An outcome comparison between primary liver transplantation and retransplantation based on the pretransplant MELD score

LIVER RETRANSPLANTATION: PROGNOSTIC SCORES AND RESULTS IN THE STATE OF PARANÁ

BACKGROUND

Hepatic retransplantation is associated with higher morbidity and mortality when compared to primary transplantation. Given the scarcity of organs and the need for efficient allocation, evaluating parameters that can predict post-retransplant survival is crucial.

AIMS

This study aimed to analyze prognostic scores and outcomes of hepatic retransplantation.

METHODS

Data on primary transplants and retransplants carried out in the state of Paraná in 2019 and 2020 were analyzed. The two groups were compared based on 30-day survival and the main prognostic scores of the donor and recipient, namely Model for End-Stage Liver Disease (MELD), MELD-albumin (MELD-a), Donor MELD (D-MELD), Survival Outcomes Following Liver Transplantation (SOFT), Preallocation Score to Predict Survival Outcomes Following Liver Transplantation (P-SOFT), and Balance of Risk (BAR).

RESULTS

A total of 425 primary transplants and 30 retransplants were included in the study. The main etiology of hepatopathy in primary transplantation was ethylism (n=140; 31.0%), and the main reasons for retransplantation were primary graft dysfunction (n=10; 33.3%) and hepatic artery thrombosis (n=8; 26.2%). The 30-day survival rate was higher in primary transplants than in retransplants (80.5% vs. 36.7%, p=0.001). Prognostic scores were higher in retransplants than in primary transplants: MELD 30.6 vs. 20.7 (p=0.001); MELD-a 31.5 vs. 23.5 (p=0.001); D-MELD 1234.4 vs. 834.0 (p=0.034); SOFT 22.3 vs. 8.2 (p=0.001); P-SOFT 22.2 vs. 7.8 (p=0.001); and BAR 15.6 vs. 8.3 (p=0.001). No difference was found in terms of Donor Risk Index (DRI).

CONCLUSIONS

Retransplants exhibited lower survival rates at 30 days, as predicted by prognostic scores, but unrelated to the donor's condition.

An updated analysis of retransplantation following living donor liver transplantation in the United States: Insights from the latest UNOS database

There is no recent update on the clinical course of retransplantation (re-LT) after living donor liver transplantation (LDLT) in the US using recent national data. The UNOS database (2002-2023) was used to explore patient characteristics in initial LT, comparing deceased donor liver transplantation (DDLT) and LDLT for graft survival (GS), reasons for graft failure, and GS after re-LT. It assesses waitlist dropout and re-LT likelihood, categorizing re-LT cohort based on time to re-listing as acute or chronic (≤ or > 1 mo). Of 132,323 DDLT and 5955 LDLT initial transplants, 3848 DDLT and 302 LDLT recipients underwent re-LT. Of the 302 re-LT following LDLT, 156 were acute and 146 chronic. Primary nonfunction (PNF) was more common in DDLT, although the difference was not statistically significant (17.4% vs. 14.8% for LDLT; p = 0.52). Vascular complications were significantly higher in LDLT (12.5% vs. 8.3% for DDLT; p < 0.01). Acute re-LT showed a larger difference in primary nonfunction between DDLT and LDLT (49.7% vs. 32.0%; p < 0.01). Status 1 patients were more common in DDLT (51.3% vs. 34.0% in LDLT; p < 0.01). In the acute cohort, Kaplan-Meier curves indicated superior GS after re-LT for initial LDLT recipients in both short-term and long-term ( p = 0.02 and < 0.01, respectively), with no significant difference in the chronic cohort. No significant differences in waitlist dropout were observed, but the initial LDLT group had a higher re-LT likelihood in the acute cohort (sHR 1.40, p < 0.01). A sensitivity analysis focusing on the most recent 10-year cohort revealed trends consistent with the overall study findings. LDLT recipients had better GS in re-LT than DDLT. Despite a higher severity of illness, the DDLT cohort was less likely to undergo re-LT.

