Model for End-Stage Liver Disease score does not predict patient or graft survival in living donor liver transplant recipients

Machine Learning Prediction Model of Waitlist Outcomes in Patients with Primary Sclerosing Cholangitis

Background

Liver transplantation is essential for many people with primary sclerosing cholangitis (PSC). People with PSC are less likely to receive a deceased donor liver transplant compared with other causes of chronic liver disease. This disparity may stem from the inaccuracy of the model for end-stage liver disease (MELD) in predicting waitlist mortality or dropout for PSC. The broad applicability of MELD across many causes comes at the expense of accuracy in prediction for certain causes that involve unique comorbidities. We aimed to develop a model that could more accurately predict dynamic changes in waitlist outcomes among patients with PSC while including complex clinical variables.

Methods

We developed 3 machine learning architectures using data from 4666 patients with PSC in the Scientific Registry of Transplant Recipients (SRTR) and tested our models on our institutional data set of 144 patients at the University Health Network (UHN). We evaluated their time-dependent concordance index (C-index) for mortality prediction and compared it against MELD-sodium and MELD 3.0.

Results

Random survival forest (RSF), a decision tree-based survival model, outperformed MELD-sodium and MELD 3.0 in both the SRTR and the UHN test data set using the same bloodwork variables and readily available demographic data. It achieved a C-index of 0.868 (SD 0.020) and 0.771 (SD 0.085) on the SRTR and UHN test data, respectively. Training a separate RSF model using the UHN data with PSC-specific achieved a C-index of 0.91. In addition to high MELD score, increased white blood cells, time on the waiting list, platelet count, presence of Autoimmune hepatitis-PSC overlap, aspartate aminotransferase, female sex, age, history of stricture dilation, and extremes of body weight were the top-ranked features predictive of the outcomes.

Conclusions

Our RSF model offers more accurate waitlist outcome prediction in PSC. The significant performance improvement with the inclusion of PSC-specific variables highlights the importance of disease-specific variables for predicting trajectories of clinically distinct presentations.

Increased intra-abdominal pressure linked to worse long-term prognosis among patients with orthotopic liver transplantation: a retrospective, observational study

OBJECTIVE

To investigate the prognostic value of intra-abdominal pressure (IAP) among patients with orthotopic liver transplantation (OLT).

PATIENTS

We enrolled adult patients admitted in the Department of Critical Care Medicine of the First Affiliated Hospital of Sun Yat-sen University after undergoing liver transplantation from January 2018 to March 2022.

METHODS AND RESULTS

A total of 382 patients were included, with 73 patients who died within 1 year after admission. Intra-abdominal Hypertension (IAH) was defined as a sustained IAP ≥ 12 mmHg. The incidence of IAH among liver transplant patients was 46.2%. The IAP and sequential organ failure assessment (SOFA) scores were significantly lower in survivors than non-survivors (P < 0.05). Restricted cubic spline (RCS) analysis found that an IAP level above 16 mmHg was significantly associated with an elevated risk of 1-year mortality, and Kaplan-Meier survival curves further validated this finding (log-rank P < 0.001). Multivariate Cox proportional hazards regression model indicated that patients in IAH grade III (HR: 3.16, 95% CI: 1.31-7.62, P = 0.010) and IV (HR: 9.93, 95% CI: 2.84-34.7, P < 0.001) had significantly higher 1-year mortality risks adjusted by SOFA score classifications compared to individuals without IAH. Maximum IAP levels alone and a modified SOFA score incorporating IAH grade demonstrated satisfactory performance in predicting in-hospital mortality among OLT patients (AUC: 0.710, 0.834, respectively).

CONCLUSIONS

Elevated intra-abdominal pressure above 16 mmHg was significantly related with worse 1-year survival among OLT patients. Both maximum IAP alone and SOFA score incorporated with IAH components showed strong prognostic values for in-hospital mortality of these individuals.

A Brief Model Evaluated Outcomes After Liver Transplantation Based on the Matching of Donor Graft and Recipient

INTRODUCTION

A precise model for predicting outcomes is needed to guide perioperative management. With the development of the liver transplantation (LT) discipline, previous models may become inappropriate or noncomprehensive. Thus, we aimed to develop a novel model integrating variables from donors and recipients for quick assessment of transplant outcomes.

METHODS

The risk model was based on Cox regression in a randomly selected derivation cohort and verified in a validation cohort. Perioperative data and overall survival were compared between stratifications grouped by X-tile. Receiver-operating characteristic curve and decision curve analysis were used to compare the models. Violin and raincloud plots were generated to present post-LT complications distributed in different stratifications.

RESULTS

Overall, 528 patients receiving LT from 2 centers were included with 2/3 in the derivation cohort and 1/3 in the validation cohort. Cox regression analysis showed that cold ischemia time (CIT) ( P = 0.012) and Model for End-Stage Liver Disease (MELD) ( P = 0.007) score were predictors of survival. After comparison with the logarithmic models, the primitive algorithms of CIT and MELD were defined as the CIT-MELD Index (CMI). CMI was stratified by X-tile (grade 1 ≤1.06, 1.06 < grade 2 ≤ 1.87, grade 3 >1.87). In both cohorts, CMI performed better in calculating transplant outcomes than the balance of risk score, including perioperative incidents and prevalence of complications.

DISCUSSION

The model integrating variables from graft donors and recipients made the prediction more accurate and available. CMI provided new insight into outcome evaluation and risk factor management of LT.

CLINICAL CHARACTERISTICS AND OUTCOMES OF PATIENTS WITH SEVERE COVID-19 AND CIRRHOSIS OR LIVER TRANSPLANT IN A BRAZILIAN QUATERNARY CENTER

BACKGROUND

Specific associations between liver cirrhosis and liver transplant with poorer outcomes in COVID-19 are still not completely clear.

OBJECTIVE

We aimed to evaluate the clinical characteristics and outcomes of patients with severe COVID-19 and cirrhosis or liver transplant in Sao Paulo, Brazil.

METHODS

A retrospective observational study was conducted in a quaternary hospital. Patients with COVID-19 and liver cirrhosis or liver transplant were selected. The clinical and demographic characteristics, as well as the outcomes, were assessed using electronic records.

RESULTS

A total of 46 patients with COVID-19 and liver condition were included in the study. Patients with liver cirrhosis had significantly more endotracheal intubation and a higher relative risk of death than liver transplant recipients. Patients with higher MELD-Na scores had increased death rates and lower survival probability and survival time.

CONCLUSION

Patients with liver cirrhosis, especially those with higher MELD-Na scores, had poorer outcomes in COVID-19. Liver transplant recipients do not seem to be linked to poorer COVID-19 outcomes.

Computed Tomography and Magnetic Resonance Imaging Signs of Chronic Liver Rejection: A Case-Control Study

OBJECTIVE

In liver transplantation, chronic rejection is still poorly studied. This study aimed to investigate the role of imaging in its recognition.

METHODS

This study is a retrospective observational case-control series. Patients with histologic diagnosis of chronic liver transplant rejection were selected; the last imaging examination (computed tomography or magnetic resonance imaging) before the diagnosis was evaluated. At least 3 controls were selected for each case; radiological signs indicative of altered liver function were analyzed. χ 2 Test with Yates correction was used to compare the rates of radiologic signs in the case and control groups, also considering whether patients suffered chronic rejection within or after 12 months. Statistical significance was set at P < 0.050.

