MELD scores of liver transplant recipients according to size of waiting list: impact of organ allocation and patient outcomes

Liver transplantation cost in the model for end-stage liver disease era: looking beyond the transplant admission

We examined the relationship between the total cost incurred by liver transplantation (LT) recipients and their Model for End-Stage Liver Disease (MELD) score at the time of transplant. We used a novel database linking billing claims from a large private payer with the Organ Procurement and Transplantation Network registry. Included were adults who underwent LT from March 2002 through August 2007 (n = 990). Claims within the year preceding and following transplantation were analyzed according to the recipient's calculated MELD score. Cost was the primary endpoint and was assessed by the length of stay and charges. Transplant admission charges represented approximately 50% of the total cost of LT. MELD was a significant cost driver for pretransplant, transplant, and total charges. A MELD score of 28 to 40 was associated with additional charges of $349,213 (P < 0.05) in comparison with a score of 15 to 20. Pretransplant and transplant admission charges were higher by $152,819 (P < 0.05) and $64,286 (P < 0.05), respectively, in this higher MELD group. No differences by MELD score were found for posttransplant charges. Those in the highest MELD group also experienced longer hospital stays both in the pretransplant period and at the time of LT but did not have higher rates of re-admissions. In conclusion, high-MELD patients incur significantly higher costs prior to and at the time of LT. Following LT, the MELD score is not a significant predictor of cost or re-admission.

D-MELD, a simple predictor of post liver transplant mortality for optimization of donor/recipient matching

Numerous donor and recipient risk factors interact to influence the probability of survival after liver transplantation. We developed a statistic, D-MELD, the product of donor age and preoperative MELD, calculated from laboratory values. Using the UNOS STAR national transplant data base, we analyzed survival for first liver transplant recipients with chronic liver failure from deceased after brain death donors. Preoperative D-MELD score effectively stratified posttransplant survival. Using a cutoff D-MELD score of 1600, we defined a subgroup of donor-recipient matches with significantly poorer short- and long-term outcomes as measured by survival and length of stay (LOS). Avoidance of D-MELD scores above 1600 improved results for subgroups of high-risk patients with donor age >/=60 and those with preoperative MELD >/=30. D-MELD >/=1600 accurately predicted worse outcome in recipients with and without hepatitis C. There is significant regional variation in average D-MELD scores at transplant, however, regions with larger numbers of high D-MELD matches do not have higher survival rates. D-MELD is a simple, highly predictive tool for estimating outcomes after liver transplantation. This statistic could assist surgeons and their patients in making organ acceptance decisions. Applying D-MELD to liver allocation could eliminate many donor/recipient matches likely to have inferior outcome.

Transplantation risks and the real world: what does 'high risk' really mean?

Candidates for, and recipients of, transplants face numerous risks that receive varying degrees of attention from the media and transplant professionals. Characterizations such as 'high risk donor' are not necessarily accurate or informative unless they are discussed in context with the other risks patients face before and after transplantation. Moreover, such labels do not provide accurate information for informed consent discussions or decision making. Recent cases of donor-transmitted diseases from donors labeled as being at 'high risk' have engendered concern, new policy proposals and attempts to employ additional testing of donors. The publicity and policy reactions to these cases do not necessarily better inform transplant candidates and recipients about these risks. Using comparative risk analysis, we compare the various risks associated with waiting on the list, accepting donors with various risk characteristics, posttransplant survival and everyday risks we all face in modern life to provide some quantitative perspective on what 'high risk' really means for transplant patients. In our analysis, donor-transmitted disease risks are orders of magnitude less than other transplantation risks and similar to many everyday occupational and recreational risks people readily and willingly accept. These comparisons can be helpful for informing patients and guiding future policy development.

The influence of psychosocial evaluation on candidacy for liver transplantation

CONTEXT

Although medical factors clearly dominate the evaluation of appropriateness for liver transplant, psychosocial factors are an important dimension in the evaluation process.

OBJECTIVE

To understand more about the weight assigned to psychosocial factors in the decision to list patients for liver transplant and about whether such differences create hidden inequities in the transplant allocation system.

DESIGN

We conducted a mail survey of liver transplant surgeons and psychosocial evaluators at busy transplant centers assessing the importance these professionals assigned to psychosocial factors in evaluations for liver transplant candidacy.

PARTICIPANTS

Liver transplant surgeons and psychosocial evaluators from the highest volume liver transplant centers in the United States.

INTERVENTION

Mail survey.

RESULTS

Psychosocial evaluators assigned greater importance to availability of transportation, adaptation to stress, and coping skills than did surgeons. Transplant psychosocial evaluators were less likely than transplant surgeons to recommend that a patient with a history of poor social support be listed for liver transplant. We found no correlation between relative weight assigned to psychosocial factors and median wait times at transplant centers. These differences suggest that the relationship between the factors identified by psychosocial evaluators as important and transplant outcomes should be studied. Overall, more research into the predictive and ethical aspects of psychosocial evaluation for liver transplant is needed.

