Predicting early allograft failure and mortality after liver transplantation: the role of the postoperative model for end-stage liver disease score

Can elastography predict early allograft dysfunction or loss after liver transplantation? A prospective study of diagnostic accuracy

INTRODUCTION

The imbalance between the demand for liver transplants and the shortage of donors can be addressed by expanding the donor pool, including using extended criteria donors. This strategy may reduce waiting time and list mortality but can increase poor graft function rates, affecting short-term outcomes. Tools to predict and diagnose Early Allograft Dysfunction (EAD) are crucial. Elastography for Liver Stiffness Measurement (LSM) may predict EAD and graft loss early post-transplant.

METHODS

In this prospective observational study, the authors assessed the diagnostic accuracy of elastography for predicting EAD or loss in liver transplant recipients admitted to the ICU of Hospital das Clínicas, Universidade de São Paulo, from 2016 to 2018. Patients underwent daily LSM from ICU admission to day 7 post-transplant. EAD was defined by Olthoff et al.'s criteria, and allograft loss was defined by the need for retransplantation or death within 180 days.

RESULTS

EAD developed in 27 patients (44.3 %). The median LSM was 2.12 m/s (IQR 1.87-2.67 m/s) for the EAD group and 1.70 m/s (IQR 1.55-1.90 m/s) for the non-EAD group. For predicting EAD, elastography on day 1 had a c-statistic of 0.83, sensitivity 41 %, specificity 97 %, and accuracy 83 % at a cutoff of 2.39 m/s. For predicting early allograft loss, the c-statistic was 0.93, with a sensitivity 76 %, specificity 100 %, and accuracy 93 % at a cutoff of 2.25 m/s on day 1.

CONCLUSION

Elastography demonstrated robust performance in predicting EAD and early graft loss post-transplant, outperforming traditional prognostic scores. Further multicenter studies are needed to confirm these findings.

Liver stiffness: a novel imaging biomarker by ultrasound elastography for prediction of early allograft failure following liver transplantation

OBJECTIVES

The objective of this study was to evaluate the role of Liver Stiffness Measurement (LSM) and serum transaminase levels for predicting early allograft failure (EAF) after liver transplantation (LT).

METHODS

A total of 189 patients who underwent LT were prospectively recruited in the study. Of these patients, 13 cases died or received re-transplantation within 90 days after surgery were classified as EAF group, while rest 176 patients were included in the non-EAF group. LSM values and serum transaminase levels within 1 week after operation were recorded and compared between two groups. The area under the curve (AUC) was utilized to assess the performance of LSM, serum transaminase and their combination in predicting EAF.

RESULTS

The earliest significant difference in LSM between EAF and non-EAF group was observed on postoperative day 3 (POD-3) (p = 0.046). Comparing to non-EAF group, patients in the EAF group had higher aspartate-aminotransferase (AST) and alanine aminotransferase (ALT) on postoperative day 2 (POD-2)(p = 0.009, 0.033), and also demonstrated higher AST on POD-3 (p = 0.021). Furthermore, the reduction rate of AST/ALT from day 1 to day 3 (AST/ALT Red) were slower (p = 0.001, 0.014) in EAF group. Using a LSM value > 12.1 kPa and an AST level > 339U/L on POD-3 predicted EAF with a sensitivity of 89%, a specificity of 86%, and an AUC of 0.926, surpassing the traditional early allograft dysfunction (EAD) model.

CONCLUSIONS

The combination of LSM values and AST levels on the third day after LT can effectively predict EAF and facilitate timely interventions.

Advancements in Predictive Tools for Primary Graft Dysfunction in Liver Transplantation: A Comprehensive Review

Orthotopic liver transplantation stands as the sole curative solution for end-stage liver disease. Nevertheless, the discrepancy between the demand and supply of grafts in transplant medicine greatly limits the success of this treatment. The increasing global shortage of organs necessitates the utilization of extended criteria donors (ECD) for liver transplantation, thereby increasing the risk of primary graft dysfunction (PGD). Primary graft dysfunction (PGD) encompasses early allograft dysfunction (EAD) and the more severe primary nonfunction (PNF), both of which stem from ischemia-reperfusion injury (IRI) and mitochondrial damage. Currently, the only effective treatment for PNF is secondary transplantation within the initial post-transplant week, and the occurrence of EAD suggests an elevated, albeit still uncertain, likelihood of retransplantation urgency. Nonetheless, the ongoing exploration of novel IRI mitigation strategies offers hope for future improvements in PGD outcomes. Establishing an intuitive and reliable tool to predict upcoming graft dysfunction is vital for early identification of high-risk patients and for making informed retransplantation decisions. Accurate diagnostics for PNF and EAD constitute essential initial steps in implementing future mitigation strategies. Recently, novel methods for PNF prediction have been developed, and several models for EAD assessments have been introduced. Here, we provide an overview of the currently scrutinized predictive tools for PNF and EAD evaluation strategies, accompanied by recommendations for future studies.

Algorithmic Approach to Deranged Liver Functions After Transplantation

Liver transplant (LT) recipients require close follow-up with regular monitoring of the liver function tests (LFTs). Evaluation of deranged LFT should be individualized depending upon the time since LT, peri-operative events, clinical course, and any complications. These derangements can range from mild and asymptomatic to severe and symptomatic elevations requiring expedited personalized assessment and management. Pattern of LFT derangement (hepatocellular, cholestatic, or mixed), donor-recipient risk factors, timing after LT (post-operative, 1-12 months, and >12 months since LT) along with clinical context and symptomatology are important considerations before proceeding with the initial evaluation. Compliance to immunosuppression and drug interactions should be ascertained along with local epidemiology of infections. Essential initial evaluation must include an ultrasound abdomen with Doppler to rule out any structural causes such as biliary or vascular complications apart from focussed laboratory evaluation. Early allograft dysfunction, ischemia reperfusion injury, small-for-size syndrome, biliary leaks, hepatic artery, and portal vein thrombosis are usual culprits in the early post-operative period whereas viral hepatitis (acute or reactivation), opportunistic infections, and recurrence of the primary disease are more frequent in the later period. Graft rejection, biliary strictures, sepsis, and drug induced liver injury remain possible etiologies at all times points after LT. Initial evaluation algorithm must be customized based on history, clinical examination, risk factors, and pattern and severity of deranged LFT. Allograft rejection is a diagnosis of exclusion and requires liver biopsy to confirm and assess severity. Empirical treatment of rejection sans liver biopsy is discouraged.

Mortality and Morbidity Among Adult Liver Retransplant Recipients

BACKGROUND

Liver transplantation (LT) is life-saving procedure for patients with end-stage liver failure with up to 20% of patients suffering graft failure following primary transplantation. Retransplantation (ReLT) remains the only definitive treatment for irreversible graft failure.

AIMS

We aimed to explore the postoperative outcomes following liver ReLT.

METHODS

Patients who had received a liver transplant between 2003 and 2016 were retrospectively identified using the Scientific Registry of Transplant Recipients (SRTRs). Patients were stratified based on previous liver transplant history. The primary outcomes of this study were 5-year postoperative mortality, morbidity, and length of hospital stay following LT.

RESULTS

60,554 (96%) recipients were first LT recipients and 2524 (4%) were ReLT recipients. Compared with first LT, ReLT recipients had significantly higher rates of mortality (OR 1.93, 95%CI 1.76-2.12), overall morbidity (OR 1.80, 95%CI 1.65-1.96), and prolonged length of stay (OR 1.66, 95%CI 1.52-1.81) on multivariate analysis. Morbidity including cardiovascular (CVD) complications (OR 1.32, 95%CI 1.08-1.60), graft failure (OR 2.18, 95%CI 1.84-2.57), infection (OR 2.13, 95%CI 1.82-2.50), and hemorrhage (OR 2.67, 95%CI 2.00-3.61) were significantly greater in ReLT recipients. Compared to first LT, ReLT patients had a significant increase in overall 5-year mortality (p < 0.001), 5-year mortality due to CVD complications (p < 0.001), infection (p = 0.009), but not graft failure (p = 0.3543).