RESULTS

A total of 118 patients were included in the study (27 in the case group and 91 in the control group). Periportal edema was appreciable in 19 of 27 cases (70%) and in 6 of 91 controls (4%) ( P < 0.001); ascites and hepatomegaly were present in 14 of 27 cases (52%) and 12 of 27 cases (44%), respectively, and in 1 of 91 controls (1%) ( P < 0.001); splenomegaly was present in 13 of 27 cases (48%) and in 8 of 91 controls (10%) ( P < 0.001); and biliary tract dilatation was present in 13 of 27 cases (48%) and in 11 of 91 patients controls (5%) ( P < 0.001). In the controls, periportal edema was significantly less frequent beyond 12 months after transplant (1% vs 11%; P = 0.020); the other signs after 12 months were not significant.

CONCLUSIONS

The identification of periportal edema, biliary dilatation, ascites, and hepatosplenomegaly can serve as potential warning signs of ongoing chronic liver rejection. It is especially important to investigate periportal edema if it is present 1 year or more after orthotopic liver transplantation.

Benefit of living donor liver transplantation in graft survival for extremely high model for end-stage liver disease score ≥35

BACKGROUND AND AIMS

Living liver donation with high model for end-stage liver disease (MELD) score was discouraged despite organ shortage. This study aimed to compare graft survival between living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) recipients with extremely high-MELD (score of ≥35).

METHODS

Between 2008 and 2018, 359 patients who underwent liver transplantation with a MELD score ≥35 were enrolled. We compared graft survival between LDLT and DDLT after propensity score matching (PSM) and performed subgroup analysis according to donor type.

RESULTS

After PSM, there was no statistical difference in graft survival between the LDLT and DDLT groups (p = .466). Old age, acute on chronic liver failure, re-transplantation, preoperative intensive care unit stay and red blood cell (RBC) transfusion during the operation were risk factors for graft failure (p = .046, .005, .032, .015 and .001, respectively). Biliary complications were more common in the LDLT group (p = .021), while viral infection, postoperative uncontrolled ascites, and postoperative hemodialysis were more common in the DDLT group (p = .002, .018, and .027, respectively). In the LDLT group, acute chronic liver failure, intraoperative RBC transfusion, and early postoperative complications were risk factors for graft failure (p = .007, <.001, and .001, respectively).

CONCLUSION

Our study showed that LDLT is not inferior to DDLT in graft survival if appropriate risk evaluation is performed in cases of extremely high-MELD scores. This result will help overcome organ shortages in high-MELD liver transplantation.

Analysis of Short-Term and Long-Term Outcomes of Living Donor Liver Transplantation for Patients with a High Model for End-Stage Liver Disease Score

BACKGROUND

The Model of End-Stage Liver Disease (MELD) scoring system can predict short-term survival among patients awaiting liver transplantation and is used to allocate organs prioritizing liver transplantation. Patients with high MELD scores have been reported to have worse early graft dysfunction and survival. However, recent studies have shown that patients with high MELD scores had satisfactory graft survival, although they showed more postoperative complications. In this study, we examined the effect of the MELD score on the short-term and long-term prognosis of living donor liver transplantation (LDLT).

METHODS

This study included 102 patients who underwent LDLT in our institution between 2005 and 2020. The patients were divided into 3 groups according to MELD score (low MELD group: ≤20, moderate MELD group: 21-30, and high MELD group: ≥31). Perioperative factors were compared among the 3 groups, and cumulative overall survival rates were calculated using the Kaplan-Meier method.

RESULTS

The patients' characteristics were comparable, and the median age was 54 years. Hepatitis C virus cirrhosis was the most common primary disease (n = 40), followed by hepatitis B virus (n = 11). The low MELD group consisted of 68 patients (median score: 16, 10-20); the moderate MELD group, 24 patients (median score: 24, 21-30); and the high MELD group, 10 patients (median score: 35, 31-40). The mean operative time (1241 min versus 1278 min versus 1158 min, P = .19) and mean blood loss (7517 mL vs 11162 mL vs 8808 mL, P = .71) were not significantly different among the 3 groups. The vascular and biliary complication rates were similar. The periods of intensive care unit and hospital stay tended to be longer in the high MELD group, but the difference was insignificant. The 1-year postoperative survival rate (85.3 % vs 87.5 % vs 90.0 %, P = .90) and overall survival rate were also not significantly different among the 3 groups.

CONCLUSIONS

Our study showed that LDLT patients with high MELD scores do not have a worse prognosis than those with low scores.

Interpretable prediction of mortality in liver transplant recipients based on machine learning

BACKGROUND

Accurate prediction of the mortality of post-liver transplantation is an important but challenging task. It relates to optimizing organ allocation and estimating the risk of possible dysfunction. Existing risk scoring models, such as the Balance of Risk (BAR) score and the Survival Outcomes Following Liver Transplantation (SOFT) score, do not predict the mortality of post-liver transplantation with sufficient accuracy. In this study, we evaluate the performance of machine learning models and establish an explainable machine learning model for predicting mortality in liver transplant recipients.

METHOD

The optimal feature set for the prediction of the mortality was selected by a wrapper method based on binary particle swarm optimization (BPSO). With the selected optimal feature set, seven machine learning models were applied to predict mortality over different time windows. The best-performing model was used to predict mortality through a comprehensive comparison and evaluation. An interpretable approach based on machine learning and SHapley Additive exPlanations (SHAP) is used to explicitly explain the model's decision and make new discoveries.

RESULTS

With regard to predictive power, our results demonstrated that the feature set selected by BPSO outperformed both the feature set in the existing risk score model (BAR score, SOFT score) and the feature set processed by principal component analysis (PCA). The best-performing model, extreme gradient boosting (XGBoost), was found to improve the Area Under a Curve (AUC) values for mortality prediction by 6.7%, 11.6%, and 17.4% at 3 months, 3 years, and 10 years, respectively, compared to the SOFT score. The main predictors of mortality and their impact were discussed for different age groups and different follow-up periods.

CONCLUSIONS

Our analysis demonstrates that XGBoost can be an ideal method to assess the mortality risk in liver transplantation. In combination with the SHAP approach, the proposed framework provides a more intuitive and comprehensive interpretation of the predictive model, thereby allowing the clinician to better understand the decision-making process of the model and the impact of factors associated with mortality risk in liver transplantation.

Application of machine learning in liver transplantation: a review

BACKGROUND

Machine learning (ML) has been increasingly applied in the health-care and liver transplant setting. The demand for liver transplantation continues to expand on an international scale, and with advanced aging and complex comorbidities, many challenges throughout the transplantation decision-making process must be better addressed. There exist massive datasets with hidden, non-linear relationships between demographic, clinical, laboratory, genetic, and imaging parameters that conventional methods fail to capitalize on when reviewing their predictive potential. Pre-transplant challenges include addressing efficacies of liver segmentation, hepatic steatosis assessment, and graft allocation. Post-transplant applications include predicting patient survival, graft rejection and failure, and post-operative morbidity risk.

AIM

In this review, we describe a comprehensive summary of ML applications in liver transplantation including the clinical context and how to overcome challenges for clinical implementation.

METHODS

Twenty-nine articles were identified from Ovid MEDLINE, MEDLINE Epub Ahead of Print and In-Process and Other Non-Indexed Citations, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials.

CONCLUSION

ML is vastly interrogated in liver transplantation with promising applications in pre- and post-transplant settings. Although challenges exist including site-specific training requirements, the demand for more multi-center studies, and optimization hurdles for clinical interpretability, the powerful potential of ML merits further exploration to enhance patient care.