Donor age and cold ischemia interact to produce inferior 90-day liver allograft survival

BACKGROUND

Expanded regional sharing of liver allografts may increase cold ischemia and allograft failure, particularly with livers from older donors. The aim of this study was to examine whether older donor age and cold ischemic time interact to produce inferior allograft survival.

METHODS

We undertook a retrospective cohort study of adult liver transplants in the United States performed between December 1, 1995 and December 31, 2005, using data from the Organ Procurement and Transplantation Network. The primary outcome was allograft failure within 90 days.

RESULTS

Forty-four thousand seven hundred fifty-six liver transplant recipients were analyzed. Older age was defined as 45 years or more, and prolonged cold ischemia was defined as 12 hours or more. Using data from the pre-Model for End Stage Liver Disease (MELD), post-MELD and combined eras, three separate analyses of the interaction between older donor age and prolonged cold ischemia were performed. In multivariable logistic regression, the interaction of age 45 years or more and cold ischemia more than or equal to 12 hr reached statistical significance in the combined (OR 1.24, CI 1.08-1.42, P<0.01) and pre-MELD (OR 1.26, CI 1.08-1.46, P<0.01) datasets, but not in the smaller post-MELD dataset (OR 1.18, CI 0.81-1.72, P=0.38). In the combined dataset, recipients of livers from donors aged 45 years or more and cold ischemia more than or equal to 12 hr showed an adjusted absolute risk of allograft failure at 90 days of 17.3% (odds ratio 1.84), compared with 11.1% for recipients of livers from donors older than 45 years and cold ischemia less than 12 hr.

CONCLUSIONS

These findings suggest that older donor age and prolonged cold ischemia interact to increase liver allograft failure at 90 days. Proposals to expand regional sharing of older livers should be regarded with caution.

Consequences of cold-ischemia time on primary nonfunction and patient and graft survival in liver transplantation: a meta-analysis

Introduction

The ability to preserve organs prior to transplant is essential to the organ allocation process.

Objective

The purpose of this study is to describe the functional relationship between cold-ischemia time (CIT) and primary nonfunction (PNF), patient and graft survival in liver transplant.

Methods

To identify relevant articles Medline, EMBASE and the Cochrane database, including the non-English literature identified in these databases, was searched from 1966 to April 2008. Two independent reviewers screened and extracted the data. CIT was analyzed both as a continuous variable and stratified by clinically relevant intervals. Nondichotomous variables were weighted by sample size. Percent variables were weighted by the inverse of the binomial variance.

Results

Twenty-six studies met criteria. Functionally, PNF% = −6.678281+0.9134701*CIT Mean+0.1250879*(CIT Mean−9.89535)2−0.0067663*(CIT Mean−9.89535)3, r2 = .625, , p<.0001. Mean patient survival: 93 % (1 month), 88 % (3 months), 83 % (6 months) and 83 % (12 months). Mean graft survival: 85.9 % (1 month), 80.5 % (3 months), 78.1 % (6 months) and 76.8 % (12 months). Maximum patient and graft survival occurred with CITs between 7.5–12.5 hrs at each survival interval. PNF was also significantly correlated with ICU time, % first time grafts and % immunologic mismatches.

Conclusion

The results of this work imply that CIT may be the most important pre-transplant information needed in the decision to accept an organ.

The Influence of Psychosocial Evaluation on Candidacy for Liver Transplantation

Context

Although medical factors clearly dominate the evaluation of appropriateness for liver transplant, psychosocial factors are an important dimension in the evaluation process.

Objective

To understand more about the weight assigned to psychosocial factors in the decision to list patients for liver transplant and about whether such differences create hidden inequities in the transplant allocation system.

Design

We conducted a mail survey of liver transplant surgeons and psychosocial evaluators at busy transplant centers assessing the importance these professionals assigned to psychosocial factors in evaluations for liver transplant candidacy.

Participants

Liver transplant surgeons and psychosocial evaluators from the highest volume liver transplant centers in the United States.

Intervention

Mail survey

Results

Psychosocial evaluators assigned greater importance to availability of transportation, adaptation to stress, and coping skills than did surgeons. Transplant psychosocial evaluators were less likely than transplant surgeons to recommend that a patient with a history of poor social support be listed for liver transplant. We found no correlation between relative weight assigned to psychosocial factors and median wait times at transplant centers. These differences suggest that the relationship between the factors identified by psychosocial evaluators as important and transplant outcomes should be studied. Overall, more research into the predictive and ethical aspects of psychosocial evaluation for liver transplant is needed.

Child-Pugh-Turcott versus Meld score for predicting survival in a retrospective cohort of black African cirrhotic patients

AIM: To compare the performance of the Child-Pugh-Turcott (CPT) score to that of the model for end-stage liver disease (MELD) score in predicting survival of a retrospective cohort of 172 Black African patients with cirrhosis on a short and mid-term basis.

METHODS: Univariate and multivariate (Cox model) analyses were used to identify factors related to mortality. Relationship between the two scores was appreciated by calculating the correlation coefficient. The Kaplan Meier method and the log rank test were used to elaborate and compare survival respectively. The Areas Under the Curves were used to compare the performance between scores at 3, 6 and 12 mo.

