Extended Donor Criteria Have No Negative Impact on Early Outcome After Liver Transplantation: A Single-Center Multivariate Analysis

Extended criteria brain-dead organ donors: Prevalence and impact on the utilisation of livers for transplantation in Brazil

BACKGROUND

Despite its association with higher postoperative morbidity and mortality, the use of extended criteria donor (ECD) livers for transplantation has increased globally due to the high demand for the procedure.

AIM

To investigate the prevalence of ECD in donation after brain death (DBD) and its impact on organ acceptance for transplantation.

METHODS

Retrospective analysis of DBD organ offers for liver transplantation between 2017 and 2020 in a high-volume transplant centre. The incidence of the Eurotransplant risk factors to define an ECD (ET-ECD) among DBD donors and the likelihood of organ acceptance over the years were analysed. The relationship between organ refusal for transplantation, the occurrence, and the number of ET-ECD was assessed by simple and multiple logistic regression adjustment.

RESULTS

A total of 1619 organ donors were evaluated. Of these, 78.31% (n = 1268) had at least one ET-ECD criterion. There was an increase in the acceptance of ECD DBD organs for transplantation (1 criterion: from 23.40% to 31.60%; 2 criteria: from 13.10% to 27.70%; 3 criteria: From 6.30% to 13.60%). For each addition of one ET-ECD variable, the estimated chance of organ refusal was 64.4% higher (OR 1.644, 95%CI 1.469-1.839, P < 0.001). Except for the donor serum sodium > 165 mmol/L (P = 0.310), all ET-ECD criteria increased the estimated chance of organ refusal for transplantation.

CONCLUSION

A high prevalence of ECD DBD was observed. Despite the increase in their utilisation, the presence and the number of extended donor criteria were associated with an increased likelihood of their refusal for transplantation.

Differential Impact of Extended Criteria Donors After Brain Death or Circulatory Death in Adult Liver Transplantation

Using grafts from extended criteria donors (ECDs) and donation after circulatory death (DCD) donors is a strategy to address organ shortage in liver transplantation (LT). We studied the characteristics and outcomes of ECD and DCD grafts. We retrospectively studied consecutive adults who underwent deceased donor LT between 2006 and 2019. ECD was defined using modified Eurotransplant criteria. Our primary outcomes were graft and patient survival. A total of 798 grafts were used for LT, of which 93.1% were donation after brain death (DBD; 59.9% were also ECD) and 6.9% were DCD grafts (49.1% were also ECD). Among DBD graft recipients, donors having >33% liver steatosis or 3 ECD criteria resulted in poorer graft survival. Otherwise ECD graft recipients had similar graft and patient survival compared with non-ECD graft recipients. DCD graft recipients also had similar patient survival compared with DBD recipients. However, DCD grafts from an ECD appeared to have worse outcomes. DCD graft recipients experienced higher rates of early allograft dysfunction (50.9% versus 24.7%; P < 0.001) and ischemic biliopathy (16.4% versus 1.5%; P < 0.001) compared with DBD graft recipients. Use of DBD grafts from ECDs did not impact outcomes unless there was significant donor steatosis or 3 Eurotransplant criteria were met. DCD graft recipients have similar patient survival compared with DBD graft recipients as long as the donor was not an ECD. We recommend that DBD donors with 3 or more ECD features or >33% steatosis and DCD donors with any ECD features be used with caution in adult LT.

The Graz Liver Allocation Strategy-Impact of Extended Criteria Grafts on Outcome Considering Immunological Aspects

Background: Transplant centers are forced to use livers of extended criteria donors for transplantation due to a dramatic organ shortage. The outcome effect of extended donor criteria (EDCs) remains unclear. Thus, this study was designed to assess the impact of EDCs on outcome including immunological aspects after liver transplantation (LT).

Patients and Methods: Between November 2016 and March 2018, 49 patients (85.7% male) with a mean age of 57 ± 11 years underwent LT. The impact of EDCs on outcome after LT was assessed retrospectively using both MedOcs and ENIS (Eurotransplant Network Information System).

Results: About 80% of grafts derived from extended criteria donors. Alanine aminotransferase/aspartate aminotransferase (AST/ALT) levels elevated more than three times above normal values in organ donors was the only significant risk factor for primary dysfunction (PDF) and primary non-function (PNF)/Re-LT and early non-anastomotic biliary strictures (NAS). Balance of risk (BAR) score did not differ between EDC and non-EDC recipients. PDF (14.3% of all patients) and PNF (6.1% of all patients) occurred in 23.1% of EDC-graft recipients and in 10.0% of non-EDC-graft recipients (RR 2.31, p = 0.663). The 90-day mortality was 3.6%. There was no difference of early non-anastomotic biliary tract complications and biopsy proven rejections (BPR). There was no correlation of PDF/PNF with BPR and NAS, respectively; however, 66.7% of the patients with BPR also developed early NAS (p < 0.001).

Conclusion: With the Graz liver allocation strategy, excellent survival can be achieved selecting livers with no more than 2 not outcome-relevant EDCs for patients with MELD >20. Further, BPR is associated with biliary complications.

Liver Grafts with Major Extended Donor Criteria May Expand the Organ Pool for Patients with Hepatocellular Carcinoma

The major extended donor criteria (maEDC; steatosis >40%, age >65 years, and cold ischemia time >14 h) influence graft and patient outcomes after liver transplantation. Despite organ shortages, maEDC organs are often considered unsuitable for transplantation. We investigated the outcomes of maEDC organ liver transplantation in patients with hepatocellular carcinoma (HCC). Two hundred and sixty-four HCC liver transplant patients were eligible for analysis. Risk factor analysis was performed for early allograft dysfunction; primary nonfunction; 30-day and 90-day graft failure; and 30-day, 90-day, and 1-year patient mortality. One-year graft survival was higher in recipients of no-maEDC grafts. One-year patient survival did not differ between the recipients of no-maEDC and maEDC organs. The univariate and multivariate analyses revealed no association between maEDC grafts and one-year patient mortality. Graft survival differed between the recipients of no-maEDC and maEDC organs after correcting for a laboratory model of end-stage liver disease (labMELD) score with a cut-off value of 20, but patient survival did not. Patient survival did not differ between recipients who did and did not meet the Milan criteria and who received grafts with and without maEDC. Instead of being discarded, maEDC grafts may expand the organ pool for patients with HCC without impairing patient survival or recurrence-free survival.

Risk factors, surgical complications and graft survival in liver transplant recipients with early allograft dysfunction

BACKGROUND

Early allograft dysfunction (EAD) is a severe complication after liver transplantation. The associated risk factors and complications have re-gained recent interest. This study investigated risk factors, survival and complications associated with EAD in a large liver transplant center in Latin America.