Serum Glycomics on Postoperative Day 7 Are Associated With Graft Loss Within 3 Months After Liver Transplantation Regardless of Early Allograft Dysfunction

BACKGROUND

Prediction of outcome after liver transplantation (LT) is limited by the lack of robust predictors of graft failure. In this prospective study, we aimed to define a serum glycomic signature in the first week after LT that is associated with graft loss at 3 mo after LT.

METHODS

Patients were included between January 1, 2011, and February 28, 2017. Glycomic analysis was performed using DNA sequencer-associated fluorophore-associated capillary electrophoresis on a serum sample 1 wk after LT. Making use of Lasso regression, an optimal glycomic signature was identified associated with 3-mo graft survival.

RESULTS

In this cohort of 131 patients, graft loss at 3 mo occurred in 14 patients (11.9%). The optimal mode, called the GlycoTransplantTest, yielded an area under the curve of 0.95 for association with graft loss at 3 mo. Using an optimized cutoff for this biomarker, sensitivity was 86% and specificity 89%. Negative predictive value was 98%. Odds ratio for graft loss at 3 mo was 70.211 (P < 0.001; 95% confidence interval, 10.876-453.231).

CONCLUSIONS

A serum glycomic signature is highly associated with graft loss at 3 mo. It could support decision making in early retransplantation.

Delta MELD as a predictor of early outcome in adult-to-adult living donor liver transplantation

BACKGROUND/AIMS

An increased post-operative mortality risk has been reported among patients who undergo living donor liver transplantation (LDLT) with higher model for end-stage liver disease (MELD) scores. In this study, we investigated the effect of MELD score reduction on post-operative outcomes in patients with a high MELD (≥20) score by pre-transplant management.

MATERIALS AND METHODS

We retrospectively analyzed 386 LDLT cases, and patients were divided into low-MELD (<20, n=293) vs. high-MELD (≥20, n=93) groups according to their MELD score at the time of index hospitalization. Patients in the high-MELD group were managed specifically according to a treatment algorithm in an effort to decrease the MELD score. Patients in the high-MELD group were further divided into 2 subgroups: (1) responders (n=34) to pre-transplant treatment with subsequent reduction of the MELD score by a minimum of 1 point vs. (2) non-responders (n=59), whose MELD score remained unchanged or further increased on the day of LDLT. Responders vs. non-responders were compared according to etiology, demographics, and survival.

Impact of Integrating Insulin-Like Growth Factor 1 Levels into Model for End-Stage Liver Disease Score for Survival Prediction in Hepatocellular Carcinoma Patients

BACKGROUND

Liver reserve affects survival in hepatocellular carcinoma (HCC). Model for End-Stage Liver Disease (MELD) score is used to predict overall survival (OS) and to prioritize HCC patients on the transplantation waiting list, but more accurate models are needed. We hypothesized that integrating insulin-like growth factor 1 (IGF-1) levels into MELD score (MELD-IGF-1) improves OS prediction as compared to MELD.

METHODS

We measured plasma IGF-1 levels in training (n = 310) and validation (n = 155) HCC cohorts and created MELD-IGF-1 score. Cox models were used to determine the association of MELD and MELD-IGF-1 with OS. Harrell's c-index was used to compare the predictive capacity.

RESULTS

IGF-1 was significantly associated with OS in both cohorts. Patients with an IGF-1 level of ≤26 ng/mL in the training cohort and in the validation cohorts had significantly higher hazard ratios than patients with the same MELD but IGF-1 >26 ng/mL. In both cohorts, MELD-IGF-1 scores had higher c-indices (0.60 and 0.66) than MELD scores (0.58 and 0.60) (p < 0.001 in both cohorts). Overall, 26% of training and 52.9% of validation cohort patients were reclassified into different risk groups by MELD-IGF-1 (p < 0.001).

CONCLUSIONS

After independent validation, the MELD-IGF-1 could be used to risk-stratify patients in clinical trials and for priority assignment for patients on liver transplantation waiting list.

The EMALT Score: An Improved Model for Prediction of Early Mortality in Liver Transplant Recipients

PURPOSE

Needs, risks, and outcomes of patients admitted to a post liver transplant intensive care unit (POLTICU) differ in important ways from those admitted to pretransplant intensive care units (ICUs). The aim of this study was to create the optimal model to risk stratify POLTICU patients.

METHODS

Consecutive patients who underwent first deceased donor liver transplantation (LT) at a large United States center between 2008 and 2014 were followed from admission to LT and to discharge or death. Receiver-operating characteristic analysis was performed to assess the value of various scores in predicting in-hospital mortality. A predictive model was developed using logistic regression analysis.

RESULTS

A total of 697 patients underwent LT, and 3.2% died without leaving the hospital. A model for in-hospital mortality was derived from variables available within 24 hours of admission to the POLTICU. Key variables best predicting survival were white blood cell count, 24-hour urine output, and serum glucose. A model using these variables performed with an area under the curve (AUC) of 0.88, compared to the Acute Physiology and Chronic Health Evaluation III and Model for End-Stage Liver Disease, which performed with AUCs of 0.74 and 0.60, respectively.

CONCLUSION

An improved model, the early mortality after LT (EMALT) score, performs better than conventional models in predicting in-hospital mortality after LT.

Using time-varying models to estimate post-transplant survival in pediatric liver transplant recipients

PURPOSE

To distinguish clinical factors that have time-varying (as opposed to constant) impact upon patient and graft survival among pediatric liver transplant recipients.

METHODS

Using national data from 2002 through 2013, we examined potential clinical and demographic covariates using Gray's piecewise constant time-varying coefficients (TVC) models. For both patient and graft survival, we estimated univariable and multivariable Gray's TVC, retaining significant covariates based on backward selection. We then estimated the same specification using traditional Cox proportional hazards (PH) models and compared our findings.

RESULTS

For patient survival, covariates included recipient diagnosis, age, race/ethnicity, ventilator support, encephalopathy, creatinine levels, use of living donor, and donor age. Only the effects of recipient diagnosis and donor age were constant; effects of other covariates varied over time. We retained identical covariates in the graft survival model but found several differences in their impact.

CONCLUSION

The flexibility afforded by Gray's TVC estimation methods identify several covariates that do not satisfy constant proportionality assumptions of the Cox PH model. Incorporating better survival estimates is critical for improving risk prediction tools used by the transplant community to inform organ allocation decisions.

A novel learning algorithm to predict individual survival after liver transplantation for primary sclerosing cholangitis

Deciding who should receive a liver transplant (LT) depends on both urgency and utility. Most survival scores are validated through discriminative tests, which compare predicted outcomes between patients. Assessing post-transplant survival utility is not discriminate, but should be “calibrated” to be effective. There are currently no such calibrated models. We developed and validated a novel calibrated model to predict individual survival after LT for Primary Sclerosing Cholangitis (PSC). We applied a software tool, PSSP, to adult patients in the Scientific Registry of Transplant Recipients (n = 2769) who received a LT for PSC between 2002 and 2013; this produced a model for predicting individual survival distributions for novel patients. We also developed an appropriate evaluation measure, D-calibration, to validate this model. The learned PSSP model showed an excellent D-calibration (p = 1.0), and passed the single-time calibration test (Hosmer-Lemeshow p-value of over 0.05) at 0.25, 1, 5 and 10 years. In contrast, the model based on traditional Cox regression showed worse calibration on long-term survival and failed at 10 years (Hosmer-Lemeshow p value = 0.027). The calculator and visualizer are available at: http://pssp.srv.ualberta.ca/calculator/liver_transplant_2002. In conclusion we present a new tool that accurately estimates individual post liver transplantation survival.