CONCLUSION

ReLT is associated with higher rates of 5-year mortality, overall morbidity, CVD morbidity, infection, and graft failure. Higher 5-year mortality in ReLT is due to CVD and infections. These results could be used in preoperative patient assessment and prognostic counseling for ReLT.

Predicting graft failure in pediatric liver transplantation based on early biomarkers using machine learning models

The early detection of graft failure in pediatric liver transplantation is crucial for appropriate intervention. Graft failure is associated with numerous perioperative risk factors. This study aimed to develop an individualized predictive model for 90-days graft failure in pediatric liver transplantation using machine learning methods. We conducted a single-center retrospective cohort study. A total of 87 liver transplantation cases performed in patients aged < 12 years at the Severance Hospital between January 2010 and September 2020 were included as data samples. Preoperative conditions of recipients and donors, intraoperative care, postoperative serial laboratory parameters, and events observed within seven days of surgery were collected as features. A least absolute shrinkage and selection operator (LASSO) -based method was used for feature selection to overcome the high dimensionality and collinearity of variables. Among 146 features, four variables were selected as the resultant features, namely, preoperative hepatic encephalopathy, sodium level at the end of surgery, hepatic artery thrombosis, and total bilirubin level on postoperative day 7. These features were selected from different times and represent distinct clinical aspects. The model with logistic regression demonstrated the best prediction performance among various machine learning methods tested (area under the receiver operating characteristic curve (AUROC) = 0.898 and area under the precision-recall curve (AUPR) = 0.882). The risk scoring system developed based on the logistic regression model showed an AUROC of 0.910 and an AUPR of 0.830. Together, the prediction of graft failure in pediatric liver transplantation using the proposed machine learning model exhibited superior discrimination power and, therefore, can provide valuable information to clinicians for their decision making during the postoperative management of the patients.

High visceral adipose tissue area is independently associated with early allograft dysfunction in liver transplantation recipients: a propensity score analysis

OBJECTIVES

To evaluate the association between adipose tissue distribution and early allograft dysfunction (EAD) in liver transplantation (LT) recipients.

METHODS

A total of 175 patients who received LT from April 2015 to September 2020 were enrolled in this retrospective study. The areas of abdominal adipose tissue and skeletal muscle of all patients were measured based on the preoperative CT images. The appropriate statistical methods including the propensity score-matched (PSM) analysis were performed to identify the association between adipose tissue distribution and EAD.

RESULTS

Of 175 LT recipients, 55 patients (31.4%) finally developed EAD. The multivariate logistic analysis revealed that preoperative serum albumin (odds ratio (OR) 0.34, 95% confidence interval (CI) 0.17-0.70), platelet-lymphocyte ratio (OR 2.35, 95% CI 1.18-4.79), and visceral adipose tissue (VAT) area (OR 3.17, 95% CI 1.56-6.43) were independent associated with EAD. After PSM analysis, VAT area was still significantly associated with EAD (OR 3.95, 95% CI 1.16-13.51). In survival analysis, no significant difference was identified in one-year graft failure (log-rank: p = 0.487), and conversely result was identified in overall survival (OS) (log-rank: p = 0.012; hazard ratio (HR) 4.10, 95% CI 1.27-13.16).

CONCLUSIONS

LT recipients with high VAT area have higher risk for the occurrence of EAD, and high VAT area might have certain clinical value for predicting the poor OS of patients. For LT candidates with large amount of VAT, the clinicians can take clinical interventions by suggesting physical and nutritional treatments to improve outcomes after LT.

The Utility of Early Allograft Dysfunction Components in Determining 90-Day Liver Graft Survival

BACKGROUND

Early allograft dysfunction (EAD) had been established as a useful tool to asses graft and patient survival after liver transplant. We wanted to evaluate effect of EAD components on early graft survival.

METHODS

This retrospective study included 264 patients with EAD after liver transplant in the period between 2015 and 2019. The patients with retransplants were excluded from analyses. The EAD was determined with Olthoff criteria. The logistic regression model was used for analyses. The 90-day graft survival was set as a primary outcome measure.

RESULTS

The main indications for transplant in the analyzed group were hepatitis C virus infection (53 patients, 20.1%), hepatitis B infection (22, 8.3%), primary sclerosing cholangitis (28, 10.1%), and alcoholic liver disease (62, 23.5%), with a median model for end-stage liver disease score of 13.5 points. The 90-day graft loss occurred in 51 patients (19.3%). Each of the components used in EAD diagnosis was found to be correlated with 90-day graft loss. The bilirubin concentration on day 7 (odds ratio [OR], 3.1; 95% CI, 1.4-6.7; P < .001), international normalized ratio on day 7 (OR, 179; 95% CI, 39-815; P < .001), and the natural logarithm of alanine aminotransferase (OR, 3.1; 95% CI, 1.6-6.4) and aspartate aminotransferase (OR, 1.4; 95% CI, 0.4-4.9) predicted 90-day graft loss.

CONCLUSIONS

In patients with EAD, international normalized ratio ≥ 1.6 on day 7 was the strongest predictor of early graft-loss among all EAD components.

Models to predict the short-term survival of acute-on-chronic liver failure patients following liver transplantation

Background

Acute-on-chronic liver failure (ACLF) is featured with rapid deterioration of chronic liver disease and poor short-term prognosis. Liver transplantation (LT) is recognized as the curative option for ACLF. However, there is no standard in the prediction of the short-term survival among ACLF patients following LT.

Method

Preoperative data of 132 ACLF patients receiving LT at our center were investigated retrospectively. Cox regression was performed to determine the risk factors for short-term survival among ACLF patients following LT. Five conventional score systems (the MELD score, ABIC, CLIF-C OFs, CLIF-SOFAs and CLIF-C ACLFs) in forecasting short-term survival were estimated through the receiver operating characteristic (ROC). Four machine-learning (ML) models, including support vector machine (SVM), logistic regression (LR), multi-layer perceptron (MLP) and random forest (RF), were also established for short-term survival prediction.

Results

Cox regression analysis demonstrated that creatinine (Cr) and international normalized ratio (INR) were the two independent predictors for short-term survival among ACLF patients following LT. The ROC curves showed that the area under the curve (AUC) ML models was much larger than that of conventional models in predicting short-term survival. Among conventional models the model for end stage liver disease (MELD) score had the highest AUC (0.704), while among ML models the RF model yielded the largest AUC (0.940).

Conclusion

Compared with the traditional methods, the ML models showed good performance in the prediction of short-term prognosis among ACLF patients following LT and the RF model perform the best. It is promising to optimize organ allocation and promote transplant survival based on the prediction of ML models.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02164-6.

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.

Using Rotational Thromboelastometry to Identify Early Allograft Dysfunction after Living Donor Liver Transplantation

Background: Diagnostic tests for early allograft dysfunction (EAD) after living donor liver transplantation (LDLT) vary widely. We aimed to evaluate the predictive value of rotational thromboelastometry (ROTEM)-derived parameters in EAD. Materials and Methods: A total of 121 patients were reviewed. The definition of EAD proposed by Olthoff et al. included the presence of any of the following at postoperative day 7: bilirubin level ≥ 10 mg/dL, INR ≥ 1.6, or serum AST or ALT levels > 2000 IU/L. All patients underwent ROTEM assay, which consisted of an extrinsically activated thromboelastometric test (EXTEM) before and 24 h after LDLT. Results: The 1-year/2-year OS were 68.%8/64.5% and 94.4%/90.8% for the EAD and non-EAD groups, respectively (p = 0.001). Two independent risks were identified for EAD, the postoperative clotting time (CT, p = 0.026) and time to maximum clot firmness (maximum clot firmness (MCF)-t, p = 0.009) on the EXTEM. CT yielded a specificity of 82.0% and negative predictive value of 83.0%, and MCF-t displayed a specificity of 76.4% and negative predictive value of 81.9% in diagnosing EAD. The use of the 24 h post-LDLT ROTEM increased the effectiveness of predicting overall survival (OS) compared to using the Olthoff’s EAD criteria alone (p < 0.001). Conclusion: We conclude that CT and MCF on EXTEM were independent predictors of EAD. The 24 h post-LDLT ROTEM can be used with conventional laboratory tests to diagnose EAD. It increases the effectiveness of predicting OS.

