' (n = 16) survival rates were 44 and 29% vs 82 and 76% respectively (P = 0.0197).

CONCLUSIONS

Although grafts from donors ≥ 75 years allow for an expansion of the donor pool, long-term recipient survival is inferior to that encountered with younger donors. Acceptable results could be obtained by identifying 'preferred' recipients for rescue allocations.

Liver grafts from selected older donors do not have significantly more ischaemia reperfusion injury

BACKGROUND

There is a general concern that aged organs are more susceptible to ischaemia. In the light of recent proposals to change the liver allocation system by expanding regional sharing, it is feared that increased cold ischaemia time of grafts from older donors may reduce graft survival. The aim of this study was to correlate donor age and the patterns of ischaemia reperfusion injury and synthetic function early after liver transplantation.

METHODS

We performed a retrospective study of first transplants using a single-centre electronic database. Patterns of liver injury (based on transaminases and post-reperfusion biopsy), synthetic function (international normalized ratio [INR]), and graft and patient survival in recipients receiving liver grafts from donors aged ≥ 65 years (group 1, n= 50) were compared with equivalent patterns in a matched cohort of recipients transplanted with grafts from donors aged <65 years (group 2, n= 50).

RESULTS

There was no significant difference in transaminase levels from day 0 to day 6 after transplantation. When groups 1 and 2 were subdivided into two subgroups based on the duration of graft cold ischaemia time (<8 h and ≥ 8 h), there was no statistical difference in transaminase levels during the first 7 days. There were two cases (4%) of primary non-function in group 1 and one (2%) in group 2. Initial poor function did not differ significantly between the groups (26% vs. 24%; P= 0.81). In addition, there was no difference in histological changes in post-reperfusion biopsies (21% vs. 34%; P= 0.078) and rate of acute rejection episodes in the first year (30% vs. 32%; P= 0.99). There was no significant difference between groups 1 and 2 in 1-year patient and graft survivals (78% vs. 90% [P= 0.17]; 88% vs. 94% [P= 0.48], respectively).

CONCLUSIONS

Judiciously selected livers from aged donors are not associated with major increased susceptibility to ischaemia reperfusion injury.

Validation of a current definition of early allograft dysfunction in liver transplant recipients and analysis of risk factors

Translational studies in liver transplantation often require an endpoint of graft function or dysfunction beyond graft loss. Prior definitions of early allograft dysfunction (EAD) vary, and none have been validated in a large multicenter population in the Model for End-Stage Liver Disease (MELD) era. We examined an updated definition of EAD to validate previously used criteria, and correlated this definition with graft and patient outcome. We performed a cohort study of 300 deceased donor liver transplants at 3 U.S. programs. EAD was defined as the presence of one or more of the following previously defined postoperative laboratory analyses reflective of liver injury and function: bilirubin >or=10mg/dL on day 7, international normalized ratio >or=1.6 on day 7, and alanine or aspartate aminotransferases >2000 IU/L within the first 7 days. To assess predictive validity, the EAD definition was tested for association with graft and patient survival. Risk factors for EAD were assessed using multivariable logistic regression. Overall incidence of EAD was 23.2%. Most grafts met the definition with increased bilirubin at day 7 or high levels of aminotransferases. Of recipients meeting the EAD definition, 18.8% died, as opposed to 1.8% of recipients without EAD (relative risk = 10.7 [95% confidence interval: 3.6, 31.9] P < 0.0001). More recipients with EAD lost their grafts (26.1%) than recipients with no EAD (3.5%) (relative risk = 7.4 [95% confidence interval: 3.4, 16.3] P < 0.0001). Donor age and MELD score were significant EAD risk factors in a multivariate model. In summary a simple definition of EAD using objective posttransplant criteria identified a 23% incidence, and was highly associated with graft loss and patient mortality, validating previously published criteria. This definition can be used as an endpoint in translational studies aiming to identify mechanistic pathways leading to a subgroup of liver grafts with clinical expression of suboptimal function.