RESULTS: The study population comprised 172 patients, of which 68.9% were male. The mean age of the patient was 47.5 ± 13 years. Hepatitis B virus infection was the cause of cirrhosis in 70% of the cases. The overall mortality was 31.4% over 11 years of follow up. Independent factors significantly associated with mortality were: CPT score (HR = 3.3, 95% CI [1.7-6.2]) (P < 0.001) (stage C vs stage A-B); Serum creatine (HR = 2.5, 95% CI [1.4-4.3]) (P = 0.001) (Serum creatine > 1.5 mg/dL versus serum creatine < 1.5 mg/dL); MELD score (HR = 2.9, 95% CI [1.63-5.21]) (P < 0.001) (MELD > 21 vs MELD < 21). The area under the curves (AUC) that predict survival was 0.72 and 0.75 at 3 mo (P = 0.68), 0.64 and 0.62 at 6 mo (P = 0.67), 0.69 and 0.64 at 12 mo (P = 0.38) respectively for the CPT score and the MELD score.

CONCLUSION: The CPT score displays the same prognostic significance as does the MELD score in black African patients with cirrhosis. Moreover, its handling appears less cumbersome in clinical practice as compared to the latter.

Greater travel time to a liver transplant center does not adversely affect clinical outcomes

The effect of patient travel time to a transplant center on outcomes is unknown. We compared outcomes between patients living >3 hours (Group A) vs. <or=3 (Group B) hours drive away. Adult, nonacute liver failure patients entering transplant evaluation from February 27, 2002 to January 31, 2005 were analyzed. Of 166 patients, 126 (75.5%) were listed and 66 (39.5%) received transplantation. Outcomes of interest were >90 days to list, listing, survival while listed, transplantation, and posttransplantation survival. Covariates included Model for End-Stage Liver Disease (MELD) score, hepatocellular carcinoma (HCC), alcoholic liver disease, insurance type, and psychosocial score. There were 38 (23%) patients in Group A and 128 (77%) in Group B. Median MELD scores were 14.5 (range, 6-36) for Group A and 14.0 (range, 7-32) for Group B (p = 0.20). Groups were similar for age, gender, diagnosis, psychosocial score, insurance, and HCC variables. Group A was not independently associated with >90 days to list (odds ratio, 0.98; 95% confidence interval [CI], 0.4-2.4). Kaplan-Meier cumulative probabilities for listing, transplantation, and 1-yr posttransplantation survival were similar (A vs. B: 0.77 vs. 0.83, 0.70 vs. 0.69, and 0.85 vs. 0.86, respectively; all p values >0.05). Being in Group A remained insignificant in terms of probability of listing, transplantation, and posttransplantation survival by Cox proportional hazard modeling. Survival on the list was significantly better for Group A (A: 1.0, B: 0.55; p = 0.02). Fewer patients at high MELD score in Group A and referral biases may explain this difference. In conclusion, after entering evaluation, patients living >3 hours away from a transplant center have comparable outcomes to those living closer.

End-stage liver disease in a state prison population

OBJECTIVES

Information on the epidemiology of end-stage liver disease (ESLD) in US correctional populations is limited. We examined the prevalence, mortality and clinical characteristics of ESLD in the nation's second largest state prison system.

METHODS

We collected and analyzed medical and demographic data from 370,511 offenders incarcerated in Texas' prison system during a 3.5-year period.

RESULTS

ESLD was diagnosed in 484 inmates (131/100,000); 213 (57/100,000) died of ESLD. Offenders who were Hispanic, 30-49 years of age, > or =50 years of age, HIV monoinfected, hepatitis C virus (HCV) monoinfected, or HIV/HCV coinfected had elevated ESLD prevalence and mortality rates.

CONCLUSIONS

ESLD mortality in Texas' prison population is approximately 3 times higher than that of the general population, reflecting elevated rates of HCV and HIV/HCV coinfection among prisoners. Ultimately, the only viable treatment option for many prisoners with ESLD will be liver transplantation. The enormous costs of organ transplantation and immunosuppressive therapy are staggering and have the potential to decimate the healthcare budgets of most prison systems. Consequently, it is imperative that correctional healthcare programs expand HCV treatment and prevention strategies.

Is waiting time a measure of access to liver transplantation? Is shorter necessarily better?

BACKGROUND

The Model for End-Stage Liver Disease (MELD) score has been used since February 2002 to allocate livers for transplantation from deceased donors according to medical need. Allocation based on MELD scores should ensure that sicker patients receive transplants first regardless of transplantation center volume.

OBJECTIVE

To determine whether the MELD score at transplantation and waiting time of liver transplant recipients differs by transplantation center volume.

DESIGN

Analysis of the Organ Procurement and Transplantation Network database. Centers were classified according to the volume of transplantations performed in 2005: high (> or =100 transplantations), medium (50 to 99 transplantations), and low (<50 transplantations).

SETTING

Transplantation centers in the United States.