Model for end-stage liver disease score predicts complications after liver transplantation

PURPOSE

Increased model for end-stage liver disease (MELD) score measured in the early postoperative course is associated with one-year mortality and graft loss. However, the correlation with postoperative complications has not been investigated. The aim of this study was to investigate the association between postoperative MELD score and subsequent complications.

METHODS

Adult liver transplant recipients transplanted from January 2011 until December 2016 were included. MELD score days 1-5 were correlated with complications day 6-30, subdivided into type and severity according to Clavien-Dindo classification.

RESULTS

We included 246 adult liver transplant recipients. Between days 6 and 30, 671 complications occurred in 201 of the patients (82%) corresponding to 64% of all postoperative complications in the whole postoperative period (days 0-30). In multivariate analyses adjusted for recipient gender and age, preoperative MELD score, and Eurotransplant Donor Risk Index, postoperative MELD score was significantly associated with having one or more complications, any type of complication except cardiovascular and renal complications, and complication severity.

CONCLUSIONS

Postoperative MELD score days 1-5 were associated with complications arising in the subsequent period 6-30 days after transplantation. An increased MELD score should heighten the clinician's awareness of a possible complication.

Poor outcomes of early recurrent post-transplant bloodstream infection in living-donor liver transplant recipients

Bloodstream infection (BSI) is a common complication after living-donor liver transplantation (LDLT). Some patients develop recurrent BSIs. We evaluated the impacts of early recurrent BSIs (ER-BSIs) on outcomes in LDLT recipients. LDLT cases between 2008 and 2016 were included. Early BSI (E-BSI) was defined as a BSI event that occurred within 2 months after LDLT. ER-BSIs were defined as new-onset BSIs within 2 months due to another pathogen at a ≥ 48-h interval or a relapse of BSIs by the same pathogen at a ≥ 1-week interval, with negative cultures in between. The primary objective was evaluating the all-cause mortality of each group of LDLT recipients (90 days and 1 year). The secondary objectives were analyzing associated factors of each all-cause mortality and risk factors for early single BSI and ER-BSI. Among 727 LDLT recipients, 108 patients experienced 149 events of E-BSI with 170 isolated pathogens. Twenty-eight patients (25.9%, 28/108) experienced ER-BSI. The 1-year survival rates of patients without BSI, with early single BSI event, and with ER-BSIs were 92.4%, 81.3%, and 28.6%, respectively. ER-BSI was the most significant risk factor for 1-year mortality (adjusted HR = 5.31; 95% CI = 2.27–12.40). Intra-abdominal and/or biliary complications and early allograft dysfunction were risk factors for both early single BSI and ER-BSI. Interestingly, longer cold ischemic time and recipient operative time were associated with ER-BSI. LDLT recipients with ER-BSI showed very low survival rates accompanied by intra-abdominal complications. Clinicians should prevent BSI recurrence by being aware of intra-abdominal complications.

A simple scoring model for predicting early graft failure and postoperative mortality after liver transplantation

INTRODUCTION AND OBJECTIVES

Graft failure and postoperative mortality are the most serious complications after liver transplantation. The aim of this study is to establish a prognostic scoring system to predict graft and patient survival based on serum transaminases levels that are routinely used during the postoperative period in human cadaveric liver transplants.

PATIENTS AND METHODS

Postoperative graft failure and patient mortality after liver transplant were analyzed from a consecutive series of 1299 patients undergoing cadaveric liver transplantation. This was correlated with serum liver function tests and the rate of reduction in transaminase levels over the first postoperative week. A cut-off transaminase level correlating with graft and patient survival was calculated and incorporated into a scoring system.

RESULTS

Aspartate-aminotransferase (AST) on postoperative day one showed significant correlation with early graft failure for levels above 723U/dl and early postoperative mortality for levels above 750U/dl. AST reduction rate (day 1 to 3) greater than 1.8 correlated with reduced graft failure and greater than 2 with mortality. Alanine-aminotransferase (ALT) reduction in the first 48h post transplantation also correlated with outcomes.

CONCLUSION

A scoring system with these three variables allowed us to classify our patients into three groups of risk for early graft failure and mortality.

Post-operative assessment in patients after liver transplantation: imaging parameters associated with 1-year graft failure

PURPOSE

To identify post-liver transplant CT findings which predict graft failure within 1 year.

MATERIALS AND METHODS

We evaluated the CT scans of 202 adult liver transplants performed in our institution who underwent CT within 3 months after transplantation. We recorded CT findings of liver perfusion defect (LPD), parenchymal homogeneity, and the diameters and attenuations of the hepatic vessels. Findings were correlated to 1-year graft failure, and interobserver variability was assessed.

RESULTS

Forty-one (20.3%) of the 202 liver grafts failed within 1 year. Graft failure was highly associated with LPD (n = 18/25, or 67%, versus 15/98, or 15%, p < 0.001), parenchymal hypoattenuation (n = 20/41, or 48.8% versus 17/161, or 10.6%, p < 0.001), and smaller diameter of portal veins (right portal vein [RPV], 10.7 ± 2.7 mm versus 14.7 ± 2.2 mm, and left portal vein [LPV], 9.8 ± 3.0 mm versus 12.4 ± 2.2 mm, p < 0.001, respectively). Of these findings, LPD (hazard ratio [HR], 5.43, p < 0.001) and small portal vein diameters (HR, RPV, 3.33, p < 0.001, and LPV, 3.13, p < 0.05) independently predicted graft failure. All the measurements showed fair to moderate interobserver agreement (0.233~0.597).

CONCLUSION

For patients who have CT scan within the first 3 months of liver transplantation, findings of LPD and small portal vein diameters predict 1-year graft failure.

KEY POINTS

•Failed grafts are highly associated with liver perfusion defect, hypoattenuation, and small portal vein. •Right portal vein < 11.5 mm and left portal vein < 10.0 mm were associated with poor graft outcome. •Liver perfusion defect and small portal vein diameter independently predicted graft failure.

Early Graft Dysfunction Evaluation by Indocyanine Green Plasma Clearance Rate in the Immediate Postoperative Period After Liver Transplantation

BACKGROUND

Liver transplantation (LT) has evolved to improve graft and patient survival. Early graft dysfunction (EGD) and primary nonfunction are an important cause of morbi-mortality. We had formulated the scientific hypothesis that the liver function can be evaluated by the indocyanine green (IG) after LT. The aim was to evaluate the EGD by plasma disappearance rate (PDR) of IG after LT.

METHOD

Prospective and observational clinical study, from July 2014 to June 2015. IG evaluation by pulse densitometry, Limon system. Degree analysis of ischemia and reperfusion injury in groups as follows: 1 (G0/G1/G2) and 2 (G3/G4). Donor risk index (DRI), Wagener and Olthoff criteria, and prognostic predictors were evaluated. All tests were performed with bidirectional α of 0.05 and a confidence interval of 95% and support by IBM SPSS 25.

RESULTS

A total of 40 patients, mean age 53.3 ± 14.0 years and a majority of men and hepatitis C virus. PDR were more relevant with high degrees of ischemia and reperfusion injury grades G3/G4 (P = .030). The PDR related to the donor risk index showed positive significance at DRI >1.5 (P = .066). The retention rate of IG at 15 minutes demonstrated potential in assessing graft loss or death (P = .063).