Comparison of APACHE IV with APACHE II, SAPS 3, MELD, MELD-Na, and CTP scores in predicting mortality after liver transplantation

The Acute Physiology and Chronic Health Evaluation (APACHE) IV score and Simplified Acute Physiology Score (SAPS) 3 include liver transplantation as a diagnostic category. The performance of APACHE IV-liver transplantation (LT) specific predicted mortality, SAPS 3, APACHE II, Model for End-stage Liver Disease (MELD)-Na, MELD, and CTP scores in predicting in-hospital and 1 year mortality in liver transplant patients was compared using 590 liver transplantations in a single university hospital. In-hospital mortality and 1 year mortality were 2.9% and 4.2%, respectively. The APACHE IV-LT specific predicted mortality showed better performance in predicting in-hospital mortality (AUC 0.91, 95% CI [0.86–0.96]) compared to SAPS 3 (AUC 0.78, 95% CI [0.66–0.90], p = 0.01), MELD-Na (AUC 0.74, 95% CI [0.57–0.86], p = 0.01), and CTP (AUC 0.68, 95% CI [0.54–0.81], p = 0.01). The APACHE IV-LT specific predicted mortality showed better performance in predicting 1 year mortality (AUC 0.83, 95% CI [0.76–0.9]) compared to MELD-Na (AUC 0.67, 95% CI [0.55–0.79], p = 0.04) and CTP (AUC 0.64, 95% CI [0.53–0.75], p = 0.03), and also in all MELD groups and in both living and deceased donor transplantation. The APACHE IV-LT specific predicted mortality showed better performance in predicting in-hospital and 1 year mortality after liver transplantation.

Risk Factors for Post-Transplant Death in Donation after Circulatory Death Liver Transplantation

PURPOSE

In spite of the increasing success of liver transplantation, there remains inevitable risk of postoperative complications, re-operations, and even death. Risk factors that correlate with post-transplant death have not been fully identified.

MATERIALS AND METHODS

We performed a retrospective analysis of 65 adults that received donation after circulatory death liver transplantation. Binary logistic regression and Cox's proportional hazards regression were employed to identify risk factors that associate with postoperative death and the length of survival period.

RESULTS

Twenty-two recipients (33.8%) deceased during 392.3 ± 45.6 days. The higher preoperative Child-Pugh score (p = .007), prolonged postoperative ICU stay (p = .02), and more postoperative complications (p = .0005) were observed in deceased patients. Advanced pathological staging (p = .02) with more common nerve invasion (p = .03), lymph node invasion (p = .02), and para-tumor satellite lesion (p = .01) were found in deceased group. The higher pre-transplant Child-Pugh score was a risk factor for post-transplant death (OR = 4.38, p = .011), and was correlated with reduced post-transplant survival period (OR = 0.35, p = .009). Nerve invasion was also a risk factor for post-transplant death (OR = 13.85, p = .014), although it failed to affect survival period.

CONCLUSIONS

Our study emphasizes the impact of recipient's pre-transplant liver function as well as pre-transplant nerve invasion by recipient's liver cancer cells on postoperative outcome and survival period in patients receiving liver transplantation.

The Current State of Liver Transplantation in the United States: Perspective From American Society of Transplant Surgeons (ASTS) Scientific Studies Committee and Endorsed by ASTS Council

This article is a review of the salient points and a future prospective based on the 2014 Organ Procurement and Transplantation Network (OPTN)/Scientific Registry of Transplant Recipients (SRTR) liver donation and transplantation data report recently published by the American Journal of Transplantation. Emphasis of our commentary and interpretation is placed on data relating to waitlist dynamics, organ utilization rates, the impact of recent advances in the treatment of hepatitis C, and the increases in end-stage renal disease among liver transplant candidates. Finally, we share our vision on potential areas of innovation that are likely to significantly improve the field of liver transplantation in the near future.

Underutilization of Living Donor Liver Transplantation in the United States: Bias against MELD 20 and Higher

Background and Aims: Utilization of living donor liver transplantation (LDLT) and its relationship with recipient Model for End-Stage Liver Disease (MELD) needs further evaluation in the United States (U.S.). We evaluated the association between recipient MELD score at the time of surgery and survival following LDLT. Methods: All U.S. adult LDLT recipients with MELD < 25 were evaluated using the 1995-2012 United Network for Organ Sharing registry. Survival following LDLT was stratified into three MELD categories (MELD < 15 vs. MELD 15-19 vs. MELD 20-24) and evaluated using Kaplan-Meier methods and multivariate Cox proportional hazards models. Results: Overall, 2,258 patients underwent LDLT. Compared to patients with MELD < 15, overall 5-year survival following LDLT was similar among patients with MELD 15-19 (80.9% vs. 80.3%, p = 0.77) and MELD 20-24 (81.2% vs. 80.3%, p = 0.73). When compared to patients with MELD < 15, there was no significant difference in long-term post-LDLT survival among those with MELD 15-19 (HR: 1.11, 95% CI: 0.85-1.45, p = 0.45) and a non-significant trend towards lower survival in patients with MELD 20-24 (HR: 1.28, 95% CI: 0.91-1.81, p = 0.16). Only 14% of LDLTs were performed in patients with MELD 20-24 and the remaining 86% in patients with MELD < 20. Conclusion: LDLT is underutilized in patients with MELD 20 and higher.

Different Score Systems to Predict Mortality in Living Donor Liver Transplantation: Which Is the Winner? The Experience of an Egyptian Center for Living Donor Liver Transplantation

INTRODUCTION

Many scoring systems have been proposed to predict the outcome of deceased donor liver transplantation. However, their impact on the outcome in living donor liver transplantation (LDLT) has not yet been elucidated. This study sought to assess performance of preoperative Model for End-Stage Liver Disease (MELD) score in predicting postoperative mortality in LDLT and to compare it with other scores: MELDNa, United Kingdom End-Stage Liver Disease (UKELD), MELD to serum sodium ratio (MESO), updated MELD, donor age-MELD (D-MELD) and integrated MELD (iMELD).

METHODS

We retrospectively analyzed data from 86 adult Egyptian patients who underwent LDLT in a single center. Preoperative MELD, MELDNa, MESO, UKELD, updated MELD, D-MELD, and iMELD were calculated. Receiver-operator characteristic (ROC) curves and area under the curve (AUC) were used to assess the performance of MELD and other scores in predicting postoperative mortality at 3 months (early) and 12 months.

RESULTS

Among the 86 patients, mean age 48 ± 7 years, 76 (88%) were of male sex and 27 (31.4%) had died. Preoperative MELD failed to predict early mortality (AUC = 0.63; P = .066). Comparing preoperative MELD with other scores, all other scores had better predictive ability (P < .05), with D-MELD on the top of the list (AUC = 0.68, P = .016), followed closely by UKELD (AUC = 0.67, P = .025). After that were iMELD, MESO, and MELDNa with the same predictive performance (AUC = 0.65; P < .05); updated MELD had the lowest prediction (AUC = 0.640; P = .04). Moreover, all scores failed to predict mortality at 12 months (P > .05).

CONCLUSIONS

Preoperative MELD failed to predict either early or 1-year mortality after LDLT. D-MELD, UKELD, MELDNa, iMELD, and MESO could be used as better predictors of early mortality than MELD; however, we need to develop an effective score system to predict mortality after LDLT.