METHODS

Retrospective, unicenter, cohort, based on data from adult patients undergoing first deceased-donor liver transplant from January 2009 to December 2013. EAD was defined by one or more of the following: (i) bilirubin ≥10 mg/dL on postoperative day 7; (ii) international normalized ratio ≥1.6 on postoperative day 7, and (iii) alanine aminotransferase or aspartate aminotransferase >2000 IU/L within the first seven days after transplant.

RESULTS

A total of 602 patients were included; of these 34.2% developed EAD. Donor risk factors were male (P = 0.007), age between 50 and 59 years (P = 0.034), overweight (P = 0.028) or grade I obesity (P = 0.012), sodium >157 mmol/L (P = 0.002) and grade IV ischemia/reperfusion injury (P = 0.002). Cold ischemia time ≥10 h (P = 0.008) and warm ischemia time ≥40 min (P = 0.013) were the surgical factors. Male (P <0.001) was the only recipient protective factor. Compared with the non-EAD group, patients with EAD were submitted to more reoperations (24.3% vs. 13.4%, P = 0.001) and had higher graft loss rates (37.9% vs. 21.2%, P <0.001), with similar patient survival rates (P = 0.238).

CONCLUSIONS

EAD risk factors are related to donor, surgical procedure and recipient. Donor risk factors for EAD were male, age between 50 and 59 years, donor overweight or grade I obesity, sodium >157 mmol/L and grade IV ischemia/reperfusion injury. Cold ischemia time ≥10 h and warm ischemia time ≥40 min were the surgical risk factors. Male was the only recipient protective factor. Patients with EAD had higher reoperations and graft loss rates.

Recipient Selection for Optimal Utilization of Discarded Grafts in Liver Transplantation

BACKGROUND

In France, liver grafts that have been refused by at least 5 teams are considered for rescue allocation (RA), with the choice of the recipient being at the team's discretion. Although this system permits the use of otherwise discarded grafts in a context of organ shortage, outcomes and potential benefits need to be assessed.

METHODS

Between 2011 and 2015, outcomes of RA grafts (n = 33) were compared with SA grafts (n = 321) at a single French center.

RESULTS

Liver grafts in the RA group were older (63 ± 17 years vs 54 ± 18 years, P = 0.007) and had a higher DRI (1.86 ± 0.45 vs 1.61 ± 0.47, P = 0.010). Recipients in this group had a lower Model for End-Stage Liver Disease score (14 ± 5 vs 22 ± 10, P < 0.001) and had mostly hepatocellular carcinoma (67.0% vs 40.4%, P = 0.010). The balance of risk score was significantly lower in the RA group (5.5 ± 2.9 vs 9.2 ± 5.5, P < 0.001). There were higher rates of early and delayed hepatic artery thrombosis (15.2% vs 3.1%, P = 0.001) and retransplantation (18.2% vs 4.7%, P = 0.002) in the RA group. Patient survival was not different between groups, but graft survival was impaired (95% vs 82% at 1 year and 94% vs 74% at 3 years, P = 0.001).

CONCLUSION

Our results show that discarded liver grafts can be used provided that there is a strict recipient selection process, although hepatic artery thrombosis and retransplantation are more frequent. This strategy enables utilization of otherwise discarded grafts in the context of organ shortage.

The impact of major extended donor criteria on graft failure and patient mortality after liver transplantation

INTRODUCTION

Numerous extended donor criteria (EDC) have been identified in liver transplantation (LT), but different EDC have different impacts on graft and patient survival. This study aimed to identify major EDC (maEDC) that were best able to predict the outcome after LT and to examine the plausibility of an allocation algorithm based on these criteria.

METHODS

All consecutive LTs between 12/2006 and 03/2014 were included (n = 611). We analyzed the following EDC: donor age > 65 years, body mass index > 30, malignancy and drug abuse history, intensive care unit stay/ventilation > 7 days, aminotransferases > 3 times normal, serum bilirubin > 3 mg/dL, serum Na⁺ > 165 mmol/L, positive hepatitis serology, biopsy-proven macrovesicular steatosis (BPS) > 40%, and cold ischemia time (CIT) > 14 h. We analyzed hazard risk ratios of graft failure for each EDC and evaluated primary non-function (PNF). In addition, we analyzed 30-day, 90-day, 1-year, and 3-year graft survival. We established low- and high-risk graft (maEDC 0 vs. ≥ 1) and recipient (labMELD < 20 vs. ≥ 20) groups and compared the post-LT outcomes between these groups.

RESULTS

BPS > 40%, donor age > 65 years, and CIT > 14 h (all p < 0.05) were independent predictors of graft failure and patient mortality and increased PNF, 30-day, 90-day, 1-year, and 3-year graft failure rates. Three-year graft and patient survival decreased in recipients of ≥ 1 maEDC grafts (all p < 0.05) and LT of high-risk grafts into high-risk recipients yielded worse outcomes compared with other groups.

CONCLUSION

Donor age > 65 years, BPS > 40%, and CIT > 14 h are major EDC that decrease short and 3-year graft survival, and 3-year patient survival. An allocation algorithm based on maEDC and labMELD is therefore plausible.

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.

Extended Criteria Donors in Liver Transplantation

Mortality rates on the liver transplant waiting list are increasing. The shortage of organs has resulted in higher utilization of extended criteria donors (ECDs), with centers pushing the limits of what is acceptable for transplantation. Donor quality is more appropriately represented as a continuum of risk, and careful selection and matching of ECD grafts with recipients may lead to excellent outcomes. Although there is no precise definition for what constitutes an ECD liver, this review focuses on frequently cited characteristics, including donor age, steatosis, donation after cardiac death, and donors with increased risk of disease transmission.

Extended-criteria donors in liver transplantation Part II: reviewing the impact of extended-criteria donors on the complications and outcomes of liver transplantation

Extended-criteria donors (ECDs) have an impact on early allograft dysfunction (EAD), biliary complications, relapse of hepatitis C virus (HCV), and survivals. Early allograft dysfunction was frequently seen in grafts with moderate and severe steatosis. Donors after cardiac death (DCD) have been associated with higher rates of graft failure and biliary complications compared to donors after brain death. Extended warm ischemia, reperfusion injury and endothelial activation trigger a cascade, leading to microvascular thrombosis, resulting in biliary necrosis, cholangitis, and graft failure. The risk of HCV recurrence increased by donor age, and associated with using moderately and severely steatotic grafts. With the administration of protease inhibitors sustained virological response was achieved in majority of the patients. Donor risk index and EC donor scores (DS) are reported to be useful, to assess the outcome. The 1-year survival rates were 87% and 40% respectively, for donors with a DS of 0 and 3. Graft survival was excellent up to a DS of 2, however a DS >2 should be avoided in higher-risk recipients. The 1, 3 and 5-year survival of DCD recipients was comparable to optimal donors. However ECDs had minor survival means of 85%, 78.6%, and 72.3%. The graft survival of split liver transplantation (SLT) was comparable to that of whole liver orthotopic liver transplantation. SLT was not regarded as an ECD factor in the MELD era any more. Full-right-full-left split liver transplantation has a significant advantage to extend the high quality donor pool. Hypothermic oxygenated machine perfusion can be applied clinically in DCD liver grafts. Feasibility and safety were confirmed. Reperfusion injury was also rare in machine perfused DCD livers.