CONCLUSION

EGD can be assessed by PDR with high degrees of ischemia and reperfusion injury (G3/G4) and with marginal donors (DRI >1.5). The retention rate of IG at 15 minutes demonstrated potential in assessing graft loss or death of the patient.

Predictors of early recipient mortality after living donor liver transplantation in a tertiary care center in Egypt

BACKGROUND

Living donor liver transplantation (LDLT) has evolved into a widely accepted therapeutic option. Many different risk factors may affect early mortality after LDLT.

OBJECTIVES

Analyze risk factors that can affect early (<6 months) mortality of patients after LDLT in a single center.

DESIGN

Retrospective chart review of patients who underwent LDLT.

SETTING

University hospital.

PATIENTS AND METHODS

Adult cirrhotic patients who underwent LDLT were classified by early (first 6 months) or late mortality. A full pre, intra- and post-operative evaluation had been done on all patients including a full history, examination and investigations to identify risk factors that might affect mortality post-LDLT.

MAIN OUTCOME MEASURES

Determination of pre-, intra- or postoperative factors that might affect recipient mortality post-LDLT.

SAMPLE SIZE

123.

RESULTS

Pre-operative factors that increased early mortality in a univariate analysis were higher model for end-stage liver disease (MELD) scores, lower graft-recipient weigh ratio (GRWR), older donor age, and recurrent spontaneous bacterial peritonitis. Intraoperative factors included more transfusion units of blood, plasma, platelets and cryoprecipitate, a longer time for cold and warm ischemia, and a longer anhepatic phase among others. Postoperative factors included a longer ICU or hospital stay and abnormal postoperative laboratory data. In the final logistic regression model, the most significant factors were pre-operative GRWR, length of hospital stay, units of intraoperative blood transfusion, postoperative alanine aminotransferase, postoperative total leukocyte count, and MELD score.

CONCLUSION

LDLT outcomes might be improved by attempting to resolve clinical factors that have been identified as contributors to early post-LDLT mortality.

LIMITATIONS

More risk factors, such as those relevant to patient portal vein hemodynamics, should be included in an analysis of predictors of early mortality.

CONFLICT OF INTEREST

None.

Hyaluronic Acid Is a Biomarker for Allograft Dysfunction and Predicts 1-Year Graft Loss After Liver Transplantation

BACKGROUND

Allograft dysfunction after liver transplantation has a profound impact on the risks of death and retransplantation within the first year. We tested whether elevated hyaluronic acid (HA; a glycosaminoglycan cleared by hepatic sinusoidal endothelium) levels may predict excess risk of graft loss.

METHODS

This was a retrospective single-center prognostic cohort study. Patients with either a plasma sample before transplantation, an early post-transplantation sample nearest day 30 (range 10-89 d, 80% within days 15-60), or both were included. Plasma HA was measured with the use of enzyme-linked immunosorbent assays. The primary end point was 1-year graft loss (all-cause mortality and retransplantation). A secondary end point was biliary stricture.

RESULTS

In this study, 169 of 196 patients who received a liver transplant in the study period were included. Pre-transplantation HA (n = 152) did not predict graft loss. Post-transplantation HA (n = 124) was higher among patients with graft loss (median, 177 μg/L [interquartile range (IQR), 89-465] vs 54 μg/L [IQR 37-93]) and was a strong predictor of this outcome (hazard ratio per 50 μg/L, 1.24 [95% confidence interval [CI], 1.14-1.34]). The discriminatory ability of HA was high (area under the receiver operating characteristic curve, 0.86 [95% CI, 0.77-0.94]) and noninferior to other liver function tests. When adjusted for known risk factors of graft loss, HA remained an independent predictor of graft loss.

CONCLUSIONS

High post-transplantation plasma HA level was a strong predictor of 1-year all-cause mortality and retransplantation, whereas pre-transplantation levels were not, despite variety in the time span of blood sampling. Prospective studies are warranted to assess the utility of HA in liver transplantation.

Analysis of the Predictive Ability for Graft Loss and Mortality of Two Criteria for Early Allograft Dysfunction After Liver Transplantation

INTRODUCTION

The current imbalance between available donors and potential recipients for orthotopic liver transplantation (OLT) has led to a liberalization of organ acceptance criteria, increasing the risk of post-transplant complications such as early allograft dysfunction (EAD). Consequently, we need accurate criteria to detect patients with early poor graft function to guide the strategies of management. We evaluated the usefulness of two frequently used criteria: the definition from Olthoff et al and the Model for Early Allograft Function (MEAF) scoring.

PATIENTS AND METHODS

Unicentric cohort study of patients undergoing OLT between January 1, 2010, and November 20, 2016. We performed a univariate study to detect donor, recipient, and transplant factors favoring EAD, defined both by Olthoff criteria and a MEAF score higher than 7. Finally, we developed a comparative survival analysis for cases having or not EAD.

RESULTS

In all, 201 transplants met inclusion criteria. According to the stated cutoff for MEAF score, the frequency of EAD was 9.3%, with a significant association to low recipient body mass index and prolonged total graft ischemia time, resulting in lower patient 3-month postoperative survival. According to Olthoff criteria, EAD incidence was 22.1% and was associated with younger donor and recipient ages and higher Model for End-stage Liver Disease and Child-Pugh recipient scores. Its development resulted in lower graft and recipient survival at 3 months after OLT.

CONCLUSION

MEAF score and Olthoff criteria are useful tools for detection of EAD. The latter could select more appropriately patients at risk, but its calculation cannot be done until the seventh day after OLT, unlike MEAF score, available on third day.

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.

Effect of early allograft dysfunction on outcomes following liver transplantation

Early allograft dysfunction (EAD) following liver transplantation (LT) remains a challenge for patients and clinicians. We retrospectively analyzed the effect of pre-defined EAD on outcomes in a 10-year cohort of deceased-donor LT recipients with clearly defined exclusion criteria. EAD was defined by at least one of the following: AST or ALT >2000 IU/L within first-week post-LT, total bilirubin ≥10 mg/dL, and/or INR ≥1.6 on post-operative day 7. Ten patients developed primary graft failure and were analyzed separately. EAD occurred in 86 (36%) recipients in a final cohort of 239 patients. In univariate and multivariate analyses, EAD was significantly associated with mechanical ventilation ≥2 days or death on days 0, 1, PACU/SICU stay >2 days or death on days 0-2 and renal failure (RF) at time of hospital discharge (all P<.05). EAD was also significantly associated with higher one-year graft loss in both uni- and multivariate Cox hazard analyses (P=.0203 and .0248, respectively). There was no difference in patient mortality between groups in either of the Cox proportional hazard models. In conclusion, we observed significant effects of EAD on short-term post-LT outcomes and lower graft survival.

Risk factors and clinical indicators for the development of biliary strictures post liver transplant: Significance of bilirubin

AIM

To identify risk factors associated with the formation of biliary strictures post liver transplantation over a period of 10-year in Queensland.

METHODS

Data on liver donors and recipients in Queensland between 2005 and 2014 was obtained from an electronic patient data system. In addition, intra-operative and post-operative characteristics were collected and a logistical regression analysis was performed to evaluate their association with the development of biliary strictures.

RESULTS

Of 296 liver transplants performed, 285 (96.3%) were from brain dead donors. Biliary strictures developed in 45 (15.2%) recipients. Anastomotic stricture formation (n = 25, 48.1%) was the commonest complication, with 14 (58.3%) of these occurred within 6-mo of transplant. A percutaneous approach or endoscopic retrograde cholangiography was used to treat 17 (37.8%) patients with biliary strictures. Biliary reconstruction was initially or ultimately required in 22 (48.9%) patients. In recipients developing biliary strictures, bilirubin was significantly increased within the first post-operative week (Day 7 total bilirubin 74 μmol/L vs 49 μmol/L, P = 0.012). In both univariate and multivariate regression analysis, Day 7 total bilirubin > 55 μmol/L was associated with the development of biliary stricture formation. In addition, hepatic artery thrombosis and primary sclerosing cholangitis were identified as independent risk factors.