Application of metabolomics to investigate the process of human orthotopic liver transplantation: a proof-of-principle study

To improve the outcome of orthotopic liver transplantation (OLT), knowledge of early molecular events occurring upon ischemia/reperfusion is essential. Powerful approaches for profiling metabolic changes in tissues and biofluids are now available. Our objective was to investigate the applicability of two technologies to a small but well-defined cohort of patients undergoing OLT: consecutive liver biopsies by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and microdialysates of extracellular fluid by coulometric electrochemical array detection (CEAD). FT-ICR MS detected reproducibly more than 4,000 peaks, revealing hundreds of significant metabolic differences between pre- and postreperfusion grafts. These included increased urea production, bile acid synthesis and clearance of preservation solution upon reperfusion, indicating a rapid resumption of biochemical function within the graft. FT-ICR MS also identified successfully the only graft obtained by donation-after-cardiac-death as a "metabolic outlier." CEAD time-profile analysis showed that there was considerable change in redox-active metabolites (up to 18 h postreperfusion), followed by their stabilization. Collectively these results verify the applicability of FT-ICR MS and CEAD for characterizing multiple metabolic pathways during OLT. The success of this proof-of-principle application of these technologies to a clinical setting, considering the potential metabolic heterogeneity across only eight donor livers, is encouraging.

Predictive value of frozen-section analysis in the histological assessment of steatosis before liver transplantation

Histological quality assessment of donated livers is a key factor for extending the cadaveric donor pool for liver transplantation. We retrospectively compared frozen-section analysis with routine histological permanent slides and the outcomes of grafts in liver biopsies from 294 candidate donors. The kappa concordance coefficient of agreement between frozen-section analysis and routine histological analysis was very good for macrosteatosis (kappa = 0.934), microsteatosis (kappa = 0.828), and total steatosis (kappa = 0.814). The correlation between the mean amounts of macrosteatosis, microsteatosis, and total steatosis in frozen and permanent sections was also significant (P < 0.001, Spearman's test). Macrosteatosis and microsteatosis were overestimated to >30% in 4 of 32 cases (12.5%) and in 23 of 62 cases (37.1%), respectively. The only 2 histological parameters of frozen sections able to predict graft dysfunction within 7 days of transplantation were macrosteatosis and total steatosis (P = 0.018 and P = 0.015, respectively, Mann-Whitney test). None of the other histopathological features evaluated in frozen sections, including portal inflammation, lobular necrosis, myointimal thickening, biliocyte regression, cholestasis, hepatocellular polymorphism, lipofuscin storage, and fibrous septa, were significantly correlated with the graft outcome. The frozen-section histological evaluation of biopsies from cadaveric liver donors is an accurate, time-effective, and predictive method for the assessment of graft suitability.

A re-evaluation of the risk factors for the recurrence of primary sclerosing cholangitis in liver allografts

Previously, we have found that the absence of the colon after liver transplantation (LT) protects the patient from recurrent primary sclerosing cholangitis (rPSC). As our previous observation has not been confirmed in other series, we have reviewed our cohort of patients grafted for primary sclerosing cholangitis (PSC) with greater numbers and longer follow-up to reassess the rate, consequences, and risk factors for rPSC. We collected data on patients who underwent LT for PSC between January 1986 and April 2006. Data were collected for cytomegalovirus status, inflammatory bowel disease status, time of colectomy, type of colectomy, donor-recipient gender mismatch, recipient sex, extended donor criteria (EDC), and donor risk index. Accepted criteria were used to diagnose rPSC. Of a total of 230 consecutive adult patients, 61 (27%) underwent colectomy pre-/peri-LT, and 54 (23.5%) developed rPSC at a median of 4.6 (range, 0.5-12.9) years post-LT. A total of 263 deceased donor grafts were used, and 73 were EDC grafts. A diagnosis of rPSC was made in 61 of the 263 grafts (23%). The recurrence-free patient survival was significantly better (P < 0.05) in patients who underwent pre-/peri-LT colectomy and in those with non-EDC grafts. In conclusion, in this larger cohort of 230 patients and with longer follow-up of 82.5 (range, 0.0-238.6) months [in comparison with the previous report of 152 recipients with a follow-up of 52.8 (range, 1-146) months], we have shown that colectomy remains a significant risk factor for rPSC and that colectomy before and during initial LT for PSC confers a protective effect against rPSC in subsequent graft(s). Moreover, we have shown that EDC grafts are also a significant risk factor for rPSC.