Liver retransplantation: Timing is equally important

BACKGROUND AND AIM

To evaluate the effect of transplantation interval on patient and graft survival in liver retransplantation (reLT) using meta-analytical techniques.

METHODS

Literature search was undertaken until January 2022 to identify comparative studies evaluating patient survival rates, graft survival rates, and the interval time. Pooled hazard ratio (HR) or risk ratio (RR) and 95% confidence intervals (95% CI) were calculated with either the fixed or random effect model.

RESULTS

The 12 articles were included in this meta-analysis. The late reLT survival rate is better than the early reLT in the 30 days group, and there is no statistical significance in other time groups. The patient survival was significantly higher in late reLT than early reLT at 1 and 5 years (respectively: RR, 0.81 [95% CI, 0.73-0.89]; RR, 0.64 [95% CI, 0.46-0.88]). The graft survival was significantly higher in late reLT than early reLT at 1 year (RR, 0.75 [95% CI, 0.63-0.89]). The risk of death after reLT in early group was 1.43 times higher than that in late group (HR, 1.43 [95% CI, 1.21-1.71]).

CONCLUSIONS

Late reLT had significantly better survival rates than early reLT, and the transplantation interval was more reasonable to divide the early or late groups by 30 days.

Long-term outcomes of retransplantation after live donor liver transplantation: A Western experience

BACKGROUND

Despite most liver transplants in North America being from deceased donors, the number of living donor liver transplants has increased over the last decade. Although outcomes of liver retransplantation after deceased donor liver transplantation have been widely published, outcomes of retransplant after living donor liver transplant need to be further elucidated.

METHOD

We aimed to compare waitlist outcomes and survival post-retransplant in recipients of initial living or deceased donor grafts. Adult liver recipients relisted at University Health Network between April 2000 and October 2020 were retrospectively identified and grouped according to their initial graft: living donor liver transplants or deceased donor liver transplant. A competing risk multivariable model evaluated the association between graft type at first transplant and outcomes after relisting. Survival after retransplant waitlisting (intention-to-treat) and after retransplant (per protocol) were also assessed. Multivariable Cox regression evaluated the effect of initial graft type on survival after retransplant.

RESULTS

A total of 201 recipients were relisted (living donor liver transplants, n = 67; donor liver transplants, n = 134) and 114 underwent retransplant (living donor liver transplants, n = 48; deceased donor liver transplants, n = 66). The waitlist mortality with an initial living donor liver transplant was not significantly different (hazard ratio = 0.51; 95% confidence interval, 0.23-1.10; P = .08). Both unadjusted and adjusted graft loss risks were similar post-retransplant. The risk-adjusted overall intention-to-treat survival after relisting (hazard ratio = 0.76; 95% confidence interval, 0.44-1.32; P = .30) and per protocol survival after retransplant (hazard ratio:1.51; 95% confidence interval, 0.54-4.19; P = .40) were equivalent in those who initially received a living donor liver transplant.

CONCLUSION

Patients requiring relisting and retransplant after either living donor liver transplants or deceased donor liver transplantation experience similar waitlist and survival outcomes.

The Interplay between Gut Microbiota and the Immune System in Liver Transplant Recipients and Its Role in Infections

Liver transplantation (LT) is a life-saving strategy for patients with end-stage liver disease, hepatocellular carcinoma, and acute liver failure. LT success can be hampered by several short-term and long-term complications. Among them, bacterial infections, especially those due to multidrug-resistant germs, are particularly frequent, with a prevalence between 19 and 33% in the first 100 days after transplantation. In the last decades, a number of studies have highlighted how the gut microbiota (GM) is involved in several essential functions to ensure intestinal homeostasis, becoming one of the most important virtual metabolic organs. The GM works through different axes with other organs, and the gut-liver axis is among the most relevant and investigated ones. Any alteration or disruption of the GM is defined as dysbiosis. Peculiar phenotypes of GM dysbiosis have been associated with several liver conditions and complications, such as chronic hepatitis, fatty liver disease, cirrhosis, and hepatocellular carcinoma. Moreover, there is growing evidence of the crucial role of the GM in shaping the immune response, both locally and systemically, against pathogens. This paves the way to the manipulation of the GM as a therapeutic instrument to modulate infectious risk and outcome. In this minireview, we provide an overview of the current understanding of the interplay between the gut microbiota and the immune system in liver transplant recipients and the role of the former in infections.

