The new liver allocation system: moving toward evidence-based transplantation policy

Quantitative assessment of hepatic function and its relevance to the liver surgeon

BACKGROUND

Standard evaluation of patients undergoing hepatic surgery has been through radiological and quantitative determination of liver function. As more complex and extensive surgery is now being performed, often in the presence of cirrhosis/fibrosis or following administration of chemotherapy, it is questioned whether additional assessment may be required prior to embarking on such surgery. The aim of this review was to determine the current knowledge base in relation to the performance of quantitative assessment of hepatic function both pre- and post-operatively in patients undergoing hepatic resectional surgery and liver transplantation.

METHODS

An electronic search was performed of the medical literature using the MEDLINE database to identify relevant articles with cross-referencing of all identified papers to ensure full literature capture.

RESULTS AND CONCLUSIONS

The review has identified a number of different methods of dynamically assessing hepatic function, the most frequently performed being through the use of indocyanine green clearance. With the recent and further anticipated developments in hepatic resectional surgery, it is likely that quantitative assessment will become more widely practiced in order to reduce post-operative hepatic failure and improve outcome.

Hyponatremia and mortality among patients on the liver-transplant waiting list

BACKGROUND

Under the current liver-transplantation policy, donor organs are offered to patients with the highest risk of death.

METHODS

Using data derived from all adult candidates for primary liver transplantation who were registered with the Organ Procurement and Transplantation Network in 2005 and 2006, we developed and validated a multivariable survival model to predict mortality at 90 days after registration. The predictor variable was the Model for End-Stage Liver Disease (MELD) score with and without the addition of the serum sodium concentration. The MELD score (on a scale of 6 to 40, with higher values indicating more severe disease) is calculated on the basis of the serum bilirubin and creatinine concentrations and the international normalized ratio for the prothrombin time.

RESULTS

In 2005, there were 6769 registrants, including 1781 who underwent liver transplantation and 422 who died within 90 days after registration on the waiting list. Both the MELD score and the serum sodium concentration were significantly associated with mortality (hazard ratio for death, 1.21 per MELD point and 1.05 per 1-unit decrease in the serum sodium concentration for values between 125 and 140 mmol per liter; P<0.001 for both variables). Furthermore, a significant interaction was found between the MELD score and the serum sodium concentration, indicating that the effect of the serum sodium concentration was greater in patients with a low MELD score. When applied to the data from 2006, when 477 patients died within 3 months after registration on the waiting list, the combination of the MELD score and the serum sodium concentration was considerably higher than the MELD score alone in 32 patients who died (7%). Thus, assignment of priority according to the MELD score combined with the serum sodium concentration might have resulted in transplantation and prevented death.

CONCLUSIONS

This population-wide study shows that the MELD score and the serum sodium concentration are important predictors of survival among candidates for liver transplantation.

Hyponatremia and mortality among patients on the liver-transplant waiting list

BACKGROUND

Under the current liver-transplantation policy, donor organs are offered to patients with the highest risk of death.

METHODS

Using data derived from all adult candidates for primary liver transplantation who were registered with the Organ Procurement and Transplantation Network in 2005 and 2006, we developed and validated a multivariable survival model to predict mortality at 90 days after registration. The predictor variable was the Model for End-Stage Liver Disease (MELD) score with and without the addition of the serum sodium concentration. The MELD score (on a scale of 6 to 40, with higher values indicating more severe disease) is calculated on the basis of the serum bilirubin and creatinine concentrations and the international normalized ratio for the prothrombin time.

RESULTS

In 2005, there were 6769 registrants, including 1781 who underwent liver transplantation and 422 who died within 90 days after registration on the waiting list. Both the MELD score and the serum sodium concentration were significantly associated with mortality (hazard ratio for death, 1.21 per MELD point and 1.05 per 1-unit decrease in the serum sodium concentration for values between 125 and 140 mmol per liter; P<0.001 for both variables). Furthermore, a significant interaction was found between the MELD score and the serum sodium concentration, indicating that the effect of the serum sodium concentration was greater in patients with a low MELD score. When applied to the data from 2006, when 477 patients died within 3 months after registration on the waiting list, the combination of the MELD score and the serum sodium concentration was considerably higher than the MELD score alone in 32 patients who died (7%). Thus, assignment of priority according to the MELD score combined with the serum sodium concentration might have resulted in transplantation and prevented death.

CONCLUSIONS

This population-wide study shows that the MELD score and the serum sodium concentration are important predictors of survival among candidates for liver transplantation.

The development of perioperative practices for liver transplantation: advances and current trends

Transplantation is a young medical specialty that has grown rapidly over the past 50 years. Anesthesiologists, surgeons and hepatologists are all essential partners in the process of determining patient outcome. Each specialty has made landmark improvements in patient outcome. However, there is still variability in practice patterns in each of the 3 major specialties. This review will use a historic perspective to explore the unique forces that shaped specific transplant practices and those that gave rise to differences in perioperative practices. Anesthesiologists and surgeons have made significant improvements in the management of blood loss, and coagulation monitoring and intervention. This has improved operative survival and early patient outcome. Perioperative survival has improved despite a worldwide shortage of donor organs and a trend to transplant sicker patients. A smaller pool of donor organs is required to meet the needs of an expanding waiting list. The innovations to reduce deaths on the transplant wait list are reviewed along with their impact on overall patient outcome. The evolving organ shortage is the pinnacle point in shaping future transplant practices. Currently, institutional-specific practices may be reinforced by the informal "tutorship" that is used to train physicians and by the resources available at each site of practice. However, there is evidence that specific intraoperative practices such as the use of a low central venous pressure, selection of vasopressors and certain surgical techniques can modify patient outcome. Further investigation is needed to determine whether the good or the bad associated with each practice prevails and in what unique circumstance.

Prediction value of model for end-stage liver disease scoring system on prognosis in patients with acute-on-chronic hepatitis B liver failure after plasma exchange and lamivudine treatment

BACKGROUND AND AIM

We used the model for end-stage liver disease (MELD) scoring system to predict the 3-month prognosis of patients with acute-on-chronic liver failure (ACLF) after plasma exchange (PE) and lamivudine treatment, and studied the predictive factors on the prognosis of patients.