PATIENTS

20,075 transplant recipients between 27 February 2002 and 30 April 2006.

MEASUREMENTS

MELD scores and waiting times of liver transplant recipients.

RESULTS

Transplant recipients at high-volume centers had lower MELD scores (35.1% with MELD scores < or =18 vs. 22.7% and 27.0% at medium- and low-volume centers, respectively; P < 0.001), and the median MELD score was 22 compared with 24 at both medium- and low-volume centers. Despite having lower MELD scores, recipients at high-volume centers also experienced shorter waiting times (median waiting time, 69 days vs. 98 days and 94 days at medium-and low-volume centers, respectively; P < 0.001).

LIMITATIONS

The definition of transplantation center volume was subjective. The recent implementation of MELD precluded analysis of differences in long-term outcomes related to waiting time or center volume.

CONCLUSIONS

The MELD scores and waiting time of liver transplant recipients differed by transplantation center volume. High-volume centers have shorter waiting times and perform more transplantations for less sick patients. The reasons for these differences are unclear but warrant further investigation.

Pretransplant management of the cirrhotic patient

Cirrhosis is the twelfth commonest cause of death in the United States, with more than 27,000 deaths and more than 421,000 hospitalizations annually. Currently, there are more than 17,000 patients awaiting liver transplantation in the United States across the 11 United Network for Organ Sharing regions. Approximately 10% of such patients will die awaiting transplantation.

Geographic disparities in deceased donor liver transplantation within a single UNOS region

Although the Model for End-Stage Liver Disease (MELD) scoring system has improved the ability to measure medical urgency for transplantation, geographic disparities in the probability of being delisted as a result of complications of end-stage liver disease or death and in the probability of orthotopic liver transplantation (OLT) remain. The purpose of the current study was to identify factors associated with these variations among donor service areas (DSAs) in one United Network for Organ Sharing (UNOS) region. Data for 2,948 candidates listed for OLT within 4 DSAs in UNOS region 4 between February 2002 and November 2005 were obtained from UNOS. Multivariate regression models were used to identify study factors associated with delisting (due to deterioration or death) and likelihood of OLT. After risk adjustment for candidate characteristics, those listed in DSA-3 and DSA-4 were at significantly higher risk of delisting than candidates listed in DSA-2 (hazard ratio, 1.22 and 1.10 vs. 0.87 for DSA-2; P = 0.01 and 0.05, respectively). In addition, the likelihood of OLT was significantly higher for candidates listed in DSA-1 than in DSA-2, DSA-3 or DSA-4 (hazard ratio, 1.00 compared with 0.45, 0.77, and 0.51; P < 0.001 for all pairwise comparisons). Despite the implementation of the MELD system, great geographic disparities exist in the likelihood of delisting and for OLT, suggesting the need for further refinement in regional allocation strategies.

The economic impact of the utilization of liver allografts with high donor risk index

The disparity between the organ supply and the demand for liver transplantation (LT) has resulted in the growing utilization of 'marginal donor' organs. While economic outcomes for subsets of 'marginal' organs have been described for renal transplantation, similar analyses have not been performed for LT. Using UNOS data for 17 710 LTs performed between 2002 and 2005, we assessed the relationship between recipient model for end-stage liver disease (MELD) score, organ quality as defined by donor risk index (DRI, Feng et al. 2005) and hospital length of stay (LOS). Single-center cost-accounting data for 338 liver transplants were then analyzed with a multivariate linear regression model to determine the estimated cost associated with a day of LOS. Overall, 8.4% of donor organs were classified as high risk (DRI > 2-2.5) and 1.9% as very high risk (DRI > 2.5). In the lowest MELD group (0-10), the LOS difference between 'ideal' donors (DRI < 1.0) and very high risk (DRI > 2.5) was 10.6 days which was associated with an estimated incremental cost of $47 986. For patients with MELD >35, the average LOS increased from 23.2 to 41.8 days when very high DRI donors were used, resulting in an estimated increase in cost of nearly $84 000. We conclude that the use of marginal liver grafts results in increased hospital costs independent of recipient risk factors.

Characteristics of Waitlisted Patients for Liver Transplantation at a Liver Transplantation Unit in the City of Ribeirão Preto, São Paulo, Brazil, Especially Considering Child and Model for End Stage Liver Disease (MELD) Scores

Liver transplantation represents the most effective therapy for patients suffering from chronic end-stage liver disease. Until recently, in Brazil liver allocation was based on the Child-Turcotte-Pugh score and the waiting list followed a chronological criterion. The aim of this study was to show the clinical and laboratory patterns of our patients awaiting a liver transplantation. Seventy-nine medical records were reviewed in January 2005 to classify patients according to their age, sex, cause of cirrhosis, and Child and Model for End Stage Liver Disease (MELD) scores. The mean age of patients was 47 years; 70% were men. The main diagnosis was liver cirrhosis (97%): 27% alcoholic, 26% viral hepatitis, 20% alcoholic plus viral hepatitis, 13% cryptogenic, and 11% other causes. Sixty-three patients (80%) were Child B or C. The average MELD, scores for Child A, B, and C were 10 +/- 5, 13 +/- 3.4, and 21 +/- 4.3, respectively. Nine deaths (11%) on the waiting list occurred in 2005. Among these, 1 patient was Child B with MELD 10, while the others were Child C, with mean MELD scores of 21 +/- 3.8. Twelve patients (15%) received cadaveric orthotopic liver transplantation. Thus, in this small series, the higher MELD scores corresponded to Child C class and mortality on the waiting list.