The marginal liver donor--an update

The number of patients awaiting liver transplantation keeps steadily rising with no corresponding rise in suitable grafts for transplantation. There also is an increasing trend of patients dying or being taken off waiting lists because of deterioration while waiting for a transplant. Over the preceding years the use of marginal grafts in liver transplantation has been driven by the critical shortage of donor organs and by emerging data that their use has resulted in a favourable outcome. This review revisits the factors defining marginality of a graft, and the issues faced by transplant units in making the decision to use such a graft. It also looks at the innovations in transplantation geared towards increasing the donor pool and the resulting issues of matching marginal grafts to suitable recipients.

Effect modification in liver allografts with prolonged cold ischemic time

Although prolonged cold ischemia time (PCIT) is generally associated with worse outcomes following liver transplantation, evidence suggests that some recipients and some donors might be more sensitive to PCIT than others. The purpose of this study was to identify factors that predict a higher risk of graft loss after a transplant with PCIT when compared with a similar transplant with average CIT (ACIT). 14 637 recipients reported to United Network for Organ Sharing (UNOS) in the model for end-stage liver disease (MELD) era were studied by interaction term analysis in proportional hazards models. Recipient diabetes, obesity and donor African American (AA) ethnicity were found to significantly amplify the adverse effects of PCIT. Graft loss was 1.85-fold higher in diabetic or obese PCIT recipients compared with diabetic or obese ACIT recipients, (vs. 1.17 for the same comparison in non-diabetic non-obese recipients). Similarly, graft loss was 1.80-fold higher in AA PCIT donors compared with AA ACIT donors, (vs. 1.31 for the same comparison in non-AA donors). Other factors may also exist, but current clinical practices might already mitigate the risks from those factors. As such, we recommend expanding clinical practice to include our findings, but not abandoning current judgment based on factors already perceived to amplify the adverse effects of PCIT.

Critical use of extended criteria donor liver grafts in adult-to-adult whole liver transplantation: a single-center experience

This study presents our experience with the use of extended criteria donor (ECD) liver grafts. One hundred fifteen liver transplants were divided into 2 groups: standard (S) and nonstandard (NS). Fifty-eight patients in group S received a liver procured from an ideal donor, whereas 57 patients in group NS received an organ from an ECD. On the basis of the number of risk factors, patients were divided into 3 subgroups: the S group with 58 receiving a standard graft, the NS1 group with 44 receiving a graft with 1 or 2 risk factors, and the NS2 group with 13 receiving a graft with 3 to 4 risk factors. Patient survival was not different at 6, 12, and 24 months (P > 0.05), whereas graft survival was different (P = 0.0079). Both patient survival and graft survival were influenced by the cumulative number of risk factors. The univariate analysis of the donor risk factors detected hemodynamic factors as predictive of graft failure (P = 0.024) and death (P = 0.018). In the multivariate analysis, which was adjusted for recipient age and donor and recipient gender, hemodynamic risk factors and Model for End-Stage Liver. Disease score in the recipient were the only variables independently associated with graft failure (P = 0.006, P = 0.012, negatively). Finally, we observed a reduction of dropout from the list to 9% from 14.1% (P = 0.04) and of mortality on the list to 32.55% from 41.01% (P = 0.11). Critical use of ECD liver grafts allowed recipients in the waiting list to have a greater chance of being transplanted.