METHODS

A total of 280 patients treated with lamivudine were randomly divided into PE and control groups. The relationship between mortality and influential factors of patients was studied by univariate and multivariate analysis.

RESULTS

The mortality (49.4%) of patients in the PE group with a MELD score from 30 to 40 was lower than that (86.1%) of the control group (chi(2) = 24.546, P < 0.01). The total bilirubin (TBIL) rebound rate of the dead group was significantly higher than that of the survival group (P < 0.01). Univariate analysis showed that mortality was significantly related to age (P = 0.003), treatment method (P = 0.000), TBIL (P = 0.010), MELD score (P = 0.001), international normalised ratio (P = 0.014), pretreatment HBV-DNA load (P = 0.000), decline of hepatitis B virus (HBV)-DNA load during therapy (P = 0.013), encephalopathy (P = 0.019), and hepatorenal syndrome (P = 0.026). In multivariate analysis, MELD scores of 30-40, treatment method (P = 0.003), pretreatment HBV-DNA load (P = 0.009), decline of HBV-DNA load during therapy (P = 0.016), and encephalopathy (P = 0.015) were independent predictors of mortality; for MELD scores above 40, only the MELD score (P = 0.012) was an independent predictive.

CONCLUSIONS

PE significantly decreased the mortality of patients with a MELD score of 30-40. For ACLF patients with a MELD score of 30-40, a low viral load pretreatment and quick decline of HBV-DNA load are good predictors for the survival with PE and lamivudine treatment.

Management of chronic liver failure until liver transplantation

Chronic liver failure is an important cause of morbidity and mortality and is the long-term consequence of many chronic liver diseases. In addition to determining the specific cause of the chronic liver disease, which may be amenable to targeted therapy, it is important to treat the sequelae of chronic liver failure effectively to improve quality of life, to prolong survival, and to provide a bridge to liver transplantation. Once a patient who has chronic liver failure develops hepatic decompensation, liver transplantation is the definitive treatment for those who qualify. Management of chronic liver failure is the focus of this article.

Model for End-Stage Liver Disease (MELD) system to allocate and to share livers: experience of two Italian centers

BACKGROUND

The use of the Model for End-stage Liver Disease (MELD) score to prioritize patients on liver waiting lists and to share organs among centers was effective according to US data, but few reports are available in Europe.

MATERIALS AND METHODS

We evaluated the outcome of 887 patients listed between April 2004 and July 2006 in a common list by two transplant centers (University of Bologna [BO] and University of Modena [MO] ordered according to the MELD system. Patients with hepatocellular carcinoma had a score calculated according to their real MELD, tumor stage, and waiting time.

RESULTS

Five hundred eighty-six (67%) patients were listed from BO and 291 (33%) from MO. The clinical features of recipients (sex, age, blood group, and real MELD) were comparable between centers. The number of liver transplantations performed was 307, and 273 (89%) recipients had a calculated MELD >or=20. Liver transplantations were equally distributed according to the number of patients listed: 215 out of 586 (36.7%) for BO and 92 out of 291 (31.6%) for MO. The median real MELD of patients transplanted was 20, and 246 out of 307 (80.1%) grafts transplanted were functioning. The dropouts from the list were 124 (14%), and 87 (70%) of these patients had a calculated MELD >or=20.

CONCLUSION

The MELD system was effective to share livers among the two Italian centers. According to this policy, livers were allocated to the recipients with the highest probability of dropout and who had a satisfactory survival after liver transplantation.

Diagnostic accuracy of multi-/single-detector row CT and contrast-enhanced MRI in the detection of hepatocellular carcinomas meeting the milan criteria before liver transplantation

Liver transplantation has been considered to be the only causal treatment for liver cirrhosis patients with hepatocellular carcinoma (HCC) due to its theoretical advantage of eliminating both the tumor and liver disease. However, because of the shortage of donor organs, it is strongly recommended that liver transplantations should be performed on cirrhotic patients with HCCs only when the patients meet the predetermined criteria in terms of number and extent of HCCs. Imaging is thus decisive in the patient inclusion or exclusion from transplantation lists. The imaging techniques used are CT, MRI and ultrasonography. The latter has been proven to be ineffective for HCC surveillance in transplant recipients because of its heavy operator dependence and unreliable detection of small and intermediately sized HCCs. The purpose of this article, then, is to systematically review the diagnostic performances of single-/multidetector row CT, dynamic gadolinium-enhanced MRI, superparamagnetic iron oxide (SPIO)-enhanced MRI and double-contrast MRI using both gadolinium and SPIO for the detection of HCCs with special emphasis on liver transplantation.

Liver and intestine transplantation in the United States, 1997-2006

Liver transplantation in 2006 generally resembled previous years, with fewer candidates waiting for deceased donor liver transplants (DDLT), continuing a trend initiated with the implementation of the model for end-stage liver disease (MELD). Candidate age distribution continued to skew toward older ages with fewer children listed in 2006 than in any prior year. Total transplants increased due to more DDLT with slightly fewer living donor liver transplants (LDLT). Waiting list deaths and time to transplant continued to improve. In 2006, there also were fewer DDLT for patients with MELD <15, fewer pediatric Status 1A/B transplants and more transplants from donation after cardiac death (DCD) donors. Adjusted patient and graft survival rates were similar for LDLT and DDLT. This article also contains in-depth analyses of transplantation for hepatocellular carcinoma (HCC). Recipients with HCC had lower adjusted 3-year posttransplant survival than recipients without HCC. HCC recipients who received pretransplant ablative treatments had superior adjusted 3-year posttransplant survival compared to HCC recipients who did not. Intestinal transplantation continued to slowly increase with the largest number of candidates on the waiting list since 1997. Survival rates have increased over time. Small children waiting for intestine grafts continue to have the highest waiting list mortality.

Development of a survival evaluation model for liver transplant recipients with hepatocellular carcinoma secondary to hepatitis B

AIM

To develop a model using easily obtainable, objective, verifiable preoperative parameters, to help evaluate post transplant survival probability for hepatocellular carcinoma (HCC) patients with hepatitis B.