Predictive factors of short term outcome after liver transplantation: A review

Liver transplantation represents a fundamental therapeutic solution to end-stage liver disease. The need for liver allografts has extended the set of criteria for organ acceptability, increasing the risk of adverse outcomes. Little is known about the early postoperative parameters that can be used as valid predictive indices for early graft function, retransplantation or surgical reintervention, secondary complications, long intensive care unit stay or death. In this review, we present state-of-the-art knowledge regarding the early post-transplantation tests and scores that can be applied during the first postoperative week to predict liver allograft function and patient outcome, thereby guiding the therapeutic and surgical decisions of the medical staff. Post-transplant clinical and biochemical assessment of patients through laboratory tests (platelet count, transaminase and bilirubin levels, INR, factor V, lactates, and Insulin Growth Factor 1) and scores (model for end-stage liver disease, acute physiology and chronic health evaluation, sequential organ failure assessment and model of early allograft function) have been reported to have good performance, but they only allow late evaluation of patient status and graft function, requiring days to be quantified. The indocyanine green plasma disappearance rate has long been used as a liver function assessment technique and has produced interesting, although not univocal, results when performed between the 1(th) and the 5(th) day after transplantation. The liver maximal function capacity test is a promising method of metabolic liver activity assessment, but its use is limited by economic cost and extrahepatic factors. To date, a consensual definition of early allograft dysfunction and the integration and validation of the above-mentioned techniques, through the development of numerically consistent multicentric prospective randomised trials, are necessary. The medical and surgical management of transplanted patients could be greatly improved by using clinically reliable tools to predict early graft function.

The travails of setting up a living donor liver transplant program: Experience from Pakistan and lessons learned

Living donor liver transplantation (LDLT) is the only treatment option for patients with end-stage liver disease (ESLD) where cadaveric donors are not available. In developing countries, the inception of LDLT programs remains a challenge. The first successful liver transplantation program in Pakistan started transplantation in 2012. The objective of this study was to report outcomes of 100 LDLT recipients in a developing country and to highlight the challenges encountered by a new LDLT program in a resource-limited setting. We retrospectively reviewed recipients who underwent LDLT between April 2012 and August 2014. Demographics, etiology, graft characteristics, and operative variables were assessed. Outcome was assessed on the basis of morbidity and mortality. All complications of ≥ 3 on the Clavien-Dindo grading system were included as morbidity. Estimated 1-year survival was calculated using Kaplan-Meier curves, and a Log-rank test was used to determine the significance. Outcomes between the first 50 LDLTs (group 1) and latter 50 LDLTs (group 2) were also compared. Median age was 46.5 (0.5-72) years, whereas the median MELD score was 15.5 (7-37). The male to female ratio was 4:1. ESLD secondary to hepatitis C virus was the most common indication (73% patients). There were 52 (52%) significant (≥ grade 3) complications. The most common morbidities were bile leaks in 9 (9%) and biliary strictures in 14 (14%) patients. Overall mortality in patients who underwent LDLT for ESLD was 10.6%. Estimated 1-year survival was 87%. Patients who underwent transplantation in the latter period had a significantly lower overall complication rate (36% versus 68%; P = 0.01). Comparable outcomes can be achieved in a new LDLT program in a developing country. Outcomes improve as experience increases.

A new formula as a predictive score of post-liver transplantation outcome: postoperative MELD-lactate

INTRODUCTION

Liver transplantation (OLT) involves a 5% to 10% 30-day mortality rate. Multiple scores have been used as predictors of early postoperative mortality, such as the original Model for End-stage Liver Disease (MELD) and MELD sodium. Investigations have been conducted over the last 5 years to find new predictors of early post-OLT mortality.

OBJECTIVE

The aim of this study was to develop a new mathematical model to predict the individual chance of 30-day mortality after OLT.

METHODS

The study was conducted on 58 patients submitted to OLT at the University Hospital, between October 2008 and March 2012. The 29 latest survivor and 29 latest nonsurvivor cases were selected. Arterial blood sodium, lactate, international normalized ratio, total bilirubin, and creatinine values were determined 1 hour after the end of surgery. The MELD original equation, MELD sodium, and new MELD lactate were also elaborated. The results were analyzed by the Mann-Whitney and Wilcoxon tests. The level of significance was set at .05.

RESULTS

The new formula elaborated was as follows: MELD lactate = 5.68 × loge (lactate) + 0.64 × (Original MELD) + 2.68. The MELD lactate values were significantly higher than the MELD sodium and original MELD values (P < .05). The area under the receiver operating characteristic curve of MELD lactate in predicting the outcome of patients submitted to OLT was 0.80, as opposed to 0.71 for the original MELD and 0.72 for MELD sodium (P < .05).

CONCLUSION

The postoperative MELD lactate score proved to be more specific and sensitive than the original MELD and MELD sodium as a predictive model of the outcome of patients submitted to OLT.

Outcomes among older adult liver transplantation recipients in the model of end stage liver disease (MELD) era

BACKGROUND

Since 2002, the Model of End Stage Liver Disease (MELD) score has been the basis of the liver transplant (LT) allocation system. Among older adult LT recipients, short-term outcomes in the MELD era were comparable to the pre-MELD era, but long-term outcomes remain unclear.

MATERIAL AND METHODS

This is a retrospective cohort study using the UNOS data on patients age ≥ 50 years who underwent primary LT from February 27, 2002 until October 31, 2011.

RESULTS

A total of 35,686 recipients met inclusion criteria. The cohort was divided into 5-year interval age groups. Five-year over-all survival rates for ages 50-54, 55-59, 60-64, 65-69, and 70+ were 72.2%, 71.6%, 69.5%, 65.0%, and 57.5%, respectively. Five-year graft survival rates after adjusting for death as competing risk for ages 50-54, 55-59,60-64, 65-69 and 70+ were 85.8%, 87.3%, 89.6%, 89.1% and 88.9%, respectively. By Cox proportional hazard modeling, age ≥ 60, increasing MELD, donor age ≥ 60, hepatitis C, hepatocellular carcinoma (HCC), dialysis and impaired pre-transplant functional status (FS) were associated with increased 5-year mortality. Using Fine and Gray sub-proportional hazard modeling adjusted for death as competing risk, 5-year graft failure was associated with donor age ≥ 60, increasing MELD, hepatitis C, HCC, and impaired pre-transplant FS.

CONCLUSIONS

Among older LT recipients in the MELD era, long-term graft survival after adjusting for death as competing risk was improved with increasing age, while over-all survival was worse. Donor age, hepatitis C, and pre-transplant FS represent potentially modifiable risk factors that could influence long-term graft and patient survival.

Section 12. Living donor liver transplantation for patients with high model for end-stage liver disease scores and acute liver failure

Living donor liver transplantation (LDLT) for patients with high model for end-stage liver disease score and acute liver failure patients have little or not gained any substantial following among Western centers because of the "donor high risk-low recipient benefit scenario" that puts the donor at a significant risk against the survival odds for a recipient who is receiving a partial graft and considered marginal by Western standards. In most Asian countries, there is sometimes no other source of live graft but a willing live liver donor. There are individual Asian center reports that conclude that LDLT has comparable outcome to deceased donor liver transplant. However, the outcomes of a large number of patients after undergoing adult LDLT for high model for end-stage liver disease scores and acute liver failure at a single center have not been investigated. Here in, we present our experience with such subgroup of patients undergoing LDLT.