Impact of recipient MELD score on resource utilization

The model for end stage liver disease (MELD) system prioritizes deceased donor organs to the sickest patients who historically require higher healthcare expenditures. Limited information exists regarding the association of recipient MELD score with resource use. Adult recipients of a primary liver allograft (n = 222) performed at a single center in the first 27 months of the MELD system were analyzed. Costs were obtained for each recipient for the 12 defined categories of resource utilization from the time of transplant until discharge. True (calculated) MELD scores were used. Inpatient transplant costs were significantly associated with recipient MELD score (r = 0.20; p = 0.002). Overall 1-year patient survival was 85.0% and was not associated with MELD score (p = 0.57, log rank test). Recipient MELD score was significantly associated with costs for pharmacy, laboratories, radiology, dialysis and physical therapy. Multivariate linear regression revealed that MELD score was most strongly associated with cost compared to other demographic and clinical factors. Recipient MELD score is correlated with transplant costs without significantly impacting survival.

Liver transplantation: an update

PURPOSE OF REVIEW

Recent attention in liver transplantation has focused on equity in organ allocation and management of post-transplant complications.

RECENT FINDINGS

Adoption of the model for end-stage liver disease (MELD) for liver allocation has been successful in implementing a system based on medical urgency rather than waiting time. Refinements are being studied in reducing geographic disparities and improving transplant benefit by balancing pre-transplant mortality and post-transplant survival. With hepatocellular carcinoma becoming a bigger proportion of liver transplants since MELD, emerging literature is examining expansion of the current criteria for transplantation of hepatocellular carcinoma. Hepatitis C virus infection is associated with worse patient and graft survival post-transplantation than other liver diseases. The optimal timing and delivery of current antiviral therapy and immunosuppressive strategies in reducing the severity of hepatitis C virus recurrence post-transplantation are discussed. Chronic renal dysfunction after liver transplantation is a source of considerable morbidity. Nephron-sparing immunosuppression regimens are emerging with encouraging results.

SUMMARY

Organ allocation tends to evolve under MELD with a focus on reducing geographic disparities and maximizing transplant benefit. Hepatitis C virus, hepatocellular carcinoma and chronic renal dysfunction are a major challenge and continued research in these areas will undoubtedly lead to better outcomes for transplant recipients.

Liver allocation for hepatocellular carcinoma: a European Center policy in the pre-MELD era

BACKGROUND

Policies to decrease dropout during waiting time for liver transplantation (LT) are under debate.

METHODS

We evaluated the allocation system from 1996 to 2003, when recipients had priority related to Child-Pugh score and donors >60 years were mainly offered to recipients with hepatocellular carcinoma (HCC). The outcomes of 656 patients with chronic liver disease (142 HCC and 514 non-HCC) listed for LT were prospectively evaluated, considering recipient and donor features.

RESULTS

Transplantation and dropout rates were similar between HCC and non-HCC patients: 64.1% vs. 70.6% and 26% vs. 22.6%. Multivariate analysis showed the probability of being transplanted within 3 months was related to Child-Pugh score >10 and to HCC, whereas the probability of being removed from the list within 3 months was only related to Child-Pugh score >10. HCC patients had a lower median waiting time (97 vs. 197 days, P<0.001), a higher rate of donors > 60 years (50.5% vs. 33.5%, P<0.005) and with steatosis (31.6% vs. 14.3%, P<0.01), but a lower Child-Pugh score (9.1+/-2.1 vs. 9.6+/-1.7, P<0.05) than non-HCC patients. The 5-year patient survival was comparable since registration on the list and since LT: 56.9% and 77% in the HCC group vs. 61.4% and 79% in the non-HCC patients. Donors > 60 years affected outcome after LT in the non-HCC group, but not in the HCC patients.

CONCLUSION

By allocating donors >60 years mainly to HCC patients, we controlled dropout without affecting their survival and the outcome of non-HCC patients.

Preoperative characteristics and intraoperative transfusion and vasopressor requirements in patients with low vs. high MELD scores

Recent changes in organ allocation based on the model for end-stage liver disease (MELD) prioritize the most ill patients on the waiting list for liver transplantation. While patients undergoing liver transplantation in the MELD era are more acutely ill, the impact of the policy changes on perioperative management has not been completely assessed. We retrospectively reviewed the records of 124 primary adult liver transplant patients. Patients were divided into low (< or = 30) and high MELD (>30) score groups. Preoperative characteristics and intraoperative management were compared between the 2 groups. Patients with high MELD scores had lower baseline hematocrit and fibrinogen levels and were more likely to require ventilatory and vasopressor support before transplantation. Intraoperative transfusion requirements and use of vasopressors were also significantly increased in patients with high MELD scores compared to patients with low MELD scores. In conclusion, these data suggest that pretransplant MELD scores provide important information for perioperative management of patients undergoing liver transplantation.