METHODS

We retrospectively examined a cohort of 150 consecutive primary cadaveric liver transplants with HCC in our center over 6 years. Thirteen preoperative biochemical parameters and six tumor-related factors were analyzed to identify their correlation with post transplant survival using the Cox proportional-hazards regression model. The predictive power of a new model and the model for end stage liver disease was compared by the receiver operating characteristic curve.

RESULTS

In univariate analysis, the factors significantly associated with post transplant survival were serum concentrations of albumin, total bilirubin, alkaline phosphatase, alpha-fetoprotein, gamma-glutamyltransferase, aspartate aminotransferase, sodium, tumor diameter and the number of tumor nodules. Multivariate analysis showed alpha-fetoprotein, serum sodium, alkaline phosphatase and the number of tumor nodules were significantly associated with the post transplant outcome. Based on the four variables, we established a new model with a c-statistic of 0.72 which was significantly greater than 0.50 (P = 0.001), and the c-statistic of MELD was 0.59 (P = 0.146).

CONCLUSION

The new model based on four objective tumor-related parameters has the capacity to evaluate the risk of post transplant mortality for HCC patients with hepatitis B.

Deceased donor kidney and liver transplantation to nonresident aliens in the United States

BACKGROUND

Policies governing the allocation of deceased donor organs to nonresident aliens (NRAs) have existed from the early days of transplantation. However, there is a paucity of research describing this population. The aim of the present study is to examine characteristics and allocation patterns for NRAs compared to U.S. citizens in the context of the two most common forms of solid organ transplantation.

METHODS

The study included kidney and liver transplant candidates and deceased donor transplant recipients from 1988-2005 in the United States. We describe demographic characteristics, insurance coverage, geographic variability, and donor relationship based on citizenship and residency status. We additionally examined the association of citizenship with time to transplantation utilizing survival models.

RESULTS

From 1988-2005, there were 2724 solitary kidney and 2072 liver NRA candidate listings with United Network for Organ Sharing. NRA recipients had more self-pay (liver 36% and kidney 22%) and foreign sources (liver 26% and kidney 13%) of insurance coverage. Transplants to NRAs were more frequent than deceased donations deriving from NRAs for both organs. Adjusted models indicated that NRA kidney candidates received transplants at the same rate as U.S. citizens while liver NRA candidates received transplants more rapidly during the pre-Model for End-Stage Liver Disease (MELD; adjusted hazard ratio [AHR] 1.2, confidence interval [CI] 1.2-1.3) and post-MELD (AHR 1.5, CI 1.3-1.7) eras.

CONCLUSIONS

NRAs are demographically and socioeconomically diverse and have historically had a more rapid progression on the waiting list to receive a liver transplant. Further discussion and investigation concerning the ethical, economic, and public health ramifications of transplantation to NRA patients are warranted.

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.

Review article: renal function assessment in cirrhosis - difficulties and alternative measurements

BACKGROUND

Renal function in patients with cirrhosis is important prognostically, both before and following liver transplantation. Its prognostic impact is reflected by the inclusion of serum creatinine in the model for end-stage liver disease score, which is now used for recipient prioritization on liver transplantation waiting lists in the USA.

AIM

To review the accuracy of the surrogate markers for the assessment of renal function, i.e. glomerular filtration rate, particularly in patients with cirrhosis.

METHOD

We reviewed the available literature in PubMed regarding the markers for GFR evaluation and the factors which affect their accuracy in cirrhosis.

RESULTS

Although creatinine is widely available, it is an unreliable marker of glomerular filtration rate, particularly in patients with cirrhosis. Clearance of exogenous markers is considered the 'gold standard', but this methodology has many drawbacks, particularly poor applicability. Several mathematical formulae for estimated glomerular filtration rate are used to overcome some of these limitations: Cockcroft-Gault and Modification of Diet in Renal Disease formulae are the most frequently applied, but they are based on serum creatinine.

CONCLUSIONS

Due to the inaccuracy of serum creatinine and its derived formulae in estimating glomerular filtration rate, alternative serum markers, such as cystatin C, and new formulae are desirable. These need formal evaluation in patients with cirrhosis so as to have a reliable surrogate of glomerular filtration rate, and to obviate many problems that are associated with using creatinine and estimated glomerular filtration rate.

An integrated MELD model including serum sodium and age improves the prediction of early mortality in patients with cirrhosis

The Model for End-Stage Liver Disease (MELD) is widely used to predict the short-term mortality in patients with cirrhosis, but potential limitations of this score have been reported. The aim of this study was to improve the score's prognostic accuracy by assessing new objective variables. Data of 310 consecutive patients with cirrhosis who underwent elective transjugular intrahepatic portosystemic shunt placement between July 1995 and March 2005 were analyzed retrospectively. Bivariate and multivariate analyses were performed by proportional hazard Cox regression models. The area under the receiver operating characteristic curve (auROC) and the likelihood ratio test were used to evaluate the performance of the models for predicting early mortality. Findings were validated in a cohort of 451 consecutive patients with cirrhosis on waiting list for liver transplantation. Bivariate analyses showed that the following variables correlated with time to death: age, serum bilirubin, serum creatinine, international normalized ratio of prothrombin time, serum albumin, serum sodium, and MELD. Multivariate analysis revealed that MELD, serum sodium, and age were independently associated with the risk of death. The integrated MELD model (iMELD, incorporating serum sodium and age) was better than original MELD in predicting 12-month mortality: auROC increased by 13.4% and the likelihood ratio statistic from 23.5 to 48.2. The improved accuracy of iMELD was confirmed in the validation sample of 451 patients with cirrhosis on the waiting list for liver transplantation by increasing auROC (+8%) and likelihood ratio statistic (from 41.4 to 82.0). This study shows that in patients with cirrhosis, serum sodium and age are predictors of mortality independent of the MELD score. The incorporation of these variables into the original MELD formula improves the predictive accuracy of time to death.