Retransplantation outcomes for hepatitis C in the United States before and after direct-acting antiviral introduction

The success of direct-acting antiviral (DAA) therapy has led to near-universal cure for patients chronically infected with hepatitis C virus (HCV) and improved post-liver transplant (LT) outcomes. We investigated the trends and outcomes of retransplantation in HCV and non-HCV patients before and after the introduction of DAA. Adult patients who underwent re-LT were identified in the Organ Procurement and Transplantation Network/United Network for Organ Sharing database. Multiorgan transplants and patients with >2 total LTs were excluded. Two eras were defined: pre-DAA (2009-2012) and post-DAA (2014-2017). A total of 2112 re-LT patients were eligible (HCV: n = 499 pre-DAA and n = 322 post-DAA; non-HCV: n = 547 pre-DAA and n = 744 post-DAA). HCV patients had both improved graft and patient survival after re-LT in the post-DAA era. One-year graft survival was 69.8% pre-DAA and 83.8% post-DAA (P < .001). One-year patient survival was 73.1% pre-DAA and 86.2% post-DAA (P < .001). Graft and patient survival was similar between eras for non-HCV patients. When adjusted, the post-DAA era represented an independent positive predictive factor for graft and patient survival (hazard ratio [HR]: 0.67; P = .005, and HR: 0.65; P = .004) only in HCV patients. The positive post-DAA era effect was observed only in HCV patients with first graft loss due to disease recurrence (HR: 0.31; P = .002, HR 0.32; P = .003, respectively). Among HCV patients, receiving a re-LT in the post-DAA era was associated with improved patient and graft survival.

Selected liver grafts from donation after circulatory death can be safely used for retransplantation - a multicenter retrospective study

Due to the growing number of liver transplantations (LTs), there is an increasing number of patients requiring retransplantation (reLT). Data on the use of grafts from extended criteria donors (ECD), especially donation after circulatory death (DCD), for reLT are lacking. We aimed to assess the outcome of patients undergoing reLT using a DCD graft in the Netherlands between 2001 and July 2018. Propensity score matching was used to match each DCD-reLT with three DBD-reLT cases. Primary outcomes were patient and graft survival. Secondary outcome was the incidence of biliary complications, especially nonanastomotic strictures (NAS). 21 DCD-reLT were compared with 63 matched DBD-reLTs. Donors in the DCD-reLT group had a significantly lower BMI (22.4 vs. 24.7 kg/m² , P-value = 0.02). Comparison of recipient demographics and ischemia times yielded no significant differences. Patient and graft survival rates were comparable between the two groups. However, the occurrence of nonanastomotic strictures after DCD-reLT was significantly higher (38.1% vs. 12.7%, P-value = 0.02). ReLT with DCD grafts does not result in inferior patient and graft survival compared with DBD grafts in selected patients. Therefore, DCD liver grafts should not routinely be declined for patients awaiting reLT.

Early Vs Late Liver Retransplantation: Different Characteristics and Prognostic Factors

BACKGROUND

East Asia is a known endemic area for hepatitis B, and living donor liver transplantation is mainly performed. Liver retransplantation (ReLT) is expected to become an increasing problem because of a shortage of organs. This study aimed to compare early and late ReLT with consideration of specific circumstances and disease background of East Asians.

METHODS

Between October 1996 and January 2015, 51 patients underwent ReLT; we performed a retrospective analysis of data obtained from medical records of the patients. Clinical characteristics, indication, causes of death, survival rate, and prognostic factors were investigated.

RESULT

The survival rate for early ReLT (n = 18) was 51.5% and that for late ReLT (n = 33) was 50.1% at 1 year postoperatively. Continuous venovenous hemodialysis and the use of mechanical ventilators were more frequent, and pre-retransplant intensive care unit stay and prothrombin time was longer in early ReLT than in late ReLT. Operation time was longer and the amount of intraoperative blood loss was greater in late ReLT than in early ReLT. Multivariate analysis showed that a higher C-reactive protein level increased mortality in early ReLT (P = .045), whereas a higher total bilirubin level increased the risk of death in late ReLT (P = .03).