Relationship between GH/IGF-1 axis, graft recovery, and early survival in patients undergoing liver transplantation

BACKGROUND

High levels of IGF-1 have been reported in patients with initial poor function of the graft after liver transplantation (LT). Correlation with other clinical variables or early survival has not been extensively investigated.

AIM

To evaluate the GH/IGF-1 profile as a function of liver recovery and patients' early survival after LT.

METHODS

30 transplanted patients (23 survivors and 7 nonsurvivors), were retrospectively enrolled in the study. GH and IGF-1 serum levels were assessed at baseline, graft reperfusion, and 1, 7, 15, 30 , 90, and 360 days after LT. Individual biochemical variables were also recorded.

RESULTS

After grafting, IGF-1 in blood linearly correlated with cholesterol (r = 0.6, P = 0.001). IGF-1 levels from day 15 after surgery were statistically higher in survivors as compared to nonsurvivors. ROC curves analysis identified an IGF-1 cut-off >90 μg/L, from day 15 after surgery, as a good predictor of survival (sensitivity 86%, specificity 95%, and P < 0.001).

CONCLUSIONS

After LT, GH levels correlate with the extent of cytolysis, while IGF-1 is an indicator of liver synthetic function recovery. IGF-1 levels >90 μg/L (day 15-30) seem to be an indicator of short-term survival.

Impact of preoperative uncontrollable hepatic hydrothorax and massive ascites in adult liver transplantation

PURPOSE

Uncontrollable hepatic hydrothorax and massive ascites (H&MA) requiring preoperative drainage are sometimes encountered in liver transplantation (LT). We retrospectively analyzed the characteristics of such patients and the impact of H&MA on the postoperative course.

METHODS

We evaluated 237 adult patients who underwent LT in our institute between April 2006 and October 2010.

RESULTS

Recipients with uncontrollable H&MA (group HA: n = 36) had more intraoperative bleeding, higher Child-Pugh scores, lower serum albumin concentrations and higher blood urea nitrogen concentrations than those without uncontrollable H&MA (group C: n = 201). They were also more likely to have preoperative hepatorenal syndrome and infections. The incidence of postoperative bacteremia was higher (55.6 vs. 46.7%, P = 0.008) and the 1- and 3-year survival rates were lower (1 year: 58.9 vs. 82.9%; 3 years: 58.9 vs. 77.7%; P = 0.003) in group HA than in group C. The multivariate proportional regression analyses revealed that uncontrollable H&MA and the Child-Pugh score were independent risk factors for the postoperative prognosis.

CONCLUSIONS

Postoperative infection control may be an important means of improving the outcome for patients with uncontrollable H&MA undergoing LT, and clinicians should strive to perform surgery before H&MA becomes uncontrollable.

APACHE IV is superior to MELD scoring system in predicting prognosis in patients after orthotopic liver transplantation

This study aims to compare the efficiency of APACHE IV with that of MELD scoring system for prediction of the risk of mortality risk after orthotopic liver transplantation (OLT). A retrospective cohort study was performed based on a total of 195 patients admitted to the ICU after orthotopic liver transplantation (OLT) between February 2006 and July 2009 in Guangzhou, China. APACHE IV and MELD scoring systems were used to predict the postoperative mortality after OLT. The area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow C statistic were used to assess the discrimination and calibration of APACHE IV and MELD, respectively. Twenty-seven patients died during hospitalization with a mortality rate of 13.8%. The mean scores of APACHE IV and MELD were 42.32 ± 21.95 and 18.09 ± 10.55, respectively, and APACHE IV showed better discrimination than MELD; the areas under the receiver operating characteristic curve for APACHE IV and MELD were 0.937 and 0.694 (P < 0.05 for both models), which indicated that the prognostic value of APACHE IV was relatively high. Both models were well-calibrated (The Hosmer-Lemeshow C statistics were 1.568 and 6.818 for APACHE IV and MELD, resp.; P > 0.05 for both). The respective Youden indexes of APACHE IV, MELD, and combination of APACHE IV with MELD were 0.763, 0.430, and 0.545. The prognostic value of APACHE IV is high but still underestimates the overall hospital mortality, while the prognostic value of MELD is poor. The function of the APACHE IV is, thus, better than that of the MELD.

A validated model for predicting outcome after liver transplantation: implications on transplanting the extremely sick

Given the organ shortage, there is a need to optimize outcome after liver transplantation (LT). We defined posttransplant hospital length of stay > 60 days (LOS > 60) as a surrogate of suboptimal outcome. In the first phase of the study, a 'Study cohort' (SC) of 643 patients was used to identify risk factors and construct a mathematical model to identify recipients with anticipated inferior results. In the second phase, a cohort of 417 patients was used for validation of the model ['Validation Cohort' (VC)]. In the SC, 65 patients (10.1%) had LOS > 60 days. One- and 3-year patient/graft survival rates were 81.9%/76.1% and 73.4%/67.4%, respectively. Patient and graft survival rates of those with LOS > 60 days were inferior (P < 0.0001), while transplant cost was greater [3.42 relative units (RU) vs. 1 RU, P < 0.0001]. In a multivariable analysis, pretransplant dialysis (P < 0.001), mechanical ventilation (P < 0.015), MELD (P < 0.003), and age (P < 0.009) were predictors of LOS > 60 days [ROC curve - 0.75 (95% CI 0.70, 0.81)]. In the VC, 53 patients (12.7%) were expected to have adverse outcome by the model. These patients had longer LOS (P < 0.0001), higher cost (<0.0001), and inferior patient and graft survival (P < 0.007).

Outcome of using small-for-size grafts in living donor liver transplantation recipients with high model for end-stage liver disease scores: a single center experience

AIMS

To evaluate the impact of small-for-size grafts (SFSG) in adult-to-adult living donor liver transplantation (AALDLT) on outcomes of recipients with different model for end-stage liver disease (MELD) score in a single liver transplant center.

MATERIALS AND METHODS

Clinical data of 118 patients underwent right-lobe AALDLT from January 2004 to December 2011 were retrospectively analyzed, Patients were divided into Group L (MELD score ≤ 25) and Group H (MELD score > 25) according to MELD score. The patients were further stratified into Group LS (MELD score ≤ 25, GBWR < 0.8%), Group LN (MELD score ≤ 25, GBWR ≥ 0.8%), Group HS (MELD score > 25, GBWR < 0.8%), and Group HN (MELD score > 25, GBWR ≥ 0.8%) to investigate the impact of graft size on recipients' complications and outcomes. Pre-operative characteristics, post-operative complications graded by the Clavien score and patient survival were analyzed.

RESULTS

MELD scores between the two groups were significant different (12.4 ± 4.9 vs 34.5 ± 7.5, P = 0.026). There was no significant difference in preoperative demographic data as well as postoperative liver function. Complication rate, length of ICU and hospital stay, graft loss, and mortality were similar in both groups. The 1- and 3- year survival were similar between group H and group L. When recipients were further stratified into group LS, LN, HS, and HN, no significant difference was found among groups in 1- and 3- year survival rate. In multivariate analysis, HCC was not a predictor for long term survival.

CONCLUSION

Our single institution experience demonstrates that it is safe to use SFSGs in high pre-MELD score recipients with the improvement of intensive care and the selection of listing criteria.

Survival outcomes of right-lobe living donor liver transplantation for patients with high Model for End-stage Liver Disease scores

BACKGROUND

Controversy exists over whether living donor liver transplantation (LDLT) should be offered to patients with high Model for End-stage Liver Disease (MELD) scores. This study tried to determine whether a high MELD score would result in inferior outcomes of right-lobe LDLT.