Extended criteria donors in liver transplantation Part I: reviewing the impact of determining factors

The definition and factors of extended criteria donors have already been set; however, details of the various opinions still differ in many respects. In this review, we summarize the impact of these factors and their clinical relevance. Elderly livers must not be allocated for hepatitis C virus (HCV) positives, or patients with acute liver failure. In cases of markedly increased serum transaminases, donor hemodynamics is an essential consideration. A prolonged hypotension of the donor does not always lead to an increase in post-transplantation graft loss if post-OLT care is proper. Hypernatremia of less than 160 mEq/L is not an absolute contraindication to accept a liver graft per se. The presence of steatosis is an independent and determinant risk factor for the outcome. The gold standard of the diagnosis is the biopsy. This is recommended in all doubtful cases. The use of HCV+ grafts for HCV+ recipients is comparable in outcome. The leading risk factor for HCV recurrence is the actual RNA positivity of the donor. The presence of a proper anti-HBs level seems to protect from de novo HBV infection. A favourable outcome can be expected if a donation after cardiac death liver is transplanted in a favourable condition, meaning, a warm ischemia time < 30 minutes, cold ischemia time < 8-10 hours, and donor age 50-60 years. The pathway of organ quality assessment is to obtain the most relevant information (e.g. biopsy), consider the co-existing donor risk factors and the reserve capacity of the recipient, and avoid further technical issues.

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.

Early markers of reperfusion injury after liver transplantation: association with primary dysfunction

BACKGROUND

In patients with end-stage liver disease, liver transplantation is the only available curative treatment. Although the outcome and quality of life in the patients have improved over the past decades, primary dys- or nonfunction (PDF/PNF) can occur. Early detection of PDF and PNF is crucial and could lead to individual therapies. This study was designed to identify early markers of reperfusion injury and PDF in liver biopsies taken during the first hour after reperfusion.

METHODS

Biopsies from donor livers were prospectively taken as a routine during the first hour after reperfusion. Recipient data, transaminases and outcome were routinely monitored. In total, 10 biopsy specimens taken from patients with 90-day mortality and PDF, and patients with long-term survival but without PDF were used for DNA microarrays. Markers that were significantly up- or down-regulated in the microarray were verified using quantitative real-time PCR.

RESULTS

Age, indications and labMELD score were similar in both groups. Peak-transaminases during the first week after transplantation were significantly different in the two groups. In total, 20 differentially regulated markers that correlated to PDF were identified using microarray analysis and verified with quantitative real-time PCR.

CONCLUSIONS

The markers identified in this study could predict PDF at a very early time point and might point to interventions that ameliorate reperfusion injury and thus prevent PDF. Identification of patients and organs at risk might lead to individualized therapies and could ultimately improve outcome.

Quantification of degree of steatosis in extended criteria donor grafts with standardized histologic techniques: implications for graft survival

The gap between the availability of livers from organ donors and the increased demand has led many centers to apply strategies to reduce this deficit. Splitting of cadaveric organs for use in 2 recipients; domino transplantation; and organs from living donors, non-heart-beating donors, and extended-criteria donors (ECDs) are all currently used in orthotopic liver transplantation (OLT). Fatty changes in the donor liver are a risk factor for poor function after OLT; however, the presence of steatosis, frequently present in livers from ECDs, does not exclude the use of these organs. Since January 2000 at our institution, we observed 39 steatotic grafts that were stratified istologically as follows: low steatosis, 5% to 15%; mild steatosis, 16% to 30%; moderate steatosis, 31% to 60%; and severe steatosis (>60%). Histologic techniques can enable identification of the type of fatty change as macrovesicular and microvesicular. These alterations have different effects on primary nonfunction and primary dysfunction. Fifteen grafts, all with severe or moderate, macrovesicular changes were discarded. Twenty-four fatty grafts with low to moderate steatosis were utilized for transplant. Sections from 2 liver biopsies (1 wedge in the left lobe and 1 needle in the right lobe) were stained with hematoxylin-eosin, Masson trichrome, Gomori reticulin, and oil red O. The OLT was performed only in patients with a MELD (Model for End-Stage Liver Disease) score lower than 27. The rate of primary dysfunction was 12.5%, and of primary nonfunction 8.4%. The 6-month graft survival for all fatty livers was 80%. We encourage the careful use of grafts with low to moderate steatosis in recipients without additional risks.

Ethical considerations surrounding survival benefit-based liver allocation

The disparity between the demand for and supply of donor livers has continued to grow over the last 2 decades, and this has placed greater weight on the need for efficient and effective liver allocation. Although the use of extended criteria donors has shown great potential, it remains unregulated. A survival benefit-based model was recently proposed to answer calls to increase efficiency and reduce futile transplants. However, it was previously determined that the current allocation system was not in need of modification and that instead geographic disparities should be addressed. In contrast, we believe that there is a significant need to replace the current allocation system and complement efforts to improve donor liver distribution. We illustrate this need first by identifying major ethical concerns shaping liver allocation and then by using these concerns to identify strengths and shortcomings of the Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease system and a survival benefit-based model. The latter model is a promising means of improving liver allocation: it incorporates a greater number of ethical principles, uses a sophisticated statistical model to increase efficiency and reduce waste, minimizes bias, and parallels developments in the allocation of other organs. However, it remains limited in its posttransplant predictive accuracy and may raise potential issues regarding informed consent. In addition, the proposed model fails to include quality-of-life concerns and prioritize younger patients. We feel that it is time to take the next steps toward better liver allocation not only through reductions in geographic disparities but also through the adoption of a model better equipped to balance the many ethical concerns shaping organ allocation. Thus, we support the development of a similar model with suggested amendments.