CONCLUSION

Patients with early ReLT are likely to be sicker pre-retransplantation and require adequate treatment of the pretransplant infectious disease. On the other hand, late ReLT is likely to be technically more difficult and should be decided before the total bilirubin level increases substantially.

Primary non-function is frequently associated with fatty liver allografts and high mortality after re-transplantation

BACKGROUND & AIMS

The shortage of liver donations demands the use of suboptimal grafts with steatosis being a frequent finding. Although ≤30% macrovesicular steatosis is considered to be safe the risk for primary non-function (PNF) and outcome after re-transplantation (re-OLT) is unknown.

METHODS

Among 1205 orthotopic liver transplantations performed at our institution the frequency, survival and reason of re-OLT were evaluated. PNF (group A) cases and those with initial transplant function but subsequent need for re-OLT (group B) were analysed. Histopathology and clinical judgement determined the cause of PNF and included an assessment of hepatic steatosis. Additionally, survival of fatty liver allografts (group C) not requiring re-OLT was considered in Kaplan-Meier and multivariate regression analysis.

RESULTS

A total of 77 high urgency re-OLTs were identified and included 39 PNF cases. Nearly 70% of PNF cases were due to primary fatty liver allografts. The 3-month in-hospital mortality for PNF cases after re-OLT was 46% and the mean survival after re-OLT was 0.5 years as compared to 5.2 and 5.1 years for group B, C, respectively, (P<.008). In multivariate Cox regression analysis only hepatic steatosis was associated with an inferior survival (HR 4.272, P=.002). The MELD score, donor BMI, age, cold ischaemic time, ICU stay, serum sodium and transaminases did not influence overall survival.

CONCLUSIONS

Our study highlights fatty liver allografts to be a major cause for PNF with excessive mortality after re-transplantation. The findings demand the development of new methods to predict risk for PNF of fatty liver allografts.

Outcomes of liver retransplantation in patients with primary sclerosing cholangitis

Liver retransplantation in patients with primary sclerosing cholangitis (PSC) has not been well studied. The aims of this study were to characterize patients with PSC listed for and undergoing retransplantation and to describe the outcomes in these patients. The United Network for Organ Sharing/Organ Procurement and Transplantation Network database was used to identify all primary liver transplantations and subsequent relistings and first retransplantations in adults with PSC between 1987 and 2015. A total of 5080 adults underwent primary transplantation for PSC during this period, and of the 1803 who experienced graft failure (GF), 762 were relisted, and 636 underwent retransplantation. Younger patients and patients with GF due to vascular thrombosis or biliary complications were more likely to be relisted, whereas those with Medicaid insurance or GF due to infection were less likely. Both 5-year graft and patient survival after retransplantation were inferior to primary transplantation (P < 0.001). Five-year survival after retransplantation for disease recurrence (REC), however, was similar to primary transplantation (graft survival, P = 0.45; patient survival, P = 0.09) and superior to other indications for retransplantation (graft and patient survival, P < 0.001). On multivariate analysis, mechanical ventilation, creatinine, bilirubin, albumin, advanced donor age, and a living donor were associated with poorer outcomes after retransplantation. In conclusion, although survival after liver retransplantation in patients with PSC was overall inferior to primary transplantation, outcomes after retransplantation for PSC REC were similar to primary transplantation at 5 years. Retransplantation may therefore represent a treatment option with the potential for excellent outcomes in patients with REC of PSC in the appropriate clinical circumstances. Liver Transplantation 23 769-780 2017 AASLD.