CONCLUSION

In addition to known risk factors, bilirubin levels in the early post-operative period could be used as a clinical indicator for biliary stricture formation.

Low Graft Attenuation at Unenhanced CT: Association with 1-Month Mortality or Graft Failure after Liver Transplantation

Purpose To investigate whether low graft attenuation at unenhanced computed tomography (CT) is associated with 1-month mortality or graft failure after liver transplant and determine its diagnostic performance. Materials and Methods Included were 663 recipients who underwent CT imaging within 7 days after liver transplant between December 2014 and August 2016. Initial poor function (IPF) was diagnosed by using a combination of laboratory values within 7 days after liver transplant and subdivided patients into primary and secondary IPF. At 1 month after the operation, mortality and graft failure or survival in recipients was categorized. Two radiologists who were blinded to clinical data retrospectively and independently evaluated graft attenuation on unenhanced CT images (high or isoattenuation, graft attenuation greater than or equal to that of spleen; low, graft attenuation less than that of spleen). The interobserver agreement was evaluated by using intraclass correlation coefficient and κ statics. Incidence of low graft attenuation between recipients with IPF and those with normal function was compared by using χ² test. The relationship between graft attenuation and outcome in primary and secondary IPF was evaluated by using log-rank test. Results Of 663 recipients, 114 had IPF (80 primary; 34 secondary). After 1 month, 11 had graft failure or died, whereas 652 survived. Low graft attenuation was more common in patients with IPF than in normal-function patients (P < .001). In the primary group (those without identifiable cause), 15 patients had low graft attenuation, which led to mortality or graft failure within 1 month in seven of those patients. No recipient with high or isoattenuation had 1-month mortality or graft failure (P < .001). The secondary group (those with identifiable cause) showed no significant association between graft attenuation and 1-month mortality and graft failure (P = .181). Values of low graft attenuation for 1-month mortality and graft failure in primary IPF were positive predictive value, 46.7%; negative predictive value, 100%; sensitivity, 100%; specificity, 89.0%; and accuracy, 90.0%. There was excellent interobserver agreement in the assessment of graft attenuation (intraclass correlation coefficient, 0.957; κ = 1.00). Conclusion Low graft attenuation can be associated with 1-month mortality or graft failure in liver graft recipients with primary IPF. ^© RSNA, 2017.

Role of the postoperative cholesterol in early allograft dysfunction and survival after living donor liver transplantation

BACKGROUND

Many studies have confirmed that serum total cholesterol (sTC) concentrations were associated with underlying liver damage and the synthesis capacity of liver. However, the role of postoperative sTC level on evaluating graft function and predicting survival of recipients who underwent liver transplantation has not been discussed.

METHODS

Clinical data of 231 living donor liver transplantation recipients from May 2003 to January 2015 were retrospectively collected. Patients were stratified into the low sTC group (sTC <1.42 mmol/L, 57 recipients) and high sTC group (sTC =1.42 mmol/L, 174 recipients) according the sTC level on postoperative day 3 based on receiver-operating characteristic curve analysis. The clinical characteristics and postoperative short- and long-term outcomes were compared between the two groups.

RESULTS

Recipients with sTC <1.42 mmol/L experienced more severe preoperative disease conditions, a higher incidence of postoperative early allograft dysfunction (38.6% vs 10.3%, P<0.001), 90-day mortality (28.1% vs 10.9%, P=0.002) and severe complications (29.8% vs 17.2%, P=0.041) compared to recipients with sTC =1.42 mmol/L. The multivariate analysis demonstrated that sTC <1.42 mmol/L had a 4.08-fold (95% CI: 1.83-9.11, P=0.001) and 2.72-fold (95% CI: 1.23-6.00, P=0.013) greater risk of developing allograft dysfunction and 90-day mortality, and patients with sTC <1.42 mmol/L had poorer overall recipient and graft survival rates at 1-, 3-, and 5-year than those with sTC =1.42 mmol/L (67%, 61% and 61% vs 83%, 71% and 69%, P=0.025; 65%, 59% and 59% vs 81%, 68% and 66%, P=0.026, respectively). Cox multivariate analysis showed that sTC <1.42 mmol/L was an independent predicting factor for total recipient survival (HR=2.043; 95% CI: 1.173-3.560; P=0.012) and graft survival (HR=1.905; 95% CI: 1.115-3.255; P=0.018).

CONCLUSIONS

sTC <1.42 mmol/L on postoperative day 3 was an independent risk factor of postoperative early allograft dysfunction, 90-day mortality, recipient and graft survival, which can be used as a marker for predicting postoperative short- and long-term outcomes.

Clinical significance of lactate clearance for the development of early allograft dysfunction and short-term prognosis in deceased donor liver transplantation

This retrospective study evaluated lactate clearance (LC), measured at 6, 12, 18, and 24 hours after reperfusion, as a predictor of early allograft dysfunction (EAD) and short-term outcomes in patients receiving deceased donor liver transplantation. Of 181 transplant recipients, 44 (24.3%) developed EAD and had lower LCs than those who did not develop EAD. A receiver operating characteristic analysis showed that LC determined at 6 hours showed the highest area under curve value of 0.828 (95% confidence interval [CI]: 0.755-0.990) for predicting the development of EAD at a cutoff value of 25.8% with 76.7% sensitivity and 77.9% specificity. LC values that fell below the cutoff values were significantly associated with EAD in a multivariate analysis, with values at 6 hours having the highest adjusted odds ratio (11.891, 95% CI: 4.469-31.639). In-hospital and 6 month mortalities were higher in patients with LC values below the cutoffs compared with those above the cutoff values at each time point. Thus, LC calculated shortly after reperfusion of an allograft is significantly discriminative for the development of EAD and is associated with short-term prognosis after deceased donor liver transplantation.

A new index predicts early allograft dysfunction following living donor liver transplantation: A propensity score analysis

OBJECTIVE/AIM

The aim of this study was to identify a new index to predict early allograft dysfunction following living donor liver transplantation.

METHODS

The study enrolled 260 adult living donor liver transplantation recipients. Postoperative laboratory variables were assessed for their association with the prevalence of early allograft dysfunction using the inverse probability of treatment weighting and propensity-score matching (n=93 pairs) analysis.

RESULTS

Forty-seven recipients (18.1%) developed early allograft dysfunction. In multivariable analysis, the alanine aminotransferase and gamma-glutamyl transpeptidase levels on postoperative day 1 were independent predictors of early allograft dysfunction. The alanine aminotransferase to gamma-glutamyl transpeptidase ratio (AGR) was developed. All cases were divided into two groups (Group 1 [AGR≥8.47, n=103] and Group 2 [AGR<8.47, n=157]). AGR≥8.47 (OR 10.345, 95%CI 4.502-23.772, p<0.001), hepatorenal syndrome (OR 3.016, 95%CI 1.119-8.125, p=0.029), and graft to recipient weight ratio <0.8% (OR 2.155, 95%CI 1.004-4.624, p=0.049) were independent risk factors for early allograft dysfunction. The prevalence of early allograft dysfunction was higher in group 1 (after adjusting for inverse probability of treatment weighting [n=39; 37.9% vs n=8; 5.1%] and propensity-score matching [n=33; 35.5% vs n=2; 2.2%]) than that in group 2 (p<0.001).

CONCLUSIONS

The postoperative AGR is a practical index for predicting early allograft dysfunction after living donor liver transplantation.