Isolation of human hepatocytes by a two-step collagenase perfusion procedure

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. As such, hepatocytes are an important model for a large variety of research questions. In particular, the use of human hepatocytes is especially important in the fields of pharmacokinetics, toxicology, liver regeneration and translational research. Thus, this method presents a modified version of a two-step collagenase perfusion procedure to isolate hepatocytes as described by Seglen (1). Previously, hepatocytes have been isolated by mechanical methods. However, enzymatic methods have been shown to be superior as hepatocytes retain their structural integrity and function after isolation. This method presented here adapts the method designed previously for rat livers to human liver pieces and results in a large yield of hepatocytes with a viability of 77±10%. The main difference in this procedure is the process of cannulization of the blood vessels. Further, the method described here can also be applied to livers from other species with comparable liver or blood vessel sizes.

The difficulty in defining extended donor criteria for liver grafts: the Eurotransplant experience

Donor criteria for liver grafts have been expanded because of organ shortage. Currently, no exact definitions for extended donor grafts have been established. The aim of this study was to analyze the impact of donor-specific risk factors, independent of recipient characteristics. In collaboration with Eurotransplant and European Liver Transplant Register, solely donor-specific parameters were correlated with 1-year survival following liver transplantation. Analyses of 4701 donors between 2000 and 2005 resulted in the development of a nomogram to estimate graft survival for available grafts. Predictions by nomogram were compared to those by Donor Risk Index (DRI). In the multivariate analysis, cold ischemic time (CIT), highest sodium, cause of donor death, γ-glutamyl transferase (γ-GT), and donor sex (female) were statistically significant factors for 3 months; CIT, γ-GT, and cause of donor death for 12-month survival. The median DRI of this study population was 1.45 (Q1: 1.17; Q3: 1.67). The agreement between the nomogram and DRI was weak (kappa = 0.23). Several donor-specific risk factors were identified for early survival after liver transplantation. The provided nomogram will support quick organ quality assessment. Nevertheless, this study showed the difficulties of determining an exact definition of extended criteria donors.

Septuagenarian and octogenarian donors provide excellent liver grafts for transplantation

BACKGROUND

Wider utilization of liver grafts from donors ≥ 70 years old could substantially expand the organ pool, but their use remains limited by fear of poorer outcomes. We examined the results at our center of liver transplantation (OLT) using livers from donors ≥ 70 years old.

METHODS

From February 2003 to August 2010, we performed 450 OLT including 58 (13%) using donors ≥ 70 whose outcomes were compared with those using donors <70 years old.

RESULTS

Cerebrovascular causes of death predominated among donors ≥ 70 (85% vs 47% in donors <70; P < .001). In contrast, traumatic causes of death predominated among donors <70 (36% vs 14% in donors ≥ 70; P = .002). Unlike grafts from donors <70 years old, grafts from older individuals had no additional risk factors (steatosis, high sodium, or hemodynamic instability). Both groups were comparable for cold and warm ischemia times. No difference was noted in posttransplant peak transaminases, incidence of primary nonfunction, hepatic artery thrombosis, biliary strictures, or retransplantation rates between groups. The 1- and 5-year patient survivals were 88% and 82% in recipients of livers <70 versus 90% and 84% in those from ≥ 70 years old (P = .705). Recipients of older grafts, who were 6 years older than recipients of younger grafts (P < .001), tended to have a lower laboratory Model for End-Stage Liver Disease score (P = .074).

CONCLUSIONS

Short and mid-term survival following OLT using donors ≥ 70 yo can be excellent provided that there is adequate donor and recipient selection. Septuagenarians and octogenarians with cerebrovascular ischemic and bleeding accidents represent a large pool of potential donors whose wider use could substantially reduce mortality on the OLT waiting list.

The aggressive phenotype revisited: utilization of higher-risk liver allografts

Organ shortage has led to increased utilization of higher risk liver allografts. In kidneys, aggressive center-level use of one type of higher risk graft clustered with aggressive use of other types. In this study, we explored center-level behavior in liver utilization. We aggregated national liver transplant recipient data between 2005 and 2009 to the center-level, assigning each center an aggressiveness score based on relative utilization of higher risk livers. Aggressive centers had significantly more patients reaching high MELDs (RR 2.19, 2.33 and 2.28 for number of patients reaching MELD>20, MELD>25 and MELD>30, p<0.001), a higher organ shortage ratio (RR 1.51, 1.60 and 1.51 for number of patients reaching MELD>20, MELD>25 and MELD>30 divided by number of organs recovered at the OPO, p<0.04), and were clustered within various geographic regions, particularly regions 2, 3 and 9. Median MELD at transplant was similar between aggressive and nonaggressive centers, but average annual transplant volume was significantly higher at aggressive centers (RR 2.27, 95% CI 1.47-3.51, p<0.001). In cluster analysis, there were no obvious phenotypic patterns among centers with intermediate levels of aggressiveness. In conclusion, highwaitlist disease severity, geographic differences in organ availability, and transplant volume are the main factors associated with the aggressive utilization of higher risk livers.

The PRAISE study: a prospective, multi-center, randomized, double blinded, placebo-controlled study for the evaluation of iloprost in the early postoperative period after liver transplantation (ISRCTN12622749)

Background

Liver graft dysfunction can deteriorate to complete organ failure and increases perioperative morbidity and mortality after liver transplantation. Therapeutic strategies reducing the rate of graft dysfunction are of current clinical relevance. One approach is the systemic application of prostaglandins, which were demonstrated to be beneficial in reducing ischemia-reperfusion injury. Preliminary data indicate a positive effect of prostacyclin analogue iloprost on allograft viability after liver transplantation. The objective of the study is to evaluate the impact of iloprost in a multi-center trial.

Methods/Design

A prospective, double-blinded, randomized, placebo-controlled multicenter study in a total of 365 liver transplant recipients was designed to assess the effect of intravenous iloprost after liver transplantation. Primary endpoint will be the primary graft dysfunction characterized as presentation of one or more of the following criteria: ALAT or ASAT level > 2000 IU/ml within the first 7 postoperative days, bilirubine ≥ 10 mg/dl on postoperative day 7; INR ≥ 1.6 on postoperative day 7 or initial non-function. Secondary endpoints are parameters of post-transplant morbidity, like rates of infections, biliary complications, need of clotting factors or renal replacement therapy and the graft and patient survival.

Discussion

A well-established treatment concept to avoid graft dysfunction after liver transplantation does not exist at the moment. If the data of this research project confirm prior findings, iloprost would improve the general outcome after liver transplantation.

Trial Registration

German Clinical Trials Register: DRKS00003514. Current Controlled Trials Register: ISRCTN12622749.