Predictors of outcomes after pediatric liver transplantation: an analysis of more than 800 cases performed at a single institution

BACKGROUND

Pediatric liver transplantation (PLTx) is the standard of care for treatment of liver failure in children. Unfortunately, there are few studies with substantial numbers of patients that identify outcomes predictors. The goal of this study was to determine factors that influence outcomes in a large, single-center cohort of PLTx.

STUDY DESIGN

This retrospective review between 1984 to 2006 included all recipients 18 years of age and younger undergoing PLTx. Multiorgan graft recipients were excluded (n = 48). Data sources included transplantation center database and hospital medical records. Outcomes measures were overall patient and graft survival. Demographic, laboratory, and perioperative variables were analyzed. Univariate and multivariate statistical analysis was undertaken using log-rank test and Cox's proportional hazards model. A p value < 0.05 was considered significant at the multivariate level.

RESULTS

Eight hundred fifty-two PLTx were performed in 657 children; 55% were girls, 45% were Hispanic, and median age was 29.5 months. Biliary atresia and acute liver failure were the most common causes of liver disease. Fifty-two percent were hospitalized before PLTx. Graft types were whole (75%) and segmental (25%). Indications for re-PLTx (n = 195) included graft nonfunction (22%), immunologic (34%), and vascular complications (35%). Overall 1-, 5-, and 10-year survival rates were 85%, 81%, and 78% (patient), and 78%, 72%, and 67% (graft). Independent significant predictors of worse patient survival were renal function, pretransplantation ventilator dependence, and causes of liver disease. Independent significant predictors of worse graft survival were renal function and warm ischemia time.

CONCLUSIONS

As one of the largest, single-center analyses of PLTx, this study enables accurate statistical analysis and demonstrates excellent longterm outcomes. Independent prognosticators of graft survival were renal function and warm ischemia time, and those for patient survival were renal function, mechanical ventilation, and causes of liver disease. These factors can aid in the medical decision making required for optimal use of scarce donor organs.

Impact of Pretransplant MELD Score on Posttransplant Outcome in Orthotopic Liver Transplantation for Patients with Acute-on-Chronic Hepatitis B Liver Failure

This study was performed to evaluate the usefulness of the model for end-stage liver disease (MELD) score in comparison with the Child-Turcotte-Pugh (CTP) score to predict short-term postoperative survival and 3-month morbidity among patients with acute-on-chronic hepatitis B liver failure undergoing orthotopic liver transplantation.

METHODS

We retrospectively analyzed data from all patients undergoing orthotopic liver transplantation in our unit from December 1999 to November 2005, on the admission day MELD and CTP scores were calculated for each patient according to the original formula. We evaluated the accuracy of MELD and CTP to predict postoperative short-term survival and 3-month morbidity using receiver operating characteristic (ROC) analysis and Kaplan-Meier analysis, respectively.

RESULTS

Seven of 42 patients died within 3-months follow-up. The MELD scores for nonsurvivors (32.97 +/- 7.11) were significantly higher than those for survivors (24.90 +/- 4.96; P < .05), CTP scores were significantly higher, too (12.57 +/- 0.98, 11.51 +/- 1.17; P < .05). ROC analysis identified the MELD best cut-off point to be 25.67 to predict postoperative morbidity (area under the curve [AUC] = 0.841; sensitivity = 85.7%; specificity = 60.0%), and the CTP best cut-off point was 11.5 (AUC = 0.747; sensitivity = 85.7%; specificity = 54.3%). MELD score was superior to CTP score to predict postoperative short-term survival and 3-month morbidity among patients with acute-on-chronic hepatitis B liver failure undergoing orthotopic liver transplantation.

CONCLUSION

MELD score was an objective predictive system and more efficient than CTP score to evaluate the risk of 3-month morbidity and short-term prognosis in patients with acute-on-chronic hepatitis B liver failure undergoing orthotopic liver transplantation.

A new priority policy for patients with hepatocellular carcinoma awaiting liver transplantation within the model for end-stage liver disease system

The best prioritization of patients with hepatocellular carcinoma (HCC) waiting for liver transplantation under the model for end-stage liver disease (MELD) allocation system is still being debated. We analyzed the impact of a MELD adjustment for HCC, which consisted of the addition of an extra score (based on the HCC stage and waiting time) to the native MELD score. The outcome was analyzed for 301 patients with chronic liver disease listed for liver transplantation between March 1, 2001 and February 28, 2003 [United Network for Organ Sharing (UNOS)-Child-Turcotte-Pugh (CTP) era, 163 patients, 28.8% with HCC] and between March 1, 2003 and February 28, 2004 (HCC-MELD era, 138 patients, 29.7% with HCC). In the HCC-MELD era, the cumulative dropout risk at 6 months was 17.6% for patients with HCC versus 22.3% for those patients without HCC (P = NS), similar to that in the UNOS-CTP era. The cumulative probability of transplantation at 6 months was 70.3% versus 39.0% (P = 0.005), being higher than that in the UNOS-CTP era for patients with HCC (P = 0.02). At the end of the HCC-MELD era, 12 patients with HCC (29.3%) versus 57 without HCC (58.8%) were still on the list (P = 0.001). Both native and adjusted MELD scores were higher (P < 0.05) and progressed more in patients with HCC who dropped out than in those who underwent transplantation or remained on the list (the initial-final native MELD scores were 17.3-23.1, 15.5-15.6, and 12.8-14.1, respectively). The patients without HCC remaining on the list showed stable MELD scores (initial-final: 15.1-15.4). In conclusion, the present data support the strategy of including the native MELD scores in the allocation system for HCC. This model allows the timely transplantation of patients with HCC without severely affecting the outcome of patients without HCC.

Modification of acid-base balance in cirrhotic patients undergoing liver resection for hepatocellular carcinoma

OBJECTIVE

To examine modifications of acid-base balance of cirrhotic patients undergoing hepatectomy for hepatocellular carcinoma (HCC).

SUMMARY BACKGROUND DATA

Acid-base disorders are frequently observed in cirrhotics; however, modifications during hepatectomy and their impact on prognosis have never been investigated.