Negativization of viremia prior to liver transplant reduces early allograft dysfunction in hepatitis C-positive recipients

Although early allograft dysfunction (EAD) negatively impacts survival from the first months following liver transplantation (LT), direct-acting antiviral agents (DAAs) have revolutionized hepatitis C virus (HCV) therapy. We investigated the EAD definition best predicting 90-day graft loss and identified EAD risk factors in HCV-positive recipients. From November 2002 to June 2016, 603 HCV-positive patients (hepatocellular carcinoma, 53.4%) underwent a first LT with HCV-negative donors. The median recipient Model for End-Stage Liver Disease (MELD) score was 15, and the median donor age was 63 years. At LT, 77 (12.8%) patients were HCV RNA negative; negativization was achieved and maintained by pre-LT antiviral therapy (61 patients) or pre-LT plus a pre-emptive post-LT course (16 patients); 60 (77.9%) patients received DAAs and 17 (22.1%) interferon. We compared 3 different EAD definitions: (1) bilirubin ≥ 10 mg/dL or international normalized ratio ≥ 1.6 on day 7 after LT or aspartate aminotransferase or alanine aminotransferase > 2000 IU/L within 7 days of LT; (2) bilirubin > 10 mg/dL on days 2-7 after LT; and (3) MELD ≥ 19 on day 5 after LT. EAD defined by MELD ≥ 19 on day 5 after LT had the lowest negative (0.1) and the highest positive (1.9) likelihood ratio to predict 90-day graft loss. At 90 days after LT, 9.2% of recipients with EAD lost their graft as opposed to 0.7% of those without EAD (P < 0.001). At multivariate analysis, considering variables available at LT, MELD at LT of >25 (OR = 7.4) or 15-25 (OR = 3.2), graft macrovesicular steatosis ≥ 30% (OR = 6.7), HCV RNA positive at LT (OR = 2.7), donor age > 70 years (OR = 2.0), earlier LT era (OR = 1.8), and cold ischemia time ≥ 8 hours (OR = 1.8) were significant risk factors for EAD. In conclusion, in HCV-positive patients, MELD ≥ 19 on day 5 after LT best predicts 90-day graft loss. Preventing graft infection by pre-/peri-LT antiviral therapy reduces EAD incidence and could be most beneficial in high-MELD patients and recipients of suboptimal grafts. Liver Transplantation 23 915-924 2017 AASLD.

The postoperative Model for End stage Liver Disease score as a predictor of short-term outcome after transplantation of extended criteria donor livers

BACKGROUND

Recently, the postoperative Model for End stage Liver Disease score (POPMELD) was suggested as a definition of postoperative graft dysfunction and a predictor of outcome after liver transplantation (LT).

AIM

The aim of the present study was to validate this concept in the context of extended criteria donor (ECD) organs.

PATIENTS AND METHODS

Single-center prospectively collected data (OPAL study/01/11-12/13) of 116 ECD LTs were utilized. For each recipient, the Model for End stage Liver Disease (MELD) score was calculated for 7 postoperative days (PODs). The ability of international normalized ratio, bilirubin, aspartate aminotransferase, Donor Risk Index, a recent definition of early allograft dysfunction, and the POPMELD was compared to predict 90-day graft loss. Predictive abilities were compared by receiver operating characteristic curves, sensitivity and specificity, and positive and negative predictive values.

RESULTS

The median Donor Risk Index was 1.8. In all, 60.3% of recipients were men [median age of 54 (23-68) years]. The median POD1-7 peak-aspartate aminotransferase value was 1052 (194-17 577) U/l. The rate of early allograft dysfunction was 22.4%. The 90-day graft survival was 89.7%. Out of possible predictors of the 90-day graft loss MELD on POD5 was the best predictor of outcome (area under the curve=0.84). A MELD score of 16 or more on POD5 predicted the 90-day graft loss with a specificity of 80.8%, a sensitivity of 81.8%, and a positive and negative predictive value of 31 and 97.7%.

CONCLUSION

A MELD score of 16 or more on POD5 is an excellent predictor of outcome in ECD donor LT. Routine evaluation of POPMELD scores might support clinical decision-making and should be reported routinely in clinical trials.

Rat Liver Enzyme Release Depends on Blood Flow-Bearing Physical Forces Acting in Endothelium Glycocalyx rather than on Liver Damage

We have found selective elevation of serum enzyme activities in rats subjected to partial hepatectomy (PH), apparently controlled by hemodynamic flow-bearing physical forces. Here, we assess the involvement of stretch-sensitive calcium channels and calcium mobilization in isolated livers, after chemical modifications of the endothelial glycocalyx and changing perfusion directionality. Inhibiting in vivo protein synthesis, we found that liver enzyme release is influenced by de novo synthesis of endothelial glycocalyx components, and released enzymes are confined into a liver “pool.” Moreover, liver enzyme release depended on extracellular calcium entry possibly mediated by stretch-sensitive calcium channels, and this endothelial-mediated mechanotransduction in liver enzyme release was also evidenced by modifying the glycocalyx carbohydrate components, directionality of perfusing flow rate, and the participation of nitric oxide (NO) and malondialdehyde (MDA), leading to modifications in the intracellular distribution of these enzymes mainly as nuclear enrichment of “mitochondrial” enzymes. In conclusion, the flow-induced shear stress may provide fine-tuned control of released hepatic enzymes through mediation by the endothelium glycocalyx, which provides evidence of a biological role of the enzyme release rather to be merely a biomarker for evaluating hepatotoxicity and liver damage, actually positively influencing progression of liver regeneration in mammals.

MELD score measured day 10 after orthotopic liver transplantation predicts death and re-transplantation within the first year

OBJECTIVE

The impact of early allograft dysfunction on the outcome after liver transplantation is yet to be established. We explored the independent predictive value of the Model for End-Stage Liver Disease (MELD) score measured in the post-transplant period on the risk of mortality or re-transplantation.

MATERIAL AND METHODS

Retrospective cohort study on adults undergoing orthotopic deceased donor liver transplantation from 2004 to 2014. The MELD score was determined prior to transplantation and daily until 21 days after. The risk of mortality or re-transplantation within the first year was assessed according to quartiles of MELD using unadjusted and adjusted stepwise Cox regression analysis.

RESULTS

We included 374 consecutive liver transplant recipients of whom 60 patients died or were re-transplanted. The pre-transplant MELD score was comparable between patients with good and poor outcome, but from day 1 the MELD score significantly diversified and was higher in the poor outcome group (MELD score quartile 4 versus quartile 1-3 at day 10: HR 5.1, 95% CI: 2.8-9.0). This association remained after adjustment for non-identical blood type, autoimmune liver disease and hepatocellular carcinoma (adjusted HR 5.3, 95% CI: 2.9-9.5 for MELD scores at day 10). The post-transplant MELD score was not associated with pre-transplant MELD score or the Eurotransplant donor risk index.

CONCLUSION

Early determination of the MELD score as an indicator of early allograft dysfunction after liver transplantation was a strong independent predictor of mortality or re-transplantation and was not influenced by the quality of the donor, or preoperative recipient risk factors.

Primary graft dysfunction of the liver: definitions, diagnostic criteria and risk factors

Primary graft dysfunction is a multifactorial syndrome with great impact on liver transplantation outcomes. This review article was based on studies published between January 1980 and June 2015 and retrieved from PubMed database using the following search terms: "primary graft dysfunction", "early allograft dysfunction", "primary non-function" and "liver transplantation". Graft dysfunction describes different grades of graft ischemia-reperfusion injury and can manifest as early allograft dysfunction or primary graft non-function, its most severe form. Donor-, surgery- and recipient-related factors have been associated with this syndrome. Primary graft dysfunction definition, diagnostic criteria and risk factors differ between studies. RESUMO A disfunção primária do enxerto hepático é uma síndrome multifatorial com grande impacto no resultado do transplante de fígado. Foi realizada uma ampla revisão da literatura, consultando a base de dados PubMed, em busca de estudos publicados entre janeiro de 1980 e junho de 2015. Os termos descritivos utilizados foram: "primary graft dysfunction", "early allograft dysfunction", "primary non-function" e "liver transplantation". A disfunção traduz graus diferentes da lesão de isquemia e reperfusão do órgão, e pode se manifestar como disfunção precoce ou, na forma mais grave, pelo não funcionamento primário do enxerto. Fatores relacionados ao doador, ao transplante e ao receptor contribuem para essa síndrome. Existem definições diferentes na literatura quanto ao diagnóstico e aos fatores de risco associados à disfunção primária.