HTK-N, a modified HTK solution, decreases preservation injury in a model of microsteatotic rat liver transplantation

BACKGROUND

Ischemia/reperfusion injury is an obstacle especially in steatotic livers, including those with steatosis induced by acute toxic stress. Recently, a modified histidine-tryptophan-ketoglutarate (HTK) solution, HTK-N, has been developed. This solution contains N-acetylhistidine, amino acids, and iron chelators. This study was designed to test the effects of HTK-N on preservation injury to rat livers after acute toxic injury.

METHODS

Microvesicular steatosis was induced by a single dose of ethanol (8 g/kg BW). Livers were harvested and stored at 4 °C for 8 h with HTK or HTK-N before transplantation. Tissue and blood samples were taken at 1, 8, and 24 h after reperfusion to compare serum liver enzymes (aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase), standard histology, and immunohistochemistry for myeloperoxidase (MPO), caspase-3, and inducible nitric oxide synthase. Survival was compared after 1 week. For statistics, Analysis of Variance and t test were used.

RESULTS

HTK-N improved survival from 12.5% in HTK to 87.5% (p < 0.05). Furthermore, liver enzymes were decreased to 2-75% of HTK values (p < 0.05). Necrosis and leukocyte infiltration and MPO, caspase-3, and iNOS expression after transplantation were decreased (p < 0.05).

CONCLUSIONS

This study demonstrates that HTK-N protects liver grafts with microvesicular steatosis caused by acute toxic injury from cold ischemic injury better than standard HTK most likely via inhibition of hypoxic injury and oxidative stress and amelioration of the inflammatory reaction occurring upon reperfusion.

[Extended donor criteria defined by the German Medical Association : study on their usefulness as prognostic model for early outcome after liver transplantation]

INTRODUCTION

Expansion of the donor pool by the use of grafts with extended donor criteria reduces waiting list mortality with an increased risk for graft and patient survival after liver transplantation. The ability of the number of fulfilled extended donor criteria as currently defined by the German Medical Association (BÄK-Score) to predict early outcome is unclear.

PATIENTS

A total of 291 consecutive adult liver transplantations (01.01.2007-31.12.2010) in 257 adult recipients were analyzed.

METHODS

Primary study endpoints were 30 day mortality, 3 month mortality, 3 month patient and graft survival and the necessity of acute retransplantation within 30 days. For primary study endpoints a ROC curve analysis was performed to calculate sensitivity, specificity and overall model correctness of the BÄK score as a predictive model. Further methods included Kaplan-Meier estimates, log-rank tests, Cox regression analysis, logistic regression analysis and χ(2)-tests.

RESULTS

The number of extended donor criteria fulfilled had no statistically significant influence on the primary study endpoints (p > 0.05) or on patient survival (p > 0.05). ROC curve analysis revealed areas under the curve ≤ 0.561 for the prediction of primary study endpoints (overall model correctness < 58%, sensitivity < 52%).

CONCLUSIONS

The number of fulfilled extended donor criteria as currently defined by the German Medical Association is unable to predict early outcome after liver transplantation.

Ischemia/Reperfusion injury in liver surgery and transplantation: pathophysiology

Liver ischemia/reperfusion (IR) injury is caused by a heavily toothed network of interactions of cells of the immune system, cytokine production, and reduced microcirculatory blood flow in the liver. These complex networks are further elaborated by multiple intracellular pathways activated by cytokines, chemokines, and danger-associated molecular patterns. Furthermore, intracellular ionic disturbances and especially mitochondrial disorders play an important role leading to apoptosis and necrosis of hepatocytes in IR injury. Overall, enhanced production of reactive oxygen species, found very early in IR injury, plays an important role in liver tissue damage at several points within these complex networks. Many contributors to IR injury are only incompletely understood so far. This paper tempts to give an overview of the different mechanisms involved in the formation of IR injury. Only by further elucidation of these complex mechanisms IR injury can be understood and possible therapeutic strategies can be improved or be developed.

Impact of stable PGI₂ analog iloprost on early graft viability after liver transplantation: a pilot study

BACKGROUND

Ischemia/reperfusion injury after liver transplantation (LT) may be associated with primary graft dysfunction (PDF) or non-function. Prostaglandins were demonstrated to be beneficial in reducing ischemic injury by improving microcirculation and protecting endothelial cells. The aim of this study was to analyze the effect of the continuously administered prostaglandin I(2) analog iloprost on allograft function after LT.

METHODS

Eighty patients were prospectively randomized and assigned to two groups. Patients in the treatment group received iloprost for seven d after transplantation, and those in the control group did not. The primary end point was graft dysfunction.

RESULTS

The incidence of PDF was 20% (n = 8) in the control group and 5% (n = 2) in the treatment group, respectively (p = 0.087). Four patients in the control group underwent re-transplantation for initial non-function (INF). There was no evidence for INF in the treatment group. Iloprost was associated with improved allograft function. Clinical course and outcome were comparable.

CONCLUSIONS

We suggest iloprost to be beneficial for early post-transplant liver function. If the rate of PDF can be significantly reduced with this treatment concept, it should be analyzed in a larger number of patients (ISRCTN95672167).

LabMELD-based organ allocation increases total costs of liver transplantation: a single-center experience

INTRODUCTION

In 2006, model for end-stage liver disease (MELD)-based allocation was implemented in the Eurotransplant (ET) region. Sick patients, who in general require more resources, are prioritized. In this analysis, the effect of MELD on costs for liver transplantation (LTx) was assessed.

METHODS

Total costs for LTx before and after implementation of MELD were identified in 256 patients from January 2005-December 2007. Forty-nine patients (Re-LTx, HU listings, and 30-d mortality) were excluded from further analysis. The costs of LTx in 207 patients have been correlated with their corresponding labMELD; 84 and 123 LTx before and after implementation of MELD were compared, and patient survival was monitored.

RESULTS

A positive correlation exists between labMELD and costs (r(2) = 0.28; p < 0.05). Only nominal correlation existed between the Child-Pugh classification and costs. The labMELD scores can be stratified into four groups (I: 6-10, II: 11-18, III: 19-24, and IV: >24), with an increase of €15.672 ± 2.233 between each group (p < 0.05). Recipients' labMELD at the time of LTx increased significantly in the MELD-based allocation system. Costs increased by €11.650/patient (p < 0.05), while median survival decreased from 1219 to 869 d (p < 0.05).

CONCLUSION

LabMELD-based allocation increased total costs of LTx. In accordance with other studies, the sickest patients need the most resources.

