A simple model to estimate survival after retransplantation of the liver

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.

Retransplantation for recurrent hepatitis C in the MELD era: maximizing utility

1. Retransplantation (re-LT) for hepatitis C virus (HCV) recurrence is controversial. Although re-LT accounts for 10% of all liver transplants (LTs), the number of patients requiring re-LT is expected to grow as primary LT recipients survive long enough to develop graft failure from recurrent disease. 2. Utility, as applied to the medical ethics of transplantation, refers to allocating organs to those individuals who will make the best use of them. The utility function (U) of liver transplantation is represented by the product of outcome (O = 1-year survival with LT) times emergency (E = 3-month mortality without LT), i.e., U = O x E. 3. For primary LT, maximal U is achieved by allocating organs at the highest model for end-stage liver disease (MELD) score (i.e., "sickest first"). No significant differences exist between HCV and non-HCV diagnoses. 4. For re-LT, maximal utility for HCV and non-HCV diagnoses are achieved at MELD scores of 21 and 24, respectively. Utility starts to decline at MELD scores above 28. 5. The current allocation system (MELD) fails to maximize utility with regard to re-LT.

Predicting outcome after liver transplantation: utility of the model for end-stage liver disease and a newly derived discrimination function

BACKGROUND

The Model for End-Stage Liver Disease (MELD) has been found to accurately predict pretransplant mortality and is a valuable system for ranking patients in greatest need of liver transplantation. It is unknown whether a higher MELD score also predicts decreased posttransplant survival.

METHODS

We examined a cohort of patients from the United Network for Organ Sharing (UNOS) database for whom the critical pretransplant recipient values needed to calculate the MELD score were available (international normalized ratio of prothrombin time, total bilirubin, and creatinine). In these 2,565 patients, we analyzed whether the MELD score predicted graft and patient survival and length of posttransplant hospitalization.

RESULTS

In contrast with its ability to predict survival in patients with chronic liver disease awaiting liver transplant, the MELD score was found to be poor at predicting posttransplant outcome except for patients with the highest 20% of MELD scores. We developed a model with four variables not included in MELD that had greater ability to predict 3-month posttransplant patient survival, with a c-statistic of 0.65, compared with 0.54 for the pretransplant MELD score. These pretransplant variables were recipient age, mechanical ventilation, dialysis, and retransplantation. Recipients with any two of the three latter variables showed a markedly diminished posttransplant survival rate.

CONCLUSIONS

The MELD score is a relatively poor predictor of posttransplant outcome. In contrast, a model based on four pretransplant variables (recipient age, mechanical ventilation, dialysis, and retransplantation) had a better ability to predict outcome. Our results support the use of MELD for liver allocation and indicate that statistical modeling, such as reported in this article, can be used to identify futile cases in which expected outcome is too poor to justify transplantation.

A model to predict the development of mental status changes of unclear cause after liver transplantation

Postoperative mental status changes are common after liver transplantation (LT). A clear cause of these mental status changes cannot be identified in a significant proportion of patients. In adult liver transplant recipients, our goals are to: (1) identify independent predictors for the development of post-LT mental status changes of unclear cause and (2) derive a practical formula to predict the risk for developing this complication by using simple clinical parameters. Eligible patients had documented mental status changes of at least 3 days' duration, occurring within 1 month of LT. Exclusion criteria were known structural brain disorders, major organ dysfunction, or metabolic causes of altered mentation. Age- and sex-matched controls were liver transplant recipients without post-LT neurological sequelae. Data were collected on preoperative, intraoperative, and postoperative variables. Univariate and multivariate analyses were performed to detect factors predictive of the development of post-LT mental status of unclear cause. There were 40 cases and 40 controls. Independent predictors of mental status changes of unclear cause included alcoholic and metabolic liver diseases; pre-LT mechanical ventilation; Model for End-Stage Liver Disease (MELD) score greater than 15; and nonelective LT. Using these four preoperative factors, a simple predictive rule was developed. Risk for developing altered mental status of unclear cause after LT was 78% to 89% if all four predictors were present versus 0.8% to 2.4% if no predictors were present. In conclusion, alcoholic and metabolic liver diseases, pre-LT mechanical ventilation, MELD score greater than 15, and nonelective LT are independent predictive factors for post-LT altered mental status changes of unclear cause. A simple model can be used to calculate the risk for developing altered mental status post-LT.