Transplant center quality assessment using a continuously updatable, risk-adjusted technique (CUSUM)

Access to timely, risk-adjusted measures of transplant center outcomes is crucial for program quality improvement. The cumulative summation technique (CUSUM) has been proposed as a sensitive tool to detect persistent, clinically relevant changes in transplant center performance over time. Scientific Registry of Transplant Recipients data for adult kidney and liver transplants (1/97 to 12/01) were examined using logistic regression models to predict risk of graft failure (kidney) and death (liver) at 1 year. Risk-adjusted CUSUM charts were constructed for each center and compared with results from the semi-annual method of the Organ Procurement and Transplantation Network (OPTN). Transplant centers (N = 258) performed 59 650 kidney transplants, with a 9.2% 1-year graft failure rate. The CUSUM method identified centers with a period of significantly improving (N = 92) or declining (N = 52) performance. Transplant centers (N = 114) performed 18 277 liver transplants, with a 13.9% 1-year mortality rate. The CUSUM method demonstrated improving performance at 48 centers and declining performance at 24 centers. The CUSUM technique also identified the majority of centers flagged by the current OPTN method (20/22 kidney and 8/11 liver). CUSUM monitoring may be a useful technique for quality improvement, allowing center directors to identify clinically important, risk-adjusted changes in transplant center outcome.

Living donor liver transplantation in high-risk vs. low-risk patients: optimization using statistical models

Living donors represent a recognized alternative for facilitating the access to transplantation in a period of organ shortage. However, which candidates should be preferentially considered for living-donor liver transplantation (LDLT) is debated. The aim of this study was to create statistical models to determine which strategies of selection for LDLT provide the most efficient contribution. The study included 331 patients listed for deceased-donor transplantation (DDLT) and 128 transplanted with living donors. Statistical models predicting the events following listing were created and combined in a multistate model allowing the testing of different strategies of selection for LDLT and to compare their results. Taking 3-yr survival after listing as the principal end-point, selecting the 20% patients at highest risk of death on the waiting list gave better results than selecting the 20% patients at lowest risk of death after LDLT (70% vs. 64%, respectively). These strategies resulted in waiting list mortality rates of 17% and 8%, respectively. One-year survival after LDLT was lower in high-risk patients (85%) than in low-risk patients (91%). However, the 1-yr survival benefit derived from LDLT was 75% in high-risk patients while it was nil in low-risk patients. In conclusion, LDLT is more effective for overcoming the consequences of organ shortage when performed in patients at high risk of death on the waiting list. On an individual basis, the sickest patients are those who derive the most important benefit from LDLT. This study provides incentives for considering LDLT in high-risk patients.

Patient selection in an era of donor liver shortage: current US policy

In the past, organ allocation in the US was based on anecdotal experience, self-interest and the opinions of single centers, with little support in the way of scientific evidence, mathematical survival modeling or validation. As organ transplantation became more successful, and as disparity between the number of patients on the waiting list and available organs became larger, a more justifiable donor allocation scheme became necessary. The current allocation scheme for donor livers is based on the model for end-stage liver disease/pediatric end-stage liver disease, which was introduced in 2002 by the United Network for Organ Sharing. This new allocation system has improved accuracy for predicting pretransplant mortality. In addition, the number of liver transplantations has risen for almost all etiologic categories, most noticeably for patients with hepatocellular carcinoma. Fewer patients have been registered on the liver transplant waiting list and fewer have been removed from the list because they have died or become too sick for transplantation. So far, this new allocation system has been a success, but it does have its shortcomings, and even with improvements to the system, the use of the donor organ pool still needs to be optimized.

Survival of liver transplant candidates with acute renal failure receiving renal replacement therapy

BACKGROUND

Acute renal failure (ARF) in the setting of end-stage liver disease has a dismal prognosis without liver transplantation. Renal replacement therapy (RRT) is a common bridge to liver transplant despite a paucity of supportive data. We investigated our single-center patient population to determine efficacy of RRT in liver transplant candidates with ARF.

METHODS

We identified 102 liver transplant candidates receiving RRT for ARF between April 30, 1999 and January 31, 2004. Patients that had initiated RRT intra- or postoperatively or received outpatient hemodialysis or peritoneal dialysis prior to admission were excluded. Survival to liver transplant, short-term mortality following liver transplant, and selected clinical characteristics were examined.

RESULTS

Of patients who received RRT, 35% survived to liver transplant or discharge. Mortality was 94% in patients not receiving a liver and was associated with a higher Acute Physiological and Chronic Health Evaluation (APACHE) II, lower mean arterial pressure, and the use of continuous renal replacement therapy (CRRT). Patients receiving CRRT had greater severity of illness than those on hemodialysis. The 1-year mortality of patients initiating RRT prior to liver transplant was 30% versus 9.7% for all other liver recipients (P < 0.0045).