Risk factors of survival after liver transplantation for HCC: a multivariate single-center analysis

BACKGROUND

The selection criteria for liver transplantation (LT) in patients with hepatocellular cancer (HCC) are well defined. Increasing evidence suggests that the effectiveness of pre-transplant bridging influences the individual course after LT significantly. Thus, the aim of this study was to determine its impact on tumor progression during waiting time and identify patient subgroups with favorable oncological long-term outcome.

METHODS

Prospectively collected data of 78 consecutive patients undergoing LT for HCC between 2001 and 2007 were analyzed retrospectively. Survival rates were assessed using the Kaplan-Meier estimate. Clinicopathologic prognostic factors were identified by Cox regression analysis.

RESULTS

After 48.9 months of median follow-up, the five-yr overall survival rate is 57% with a five-yr recurrence-free survival rate of 74%. Progressive disease (PD) during bridging was developed in 32% of patients, and a trend toward impaired overall survival in patients with PD before LT was detected in multivariate analysis (p = 0.073). HCC ≥3 cm was associated with a three times increased risk of recurrent disease. Neither fulfillment of MILAN criteria nor bridging with transarterial chemoembolization had an impact on the outcome.

CONCLUSION

PD during waiting time influences the oncological course after LT. However, even with an increasing organ shortage, further studies are warranted to define clear selection criteria based on the biological tumor behavior and allow a more personalized treatment.

Outcome of liver transplantation based on donor graft quality and recipient status

BACKGROUND

Availability of suitable donor organs has always limited the number of liver transplantations performed. Use of marginal donor organs is an alternative to overcome organ shortage.

OBJECTIVE

To analyze the effect of various combinations of donor organ quality and recipient status on the outcome of liver transplantation.

MATERIALS AND METHODS

Data from 260 whole-liver transplantations performed between January 2003 and September 2009 were analyzed retrospectively. Study groups were established according to donor organ quality (marginal score 0-1 vs 2-5) and recipient status (Model for End-Stage Liver Disease [MELD] score <17 or >17). In patients at low risk, 102 received optimal grafts (good-to-good group [G/G], and 75 received marginal grafts (bad-to-good group [B/G]. In patients at high risk, 46 received optimal grafts (good-to-bad group [G/B], and 37 received marginal grafts (bad-to-bad group [B/B].

RESULTS

No differences were observed in cumulative patient and graft survival rates; however, total survival differed in the early period after transplantation, that is, within 1 year. There was a higher rate of overall postoperative complications including initial poor graft function, bleeding, infection, and kidney failure in group B/B compared with group G/B (25 of 37 patients [67.5%] vs 27 of 46 patients [59.0%]), group B/G (25 of 37 patients [68%] vs 39 of 75 patients [52%], and group G/G (25 of 37 patients [68%] vs 43 of 102 patients [42%]) (P = .04). Patients with a high MELD score (G/B and B/B) demonstrated increased risk of postoperative complications. Use of donor organs with marginal score of 2 or higher in patients with high MELD scores increased early patient mortality.

CONCLUSION

In summary, patients with a high MELD score (G/B and B/B) are at an increased risk of post-OLT complications. In contrast, use of marginal grafts (B/G and B/B) increased the rate of hepatitis C virus recurrence and decreased the response rate to antiviral therapy. The combination of impaired donor grafts and recipients at high risk should be avoided.

The natural history of inflammatory bowel disease and primary sclerosing cholangitis after liver transplantation--a single-centre experience

OBJECTIVE

To describe the natural history of primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) after liver transplant, the predictors of PSC and IBD recurrence, and the interaction of these disease processes.

METHODS

Data regarding patients who received liver transplants for PSC at the University of Alberta Hospital (Edmonton, Alberta) from 1989 to 2006 were retrospectively reviewed. Recurrent PSC (rPSC) was defined by the Mayo Clinic criteria. Cox proportional hazards modelling and Kaplan-Meier statistics were used.

RESULTS

Fifty-nine patients were studied, with a median follow-up of 68 months. A total of 71.2% of patients were diagnosed with IBD pretransplant. Clinical IBD severity post-transplant compared with severity pretransplant was unchanged in 67%, worse in 26.5% and improved in 6.1% of patients. Twenty-five per cent of patients developed rPSC posttransplant. The occurrence of at least one episode of acute cellular rejection (hazard ratio 5.7; 95% CI 1.3 to 25.8) and cytomegalovirus mismatch (hazard ratio 4.2; 95% CI 1.1 to 15.4) were found to be significant predictors of rPSC. Although not statistically significant, there was no rPSC in patients without pre- or post-transplant IBD, and in only one patient with a colectomy. Actuarial patient survival rates at one, five and 10 years posttransplant were 97%, 86% and 79%, respectively. Although a significant proportion of patients experienced worsening IBD post-transplantation, the presence or severity of IBD did not influence rPSC or patient survival.

CONCLUSION

Acute cellular rejection and cytomegalovirus mismatch were both identified as independent predictors of rPSC. The impact of steroids and the ideal immunosuppressive regimen for the control of both IBD and PSC post-transplant requires further examination in prospective studies.

Correlation between selected prognostic factors and postoperative course in liver transplant recipients

AIM

The objective was to identify the major prognostic factors influencing liver function after transplantation that predict the postoperative course and long-term survival among liver transplant recipients. We analyzed the results of biochemical, microbiological, serologic, and pathologic studies of the donor and recipient, as well as intraoperative data.

MATERIALS AND METHODS

Of 542 liver transplant recipients, 215 (39.7%) were analyzed in the period from 1989 to 2006. Patients were divided according to the mechanism leading to the liver disease: group I, hepatitis C virus (HCV) infection (n = 80, 37.0%); group II, hepatitis B virus (HBV) infection (n = 33, 15.0%); group III, HBV and HCV infection (n = 13, 6.0%); group IV, alcoholic liver disease (ALD) (n = 66, 31.0%); and group V, autoimmune hepatitis (AIH) (n = 23, 11.0%).

RESULTS

Prediction of patient survival based on clinical parameters showed a better prognostic value than that based only on liver function tests. Transplant urgency scores-Model for End-Stage Liver Disease (MELD), delta MELD and United Network for Organ Sharing (UNOS)-enabled us to predict early and long-term patient survival after liver transplantation. Update of these scores, reflecting the patient's condition, enabled us to evaluate pretransplant life-threatening factors and urgency level. Organ donation predictive factors were age, viral status, and degree of liver steatosis. Cold and warm ischemia times still were major prognostic factor. Routine biliary drainage resulted in worse long-term survival than non-drained patients. Liver transplantation for ALD showed the highest complication rate. Chronic liver rejection occurred more frequently in the AIH transplanted group. The most useful predictive factors for 1-year survival were urea/creatinine and liver function tests: aspartate and alanine aminotransferases, gamma-glutamyl transpeptidase the International normalized ratio, and Quick.