The natural history and outcome of liver transplantation in hepatitis C virus-infected recipients

1. Recurrence of hepatitis C infection is universal and immediate after liver transplantation. 2. Graft and patient survival is reduced in liver transplantation recipients with recurrent hepatitis C virus infection compared with hepatitis C virus-negative recipients. 3. The natural history of chronic hepatitis C is accelerated after liver transplantation compared with nontransplantation chronic hepatitis C; 20% to 40% of patients progress to allograft cirrhosis within 5 years, compared with less than 5% of nontransplantation patients. 4. The rate of fibrosis progression is not uniform and may change over time. 5. The rate of progression from cirrhosis to decompensation is accelerated after liver transplantation. The rate of decompensation is >40% at 1 year and >60% at 3 years, compared with <5% and <10%, respectively, in immunocompetent patients. 6. The rate of progression from decompensation to death is also accelerated after liver transplantation. The 3-year survival is <10% after the onset of hepatitis C virus-related allograft failure, compared with 60% after decompensation in immunocompetent patients.

Retransplantation for recurrent hepatitis C: the argument against

1. Cirrhosis from chronic hepatitis C is the most common indication for liver grafting today. The course of hepatitis C is accelerated after liver transplantation, and no current therapy reliably prevents or arrests it. 2. It is anticipated that 20% or more of hepatitis C virus-positive transplant recipients will develop allograft cirrhosis, and the only solution will be retransplantation. 3. Results of retransplantation are inferior to primary transplantation. 4. Recipient risk factors that adversely affect mortality after repeated liver grafting include age older than 50 years, renal insufficiency, and severity of hyperbilirubinemia. When present, they reduce survival after retransplantation to approximately 40% or less. 5. Retransplantation on a large scale for recurrent hepatitis C is problematic from the perspectives of outcome, resource utilization, and fairness to candidates awaiting primary grafts.

Outcomes for pediatric liver retransplantation from living donors

BACKGROUND

The only therapeutic option for patients with a failing allograft is retransplantation. Living donor liver transplantation (LDLT) is a well-accepted therapeutic option for end-stage liver disease, but retransplantation from a living donor (Re-LDLT) has not previously been discussed.

METHODS

A total of 547 LDLTs were performed in 519 children (<18 years old) at Kyoto University Hospital from June 1990 to October 2002. During the same study period, a total of 28 Re-LDLTs were performed in 27 recipients (Re-LDLT performed twice in 1 patient). Patient survival was analyzed with respect to various preoperative factors, such as functional status, pretransplantation apheresis, cause of primary graft failure, interval from primary to subsequent transplants, and laboratory values of total bilirubin and creatinine.

RESULTS

Kaplan-Meier survival rate from the date of Re-LDLT to 1 year was 47.6%. Functional status, pretransplantation apheresis, interval to Re-LDLT, and bilirubin and creatinine levels all exerted an adverse impact on survival after Re-LDLT. Pathologically proven major causes of primary graft failure were chronic rejection (n=10, 35.7%), chronic cholangitis (n=6, 21.4%), and vascular complications (n=7, 25.0%). Among these causes, vascular complications displayed the strongest adverse impact on survival, compared with chronic cholangitis and chronic rejection (1-year survival was 35.7% in vascular complications; 66.7% in chronic cholangitis; and 60.0% in chronic rejection).

CONCLUSIONS

Re-LDLT can save patients with a failing allograft. To achieve better results after Re-LDLT, further investigations are necessary to understand the factors leading to poor outcome after Re-LDLT.