Biomarkers to assess graft quality during conventional and machine preservation in liver transplantation

A global rising organ shortage necessitates the use of extended criteria donors (ECD) for liver transplantation (LT). However, poor preservation and extensive ischemic injury of ECD grafts have been recognized as important factors associated with primary non-function, early allograft dysfunction, and biliary complications after LT. In order to prevent for these ischemia-related complications, machine perfusion (MP) has gained interest as a technique to optimize preservation of grafts and to provide the opportunity to assess graft quality by screening for extensive ischemic injury. For this purpose, however, objective surrogate biomarkers are required which can be easily determined at time of graft preservation and the various techniques of MP. This review provides an overview and evaluation of biomarkers that have been investigated for the assessment of graft quality and viability testing during different types of MP. Moreover, studies regarding conventional graft preservation by static cold storage (SCS) were screened to identify biomarkers that correlated with either allograft dysfunction or biliary complications after LT and which could potentially be applied as predictive markers during MP. The pros and cons of the different biomaterials that are available for biomarker research during graft preservation are discussed, accompanied with suggestions for future research. Though many studies are currently still in the experimental setting or of low evidence level due to small cohort sizes, the biomarkers presented in this review provide a useful handle to monitor recovery of ECD grafts during clinical MP in the near future.

Hepatic retransplant: what have we learned?

Hepatic retransplant accounts for 5% to 15% of liver transplants in most series and is associated with significantly increased hospital costs and inferior patient survival when compared with primary liver transplant. Early retransplants are usually due to primary graft nonfunction or vascular thrombosis, whereas later retransplants are most commonly necessitated by chronic rejection or recurrent primary liver disease. Hepatic retransplant remains the sole option for survival in many patients facing allograft failure after liver transplant. With improved techniques to match retransplant candidates with appropriate donor grafts, it is hoped that the outcomes of retransplant will continue to improve in future.

Have we changed the liver retransplantation survival?

INTRODUCTION

Orthotropic liver retransplantation (RT) is the therapeutic option for the failure of an allograft. Patient and graft survival rates after RT are inferior to primary liver transplantation (OLT). Because of the limited number of donors, it is essential that we optimize their use. We reviewed 68 consecutive retransplantations to evaluate their results.

MATERIALS AND METHODS

Using registry data from our Liver Transplantation Unit, we performed a retrospective cohort study of adult RT between 1991 and 2010. Patients were divided into 2 groups (urgent vs elective RT) to compare the utility of RT. We also analyzed data collected at the time of RT, including age, gender, indications for primary OLT and RT (hepatitis C virus [HCV]+ and HCV-). At various stages (1991-2000, 2001-2006, and 2007-2010), we calculated probability survival curves according to the Kaplan-Meier method with comparisons using the log-rank test.

RESULTS

Among 771 adult liver transplantations, 68 (8.8%) underwent late secondary OLT. 21 (31%) cases were urgent and 47 elective RT (69%). Vascular complications was the most common cause for urgent RT, and chronic rejection, for elective RT. Differences were also detected in the overall survival of RT patients; mortality was significantly lower among the urgent procedures (15% vs 47.8%). Significantly differences were also detected in overall survival for RT patients between 2007 and 2010 (81.7% with urgent RT and 76.5% with elective situations).

CONCLUSION

These data confirmed the utility of RT in elective and emergency situations. Overall survival of elective RT patients has improved in recent years. Liver RT requires a multidisciplinary team to decide the inclusion and prioritization of elective RT cases on the OLT waiting list.

Liver retransplantation in adults: the largest multicenter Italian study

This study is the largest Italian survey on liver retransplantations (RET). Data report on 167 adult patients who received 2 grafts, 16 who received 3 grafts, and one who received 4 grafts over a 11 yr period.

There was no statistically significant difference in graft survival after the first or the second RET (52, 40, and 29% vs 44, 36, and 18% at 1,5,and 10 yr, respectively: Log-Rank test, p = 0.30).

Survivals at 1, 5, and 10 years of patients who underwent 2 (n = 151) or 3 (n = 15) RETs, were 65, 48,and 39% vs 59, 44, and 30%, respectively (p = 0.59).

Multivariate analysis of survival showed that only the type of graft (whole vs reduced) was associated with a statistically significant difference (HR = 3.77, Wald test p = 0. 05); the donor age appeared to be a relevant factor as well, although the difference was not statistically significant (HR = 1.91, Wald test p = 0.08).