METHODS

Two hundred and two hepatectomies for HCC on cirrhosis were reviewed. Arterial blood samples were collected immediately before and at the end of resection. Preresection and postresection acid-base parameters were compared and related to patient characteristics and postoperative course. The accuracy of acid-base parameters in predicting postoperative liver failure, defined as an impairment of liver function after surgery that led to patient death or required transplantation, was assessed using receiver operating characteristic analysis (ROC).

RESULTS

All patients showed a significant reduction in pH, bicarbonate, and base excess at the end of hepatectomy (P < 0.001 in all cases), worsened by intraoperative blood loss (P < 0.010) and preoperative Model for end-stage liver disease score > or =11 (P < 0.010). ROC curve analysis identifies patients with postresection bicarbonate <19.4 mmol/L at high risk for liver failure (50.0%) whereas levels >22.1 mmol/L did not lead to the event (0%; P < 0.001). Postoperative prolongation of prothrombin time and increases in bilirubin, creatinine, and morbidity were also more frequent in patients with lower postresection bicarbonate, resulting in a longer in-hospital stay.

CONCLUSION

In cirrhotic patients, a trend toward a relative acidosis can be expected during surgery and is worsened by the severity of the underlying liver disease and intraoperative blood loss. Postresection bicarbonate level lower than 19.4 mmol/L is an adverse prognostic factor.

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.

Laboratory Test Variability and Model for End-Stage Liver Disease Score Calculation: Effect on Liver Allocation and Proposal for Adjustment

BACKGROUND

The use of the Model for End-Stage Liver Disease (MELD) score to prioritize patients on liver waiting lists must take the bias of different laboratories into account.

METHODS

We evaluated the outcome of 418 patients listed during 1 year whose MELD score was computed by two laboratories (lab 1 and lab 2). The two labs had different normality ranges for bilirubin (maximal normal value [Vmax]: 1.1 for lab 1 and 1.2 for lab 2) and creatinine (Vmax: 1.2 for lab 1 and 1.4 for lab 2). The outcome during the waiting time was evaluated by considering the liver transplantations and the dropouts, which included deaths on the list, tumor progression, and patients who were too sick.

RESULTS

Although the clinical features of patients were similar between the two laboratories, 36 (13.1%) out of 275 were dropped from the list in lab 1, compared to 5 (3.5%) out of 143 in lab 2 (P<0.01). The differences were mainly due to the deaths on the list (8% lab 1 vs. 2.1% lab 2, P<0.05). The competing risk analysis confirmed the different risk of dropout between the two labs independently of the MELD score, blood group, and preoperative diagnosis. The bias on MELD calculation was considered and bilirubin and creatinine values were "normalized" to Vmax of lab 1 (corrected value=measured value x Vmax lab 1/Vmax lab 2). By comparing receiver operating characteristic curves, the ability of MELD to predict the 6-month dropouts significantly increased from an area under the curve of 0.703 to 0.716 after "normalization" (P<0.05).

CONCLUSIONS

Normalization of MELD is a correct and good compromise to avoid systematic bias due to different laboratory methods.

Use of a pediatric end-stage liver disease score for deceased donor allocation: the United States experience

The Pediatric end-stage liver disease (PELD) score was developed as a measure of the severity of chronic liver disease that would predict mortality or children awaiting liver transplant. From multivariate analyses a model was derived that included five objective factors which together comprise the PELD score. The factors are growth failure, age less than 1 year, international normalized ratio (INR), serum albumin and total bilirubin.

Reduced mortality with right-lobe living donor compared to deceased-donor liver transplantation when analyzed from the time of listing

Right lobe living donor liver transplantation (RLDLT) is not yet a fully accepted therapy for patients with end-stage liver failure in the Western hemisphere because of concerns about donor safety and inferior recipient outcomes. An outcome analysis from the time of listing for all adult patients who were listed for liver transplantation (LT) at our center was performed. From 2000 to 2006, 1091 patients were listed for LT. One hundred fifty-four patients (LRD; 14%) had suitable live donors and 153 (99%) underwent RLDLT. Of the remaining patients (DD/Waiting List; n = 937), 350 underwent deceased donor liver transplant (DDLT); 312 died or dropped off the waiting list; and 275 were still waiting at the time of this analysis. The LRD group had shorter mean waiting times (6.0 months vs. 9.8 months; p < 0.001). Although medical model for end-stage liver disease (MELD) scores were similar at the time of listing, MELD scores at LT were significantly higher in the DD/Waiting List group (15.4 vs. 19.5; p = 0.002). Patients in Group 1 had a survival advantage with RLDLT from the time of listing (1-year survival 90% vs. 80%; p < 0.001). To our knowledge, this is the first report to document a survival advantage at time of listing for RLDLT over DDLT.

Risk factors for liver transplantation waiting list mortality

BACKGROUND AND AIM

The gap between the demand for liver transplantation and organ donation rates has a major impact on waiting list mortality. Understanding the risk factors that predict liver transplant waiting list death may help optimize organ allocation policy and reduce waiting list deaths.

METHODS

We analyzed risk factors associated with waiting list mortality in the Liver Transplant Unit Victoria for the period 1988 through 2004.

RESULTS

The mean annual waiting list mortality for the period examined was 10.2% (10.6% for adult and 6.4% for pediatric patients). Factors associated with waiting list death included female sex, fulminant hepatic failure, primary non-function, blood group O, more urgent United Network for Organ Sharing (UNOS)-derived medical status, a Child-Turcotte-Pugh (CTP) score >or=11, a model for end-stage liver disease (MELD) score >or=20, and a pediatric end-stage liver disease score >or=20. UNOS-derived medical status, CTP class, and MELD score were significant at the multivariate level.

CONCLUSIONS

Disease severity scores, such as MELD, predict the risk of liver transplantation waiting list mortality. Use of such scores in organ allocation in Australian liver transplant units may result in reduced waiting list mortality.