To transplant or not to transplant recurrent hepatitis C and liver failure

In summary, re-OLT accounts for 10% of all OLTs performed and is associated with significantly increased resource use, and decreased survival compared with primary OLT. After transplantation into an HCV-infected recipient, infection of the allograft by HCV is invariable. As patients survive longer after liver transplantation, it is likely that allograft failure related to HCV recurrence will occur. Results of re-OLT for HCV are inferior to those of primary grafting, paralleling the results for retransplantation for other indications. Many studies have demonstrated that HCV infection significantly impairs patient and allograft survival after liver retransplantation, regardless of etiology of allograft failure. Patient survival rates with HCV infection are 57% to 65% at 1 year, as compared with 65% to 82% among patients without HCV infection. Experience with retransplantation is limited, however, and studies are difficult to interpret because of small sample sizes and lack of uniform definitions of survival, HCV recurrence, and allograft failure. Similar to outcomes after retransplantation for non-HCV related indications, the most common causes of death are sepsis and multi-organ failure. The high mortality associated with retransplantation has not universally been caused by recurrent disease, however recent studies have demonstrated that re-recurrent HCV occurs and the natural history is similar, if not more accelerated, after the second transplant. HCV infection may, in fact, increase mortality in a group of patients already predisposed to an inferior outcome. Preoperative serum creatinine and bilirubin have been consistently associated with survival after retransplantation and favorable results are attainable with strict selection criteria. The increasing use of expanded donor criteria, in particular, LRLT, raises important practical and ethical issues with regards to the HCV-positive transplant recipient and will become a challenge to the transplant community as a whole. With the donor morbidity and mortality associated with LRLT currently estimated at 32% and 0.3%, respectively, one must determine how much risk is acceptable to the donor in relation to the outcome in the recipient. This is especially true in HCV-infected recipients, in whom HCV re-recurrence may occur in the second allograft and lead to accelerated failure. LRLT, however, would not deplete the organ pool and would lead to the use of scarce cadaveric organs to patients who are awaiting primary liver transplantation. Despite inferior outcomes, a better tactic may be to consider retransplantation for recurrent HCV in those whose primary transplant was a LDLT, as the initial allograft did not deplete the donor pool. Given the shortage of donor organs and the increasing number of patients with HCV-induced allograft cirrhosis, identifying ways to improve allograft survival in HCV-infected patients represents an important focus for further research. Additional studies are needed to further explore the mechanisms underlying the reduction in survival and to identify which HCV-positive individuals are at greatest risk for poor survival. Studies are beginning to emerge that demonstrate that HCV recurrence can be modified with combination antiviral therapy and that the HCV virus can be eliminated. Additional longitudinal prospective studies are needed to assess the exact impact of HCV on survival after retransplantation, the effects of the newer immunosuppressive agents such as sirolimus and mycophenolate mofetil on HCV, the use of preemptive antiviral therapy on HCV eradication and fibrosis modification, and the appropriateness of expanded donor criteria. Until we have longer follow-up and greater experience with the HCV-positive recipient with allograft failure, retransplantation should be considered a viable option for highly selected patients, particularly in patients in whom renal failure and severe hyperbilirubinemia have not occurred.

Risk factors for death following liver retransplantation

AIM

Our goal was to retrospectively analyze graft loss and mortality risk factors using multi-centre data on liver retransplantation.

MATERIAL AND METHODS

Between 1991-1995, 640 patients underwent 718 liver transplants in Barcelona. Mean age of the 74 patients receiving a second transplant was 47.6 years (range 19-65). Causes of retransplantation were immunologic in 26 patients (35.1%), technical in 23 (31.1%), primary dysfunction in 12 (16.2%), recurrent original disease in 7 (9.5%), and other causes in 6 (8.1%). Mean time between first and second transplant was less than 7 days in 20 patients (27%), between 8 and 30 days in 4 (5.4%) and more than 30 days in 50 patients (67.6%). Recipient, donor, and operative variables were analyzed using univariate (Kaplan-Meier curves) and multivariate techniques (Cox regression) to identify risk factors.

RESULTS

Retransplant patient survival at 1 and 5 years was 60.8% and 49.5%, respectively, compared to 75.6% and 64.8% in a series of 640 first transplant patients. Mortality risk factors identified by multivariate analysis were bilirubin >12 mg/dL (RR 2.3; P=.010), recipient age (RR increase 0.04 for each additional year; P=.02), cause for retransplant (immunologic RR 4.01, technical RR 2.7 and other causes RR 6.9; compared to primary dysfunction RR 1; P=.020). Urea >54 mg/dL (0.02) and multiple transfusions >15 units red blood cells (0.001) were only significant in the univariate analysis.

CONCLUSIONS

In our experience, retransplantation for primary dysfunction is the setting that has the best prognosis. Of the other causes, retransplantation should be performed before the total bilirubin reaches >12 mg/dL or before the appearance of variables indicative of severe renal insufficiency.

Validation and refinement of survival models for liver retransplantation

Orthotopic liver retransplantation (re-OLT) is highly controversial. The objectives of this study were to determine the validity of a recently developed United Network for Organ Sharing (UNOS) multivariate model using an independent cohort of patients undergoing re-OLT outside the United States, to determine whether incorporation of other variables that were incomplete in the UNOS registry would provide additional prognostic information, to develop new models combining data sets from both cohorts, and to evaluate the validity of the model for end-stage liver disease (MELD) in patients undergoing re-OLT. Two hundred eighty-one adult patients undergoing re-OLT (between 1986 and 1999) at 6 foreign transplant centers comprised the validation cohort. We found good agreement between actual survival and predicted survival in the validation cohort; 1-year patient survival rates in the low-, intermediate-, and high-risk groups (as assigned by the original UNOS model) were 72%, 68%, and 36%, respectively (P <.0001). In the patients for whom the international normalized ratio (INR) of prothrombin time was available, MELD correlated with outcome following re-OLT; the median MELD scores for patients surviving at least 90 days compared with those dying within 90 days were 20.75 versus 25.9, respectively (P =.004). Utilizing both patient cohorts (n = 979), a new model, based on recipient age, total serum bilirubin, creatinine, and interval to re-OLT, was constructed (whole model chi(2) = 105, P <.0001). Using the c-statistic with 30-day, 90-day, 1-year, and 3-year mortality as the end points, the area under the receiver operating characteristic (ROC) curves for 4 different models were compared. In conclusion, prospective validation and use of these models as adjuncts to clinical decision making in the management of patients being considered for re-OLT are warranted.