Though late RETs have better results on long term survival relative to early RETs, no statistically significant difference can be found in early results, till three years after RET.

Considering late first RETs (interval>30 days from previous transplantation) with whole grafts the difference in graft survival in RETs due to HCV recurrence (n = 17) was not significantly different from RETs due to other causes (n = 53) (65–58 and 31% vs 66–57 and 28% respectively at 1–5 and 10 years, p = 0.66).

Adult liver transplantation in the United States

Orthotopic liver transplantation is the only definitive treatment option for patients dying of liver failure. Since its inception, the technique of liver transplantation and the management of the recipients have evolved considerably. The authors present here an up-to-date overview of the evolution of adult liver transplantation, the evaluation of the recipient and the process of listing and timing of transplantation. The authors conclude with a summary of long-term complications that should be considered when caring for the posttransplant patient. The growing population of patients with liver disease means that more transplants will be performed. Because these patients now live longer lives, it is crucial that clinicians have a basic understanding of the process and outcomes.

Risk factors in liver retransplantation: a single-center experience

Liver retransplantation (Re-OLT) is one of the most debated issues in medicine over the past decade. Re-OLT, currently is accepted for patients with irreversible failure of a hepatic graft caused by primary nonfunction (PNF), hyperacute/chronic rejection, or hepatic artery thrombosis (HAT); whereas it is still controversial for patients with recurrent viral disease, in particular hepatitis C virus (HCV) cirrhosis. Patient and graft survival rates are lower than those observed after primary liver transplantation (OLT). The aim of the present study was to analyze the risk factors that adversely affect survival after Re-OLT in a single center. Medical data were collected for 23 patients who underwent Re-OLT from November 2002 to December 2008 including six men and seven women of mean age of 51.3 years. The most frequent indications for Re-OLT were: PNF (69.5%; 16/23), HCV recurrence (8.6%; 2/23), or HAT (8.6%; 2/23). Mean Model for End-Stage Liver Disease (MELD) at Re-OLT was 27.7 (range = 9-40). After a mean follow-up of 37.4 ± 30 (standard deviation) months, 43% (10/23) of patients had died, including 70% within the first 2 months after Re-OLT. Sepsis represented the commonest cause of death (40%). Re-OLT was performed for PNF among 90% of succumbing patients. As regards dead patients, 4/10 were HCV(+) whose causes of death were sepsis (n=2), alcoholic cirrhosis (n=2), and undetermined (n=1). Comparing patients who died after liver Re-OLT versus alive patients, we did not find any significant difference in terms of mean MELD (28.6 vs 27; P=NS), MELD > 25 (60% vs 61.5%, P=NS), donor age > 60 years (30% vs 15.3%, P=NS), HCV(+) (40% vs 62%, P = NS), or time interval from OLT to Re-OLT (12.2 vs 777.7 days, P=NS). Patient survivals after Re-OLT were 67% at 3 years and 50% at 5 years, which were lower than those of first transplantations, as reported by other European and International Centers. Forty percent of deaths after Re-OLT occurred among HCV(+) recipients, but for reasons unrelated to HCV infection.

Indications for and survival after liver retransplantation

INTRODUCTION

Orthotopic liver retransplantation (re-OLT) is the therapeutic option for hepatic graft failures. Survival after re-OLT is poorer than after primary OLT. Given that there is an organ shortage, it is essential that we optimize our use of this scarce resource. We evaluated the results of re-OLT among 58 consecutive Re-OLT.

MATERIALS AND METHODS

Using registry data from our Liver Transplantation Unit, we performed a retrospective cohort study of adult urgent versus elective re-OLT between 1991 and 2008. We recorded the indications for the initial OLT, and the intervals from OLT to re-OLT as well as age and gender. Using the Rosen model to stratify patients into low-intermediate-, and high-risk groups we calculated survivals.