CONCLUSION

RRT is justifiable for liver transplant candidates with ARF. Though mortality was high, a substantial percentage (31%) of patients survived to liver transplant. Postoperative mortality is increased compared with all other liver transplant recipients, but is acceptable considering the near-universal mortality without transplantation.

The economic impact of MELD on liver transplant centers

Adoption of the model for end stage liver disease (MELD) system prioritized patients awaiting liver transplant (LT) by severity of illness including progressive renal dysfunction. Unfortunately, current reimbursement for LT is not adjusted by severity of illness or need for simultaneous liver-kidney transplantation (LKT). This study examines hospital cost and reimbursement for LT and LKT to determine the effect of MELD on transplant center (TC) financial outcomes given current reimbursement practices as well as DRG outlier threshold limits. LT was performed for 86 adults prior to and 127 following the implementation of MELD. Between the eras, there was a substantial increase in the average laboratory MELD score (17.1 to 20.7 p=0.004) and percentage of LKTs performed (5.8% to 17.3% p=0.01). Increasing MELD score was associated with higher costs ($4309 per MELD point p<0.001) and decreasing TC net income ($1512 per MELD point p<0.001). In patients not achieving the Medicare outlier status, predicted net loss was $17,700 for high-MELD patients and $19,133 for those needing LKT. In conclusion, contractual reimbursement agreements that are not indexed by severity of disease may not reflect the increased costs resulting from the MELD system. Even with outlier thresholds, Medicare reimbursement is inadequate resulting in a net loss for the TC.

MELD score and clinical type predict prognosis in hepatorenal syndrome: relevance to liver transplantation

Important progress has been made recently regarding the pathogenesis and treatment of hepatorenal syndrome (HRS). However, scant information exists about factors predicting outcome in patients with cirrhosis and HRS. Moreover, the prognostic value of the model of end-stage liver disease (MELD) score has not been validated in the setting of HRS. The current study was designed to assess the prognostic factors and outcome of patients with cirrhosis and HRS. The study included 105 consecutive patients with HRS. Forty-one patients had type 1 HRS, while 64 patients had type 2 HRS. Patients with type 1 HRS not only had more severe liver and renal failure than type 2 patients, they also had greater impairment of circulatory function, as indicated by lower arterial pressure and higher activation of vasoconstrictor factors. In the whole series, the median survival was 3.3 months. In a multivariate analysis of survival, only HRS type and MELD score were associated with an independent prognostic value. All patients with type 1 HRS had a high MELD score (> or =20) and showed an extremely poor outcome (median survival: 1 mo). By contrast, the survival of patients with type 2 HRS was longer and dependent on MELD score (> or =20, median survival 3 mo; <20, median survival 11 mo; P < .002). In conclusion, the outcome of patients with cirrhosis and HRS can be estimated by using two easily available variables, HRS type and MELD score. These data can be useful in the management of patients with HRS, particularly for patients who are candidates for liver transplantation.

Liver transplant recipient selection: MELD vs. clinical judgment

Minimization of death while waiting for liver transplantation involves accurate prioritization according to clinical status and appropriate allocation of donor livers. Clinical judgment in the Liver Transplant Unit Victoria (LTUV) was compared with Model for End-Stage Liver Disease (MELD) in a retrospective analysis of the LTUV database over the 2-year period August 1, 2002, through July 31, 2004. A total of 1,118 prioritization decisions occurred. Decisions were concordant in 758 (68%), comparing priorities assigned by clinical judgment with those assigned by MELD, P < 0.01. A total of 263 allocation decisions occurred. Decisions were concordant in 190 (72%) and 203 (77%) of the cases, comparing donor liver allocation with prioritization by MELD and clinical judgment, respectively. Of the 52 patients allocated a liver, only 23 would have been allocated on the basis of MELD while 29 had been prioritized on the waiting list in the week prior to transplantation. A total of 10 patients died on the waiting list in the 2-year period (annual adult waiting list mortality is 9.3%). Patients who subsequently died waiting were 3 times as likely to be prioritized by MELD as clinical judgment (29% vs. 9%, respectively). One half (3 of 6) of the patients who could have received a donor liver but who died waiting would have been allocated the organ on the basis of MELD. In conclusion, an allocation process based on MELD rather than clinical judgment would significantly alter organ allocation in Australia and may reduce waiting list mortality.

Liver transplantation

PURPOSE OF REVIEW

Liver transplantation continues to change as we further define appropriate criteria for allocation and utilization of this scarce resource. The following review highlights new trends and ideas in this evolving field.