Liver transplantation for fulminant hepatic failure: experience with more than 200 patients over a 17-year period

OBJECTIVE

To analyze outcomes after liver transplantation (LT) in patients with fulminant hepatic failure (FHF) with emphasis on pretransplant variables that can potentially help predict posttransplant outcome.

SUMMARY BACKGROUND DATA

FHF is a formidable clinical problem associated with a high mortality rate. While LT is the treatment of choice for irreversible FHF, few investigations have examined pretransplant variables that can potentially predict outcome after LT.

METHODS

A retrospective review was undertaken of all patients undergoing LT for FHF at a single transplant center. The median follow-up was 41 months. Thirty-five variables were analyzed by univariate and multivariate analysis to determine their impact on patient and graft survival.

RESULTS

Two hundred four patients (60% female, median age 20.2 years) required urgent LT for FHF. Before LT, the majority of patients were comatose (76%), on hemodialysis (16%), and ICU-bound. The 1- and 5-year survival rates were 73% and 67% (patient) and 63% and 57% (graft). The primary cause of patient death was sepsis, and the primary cause of graft failure was primary graft nonfunction. Univariate analysis of pre-LT variables revealed that 19 variables predicted survival. From these results, multivariate analysis determined that the serum creatinine was the single most important prognosticator of patient survival.

CONCLUSIONS

This study, representing one of the largest published series on LT for FHF, demonstrates a long-term survival of nearly 70% and develops a clinically applicable and readily measurable set of pretransplant factors that determine posttransplant outcome.

Operative parameters that predict the outcomes of hepatic transplantation

BACKGROUND

A growing discrepancy between the number of patients awaiting liver transplantation and the number of organs available mandates the use of even marginal organ donors in whom there is major risk of suboptimal graft function. A comprehensive analysis of operative parameters on the outcomes of liver transplantation has not been reported.

STUDY DESIGN

We analyzed the impact of 24 operative variables on the survival of 942 consecutive primary liver allografts performed at a single center from June 1992 through December 1997. Univariate and Cox proportional hazards analysis was used to identify those variables with independent prognostic significance in graft survival. Resource utilization for variables with multivariate significance was also analyzed.

RESULTS

Of 12 intraoperative variables found to have significance in univariate analysis, three were significant by Cox multivariate analysis: 1) lack of immediate bile production by the graft intraoperatively, 2) platelet transfusion > or = 20 U, and 3) recipient urine output < or =2.0 mL/kg/h intraoperatively. Each of the three variables was associated with marked increases in hospital and Intensive Care Unit length of stay and hospital charges accrued during the admission for transplantation.

CONCLUSION

We identified three operative parameters that predict a poor outcome after liver transplantation. The presence of these indicators suggests that early retransplantation should be considered. Early identification of grafts likely to have poor function might also provide an opportunity for therapeutic intervention to salvage graft function.

Decision for retransplantation of the liver: an experience- and cost-based analysis

OBJECTIVE

To determine the patient factors affecting patient outcome of first liver retransplantation at a single center to help in the decision process for retransplantation.

SUMMARY BACKGROUND DATA

Given the critical organ shortage, one of the most controversial questions is whether hepatic retransplantation, the only chance of survival for patients with a failing first organ, should be offered liberally despite its greater cost, worse survival, and the inevitable denial of access to primary transplantation to other patients due to the depletion of an already-limited organ supply. The authors' experience of 139 consecutive retransplantations was reviewed to evaluate the results of retransplantation and to identify the factors that could improve the results.

METHODS

From 1986 to 2000, 1,038 patients underwent only one liver transplant and 139 patients underwent a first retransplant at the authors' center (first retransplantation rate = 12%). Multivariate analysis was performed to identify variables, excluding intraoperative and donor variables, associated with graft and patient long-term survival following first retransplantation. Lengths of hospital and intensive care unit stay and hospital charges incurred during the transplantation admissions were compared for retransplanted patients and primary-transplant patients.