Early allograft dysfunction after liver transplantation: an intermediate outcome measure for targeted improvements

BACKGROUND

The term early allograft dysfunction (EAD) identifies liver transplant (LT) allografts with initial poor function and portends poor allograft and patient survival. Aims of this study are to use EAD as an intermediate outcome measure in a large single center cohort and identify donor, recipient and peri-operative risk factors.

MATERIAL AND METHODS

In 1950 consecutive primary LT, donor, recipient and peri-operative data were collected. EAD was defined by the presence of one or more of the following: total bilirubin ≥ 10 mg/dL (171 μmol/L) or, INR ≥ 1.6 on day 7, and ALT/AST > 2,000 IU/L within the first 7 days.

RESULTS

The incidence of EAD was 26.5%. 1-, 3-, and 5-year allograft and patient survival for patients who developed EAD were significantly inferior to those who did not (P < 0.01 at all time points). Multivariate analysis demonstrated associations in the development of EAD with recipient pre-operative ventilator status, donation after cardiac death allografts, donor age, allograft size, degree of steatosis, operative time and intra-operative transfusion requirements (all P < 0.01). Patients with EAD had a significantly longer hospitalization at 20.9 ± 38.9 days (median: 9; range: 4-446) compared with 10.7 ± 13.5 days (median: 7; range: 3-231) in patients with no EAD (P < 0.01).

CONCLUSIONS

This is the largest single center experience demonstrating incidence of EAD and identifying factors associated with development of EAD. EAD is a useful intermediate outcome measure for allograft and patient survival. Balancing recipient pretransplant conditions, donor risk factors and intra-operative conditions are necessary for avoiding EAD.

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.

Interferon-γ, interleukin-10 and interferon-inducible protein 10 (CXCL10) as serum biomarkers for the early allograft dysfunction after liver transplantation

Orthotopic liver transplantation (LTP) is nowadays a standard procedure, and provides the chance of survival of patients with end-stage non-treatable chronic liver disease or acute liver failure. Despite long-term survival with a good quality of life in the majority of patients, about 20% develop early allograft dysfunction (EAD), which leads to death or the need for re-transplantation. Therefore, the early diagnosis of EAD and evaluation of its risk factors are very important. Many primary pathological processes leading to EAD are accompanied by the release of different mediators and by a change of biochemical parameters detectable in the peripheral blood. The aim of this study was to investigate cytokines as well as soluble mediators in the serum of patients with and without EAD from our LTP bank, and to evaluate their predictive and prognostic values for EAD. We demonstrated for the first time that the level of IFNγ during the nearest preoperative period may serve as a predictive parameter for EAD. We additionally found that IL-10 and CXCL10 (IP-10) levels in the early postoperative period can be prognostic for EAD. We believe our data expand the spectrum of predictive and prognostic parameters for EAD in LTP.

Low serum factor V level: early predictor of allograft failure and death following liver transplantation

PURPOSE

According to the current criteria, the diagnosis of early allograft dysfunction usually cannot be established before the end of the first week after liver transplantation. Thus, early predictive tests for detecting allograft dysfunction are still warranted to prevent allograft failure. This study was undertaken to assess the role of low serum factor V activity as an early prognostic factor (postoperative day 2) after liver transplantation.

METHODS

A retrospective review of all consecutive adult patients who underwent first orthotopic whole-graft liver transplant at our institution between March 2002 and June 2011 was undertaken. Primary endpoint was graft failure within 90 days after transplantation.

RESULTS

Of all 105 patients analyzed in this study, 39 (37.1 %) were female and 66 (62.9 %) were male. Mean age was 52.7 ± 11.7 years, and median follow-up period was 2474 ± 164 days. There were overall 33 (31.4 %) deaths, 13 of those occurring on the first 90 post-transplant days. Multivariate analysis demonstrated that serum factor V lower than 41.5 % and female gender had a negative impact not only on allograft failure/death within 90 days after transplantation (RR = 5.30, CI = 1.40-20.2, p = 0.015 and RR = 5.23, CI = 1.53-21.33, p = 0.008) but also on overall mortality. For prediction of allograft failure/death occurring during the first 3 months, serum factor V level of 41.5 % or lower exhibited a specificity of 87.9 %, a sensitivity of 42.9 %, an accuracy of 81.9 %, a positive predictive value of 35.3 %, and a negative predictive value of 90.9 %.

CONCLUSIONS

Assessment of serum factor V levels on postoperative day 2 might be a promising prognostic tool for early prediction of inferior outcomes after liver transplantation.

Risk factors for early repeat ERCP in liver transplantation patients with anastomotic biliary stricture

INTRODUCTION

Anastomotic biliary strictures (ABS) are a significant clinical problem associated with decreased survival post-liver transplantation (LT). Contributing to the morbidity of ABS is the need for early (i.e. emergent or unplanned) repeat endoscopic retrograde cholangiopancreatographies (ER-ERCPs). Our aim was to determine clinical, operative, and endoscopic predictors of ER-ERCP in patients with ABS.

MATERIAL AND METHODS

Medical records of 559 patients who underwent LT at our institution from 2000-2012 were retrospectively reviewed for pertinent data. The primary endpoint was need for ER-ERCP. Seventeen potential predictors of ER-ERCP were assessed in bivariate analyses, and those with p < 0.20 were included in multivariate regression models.

RESULTS

Fifty-four LT patients developed ABS and underwent a total of 200 ERCPs, of which 40 met criteria for ER-ERCP. Predictors of ER-ERCP in bivariate analyses included balloon dilation within 3 months post-LT and donation after cardiac death (both p < 0.05). Balloon dilation within 3 months post-LT was also associated with shorter ER-ERCP-free survival (p = 0.02). Moreover, a significantly higher proportion (67%) of patients who underwent balloon dilation within 3 months post-LT subsequent experienced ≥ 1 ER-ERCP (p = 0.03), and those who experienced ≥ 1 ER-ERCP had lower stricture resolution rates at the end of endoscopic therapy compared to those who did not (79 vs. 97%, p = 0.02). In multivariate analyses, balloon dilation within 3 months post-LT was the strongest predictor of ER-ERCP (OR 3.8, 95% CI 1.7-8.6, p = 0.001).

CONCLUSIONS

Balloon dilation of ABS within 3 months post-LT is associated with an increased risk of ER-ERCP, which itself is associated with lower ABS resolution rates. Prospective studies are needed to confirm these findings and their implications for endoscopic management and follow-up of post-LT ABS.

The predictors for continuous renal replacement therapy in liver transplant recipients

BACKGROUND

Acute renal failure (ARF) after liver transplantation requiring continuous renal replacement therapy (CRRT) adversely affects patient survival. We suggested that postoperative renal failure can be predicted if a clinically simple nomogram can be developed, thus selecting potential risk factors for preventive strategy.

METHODS

We retrospectively reviewed the medical records of 153 liver transplant recipients from January 2008 to December 2011 at Severance Hospital, Yonsei University Health System, in Seoul, Korea. There were 42 patients treated with CRRT (20 and 22 patients received transplants from living and deceased donors, respectively) and 115 were not. Univariate and stepwise logistic multivariate analyses were performed. A clinical nomogram to predict postoperative CRRT application was constructed and validated internally.