METHODS

Among 411 consecutive patients who received right-lobe LDLT at our center, 143 were included in this study. The patients were divided into two groups according to their MELD scores: a high-score group (MELD score ≥25; n=75) and a low-score group (MELD score <25; n=68). Their demographic data and perioperative conditions were compared. Univariable and multivariable analyses were performed to identify risk factors affecting patient survival.

RESULTS

In the high-score group, more patients required preoperative intensive care unit admission (49.3% vs 2.9%; P<0.001), mechanical ventilation (21.3% vs 0%; P<0.001), or hemodialysis (13.3% vs 0%; P=0.005); the waiting time before LDLT was shorter (4 vs 66 days; P<0.001); more blood was transfused during operation (7 vs 2 units; P<0.001); patients stayed longer in the intensive care unit (6 vs 3 days; P<0.001) and hospital (21 vs 15 days; P=0.015) after transplantation; more patients developed early postoperative complications (69.3% vs 50.0%; P=0.018); and values of postoperative peak blood parameters were higher. However, the two groups had comparable hospital mortality. Graft survival and patient overall survival at one year (94.7% vs 95.6%; 95.9% vs 96.9%), three years (91.9% vs 92.6%; 93.2% vs 95.3%), and five years (90.2% vs 90.2%; 93.2% vs 95.3%) were also similar between the groups.

CONCLUSIONS

Although the high-score group had significantly more early postoperative complications, the two groups had comparable hospital mortality and similar satisfactory rates of graft survival and patient overall survival. Therefore, a high MELD score should not be a contraindication to right-lobe LDLT if donor risk and recipient benefit are taken into full account.

Retransplantation of the liver: review of current literature for decision making and technical considerations

Liver transplantation (LTx) is an established treatment modality for patients with end-stage liver disease, metabolic disorders, and patients with acute liver failure. When a graft fails after primary LTx, retransplantation of the liver (reLTx) is the only potential cure. ReLTx accounts for 7%-10% of all LTx in the United States. Early causes of graft failure for which reLTx may be indicated include primary graft nonfunction and vascular inflow thrombosis. ReLTx in such cases in the early postoperative period is usually straightforward as long as an appropriate secondary allograft is secured in a timely fashion. Late indications may include ischemic cholangiopathy, chronic rejection, and recurrence of the primary liver disease. ReLTx performed in the late period is often more complex and selection criteria are more stringent due to the persistent shortage of organs. The question of whether to retransplant patients with recurrent hepatitis C remains controversial, but these practices are likely to change as the epidemic progresses and new treatments evolve. We also present recent results with reLTx from Yale-New Haven Transplant Center and early results with the use of living donors for reLTx.

Is SAPS 3 better than APACHE II at predicting mortality in critically ill transplant patients?

OBJECTIVES

This study compared the accuracy of the Simplified Acute Physiology Score 3 with that of Acute Physiology and Chronic Health Evaluation II at predicting hospital mortality in patients from a transplant intensive care unit.

METHOD

A total of 501 patients were enrolled in the study (152 liver transplants, 271 kidney transplants, 54 lung transplants, 24 kidney-pancreas transplants) between May 2006 and January 2007. The Simplified Acute Physiology Score 3 was calculated using the global equation (customized for South America) and the Acute Physiology and Chronic Health Evaluation II score; the scores were calculated within 24 hours of admission. A receiver-operating characteristic curve was generated, and the area under the receiver-operating characteristic curve was calculated to identify the patients at the greatest risk of death according to Simplified Acute Physiology Score 3 and Acute Physiology and Chronic Health Evaluation II scores. The Hosmer-Lemeshow goodness-of-fit test was used for statistically significant results and indicated a difference in performance over deciles. The standardized mortality ratio was used to estimate the overall model performance.

RESULTS

The ability of both scores to predict hospital mortality was poor in the liver and renal transplant groups and average in the lung transplant group (area under the receiver-operating characteristic curve = 0.696 for Simplified Acute Physiology Score 3 and 0.670 for Acute Physiology and Chronic Health Evaluation II). The calibration of both scores was poor, even after customizing the Simplified Acute Physiology Score 3 score for South America.

CONCLUSIONS

The low predictive accuracy of the Simplified Acute Physiology Score 3 and Acute Physiology and Chronic Health Evaluation II scores does not warrant the use of these scores in critically ill transplant patients.

Adult to adult living related liver transplantation: Where do we currently stand?

Adult to adult living donor liver transplantation (AALDLT) was first preformed in the United States in 1997. The procedure was rapidly integrated into clinical practice, but in 2002, possibly due to the first widely publicized donor death, the number of living liver donors plummeted. The number of donors has since reached a steady plateau far below its initial peak. In this review we evaluate the current climate of AALDLT. Specifically, we focus on several issues key to the success of AALDLT: determining the optimal indications for AALDLT, balancing graft size and donor safety, assuring adequate outflow, minimizing biliary complications, and maintaining ethical practices. We conclude by offering suggestions for the future of AALDLT in United States transplantation centers.

Predictive factors of early graft loss in living donor liver transplantation

CONTEXT

Living donor liver transplantation has become an alternative to reduce the lack of organ donation.

OBJECTIVE

To identify factors predictive of early graft loss in the first 3 months after living donor liver transplantation.

METHODS

Seventy-eight adults submitted to living donor liver transplantation were divided into group I with 62 (79.5%) patients with graft survival longer than 3 months, and group II with 16 (20.5%) patients who died and/or showed graft failure within 3 months after liver transplantation. The variables analyzed were gender, age, etiology of liver disease, Child-Pugh classification, model of end-stage liver disease (MELD score), pretransplantation serum sodium level, and graft weight-to-recipient body weight (GRBW) ratio. The GRBW ratio was categorized into < 0.8 and MELD score into >18. The chi-square test, Student t-test and uni- and multivariate analysis were used for the evaluation of risk factors for early graft loss.

RESULTS

MELD score <18 (P<0.001) and serum sodium level > 135 mEq/L (P = 0.03) were higher in group II than in group I. In the multivariate analysis MELD scores > 18 (P<0.001) and GRBW ratios < 0.8 (P<0.04) were significant.

CONCLUSIONS

MELD scores >18 and GRBW < 0.8 ratios are associated with higher probability of graft failure after living donor liver transplantation.

A high model for end-stage liver disease score should not be considered a contraindication to living donor liver transplantation

OBJECTIVE

To analyze the outcomes of patients with high Model for End-Stage Liver Disease (MELD) scores who underwent adult-to-adult live donor liver transplantation (A-A LDLT).

MATERIALS AND METHODS

From September 2002 to October 2010, a total of 152 adult patients underwent A-A LDLT in our institution. Recipients were stratified into a low MELD score group (Group L; MELD score≤30) and a high MELD score group (Group H; MELD score>30) to compare short-term and long-term outcomes.

RESULTS

Of the 152 adult patients who underwent A-A LDLT, 9 were excluded from the analysis because they received ABO-incompatible grafts. Group H comprised 23 and Group L 120 patients. The median follow-up was 21.5 months (range, 3 to 102 m). The mean MELD score was 15.6 in Group L and 36.7 in Group H. There were no significant differences in the mean length of stay in the intensive care unit (Group L: 3.01 days vs Group H: 3.09 days, P=.932) or mean length of hospital stay (Group L: 17.89 days vs. Group H: 19.91 days, P=0.409). There were no significant differences in 1-, 3-, or 5-year survivals between patients in Groups L versus H (91.5% vs 94.7%; 86.4% vs 94.7%; and 86.4% vs 94.7%; P=.3476, log rank).