RESULTS

One-year, 5-year, and 10-year graft and patient survival rates following retransplantation were 54.0%, 42.5%, 36.8% and 61.2%, 53.7%, and 50.1%, respectively. These percentages were significantly less than those following a single hepatic transplantation at the authors' center during the same period (82.3%, 72.1%, and 66.9%, respectively). On multivariate analysis, three patient variables were significantly associated with a poorer patient outcome: urgency of retransplantation (excluding primary nonfunction), age, and creatinine. Primary nonfunction as an indication for retransplantation, total bilirubin, and factor II level were associated with a better prognosis. The final model was highly predictive of survival: according to the combination of the factors affecting outcome, 5-year patient survival rates varied from 15% to 83%. Retransplant patients had significantly longer hospital and intensive care unit stays and accumulated significantly higher total hospital charges than those receiving only one transplant. CONCLUSIONS These data confirm the utility of retransplantation in the elective situation. In the emergency setting, retransplantation should be used with discretion, and it should be avoided in subgroups of patients with little chance of success.

Decision for retransplantation of the liver: an experience- and cost-based analysis

OBJECTIVE

To determine the patient factors affecting patient outcome of first liver retransplantation at a single center to help in the decision process for retransplantation.

SUMMARY BACKGROUND DATA

Given the critical organ shortage, one of the most controversial questions is whether hepatic retransplantation, the only chance of survival for patients with a failing first organ, should be offered liberally despite its greater cost, worse survival, and the inevitable denial of access to primary transplantation to other patients due to the depletion of an already-limited organ supply. The authors' experience of 139 consecutive retransplantations was reviewed to evaluate the results of retransplantation and to identify the factors that could improve the results.

METHODS

From 1986 to 2000, 1,038 patients underwent only one liver transplant and 139 patients underwent a first retransplant at the authors' center (first retransplantation rate = 12%). Multivariate analysis was performed to identify variables, excluding intraoperative and donor variables, associated with graft and patient long-term survival following first retransplantation. Lengths of hospital and intensive care unit stay and hospital charges incurred during the transplantation admissions were compared for retransplanted patients and primary-transplant patients.

RESULTS

One-year, 5-year, and 10-year graft and patient survival rates following retransplantation were 54.0%, 42.5%, 36.8% and 61.2%, 53.7%, and 50.1%, respectively. These percentages were significantly less than those following a single hepatic transplantation at the authors' center during the same period (82.3%, 72.1%, and 66.9%, respectively). On multivariate analysis, three patient variables were significantly associated with a poorer patient outcome: urgency of retransplantation (excluding primary nonfunction), age, and creatinine. Primary nonfunction as an indication for retransplantation, total bilirubin, and factor II level were associated with a better prognosis. The final model was highly predictive of survival: according to the combination of the factors affecting outcome, 5-year patient survival rates varied from 15% to 83%. Retransplant patients had significantly longer hospital and intensive care unit stays and accumulated significantly higher total hospital charges than those receiving only one transplant. CONCLUSIONS These data confirm the utility of retransplantation in the elective situation. In the emergency setting, retransplantation should be used with discretion, and it should be avoided in subgroups of patients with little chance of success.

Long-term outcome of liver retransplantation in children

BACKGROUND

Retransplantation of the liver is the only means of prolonging survival in children whose initial graft has failed. Patient and graft survival rates after retransplantation in most series have been inferior to rates after first transplantation.

PATIENTS AND METHODS

Of 450 pediatric liver transplantations performed between January 1990 and March 2001, 50 were first retransplantations, 9 were second retransplantations, and 1 was a third retransplantation. The overall retransplantation rate was 13.3% (median age at retransplantation 4 years and median weight 15 kg). The median post-retransplantation follow-up was 73 (range, 6-139) months.

RESULTS

Kaplan-Meier patient survival rates for the group (n=50) were 71.7%, 64.7%, and 64.7% at 1, 3, and 5 years, respectively. Graft survival rates were 65.6%, 56.7%, and 56.7% at 1, 3, and 5 years, respectively. This is significantly worse than rates for children undergoing first liver transplantation. There were 17 deaths, of which 9 occurred in the first month. Biliary complications occurred in 5 (10%) patients and vascular complications in 6 (12%). Improved patient and graft survival rates were observed in the later phase of the program, although the difference was not significant. Higher preoperative serum creatinine (P=0.001) and serum bilirubin (P=0.02) levels were associated with a higher postoperative mortality.