CONCLUSION

The prognosis of patient outcomes after liver transplantation based on clinical parameters showed greater value than evaluation of the laboratory data.

Hepatic steatosis in organ donors: disparity between surgery and histology?

BACKGROUND

In times of organ shortage, use of marginal cadaveric livers has become increasingly important to reduce pressing organ demand and rising death rates while awaiting donations. Indisputably, fatty change in donor livers is a risk factor for poor initial function after orthotopic transplantation. However, identifying and rejecting marginal from good donor livers is one of the most difficult surgical tasks. Unfortunately, a liver biopsy with rapid histological diagnosis is rarely performed to identify marginal livers.

METHODS

From 2005 to 2008, we investigated 36 livers of organ donors, which were explanted but not transplanted or underwent liver wedge biopsy during organ donation. All livers underwent standard surgical procedures and were allocated by Eurotransplant International Foundation. After unsuccessful allocation, explanted livers were photographically documented, formalin-fixed, and analyzed histopathologically.

RESULTS

Seven livers were classified as good organ quality by the surgeon (19.4%); 15 were acceptable (41.6%); and 14 poor (39%). In 63.8% of livers, a frozen section was performed; 6/36 cases (16.7%) showed macrovesicular and microvesicular steatosis of less than 30%. In addition, all six cases fulfilled two or less extended donor criteria, as defined by the German Medical Association.

CONCLUSION

More marginal livers from cadaveric organ donors could have been transplanted. To extend the transplant pool of liver grafts, liver biopsies should be performed in all cases of acceptable and poor livers. If frozen section analysis is performed, a wedge liver biopsy should be taken from at least two different segments of the liver to validate the histological results.

The role of marginal donors in liver transplantation. The Hungarian experience

A májátültetések számát korlátozza a beültetésre alkalmas donorszervek mennyisége. A szervhiány megoldására az egyik lehetőség az úgynevezett marginális donorok (extended donor criteria) elfogadása a májátültetési programban. Célkitűzés: A magyar májátültetési program szervdonációs jellemzőinek vizsgálata, különös tekintettel a marginális donorokra. Módszer: Donor- és recipiensadatok retrospektív feldolgozása 2003. január és 2008. december között. A marginálisdonor-kritériumrendszert nemzetközi ajánlások alapján állítottuk fel. Eredmények: A vizsgált periódus alatt összesen 1078 donort jelentettek a klinikán. Nyolcszázharmincöt esetben (77,4%) alkalmatlannak ítélték a donormájat a transzplantációra, 243 esetben (22,6%) volt beültetésre alkalmas a donormáj. A beültetett májgraftok közül 40 (16%) származott marginális, 203 (84%) nem marginális donorból. Marginális májgraftok beültetése esetén nem volt különbség a beteg- és grafttúlélésben, a posztoperatív graftfunkciót jelző paraméterekben és az általános szövődmények gyakoriságában. A korai hepatitis C-rekurrencia gyakoribb volt marginális graft beültetése esetén. Következtetések: A májátültetésre váró betegek száma hazánkban is folyamatosan növekszik. Marginális májgraftok alkalmazása esetén a betegek morbiditása és mortalitása nem különbözik számottevően a standard donorokból származó májgraftok beültetése után tapasztalt eredményektől. Hepatitis C-vírus esetén nem javasolt marginális májgraft beültetése. A donorok felső életkori határának kiterjesztése megfontolandó.

Donor risk index and MELD interactions in predicting long-term graft survival: a single-centre experience

INTRODUCTION

Feng et al. described the donor risk index (DRI) in North American liver transplant recipients. We evaluated the effect of the DRI and model for end-stage liver disease (MELD) score on liver transplant recipients from a single center in the United Kingdom.

METHOD

Prospectively, collected data of all patients transplanted at our center between January 1995 and December 2005 were included in the analysis (n=1090). Outcomes evaluated included patient-censored and death-censored graft survival. Outcomes of liver transplantation from "high" and "low" DRI groups (> or =1.8 and <1.8, respectively) on patients categorized into low (<15), intermediate (15-30), and high (>30) MELD categories were analyzed.

RESULTS

MELD at transplant was the only significant predictor of patient survival. MELD at transplant and DRI more than 1.7 were associated with a poorer graft survival (P=0.03). There was a trend toward poorer graft survival in high DRI grafts transplanted in low and "intermediate" MELD categories (P=0.47 and 0.006, respectively). However, in the high MELD category, there was a similar graft survival for both high and low DRI grafts.

CONCLUSION

Patients with low and intermediate MELDs at transplantation may be better served by a low DRI graft, whereas patients with high MELD may not be compromised by receiving a high DRI graft.

Feasibility and effectiveness of a new algorithm in preventing hepatic artery thrombosis after liver transplantation

INTRODUCTION

The incidence of hepatic artery thrombosis (HAT) after liver transplantation (LTx) is up to 9% in adult recipients.

MATERIAL AND METHODS

To minimize HAT, we developed an algorithm that we have routinely applied since 2001. The algorithm is a cascade of potentially necessary procedures to improve hepatic artery blood flow before proceeding with LTx when arterial blood flow is impaired. Incidence, outcome, and possible therapeutic approaches of HAT were analyzed in prospectively non-controlled collected data during a 5-year period. There were 335 LTx in 299 adults (199 male, 100 female) with a median age of 49.7 years.

RESULTS

HAT was defined as early and late HAT (diagnosis within or after 30 days following LTx). After a mean follow-up of 17 months, nine HAT were documented (2.7%; five early and four late HAT). Treatment consisted of thrombolysis (n = 1), surgical thrombectomy (n = 4), and re-transplantation (n = 4). Five HAT patients died during follow-up.

DISCUSSION

Complex arterial reconstruction was associated with HAT compared to branch-patch anastomoses (P = 0.0193). Median arterial intraoperative blood flow was no risk factor for HAT. One-year patient survival after HAT was 31%. Once HAT occurs, complication rates are high and long-term results are devastating.

CONCLUSION

Therefore, we have implemented the presented algorithm, which showed an acceptable HAT rate.

[Liver transplantation: influence of donor-related factors]

OBJECTIVE

To detect donor characteristics related to graft function after orthotopic liver transplantation (OLT).

DESIGN

Retrospective cohort study.

CONTEXT

Polyvalent intensive care unit.

PATIENTS

145 liver transplant recipients and their respective donors.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

In donors: age, hypernatremia, and infection. In recipients: reperfusion syndrome, coagulopathy, infection, ARDS, shock, kidney failure, primary graft dysfunction, and mortality.