RECENT FINDINGS

Although the model for end-stage renal disease (MELD) scoring system appears to fairly accurately predict mortality while waiting for transplant, the system may be less accurate in predicting outcomes following transplantation. MELD scores offer an additional advantage to patients with hepatocellular carcinoma (HCC), bringing them to transplant sooner with overall better survivals. However, despite its advantages, the MELD scoring system does not resolve the disparity in the allocation of organs between various organ procurement organizations. Several variables appear to affect patients with hepatitis C undergoing liver transplantation. Selection of appropriate donors appears to be important when transplanting patients with hepatitis C virus (HCV) infection as increasing donor age is associated with poorer outcomes. However, the controversy over whether a living donor liver transplant (LDLT) results in poorer outcomes in HCV infected patients remains. Post-transplant medical treatment of HCV may result in both a sustained virologic response and improved histology. With improved overall survival in patients undergoing orthotopic liver transplant (OLT), increasing attention has been focused on the medical complications following transplant. Identifying specific contributing factors in the development of renal dysfunction and devising strategies to prevent its occurrence are critical to further improvements in outcome following OLT.

SUMMARY

As the gap between patients and available organs remains, continued investigation into appropriate allocation and maximization of outcomes following liver transplant will continue.

Development of the allocation system for deceased donor liver transplantation

As the number of pre- and post-transplant solid organ recipients continues to grow, it becomes important for all physicians to have an understanding of the process of organ procurement and allocation. In the United States, the current system for allocation and transplantation of human solid organs has been heavily influenced by the experience in deceased donor liver transplantation (DDLT). This review highlights the significant changes that have occurred over the past 10 years in DDLT, with specific attention to the impact of the Model for Endstage Liver Disease (MELD) score on organ allocation and pre- and post-transplant survival. DDLT is managed by the United Network for Organ Sharing (UNOS) which oversees organ procurement and allocation across geographically defined Organ Procurement Organizations (OPOs). For many years, deceased donor livers were allocated to waiting list patients based on subjective parameters of disease severity and accrued waiting time. In addition, organs have traditionally been retained within the OPO where they are procured contributing to geographic disparities in disease severity at the time of transplantation among deceased donor recipients. In response to a perceived unfairness in organ allocation, Congress issued its "Final Rule" in 1998. The Rule called for a more objective ranking of waiting list patients and more parity in disease severity among transplant recipients across OPOs. To date, little progress has been made in eliminating geographic inequities. Patients in the smallest OPOs continue to receive liver transplants at a lower level of disease severity. However, strides have been made to standardize assessments of disease severity and better prioritize waiting list patients. The MELD score has emerged as an excellent predictor of short-term mortality in patients with advanced liver disease, and patients listed for liver transplantation are now ranked based on their respective MELD scores. This has improved organ access to the most severely ill patients without compromising waiting list mortality or post-transplant survival. The current system for DDLT remains imperfect but has improved significantly in the past decade. As the number of patients in need of DDLT grows, the system will continue to evolve to meet this increasing demand.

[Liver transplantation: deciding between need and donor allocation]

Liver transplantation represents an established therapeutic option for advanced liver diseases. The spectrum of indications encompasses infectious, vascular, immunological and toxic diseases leading to cirrhosis, in addition to genetic, metabolic, developmental and selected neoplastic diseases. On the one hand the timing of liver transplantation is determined by the disease specific course until decompensation and the disease manifestation involving bile ducts or hepatocytes. On the other hand it represents gene therapy of diseases affecting the liver, or entities where the genetic defect lies in the liver. In view of the shortage of donor organs and an increasing requirement for liver transplantation the challenge is to provide an effective and fair waiting list management. Reform of allocation criteria has put the focus on urgency. This in turn leads to an increase in waiting time for elective transplantations, inclusion of end stage diseases and critical patients, higher perioperative costs, problems with the matching of organs and the problem of an effective use of organ resources. Fair allocation and medical necessity therefore define the challenges surrounding the indications for liver transplantation.

A comparison of liver transplantation outcomes in the pre- vs. post-MELD eras

BACKGROUND

The model for end stage liver disease (MELD)-based organ allocation system is designed to prioritize orthotopic liver transplantation (OLT) for patients with the most severe liver disease. However, there are no published data to confirm whether this goal has been achieved or whether the policy has affected long-term post-OLT survival.

AIM

To compare pre-OLT liver disease severity and long-term (1 year) post-OLT survival between the pre- and post-MELD eras.

METHODS

Using the United Network of Organ Sharing database, we compared two cohorts of adult patients undergoing cadaveric liver transplant in the pre-MELD (n = 3857) and post-MELD (n = 4245) eras. We created multivariable models to determine differences in: (i) pre-OLT liver disease severity as measured by MELD; and (ii) 1-year post-OLT outcomes.

RESULTS

Patients undergoing OLT in the post-MELD era had more severe liver disease at the time of transplantation (mean MELD = 20.5) vs. those in the pre-MELD era (mean MELD = 17.0). There were no differences in the unadjusted patient or graft survival at 1 year post-OLT. This difference remained insignificant after adjusting for a range of prespecified recipient, donor, and transplant centre-related factors in multivariable survival analysis.

CONCLUSIONS

Although liver disease severity is higher in the post- vs. pre-MELD era, there has been no change in long-term post-OLT patient or graft survival. These results indicate that the MELD era has achieved its primary goals by allocating cadaveric livers to the sickest patients without compromising post-OLT survival.