CONCLUSION

Results of retransplantation in children remain inferior to those after first transplantation. There is a trend toward improving results. Liver retransplantation makes an important contribution to overall survival in children.

Pretransplant model to predict posttransplant survival in liver transplant patients

OBJECTIVE

To develop a prognostic model that determines patient survival outcomes after orthotopic liver transplantation (OLT) using readily available pretransplant variables.

SUMMARY BACKGROUND DATA

The current liver organ allocation system strongly favors organ distribution to critically ill recipients who exhibit poor survival outcomes following OLT. A severely limited organ resource, increasing waiting list deaths, and rising numbers of critically ill recipients mandate an organ allocation system that balances disease severity with survival outcomes. Such goals can be realized only through the development of prognostic models that predict survival following OLT.

METHODS

Variables that may affect patient survival following OLT were analyzed in hepatitis C (HCV) recipients at the authors' center, since HCV is the most common indication for OLT. The resulting patient survival model was examined and refined in HCV and non-HCV patients in the United Network for Organ Sharing (UNOS) database. Kaplan-Meier methods, univariate comparisons, and multivariate Cox proportional hazard regression were employed for analyses.

RESULTS

Variables identified by multivariate analysis as independent predictors for patient survival following primary transplantation of adult HCV recipients in the last 10 years at the authors' center were entered into a prognostic survival model to predict patient survival. Accordingly, mortality was predicted by 0.0293 (recipient age) + 1.085 (log10 recipient creatinine) + 0.289 (donor female gender) + 0.675 urgent UNOS - 1.612 (log10 recipient creatinine times urgent UNOS). The above variables, in addition to donor age, total bilirubin, prothrombin time (PT), retransplantation, and warm and cold ischemia times, were applied to the UNOS database. Of the 46,942 patients transplanted over the last 10 years, 25,772 patients had complete data sets. An eight-factor model that accurately predicted survival was derived. Accordingly, the mortality index posttransplantation = 0.0084 donor age + 0.019 recipient age + 0.816 log creatinine + 0.0044 warm ischemia (in minutes) + 0.659 (if second transplant) + 0.10 log bilirubin + 0.0087 PT + 0.01 cold ischemia (in hours). Thus, this model is applicable to first or second liver transplants. Patient survival rates based on model-predicted risk scores for death and observed posttransplant survival rates were similar. Additionally, the model accurately predicted survival outcomes for HCV and non-HCV patients.

CONCLUSIONS

Posttransplant patient survival can be accurately predicted based on eight straightforward factors. The balanced application of a model for liver transplant survival estimate, in addition to disease severity, as estimated by the model for end-stage liver disease, would markedly improve survival outcomes and maximize patients' benefits following OLT.

Pretransplant model to predict posttransplant survival in liver transplant patients

OBJECTIVE

To develop a prognostic model that determines patient survival outcomes after orthotopic liver transplantation (OLT) using readily available pretransplant variables.

SUMMARY BACKGROUND DATA

The current liver organ allocation system strongly favors organ distribution to critically ill recipients who exhibit poor survival outcomes following OLT. A severely limited organ resource, increasing waiting list deaths, and rising numbers of critically ill recipients mandate an organ allocation system that balances disease severity with survival outcomes. Such goals can be realized only through the development of prognostic models that predict survival following OLT.

METHODS

Variables that may affect patient survival following OLT were analyzed in hepatitis C (HCV) recipients at the authors' center, since HCV is the most common indication for OLT. The resulting patient survival model was examined and refined in HCV and non-HCV patients in the United Network for Organ Sharing (UNOS) database. Kaplan-Meier methods, univariate comparisons, and multivariate Cox proportional hazard regression were employed for analyses.

RESULTS

Variables identified by multivariate analysis as independent predictors for patient survival following primary transplantation of adult HCV recipients in the last 10 years at the authors' center were entered into a prognostic survival model to predict patient survival. Accordingly, mortality was predicted by 0.0293 (recipient age) + 1.085 (log10 recipient creatinine) + 0.289 (donor female gender) + 0.675 urgent UNOS - 1.612 (log10 recipient creatinine times urgent UNOS). The above variables, in addition to donor age, total bilirubin, prothrombin time (PT), retransplantation, and warm and cold ischemia times, were applied to the UNOS database. Of the 46,942 patients transplanted over the last 10 years, 25,772 patients had complete data sets. An eight-factor model that accurately predicted survival was derived. Accordingly, the mortality index posttransplantation = 0.0084 donor age + 0.019 recipient age + 0.816 log creatinine + 0.0044 warm ischemia (in minutes) + 0.659 (if second transplant) + 0.10 log bilirubin + 0.0087 PT + 0.01 cold ischemia (in hours). Thus, this model is applicable to first or second liver transplants. Patient survival rates based on model-predicted risk scores for death and observed posttransplant survival rates were similar. Additionally, the model accurately predicted survival outcomes for HCV and non-HCV patients.