Influence of flow and addition of oxygen during porcine liver hypothermic machine perfusion

INTRODUCTION

In contrast with kidneys, data on hypothermic machine perfusion (HMP) of livers remain scarce. Optimal liver HMP is poorly defined. Superiority of liver HMP over simple cold storage (SCS), the current standard preservation, must be proven before HMP is applied clinically. In this study, morphology and adenosine triphosphate (ATP) contents of HMP livers at different flows and with versus without O(2) studied in a porcine ex vivo model were compared to SCS.

METHODS

Pig livers were procured, flushed with HTK and preserved via SCS or HMP at 3 HMP settings: high flow (HF); low flow (LF); low flow + O(2) (300 mm Hg) (LFO). HMP livers were perfused via the hepatic artery (HA) and portal vein (PV) with KPS-1 TM at 4 degrees C to 6 degrees C for 24 hours with HF: PV: 3 to 5 mm Hg, 1 mL/g liver/min for HA and 25 mm Hg; LF: PV: 3 to 5 mm Hg, 0.5 ml/g liver/min with HA: 20 mm Hg. Morphology and ATP levels were measured in preserved liver tissues.

RESULTS

Throughout the SCS preservation, livers remained intact. In HMP livers, vacuoles appeared after 4 hours of preservation in the HF group and after 12 hours in the LF livers. LFO livers remained intact with limited vacuoles. Compared to SCS, HMP livers showed dilated sinusoids, particularly in the HF group. ATP remained relatively constant or even increased during HMP, particularly in the LF group, whereas ATP decreased after SCS.

CONCLUSION

Among the various HMP settings, HMP with LFO was superior. ATP levels were the highest in LF. In contrast with all HMP groups, SCS showed the lowest ATP levels, indicating that HMP has the potential to better preserve energy stores.

Donor liver dysfunction: application of a new scoring system to identify the marginal donor

Livers from marginal donors are increasingly used for transplantation due to the shortage of donor organs. The definition of a marginal donor remains unclear; prediction of organ function is a challenge. In the literature the use of steatotic livers has been associated with poor liver function or even primary dysfunction of the allograft. Tekin et al created a scoring system that classifies a donor as marginal or nonmarginal, using a mathematical model based on donor age and steatosis degree. The aims of this study were to apply the Tekin method to identify marginal and nonmarginal donors and evaluate the influence of the cold ischemia time (CIT) on allograft evolution. We retrospectively reviewed deceased donor liver transplantations performed from October 1995 to March 2006, namely, 177 adult liver transplantations in 163 patients. Fifty-five were excluded due to retransplantation (14) or insufficient data (41). Donor age and macrovesicular steatosis were evaluated according to the mathematical formula proposed by Tekin et al, classifying the donors as marginal versus nonmarginal. The authors also analyzed the CIT, 3-month mortality, and development of primary nonfunction or primary dysfunction. The median donor age was 38.9 years (range, 6-71). The postreperfusion biopsy specimen showed moderate to intense steatosis (>30%) in 14.75% of specimens, with no steatosis or mild steatosis in 85.25%. Sixty-one grafts (50%) developed primary graft dysfunction (PGD): 10 grafts, with primary nonfunction (PNF); and 51 with initial poor function (IPF). Using the criteria provided by Tekin et al, we obtained 41 marginal and 81 nonmarginal allografts. The marginal group showed 61.9% PGD, compared with 59.2% of PGD by the nonmarginal group. The CIT was greater than 12 hours in 5 marginal group transplants and 4 PGD cases (80%). Of the nonmarginal allografts, the CIT was greater than 12 hours in 29.6%, with 75% PGD. The 3-month graft survival rate was 80% in the marginal group with ischemia time more than 12 hours: 86.1% of the same group when CIT was less than 12 hours, and 82.7% in the nonmarginal group. In contrast, when we analyzed the occurrence of allograft dysfunction, the 3-month mortality rate was 34% among, grafts with dysfunction, whereas, in those without initial dysfunction, it was 4.1%. In conclusion, the score suggested by Tekin et al that classifies the donors as ideal (nonmarginal) or marginal was not able to predict initial primary dysfunction.