Outcomes in hepatitis C virus-infected recipients of living donor vs. deceased donor liver transplantation

In this retrospective study of hepatitis C virus (HCV)-infected transplant recipients in the 9-center Adult to Adult Living Donor Liver Transplantation Cohort Study, graft and patient survival and the development of advanced fibrosis were compared among 181 living donor liver transplant (LDLT) recipients and 94 deceased donor liver transplant (DDLT) recipients. Overall 3-year graft and patient survival were 68% and 74% in LDLT, and 80% and 82% in DDLT, respectively. Graft survival, but not patient survival, was significantly lower for LDLT compared to DDLT (P = 0.04 and P = 0.20, respectively). Further analyses demonstrated lower graft and patient survival among the first 20 LDLT cases at each center (LDLT <or=20) compared to later cases (LDLT > 20; P = 0.002 and P = 0.002, respectively) and DDLT recipients (P < 0.001 and P = 0.008, respectively). Graft and patient survival in LDLT >20 and DDLT were not significantly different (P = 0.66 and P = 0.74, respectively). Overall, 3-year graft survival for DDLT, LDLT >20, and LDLT <or=20 were 80%, 79% and 55%, with similar results conditional on survival to 90 days (84%, 87% and 68%, respectively). Predictors of graft loss beyond 90 days included LDLT <or=20 vs. DDLT (hazard ratio [HR] = 2.1, P = 0.04), pretransplant hepatocellular carcinoma (HCC) (HR = 2.21, P = 0.03) and model for end-stage liver disease (MELD) at transplantation (HR = 1.24, P = 0.04). In conclusion, 3-year graft and patient survival in HCV-infected recipients of DDLT and LDLT >20 were not significantly different. Important predictors of graft loss in HCV-infected patients were limited LDLT experience, pretransplant HCC, and higher MELD at transplantation.

Transplantation for hepatocellular carcinoma: The Milan criteria and beyond

1. Liver transplantation offers excellent results for selected candidates with hepatocellular carcinoma (HCC). 2. Selection strategies have evolved but are mainly based on size and number of tumors, which are surrogates for vascular invasion. Newer techniques show promise for identifying patients at high risk for recurrence and selecting those with low risk, even though they may exceed currently established tumor size criteria. 3. Evaluation of the effectiveness of liver transplantation for HCC requires an intent-to-treat approach that must include an accounting of the dropout rate of patients while waiting. 4. Locoregional pretransplantation adjuvant treatments may have some role for downstaging and/or reducing the dropout rate before transplantation, but their posttransplantation effect on outcome remains undetermined. 5. Liver allocation for HCC candidates in the context of increasing HCC prevalence requires better and evidence-based prioritization policies.

Optimizing staging for hepatocellular carcinoma before liver transplantation: A retrospective analysis of the UNOS/OPTN database

Assignment of liver allocation priority for hepatocellular carcinoma is predicated on accurate imaging staging. We analyzed radiographically defined stage (radiologic stage [RS]) at listing and most recent extension and pathologic stage (PS) data from 789 liver transplant recipients for whom no pretransplant ablative treatment was given. There were no predetermined imaging or pathological protocols in this retrospective analysis of wait list data. Seventy-two (9.1%), 690 (87.5%), and 27 (3.4%) were listed as stage 1, 2 and >2, respectively. Computed tomography (CT) scan alone (46.4%), magnetic resonance image scan alone (37.1%), ultrasound alone (1.3%), and multiple imaging studies (15.2%) were used with no difference in time to transplant for listing or most recent scan among the recipient groups. Overall accuracy (RS = PS) was 44.1% and was not different if original listing RS or most recent RS was used for comparison with PS. No one type of imaging technique had superior accuracy (P = 0.13); however, CT scan used alone or in combination compared to not being used at all, had higher odds of being accurate (odds ratio [OR] 1.38 [1.03-1.84], P = 0.031). In addition, imaging done less than 90 days before transplant had higher odds of being accurate (OR 1.49 [1.06-2.08], P = 0.019) as did RS = 2 or 3 (OR 5.56 [2.70-11.11], P < 0.0001). We observed considerable variation in RS accuracy among the United Network for Organ Sharing and Organ Procurement and Transplantation Network regions that is unexplained. In conclusion, current imaging requirements for RS prior to liver transplantation are unacceptably inaccurate. Future policy should require more accurate modalities or combinations of techniques.

The model for end-stage liver disease score is useful for predicting economic outcomes in adult cases of living donor liver transplantation

BACKGROUND

The model for end-stage liver disease (MELD) is useful for assessing the recipients of liver transplants, namely, deceased-donor transplantation. The application of MELD for living donor liver transplantation (LDLT) is under investigation. Thus, the aim of this study was to analyze the impact of the MELD score in LDLT in Japan.

METHODS

Seventeen adult cases of LDLT during 2001 to 2005 were enrolled. Indications for LDLT were primary biliary cirrhosis, seven; liver cirrhosis, two; hepatocellular carcinoma (HCC), three; metabolic liver disease, one; primary sclerosing cholangitis, two; Caroli's disease, one; and biliary atresia, one. Total medical charges during the operative periods were retrospectively evaluated. The united network of organ sharing (UNOS) modified was obtained using preoperative clinical data.

RESULTS

The average medical expense of the 17 cases was approximately 97,901 US dollar. The UNOS-modified MELD score was 22.1. A statistically significant positive correlation was found between the MELD score and medical expense (P = 0.0086, rho = 0.657), and between the MELD score and the length of stay in the intensive care unit (ICU) (P = 0.0396, rho = 0.515). The cause of the liver disease leading to transplantation was not related to MELD score, medical expense, or length of ICU stay.

CONCLUSIONS

Although not originally designed for the application to LDLT, the MELD score is useful for predicting medical expenses in LDLT. Similar to those of deceased-donor liver transplantation, the disadvantage of high medical expenses associated with a high MELD score allow consideration of an earlier elective operation in suitable cases.