RESULTS

Among 661 adult liver transplantations, 56 patients (8.4%) underwent late re-OLT at a median of 654.4 days post-OLT. There were 17 (29%) urgent re-OLT and 41 elective cases (71%). Vascular complications were the most common cause of urgent re-OLT (64%); elective re-OLT was primarily due to chronic rejection (56.1%). Overall survival for retransplanted patients was significantly lower among urgent procedures (82.4% vs 48.8%), as well as for overall survival after re-OLT for patients with hepatitis C virus (HCV) versus other etiologies.

CONCLUSION

These data confirmed the utility of retransplantation in elective and emergency situations. Liver re-transplantation has a high morbidity and mortality. It requires multidisciplinary experience to decide inclusion and prioritization criteria for re-OLT, especially among patients with HCV.

Allocation priority in non-urgent liver transplantation: An overview of proposed scoring systems

Given the lack of donors, a correct organ allocation system for candidates to liver transplantation is essential to increase graft and patient survival. The most used organ allocation tools are Child-Turcotte-Pugh and model for end-stage liver disease. It is generally accepted that model for end-stage liver disease score is superior to the Child-Turcotte-Pugh classification in predicting the short-term survival of cirrhotic patients awaiting liver transplantation. Since 2002, model for end-stage liver disease is widely used for liver allocation. In recent years, to overcome limitations of the consolidated scores, some adjustments to the original model for end-stage liver disease formula and new scoring systems have been proposed. Published data suggest that integrating serum sodium and model for end-stage liver disease may improve the score prognostic accuracy but further studies are necessary to confirm this issue. The updated model for end-stage liver disease, obtained through a revision of traditional model for end-stage liver disease parameters and tested in a large cohort of patients, is of great interest at the moment. In conclusion, several scoring systems have been described for organ allocation, but today, none is definitely able to overcome the limitations of the Child-Turcotte-Pugh and model for end-stage liver disease systems.

Overview of the MELD score and the UNOS adult liver allocation system

On February 27, 2002, the United Network for Organ Sharing (UNOS) introduced a new allocation policy for cadaveric liver transplants, based on the Model for End-Stage Liver Disease (MELD) score. This new policy stratifies the patients based on their risk of death while on the waiting list. We analyzed the background and main features of this new allocation policy to evaluate the effects on waiting list dynamics as well as the accuracy of MELD as a predictor of pretransplantation mortality and posttransplantation outcome. MELD has proved to be accurate as a predictor of waiting list mortality, but seems to be less accurate to predict posttransplantation outcome. Immediate effects of the new policy were a reduction in the waiting list, while organs were primarily directed to sicker patients with reduced waiting times. There was a statistically but not significantly reduced number of patients removed from the list due to death or severity of sickness. The balance between medical urgency and transplant benefit is still to be defined as is the relationship between pretransplantation criteria and posttransplantation outcomes, and the way this relationship should be included in the allocation policy.

The model for end-stage liver disease comes of age

The care of patients who have chronic liver disease has evolved considerably since the Model for End-stage Liver Disease (MELD) was first described 6 years ago. This article traces the progress in liver allocation and clinical liver disease research that includes the MELD score and highlights the management of areas in which MELD and the principles underlying MELD enhance the clinician's ability to understand better the patient who has chronic liver disease.

The model for end-stage liver disease (MELD)

The Model for End-stage Liver Disease (MELD) was initially created to predict survival in patients with complications of portal hypertension undergoing elective placement of transjugular intrahepatic portosystemic shunts. The MELD which uses only objective variables was validated subsequently as an accurate predictor of survival among different populations of patients with advanced liver disease. The major use of the MELD score has been in allocation of organs for liver transplantation. However, the MELD score has also been shown to predict survival in patients with cirrhosis who have infections, variceal bleeding, as well as in patients with fulminant hepatic failure and alcoholic hepatitis. MELD may be used in selection of patients for surgery other than liver transplantation and in determining optimal treatment for patients with hepatocellular carcinoma who are not candidates for liver transplantation. Despite the many advantages of the MELD score, there are approximately 15%-20% of patients whose survival cannot be accurately predicted by the MELD score. It is possible that the addition of variables that are better determinants of liver and renal function may improve the predictive accuracy of the model. Efforts at further refinement and validation of the MELD score will continue.