RESULTS

Hepatic encephalopathy (HEP; odds ratio OR, 5.47), deceased donor liver donations (OR, 3.47), Model for End-Stage Liver Disease (MELD) score (OR, 1.09), intraoperative blood loss (L; OR, 1.16), and tumor (hepatocellular carcinoma) as the indication for liver transplantation (OR, 0.11) were identified as independent predictive factors for postoperative CRRT on multivariate analysis. A clinical prediction model constructed for calculating the probability of CRRT post-transplantation was 1.7000 × HEP + [-4.5427 + 1.2440 × (deceased donor) + 0.0830 × (MELD score) + 0.000149 × the amount of intraoperative bleeding (L) - 2.1785 × tumor]. The validation set discriminated well with an area under the curve (AUC) of 0.90 (95% confidence interval, 0.85-0.95). The predicted and the actual probabilities were calibrated with the clinical nomogram.

CONCLUSIONS

We developed a predictive model of postoperative CRRT in liver transplantation patients. Perioperative strategies to modify these factors are needed.

A score model for the continuous grading of early allograft dysfunction severity

Early allograft dysfunction (EAD) dramatically influences graft and patient outcomes. A lack of consensus on an EAD definition hinders comparisons of liver transplant outcomes and management of recipients among and within centers. We sought to develop a model for the quantitative assessment of early allograft function [Model for Early Allograft Function Scoring (MEAF)] after transplantation. A retrospective study including 1026 consecutive liver transplants was performed for MEAF score development. Multivariate data analysis was used to select a small number of postoperative variables that adequately describe EAD. Then, the distribution of these variables was mathematically modeled to assign a score for each actual variable value. A model, based on easily obtainable clinical parameters (ie, alanine aminotransferase, international normalized ratio, and bilirubin) and scoring liver function from 0 to 10, was built. The MEAF score showed a significant association with patient and graft survival at 3-, 6- and 12-month follow-ups. Hepatic steatosis and age for donors; cold/warm ischemia times and postreperfusion syndrome for surgery; and intensive care unit and hospital stays, Model for End-Stage Liver Disease and Child-Pugh scores, body mass index, and fresh frozen plasma transfusions for recipients were factors associated significantly with EAD. The model was satisfactorily validated by its application to an independent set of 200 patients who underwent liver transplantation at a different center. In conclusion, a model for the quantitative assessment of EAD severity has been developed and validated for the first time. The MEAF provides a more accurate graft function assessment than current categorical classifications and may help clinicians to make early enough decisions on retransplantation benefits. Furthermore, the MEAF score is a predictor of recipient and graft survival. The standardization of the criteria used to define EAD may allow reliable comparisons of recipients' treatments and transplant outcomes among and within centers.

Association between anesthesiologist experience and mortality after orthotopic liver transplantation

The anesthesiologist has been recognized as an integral member of the liver transplant team, and previous studies have demonstrated that inter-anesthesiologist variability can be a driver of outcomes for high-risk patients. We hypothesized that anesthesiologist experience, defined as the number of previous liver transplants performed at our institution, the Icahn School of Medicine at Mount Sinai, would be independently associated with outcomes for liver transplant patients. Eight hundred forty-nine liver transplants performed between January 2003 and January 2013 with a total of 22 anesthesiologists were analyzed. Each transplant was assigned an incremental case number that corresponded to the number of transplants that the attending anesthesiologist had already performed at our institution. Several perioperative covariates were controlled for in the context of a generalized linear mixed effects model to detail the influence of threshold levels of the incremental case number on the primary outcome, 30-day mortality, and a secondary outcome, 30-day graft failure. Sensitivity analyses were conducted to confirm the robustness of these findings. An incremental case number ≤ 5 was associated with a significantly greater risk of 30-day mortality (odds ratio = 2.24, 95% confidence interval = 1.11-4.54, P = 0.025), and there was evidence suggestive of a greater risk of 30-day graft failure (odds ratio = 1.93, 95% confidence interval = 0.95-3.93, P = 0.071). Sensitivity analyses ruled out threats to the validity of these findings, including dropout effects and time trends in the overall performance of the transplantation unit. In conclusion, this study shows that an anesthesiologist's level of experience has a significant effect on outcomes for liver transplant recipients, with increased mortality and possibly graft failure during a provider's first 5 cases. These findings may indicate the need for increased training and supervision for anesthesiologists joining the liver transplant team.

Liver transplantation for acute liver failure: are there thresholds not to be crossed?

Factors predicting survival after liver transplantation (LT) for irreversible acute liver failure (ALF) are rare. The aim of this study was to identify prognostic preoperative factors of patients with ALF that predict mortality after LT to avoid futile transplantation. From chart review, we identified 57 patients receiving transplants for ALF from 12/2000 to 09/2010. Recipient and donor data were analyzed and correlated with in-hospital mortality and patient survival by univariable/multivariable logistic regression and Cox proportional hazards. The survival rates at 30 days and 12 months were 77.2% and 64.9%, respectively. The in-hospital mortality rate was 29.8%. Follow-up of patients discharged from the hospital alive showed 30-day and 12-month survivals of 100% and 92.5%, respectively. Multivariable analysis of factors known preoperatively showed that the lowest pH of the recipient before LT (P = 0.03) was independently associated with in-hospital mortality, and the recipient's BMI (P = 0.03) and the lowest pH before LT (P = 0.03) were independently associated with patient survival. A pH of 7.26 was the calculated cutoff (ROC) for increased in-hospital mortality. Donor factors did not affect patient survival. Patients with ALF and a pH ≤ 7.26 have the worst outcome after liver transplantation. Therefore, emergency liver transplantation should be critically discussed for each individual.

Donor PNPLA3 rs738409 genotype affects fibrosis progression in liver transplantation for hepatitis C

The rs738409 G>C single nucleotide polymorphism occurring in the patatin-like phospholipase 3 gene has been identified as a novel genetic marker for hepatic steatosis. Recent studies also associated rs738409 with fibrosis in hepatitis C (HCV). Therefore, we sought to determine the impact of donor and recipient rs738409 genotype on the progression of fibrosis after liver transplantation for HCV. This cohort study included 101 patients infected with HCV who underwent liver transplantation between January 2008, and June 2011. Donor and recipient rs738409 genotypes were determined from donor wedge biopsies and recipient explants. The time to Ishak stage 3 fibrosis, or HCV-related mortality/graft loss was analyzed by the Cox model adjusting for HCV-Donor Risk Index, warm ischemic time, pretransplant Model for Endstage Liver Disease (MELD) and viral load. The rs738409 CC variant was present in 56% of donors and 57% of recipients. The median follow-up period was 620 days. A total of 39 patients developed the primary outcome of ≥stage 3 fibrosis or HCV-related mortality/graft loss, the time to which differed by donor (P = 0.019) but not recipient (P = 0.89) genotype. In the multivariate model, donor GC or GG variants had 2.53 times the risk (95% confidence interval [CI] 1.25-5.02, P = 0.008) compared to CC variants. In the alternative endpoint: stage 3 fibrosis or all-cause mortality/graft loss, the effect of donor genotype was attenuated but remained significant at 1.98 (95% CI 1.11-3.53).

CONCLUSIONS

The rs738409 genotype is an important predictor of posttransplant outcome in HCV. Liver, and not adipocytes, is the site at which this effect occurs. Our finding may be useful in donor selection for liver transplantation with HCV, and may guide decisions regarding early antiviral treatment.

Postoperative care/critical care of the transplant patient

Critical care of the general surgical patient requires synthesis of the patient's physiology, intraoperative events, and preexisting comorbidities. Evaluating an abdominal solid-organ transplant recipient after surgery adds a new dimension to clinical decisions because the transplanted allograft has undergone its own physiologic challenges and now must adapt to a new environment. This donor-recipient interaction forms the foundation for assessment of early allograft function (EAF). The intensivist must accurately assess and support EAF within the context of the recipient's current physiology and preexisting comorbidities. Optimizing EAF is essential because allograft failure is a significant predictor of recipient morbidity and mortality.