CONCLUSION

The short-term and long-term outcomes of patients with high MELD scores who underwent A-A LDLT were similar to those of patients with low MELD scores. Therefore, we suggest that high MELD scores are not a contraindication to LDLT.

Which score system can best predict recipient outcomes after living donor liver transplantation?

INTRODUCTION

Many scoring systems have been suggested to predict the outcomes of deceased donor liver transplantations. The aims of this study were to compare the Model for End-Stage Liver Disease (MELD) score with respect to other scores among patients who underwent living donor liver transplantation (LDLT) seeking to evaluate the best system to correlate with postoperative outcomes after LDLT.

METHODS

We analyzed retrospectively data from 202 adult patients who underwent LDLT from January 2008 to July 2010. We calculated preoperative MELD, MELD-sodium, MELD to serum sodium ratio (MESO), integrated MELD, United Kingdom MELD, Child-Turcotte-Pugh, Acute Physiology and Chronic Health evaluation II (APACHE II), and Sequential Organ Failure Assessment (SOFA) scores in all patients. We analyzed the correlation of each score with postoperative laboratory results, as well as survival at 1, 3, 6 and 12 months after LDLT.

RESULTS

There was significant positive correlation between all scores and peak total bilirubin during the first 7 days after LDLT. The MELD score showed the greatest correlation with peak total bilirubin (r=0.745). APACHE II and SOFA scores at 6 months and 1 year after LDLT and MESO score at 1 year after LDLT showed acceptable discrimination performance {area under the receiver operating characteristic curves (AUC)>0.7, while other scoring systems showed poor discrimination. However, the AUCs of each score were not significantly different from the MELD score AUC.

CONCLUSION

The MELD score most correlated with total bilirubin after LDLT, while the APACHE II and SOFA scores seemed to correlate with mortality after LDLT.

Posttransplant mortality risk assessment for adult-to-adult right-lobe living donor liver recipients with benign end-stage liver disease

OBJECTIVE

A model for living donor liver transplantation (LDLT) outcomes, in concert with pretransplant disease severity assessment, would facilitate informed decision-making on both sides considering donation and transplantation. So far, however, few of studies have focused on models specifically for adult-to-adult right-lobe LDLT recipients with benign end-stage liver diseases. Therefore, we aimed to develop such a prognostic model based on easily obtainable and objective pretransplant characteristics.

METHODS

With data retrospectively collected on 120 recipients, we used Cox proportional-hazards regression to analyze six donor characteristics and 33 pretransplant recipient variables for correlation with posttransplant mortality. In both a modeling set and a prospective validation set with 30 recipients, the performances of the new Cox model, MELD, and MELD-Na+ were assessed by measuring both calibration ability and discriminative power with the Hosmer-Lemeshow test and receiver operating characteristic analysis, respectively.

RESULTS

By univariate and multivariate analysis, donor age, serum total bilirubin, creatinine, and HBV-DNA level were significantly associated with posttransplant mortality. The Cox model, employing these four variables, yielded good calibration ability in the modeling set χ² = 2.465, p = 0.653) and the validation set χ² = 2.836, p = 0.586), and high discriminative power in the modeling set (c-statistic = 0.826, p = 0.001) and validation set (c-statistic = 0.816, p = 0.028). The calibration ability and discriminative power of MELD and MELD-Na+ in both sets were poor.

CONCLUSIONS

The newly derived Cox model was valuable in posttransplant mortality risk assessment for adult-to-adult right-lobe LDLT recipients with benign end-stage liver diseases.

Pretransplant prediction of posttransplant survival for liver recipients with benign end-stage liver diseases: a nonlinear model

Background

The scarcity of grafts available necessitates a system that considers expected posttransplant survival, in addition to pretransplant mortality as estimated by the MELD. So far, however, conventional linear techniques have failed to achieve sufficient accuracy in posttransplant outcome prediction. In this study, we aim to develop a pretransplant predictive model for liver recipients' survival with benign end-stage liver diseases (BESLD) by a nonlinear method based on pretransplant characteristics, and compare its performance with a BESLD-specific prognostic model (MELD) and a general-illness severity model (the sequential organ failure assessment score, or SOFA score).

Methodology/Principal Findings

With retrospectively collected data on 360 recipients receiving deceased-donor transplantation for BESLD between February 1999 and August 2009 in the west China hospital of Sichuan university, we developed a multi-layer perceptron (MLP) network to predict one-year and two-year survival probability after transplantation. The performances of the MLP, SOFA, and MELD were assessed by measuring both calibration ability and discriminative power, with Hosmer-Lemeshow test and receiver operating characteristic analysis, respectively. By the forward stepwise selection, donor age and BMI; serum concentration of HB, Crea, ALB, TB, ALT, INR, Na⁺; presence of pretransplant diabetes; dialysis prior to transplantation, and microbiologically proven sepsis were identified to be the optimal input features. The MLP, employing 18 input neurons and 12 hidden neurons, yielded high predictive accuracy, with c-statistic of 0.91 (P<0.001) in one-year and 0.88 (P<0.001) in two-year prediction. The performances of SOFA and MELD were fairly poor in prognostic assessment, with c-statistics of 0.70 and 0.66, respectively, in one-year prediction, and 0.67 and 0.65 in two-year prediction.

Conclusions/Significance

The posttransplant prognosis is a multidimensional nonlinear problem, and the MLP can achieve significantly high accuracy than SOFA and MELD scores in posttransplant survival prediction. The pattern recognition methodologies like MLP hold promise for solving posttransplant outcome prediction.

Pretransplant Model for End-stage Liver Disease score has no impact on posttransplant survival in living donor liver transplantation

BACKGROUND

A high Model For End-stage Liver Disease (MELD) score≥25 has been reported to be associated with increased posttransplant mortality and morbidity among patients undergoing living donor liver transplantation (LDLT). We reviewed the results of patients undergoing LDLT at our transplant center for decompensated cirrhosis to determine whether a high MELD impacted posttransplant survival.

METHODS

From April 2002 to May 2011, 86-176 patients (49%) who underwent LDLT at our center had the indication of decompensated cirrhosis without hepatocellular carcinoma. Data were expressed in mean values±standard error of the means (range). Patients survival rates were analyzed using Kaplan-Meier method.

RESULTS

Among the 86 patients with decompensated cirrhosis: Age was 49±2 (1-68) years and 60 (70%) were of male gender. The causes in 25 (29%) were hepatitis B and 25 (29%) hepatitis C as well as one each for hepatitis B/C and B/D coinfections: 9 (10%), alcoholic cirrhosis. MELD score was 18±1 (range=6-40). In hospital mortality was 6/86 (7%). At 1152±95 (range=7-3317) days posttransplant follow-up 64 (74%) were alive with 1-, 3-, and 5-year survival rates of 84%, 70%, and 70%, respectively. MELD scores did not differ between those who survived and those who died (17.5±8.0 versus 17.8±8.4). No difference was noted in those with MELD<25 or ≥25. In fact, the recipient with the highest MELD score (40) survived.

CONCLUSION

A high MELD score had no impact on posttransplant survival among cirrhotic patients undergoing LDLT. It should be considered to be an urgent indication rather than a contraindication to LDLT.