A cause-specific hazard rate analysis of prognostic factors among 877 adults who received primary orthotopic liver transplantation

BACKGROUND

In orthotopic liver transplantation (OLT) distinct causes of graft failure (GF) and death with a functioning graft (DFG) exist. Prognostic factors for one failure type may be distinctly different from those predictive of other types, and an accurate portrayal of these relationships may more clearly explain each factor's importance.

METHODS

A multivariable cause-specific hazard (CSH) rate analysis using Cox stepwise regression was performed among 877 adults who received primary OLT during 1996-2004 with tacrolimus+steroids as immunosuppression.

RESULTS

Older donor age (P=0.004) implied greater primary dysfunction GF, while primary sclerosing cholangitis (PSC; P=0.0002) implied greater vascular thrombosis GF. Recurrent nonmalignant liver disease GF was higher among hepatitis C virus patients (P<0.00001), and younger recipient age (P=0.005) implied greater death from recurrent (metastatic) hepatocellular carcinoma. African-American race (P<0.00001), PSC (P=0.003), and younger recipient age (P=0.005) were independently associated with greater GF due to chronic rejection. Older donor age (P=0.003) implied greater infection DFG, while older recipient age (P=0.003) and pretransplant diabetes (P=0.03) were independently associated with greater cardiovascular/cerebrovascular DFG. Finally, most of these cause-specific predictors were not significant in an overall Cox model for graft survival.

CONCLUSIONS

The CSH approach should be more widely used in investigations of prognostic factors. The result of older donor age implying greater primary dysfunction GF and infection DFG but having no association with other failure types demonstrates that its impact is specific to the graft's early posttransplant functional status. In addition, while recipient age was an important prognosticator, its direction of association reverses depending upon the outcome being analyzed.

The Use of Marginal Heart Beating Donor Livers for Transplantation in the United Kingdom

BACKGROUND

This study investigated the use of deceased heart-beating donor livers offered for transplantation during a 10-year period, during which there has been an increasing disparity between organ supply and demand in the United Kingdom.

METHODS

Summary data from the National Transplant Database were analyzed on all 7107 heart-beating cadaveric donor livers offered for transplantation in the United Kingdom between 1996 and 2006, with particular attention to livers that were not retrieved, not transplanted, or that subsequently failed to function after transplantation.

RESULTS

The difference between the number of patients registered for liver transplantation in the United Kingdom and those transplanted increased from 132 in 1996 to 333 in 2006, leading to a 77% increase in the number of waiting list deaths. Mean donor age increased by 6.1 (5.7-6.6) years during the period studied, in part because of a reduction in the proportion of donors arising from road fatalities. Despite this, the rate of primary nonfunction remained low (1.7% during 1996-2006). The absolute risk increase of primary nonfunction arising from receipt of a moderately as opposed to mildly steatotic organ was 2.6%, which translates to a "number needed to harm" of 41 patients.

CONCLUSIONS

The decline in both the number and the quality of livers offered for transplantation in the United Kingdom during the past 10 years has not been associated with a change in the rate of primary nonfunction. In these times of acute donor shortage, these data may justify a more liberal use of marginal grafts.

In vivodetection of liver steatosis in rats based on impedance spectroscopy

Hepatic steatosis is a widespread condition of high prevalence in Western populations, and its asymptomatic nature represents a hefty problem in liver surgery and transplantation. Current diagnostic methods rely mainly on biopsy and blood tests, and are thus time consuming and expensive. Here we report the use of direct impedance measurements on liver tissue as a promising alternative to conventional diagnostic methods in surgery and transplantation. Working on a dual Zucker Fat (ZF), Zucker Lean (ZL) rat experimental model, we show that certain parameters extracted from multi-frequency impedance measurements correlate well with the presence of steatosis and that these results can be adequately approximated with bi-frequency measurements extracting the impedance modulus at 1 kHz and the impedance phase angle at 5.7 kHz. We further support our findings on a theoretical model of tissue impedance, and the simulations carried out suggest a possible mechanism to expound the negative effect of steatosis in post-transplant graft function.