CONCLUSIONS

Posttransplant patient survival can be accurately predicted based on eight straightforward factors. The balanced application of a model for liver transplant survival estimate, in addition to disease severity, as estimated by the model for end-stage liver disease, would markedly improve survival outcomes and maximize patients' benefits following OLT.

Retransplantation for hepatic allograft failure: prognostic modeling and ethical considerations

Retransplantation already accounts for 10% of all liver transplants performed, and this percentage is likely to increase as patients live long enough to develop graft failure from recurrent disease. Overall, retransplantation is associated with significantly diminished survival and increased costs. This review summarizes the current causes of graft failure after primary liver transplant, prognostic models that can identify the subset of patients for retransplantation with outcomes comparable to primary transplantation, and ethical considerations in this setting, i.e., outcomes-based versus urgency-based approaches.

Preoperative factors associated with outcome and their impact on resource use in 1148 consecutive primary liver transplants

BACKGROUND

Hepatic transplantation is a highly effective but costly treatment for end-stage hepatic dysfunction. One approach to improve efficiency in the use of scarce organs for transplantation is to identify preoperative factors that are associated with poor outcome posttransplantation. This may assist both in selecting patients optimal for transplantation and in identifying strategies to improve survival.

METHODS

In the present work, we retrospectively reviewed consecutive liver transplants performed at the University of California at Los Angeles during a 6-year period and determined preoperative variables that were associated with outcome in primary grafts. In addition, we used the hospital's cost accounting database to determine the impact of these variables on the degree of resource use by high-risk patients.

RESULTS

We found five variables to have independent prognostic value in predicting graft survival after primary liver transplantation: (1) donor age, (2) recipient age, (3) donor sodium, (4) recipient creatinine, and (5) recipient ventilator requirement pretransplant. Recipient ventilator requirement and elevated creatinine were associated with significant increases in resource use during the transplant admission.

CONCLUSIONS

Patients at high risk for graft failure and costly transplants can be identified preoperatively by a set of parameters that are readily available, noninvasive, and inexpensive. Selection of recipients on the basis of these data would improve the efficiency of liver transplantation and reduce its cost.

Renal replacement therapy and orthotopic liver transplantation: the role of continuous veno-venous hemodialysis

BACKGROUND

The need for renal replacement therapy (RRT) either before or after orthotopic liver transplant (OLTX) has been reported to be a poor prognostic indicator for survival. Use of continuous veno-venous hemodialysis (CVVHD) for RRT has been reported in three series of OLTX patients with high 90-day mortality rates of 57-60%. We have examined our patient population to determine the effect of necessity and type of RRT on patient survival after OLTX.

METHODS

We analyzed 1535 OLTX that were performed at our institution from 1985 through 1999, 1037 from 1985 to 1995 (period I) and 498 from 1996 to 1999 (period II). Combined liver-kidney transplants were excluded from analysis. Hospital dialysis unit records and a prospectively maintained database on all OLTX patients served as the source of data. Patients were classified into groups defined on whether or not they received RRT, when they received RRT, and the type of RRT. Groups were compared for preoperative intensive care unit status, time on the waiting list, laboratory variables, 90-day postoperative mortality, 1-year patient survival, and absolute survival.

RESULTS

Use of RRT increased from 8.29% in period I to 12.45% in period II, along with increased median waiting times. In period I, patients receiving preoperative RRT had a 90-day mortality (0%) and a 1-year survival (89.5%) almost identical to those patients who never required RRT (1.7% and 90.6%). Patients who developed acute renal failure postoperatively requiring RRT, however, had a 90-day mortality of 28.6% and a 1-year survival of 55%. In period II, patients requiring RRT had a 90-day mortality of 39.7% and a 1-year actuarial survival of 54.5% compared with 6.9% and 88.6% in patients never requiring RRT. Patients treated with CVVHD had a 90-day mortality of 42% compared with 25% in patients treated with hemodialysis alone. However, patients receiving CVVHD both pre- and postoperatively had a 90-day mortality of 27.7% vs. 50% in those patients who only received CVVHD postoperatively. Patients who developed acute renal failure postoperatively, which required RRT, regardless of therapy, had a 1-year survival of only 41.0% compared with a 1-year survival of 73.6% in those patients started on RRT preoperatively, P=0.03.