Geographic differences in event rates by model for end-stage liver disease score

The ability of the model for end-stage liver disease (MELD) score to accurately predict death among liver transplant candidates allows for evaluation of geographic differences in transplant access for patients with similar death risk. Adjusted models of time to transplant and death for adult liver transplant candidates listed between 2002 and 2003 were developed to test for differences in MELD score among Organ Procurement and Transplantation Network (OPTN) regions and Donation Service Areas (DSA). The average MELD and relative risk (RR) of death varied somewhat by region (from 0.82 to 1.28), with only two regions having significant differences in RRs. Greater variability existed in adjusted transplant rates by region; 7 of 11 regions differed significantly from the national average. Simulation results indicate that an allocation system providing regional priority to candidates at MELD scores > or = 15 would increase the median MELD score at transplant and reduce the total number of deaths across DSA quintiles. Simulation results also indicate that increasing priority to higher MELD candidates would reduce the percentage variation among DSAs of transplants to patients with MELD scores > or = 15. The variation decrease was due to increasing the MELD score at time of transplantation in the DSAs with the lowest MELD scores at transplant.

Prediction of the prognosis in patients with acute-on-chronic hepatitis using the MELD scoring system

AIM

To predict prognosis in patients with acute-on-chronic hepatitis (AOCH) using the model for end-stage liver disease (MELD) scoring system and to study the effects of age, sex, etiology, low serum sodium, and persistent ascites on MELD.

METHODS

The MELD scores of 300 patients with AOCH were calculated according to the original formula. The 3-month mortality in patients was measured, and the validity of the models was determined by means of the concordance (c) statistic. The influential factors on MELD were also assessed.

RESULTS

The 3-month mortality of AOCH patients with a MELD score of 20-29 was 56.0%, with a score of 30-39 it was 76.5%, and with a score over 40 it was 98.2%. The concordance (c) statistic of 3-month mortality was 0.782. Univariate analysis showed that mortality was significantly related to age (P=0.047), etiology (P=0.039), serum sodium (P=0.029) and ascites (P=0.031) for patients with MELD scores 20-29. In multivariate analysis, in patients with MELD scores 20-29, age (P=0.012), etiology (P=0.024), serum sodium (P=0.005) and ascites (P=0.017) were independent predictors of mortality; for MELD scores above 30, only MELD score (P=0.015) was independently predictive.

CONCLUSIONS

The MELD scoring system is a reliable method for predicting mortality in patients with AOCH. In the group with MELD score 20-29, factors including age, etiology, presence of low serum sodium and persistent ascites may influence the MELD scoring system. The MELD score is the decisive predictor of the prognosis of patients with AOCH when the MELD score is over 30.

Recovery from liver failure after hepatectomy for hepatocellular carcinoma in cirrhosis: meaning of the model for end-stage liver disease

BACKGROUND

Hepatectomy for hepatocellular carcinoma in cirrhosis is followed by an impairment of liver function that can lead to patient death. The model for end-stage liver disease (MELD) is considered an index of hepatic functional reserve, and its assessment on postoperative course may properly identify individuals at risk of liver failure.

STUDY DESIGN

Two hundred hepatectomies for hepatocellular carcinoma in cirrhosis were reviewed. Irreversible postoperative liver failure was defined as an impairment of liver function after hepatectomy that led to patient death or required transplantation. The MELD scores at postoperative days (POD) 1, 3, 5, and 7 were calculated and kinetics of changes investigated with t-test; logistic regression was applied to identify predictive variables of postoperative liver failure.

RESULTS

Kinetics of postoperative MELD score showed an impairment of liver function between PODs 1 and 3; 185 patients in whom postoperative liver failure did not develop showed a considerable decrease in MELD score between PODs 3 and 5 (11.9+/-2.8 and 10.6+/-2.4, respectively, p<0.001). On the contrary, 15 patients, who experienced the event, showed an increase in MELD score between PODs 3 and 5 (18.2+/-3.9 and 18.3+/-3.6, respectively; p=0.845). Multivariate analysis showed preoperative MELD score (p<0.001), major hepatectomy (p=0.028), and MELD score increase between PODs 3 and 5 (p=0.011) as independent predictors of irreversible postoperative liver failure. Scores are reported as mean+/-SD.

CONCLUSIONS

Recovery from liver impairment after hepatectomy for hepatocellular carcinoma in cirrhosis starts from POD 3; MELD scores increasing between PODs 3 and 5 may identify patients at risk of liver failure and represents the trigger for beginning intensive treatment or evaluating salvage transplantation.

Liver transplantation with the Meld system: a prospective study from a single European center

The efficacy of the Meld system to allocate livers has never been investigated in European centers. The outcome of 339 patients with chronic liver disease listed according to their Meld score between 2003 and 2005 (Meld era) was compared to 224 patients listed during the previous 2 years according to their Child score (Child era). During the Meld era, hepatocellular carcinomas (HCCs) had a 'modified' Meld based on their real Meld, waiting time and tumor stage. The dropouts were deaths, tumor progressions and too sick patients. The rate of removals from the list due to deaths and tumor progressions was significantly lower in the Meld than in the Child era: 10% and 1.2% versus 16.1% and 4.9%, p < 0.05. The 1-year patient survival on the list was significantly higher in the Meld era (84% vs. 72%, p < 0.05). The prevalence of transplantation for HCC increased from 20.5% in the Child to 48.9% in the Meld era (p < 0.001), but between HCCs and non-HCCs of this latter era the dropouts were comparable (9.4% vs. 14.9%, p = n.s.) as was the 1-year patient survival on the list (83% vs. 84%, p = n.s.). The Meld allocation system improved the outcome of patients with or without HCC on the list.