RESULTS

71.7% of recipients were male. Mean recipient age was 54.5 +/- 9.9 years; 66.2% of patients were classified as Child B and and 19.3% as Child C. The mean model for end-stage liver disease (MELD) score was 14.6 +/- 4.8 and the mean APACHE II score was 17.3 +/- 4.9. A total of 64.1% of the donors were male. Mean donor age was 42.3 +/- 16.3 years, and mean APACHE II score was 22.3 +/- 5.8. Donor age > 65 years was associated to higher recipient aspartate aminotransferase (AST) levels but not to increased complications or mortality. No other donor factors (including age, sex, serum sodium, severity level, transfusions, hemodynamic alterations, renal dysfunction, or infection) were associated to evolution or prognosis. Infection was diagnosed in 18 recipients (12.4%) in the postoperative period; the incidence of infection in recipients that received an organ from infected donors was not different from those that received an organ from an uninfected donor (14.6% versus 11.5%; p > 0.05).

CONCLUSIONS

We detected no donor characteristics related to graft function or the appearance of complications in recipients during the immediate postoperative period. Donor age > 65 years and documented but appropriately treated bacteremia posed no risk for the viability of the liver after transplantation.

[Orthotopic liver transplantation. Techniques and results]

Since 1963, orthotopic liver transplantation (OLT) has developed into an established interdisciplinary therapy concept for patients with end-stage liver disease, acute irreversible liver failure, and hepatic malignancies in selected cases. In 26 centers in Germany, around 900 full-size OLTs are performed annually. The classic technique has been replaced by the "piggyback" method, which has become the standard in many centres. Improvements in surgical techniques, anaesthetic protocols, and medical management along with the introduction of new immunosuppressive regimens and early adequate therapy against infections and transplant rejection have increased patient survival. These factors have resulted in 1-year survival rates of 80-90% and led to an increase in indications for OLT. Despite decades of experience, approximately 10% of the mortality in the first 3 months still can be traced to technical complications.

Ischemic preconditioning in hepatic ischemia and reperfusion

PURPOSE OF REVIEW

Ischemic preconditioning that consists of a short period of hepatic inflow occlusion followed by reperfusion has the potential to increase tolerance to a subsequent prolonged ischemic insult. This review outlines current insight into ischemic preconditioning for hepatic ischemia and reperfusion injury in experimental and clinical settings.

RECENT FINDINGS

Experimental evidence suggests that interleukin-6 signaling and increased phosphorylation of STAT3 (signal transducer and activator of transcription-3) are involved in the protective effects of ischemic preconditioning. The benefit of ischemic preconditioning is restricted, however, by old liver and prolonged ischemic time (>60 min). To overcome this, ascorbic acid or glucose administration combined with ischemic preconditioning potentially can maintain the integrity of hepatic mitochondrial function through signal transduction pathways. The influence of ischemic preconditioning on hepatic regeneration varies with partial hepatectomy or small-for-size liver graft models, and remains controversial. Clinically, ischemic preconditioning in deceased donors protects against ischemia and reperfusion injury, as demonstrated by lowered liver enzyme levels, reduced incidence of primary nonfunction, and increased hepatic hypoxia-induced factor-1alpha concentrations.

SUMMARY

Enhanced understanding of the mechanisms of organ tolerance induced by ischemic preconditioning would strengthen the significance of this potential therapeutic strategy in liver transplantation.

Profile of cadaveric liver donors of the OPO-UNICAMP From 2002 to 2006

INTRODUCTION

Four decades after the first successful liver transplantation, the organ donation shortage challenges the scientific community to create various new strategies.

OBJECTIVES

We sought to analyze the profile of registered cadaveric liver donors for an Organ Procurement Organization (OPO) during the period of 2002 through 2006.

METHODS

This retrospective analysis of 122 deceased donors in the OPO-Unicamp corresponded to the period of 2002 through 2006.

RESULTS

Men were identified as 57.14% of donors and the overall average age was 32.88 years with 16.53% over 50 years of age. Analyzing the causes of brain death, cerebral trauma (CET) was responsible for 46.22% and cerebral vascular accidents, 33.61%. The percentage of use of vasoactive drugs was 88.43%. Observing the donors' backgrounds, we observed that 11.90% had alcoholism, 1.23% drug addiction and 27.78% infection. We verified cardiac arrest in 9.43%. In accordance with the expanded criteria of donation, 89.26% of donors fulfilled some of the criteria: 73.55%, one criterion; 14.05%, two; 1.65%, three; and no donor fulfilled 4 or 5.

CONCLUSION

The donor profile in our unit is a young man with CET and who fulfills at least one expanded donation criterion. Finally, to increase the number of donors, the use of vasoactive drugs (89.26%), cardiopulmonary resuscitation (9.43%), and infection (27.78%) were not considered reasons to discard the liver.

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.

Current concepts in transplant surgery: liver transplantation today

INTRODUCTION

The discipline of liver transplantation (LTx) has been developed over the past decades, and LTx is now considered the gold standard for the treatment of patients with end-stage liver diseases and early liver tumors in cirrhotic livers. This procedure is now performed routinely in many transplant centers, and it has provided an enormous technical innovation to the field of hepatobiliary surgery. Allocation decision of liver organs is based on medical need and timing.

MATERIALS AND METHODS

The Mayo Model for End Stage Liver Disease based on patient-specific criteria was developed and applied to prioritize patients on the waiting list. From the donor aspects of LTx, sources of organ, excluding xenotransplantation, can be brain-dead donors, living donors, and non-heart-beating donors. Today, the majority of livers are procured from cadaveric donors. In addition to the conventional LTx, other types are living-donor LTx, reuse of grafts as domino transplantation, ex situ as well as in situ split LTx, and reduced-size LTx. The transplantation procedure consists of several steps including donor selection and management, liver procurement and preservation, back-table preparation, recipient operation with liver implantation, postoperative care, immunosuppression, and follow-up.

RESULTS

The postoperative complications are divided into surgical, non-surgical, and multifactorial complications. Surgical complications account about 34% of morbidities after LTx and are mainly categorized to vascular and biliary complications. The main medical ones are non-surgical bleeding and infections. The multifactorial complications include primary non- or poor function and small-for-size syndrome. The pretransplant outcome predictors of LTx can be divided into donor, recipient, operative, and postoperative factors.

CONCLUSION

LTx is now considered a safe and standardized procedure with a substantially improved graft and patient survival and acceptable morbidity rates. However, the new problems, including recurrence of hepatitis C or hepatocellular carcinoma, chronic biliary complications, opportunistic infections, and development of de-novo malignancies are the major problems affecting the long-term outcome of transplanted patients.