CONCLUSIONS

The need for RRT has increased along with waiting time in OLTX patients. Patients developing the need for RRT postoperatively have an increased 90-day mortality and lower 1-year survival with the highest being present in patients receiving CVVHD, which was started postoperatively. These findings may reflect a trend toward a sicker population awaiting OLTX and emphasize the negative impact of renal failure on survival after OLTX.

The elderly liver transplant recipient: a call for caution

OBJECTIVE

To determine whether liver transplantation is judicious in recipients older than 60 years of age.

SUMMARY BACKGROUND DATA

The prevailing opinion among the transplant community remains that elderly recipients of liver allografts fare as well as their younger counterparts, but our results have in some cases been disappointing. This study was undertaken to review the results of liver transplants in the elderly in a large single-center setting. A secondary goal was to define, if possible, factors that could help the clinician in the prudent allocation of the donor liver.

METHODS

A retrospective review of a prospectively maintained single-institution database of 1,446 consecutive liver transplant recipients was conducted. The 241 elderly patients (older than 60 years) were compared with their younger counterparts by preoperative laboratory values, illness severity, nutritional status, and donor age. Survival data were stratified and logistic regression analyses were conducted.

RESULTS

Elderly patients with better-preserved hepatic synthetic function or with lower pretransplant serum bilirubin levels fared as well as younger patients. Elderly patients who had poor hepatic synthetic function or high bilirubin levels or who were admitted to the hospital had much lower survival rates than the sicker younger patients or the less-ill older patients. Recipient age 60 years or older, pretransplant hospital admission, and high bilirubin level were independent risk factors for poorer outcome.

CONCLUSIONS

Low-risk elderly patients fare as well as younger patients after liver transplantation. However, unless results can be improved, high-risk patients older than 60 years should probably not undergo liver transplantation.

The fate of liver grafts declined for subjective reasons and transplanted out of a local organ procurement organization

BACKGROUND

Decisions made by transplant surgeons to decline liver grafts for local use are based on both objective and ill-defined subjective parameters. These livers may be offered and subsequently transplanted at non-local centers. We analyzed the fate of these exported livers, focusing on the outcome of grafts declined for subjective reasons. The aim is to determine whether local surgeons' concerns about inferior graft function are justified.

METHODS

Over a 3-year period, 13.3% of 555 livers in our organ procurement organization (OPO) were exported and transplanted out of the local area. Donor data and reason for decline were obtained from an extensive OPO database. Objective reasons for decline were based on no appropriate matched recipient due to donor size, serologies, or malignancy with potential for spread. Subjective parameters were related to the procuring surgeon's assessment and included variables such as medical and social history, abnormal liver enzymes, older age, organ visualization, and biopsy. Recipient data were obtained from questionnaires sent to outside transplant centers.

RESULTS

There was a significantly higher rate of nonfunction in the subjective group (17.1%), compared to the objective group (0%). One-year graft and patient survival were 79 and 83% for the objective group and 59 and 68% for the subjective group (P=NS). When donors declined for medical/social history were excluded from the subjective group, leaving only grafts declined based solely on the surgeon's assessment of graft quality, there is a significant difference in graft survival (79% for objective and 46% for this subjective subgroup, P=0.03).

CONCLUSIONS

Livers declined for local use based on subjective assessment by the procuring surgeon have a high nonfunction rate, associated with a high morbidity. Therefore, the use of these grafts should be restricted to recipients at the most urgent status.

Disease recurrence following liver transplantation

Virtually all liver diseases that necessitate orthotopic liver transplantation (OLT) can recur, and recurrent disease has the potential to become the most serious problem facing transplantation in the future. In addition, recurrence following transplantation provides a model to study pathogenic mechanisms of these diseases. While some interventions (e.g., HBIG) have been shown to alter the natural history of recurrent disease, most of these disease processes are not modified by our currently available therapies. In addition, the role of different immunosuppressive protocols on disease recurrence requires further definition. As a varying proportion of the first generation of liver transplant patients develop severe recurrence and graft failure, policies of organ allocation for retransplantation will be challenged.

Modern immunosuppression

The current treatment of posttransplant lymphoproliferative disease (PTLD) includes prophylaxis at the time of transplant, decreasing or stopping immunosuppresion and initiation of antiviral therapy in patients with polymerase chain reaction or clinical evidence of PTLD, and judicial reintroduction of immunosuppression in patients who have cleared their PTLD and have begun to have rejection. The pharmacology, pharmacokinetics, notable side effects, and toxicities of the immunosuppressive agents are described in this article. At the conclusion of each section the author's current practice with these agents and treatment strategies are described.