Impact of model for end-stage liver disease (MELD) scoring system on pathological findings at and after liver transplantation

The Model for End-Stage Liver Disease (MELD) scoring system, a validated objective liver disease severity scale, was adopted in February 2002 to allocate cadaveric organs for liver transplantation (LT). To improve transplantability before succumbing to advanced disease, patients with low-stage hepatocellular carcinoma (HCC) are given extra points in this system commensurate with their predicted mortality. Our aims were to determine 1) any change in the pathological findings at LT following the implementation of this system and 2) the impact of scoring advantage given to early-stage HCC. Clinicopathologic findings were compared before (pre-MELD, n = 87) and after (MELD, n = 58) the introduction of the MELD system. The findings in the pre-MELD vs. MELD groups were as follows: HCC, 27.5% vs. 48.3% (P = 0.001); portal vein thrombosis (PVT), 13.7% vs. 25.9% (P = 0.08); cholestasis, 16.1% vs. 32.7% (P = 0.026); inflammation grade of 2 or more, 43.7% vs. 48.3% (P = not significant); hepatitis C (HCV), 45.9% vs. 51.7% (P = not significant); HCV with lymphoid aggregates, 25% vs. 60% (P = 0.003); HCV with hyperplastic hilar nodes, 15.0% vs. 36.6% (P = 0.001); and post-LT HCC recurrence, 4.1% vs. 3.4% (P = not significant). Non-HCC-related findings were further compared in the 2 subgroups of pre-MELD (n = 57) and MELD (n = 31) after exclusion of HCC and fulminant hepatic failure (FHF) cases, and only cholestasis was significantly increased in the subgroup MELD. In conclusion, increased incidence of native liver cholestasis in the MELD era may be the histologic correlate of clinically severe liver disease. The scoring advantage given to low-stage HCC did result in a significantly increased incidence of HCC in the MELD group, but it did not adversely affect the post-LT recurrence rate.

Impact of model for end-stage liver disease (MELD) score on prognosis after hepatectomy for hepatocellular carcinoma on cirrhosis

The objective of this study was to predict postoperative liver failure and morbidity after hepatectomy for hepatocellular carcinoma (HCC) with cirrhosis. The model for end-stage liver disease (MELD) score is currently accepted as a disease severity index of cirrhotic patients awaiting liver transplantation; however, its impact on prognosis after resection of HCC on cirrhosis has never been investigated. One hundred fifty-four cirrhotic patients resected in a tertiary care setting for HCC were retrospectively analyzed. For each patient, the MELD score was calculated and related to postoperative liver failure and complications (morbidity). Hospital stay and 1-year survival was also investigated. MELD accuracy in predicting postoperative liver failure and morbidity of cirrhotic patients was assessed using receiver operating characteristic (ROC) analysis. Eleven patients (7.1%) experienced postoperative liver failure leading to death or transplantation. ROC analysis identified cirrhotic patients with a MELD score equal to or above 11 at high risk for postoperative liver failure (area under the curve [AUC] = 0.92, 95% confidence interval [CI] = 0.87-0.96; sensitivity = 82%; specificity = 89%). Forty-six patients (29.9%) developed at least 1 postoperative complication: ROC analysis identified patients with a MELD score equal to or above 9 at major risk for postoperative complications (AUC = 0.85, 95% CI = 0.78-0.89; sensitivity = 87%; specificity = 63%). Cirrhotic patients with MELD score below 9 had no postoperative liver failure and low morbidity (8.1%). In conclusion, the MELD score can accurately predict postoperative liver failure and morbidity of cirrhotic patients referred for resection of HCC and should be used to select the best candidates for hepatectomy.

Quantitative survival model for short-term survival after adult-to-adult living donor liver transplantation

Adult-to-adult living donor liver transplantation (ALDLT) has been accepted as an important option for end-stage liver disease, but information regarding the risk factors remains fragmentary. We aimed to establish a predictive model for 90-day survival. In the first step, a total of 286 cases who had received primary ALDLT using a right lobe graft between 1998 and 2004 were randomly divided into 2 cohorts at a ratio of 2:1 (191 vs. 95 recipients). The larger cohort of patients was used to develop a model. The outcome was defined as 90-day survival, and a total of 39 preoperative and operative variables, including the period of surgery (1998-2001 vs. 2002-2004), were included using Cox's proportional hazard regression model. Two mismatches of human leukocyte antigen (HLA) type DR (hazard ratio [HR] = 4.45; confidence interval [CI] = 1.96-10.1), log(e)[blood loss volume] (HR = 2.43; CI = 1.64-3.60), period of surgery (1998-2001 vs. 2002-2004) (HR = 2.41; CI = 1.04-5.57), and log(e)[serum C-reactive protein or CRP] (HR = 1.64; CI = 1.13-2.38) were found to be independent risk factors. In the second step, we tried to establish a realistic survival model. In this step, we created 2 models, 1 that used all 4 variables (model 1) and 1 (model 2) in which blood loss volume was replaced with the past history of upper abdominal surgery and Model for End-Stage Liver Disease (MELD) score (> or =25), both of which showed associations with blood loss volume. These models were applied to the smaller cohort of 95 patients. Receiver operating characteristic analyses demonstrated that both models showed similar significant c-statistics (0.63 and 0.62, respectively). In conclusion, model 2 can provide a rough estimation of the 90-day survival after ALDLT.

Waiting list removal rates among patients with chronic and malignant liver diseases

Equitable liver allocation should ensure that nonelective removal rates are fairly distributed among waiting candidates. We compared removal rates for adults entered with nonmalignant (NM) (N = 9379) and hepatocellular cancer (HCC) (N = 2052) diagnoses on the Organ Procurement and Transplantation Network (OPTN) list between April 30, 2003, and December 31, 2004. Unadjusted removal rates for NM vs. HCC diagnoses were 9.4% vs. 8.7%, 13.5% vs. 16.9% and 19.1% vs. 31.8% at 90, 180 and 365 days, respectively after listing. For NM candidates, model for end-stage liver disease (MELD) score (RR = 1.16), age (RR = 1.03) and metabolic disease diagnoses (RR = 1.66) had higher risks of removal; and PSC (RR = 0.62) and alcoholic cirrhosis (RR = 0.82) had lower risks of removal. For HCC candidates, MELD score at listing (RR = 1.09), AFP (RR = 1.02), maximum tumor size (RR = 1.16) and age at listing (RR = 1.02) had increased risks of removal. The equation 1 - 0.920 exp[0.09369 (MELD at listing - 12.48) + 0.00193 (AFP - 97.4) + 0.1505 (maximum tumor size - 2.59) defined the probability of dropout for HCC candidates within 90 days of listing. We conclude that factors associated with the risk of removal for HCC are different from NM candidates, although MELD score at listing remains the most predictive for both groups. Liver transplant candidates with HCC may be prioritized using a risk score analogous to the MELD score.