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

Deep Learning-Adjusted Monitoring of In-Hospital Mortality after Liver Transplantation

Background: Surgeries represent a mainstay of medical care globally. Patterns of complications are frequently recognized late and place a considerable burden on health care systems. The aim was to develop and test the first deep learning-adjusted CUSUM program (DL-CUSUM) to predict and monitor in-hospital mortality in real time after liver transplantation. Methods: Data from 1066 individuals with 66,092 preoperatively available data point variables from 2004 to 2019 were included. DL-CUSUM is an application to predict in-hospital mortality. The area under the curve for risk adjustment with Model of End-stage Liver Disease (D-MELD), Balance of Risk (BAR) score, and deep learning (DL), as well as the ARL (average run length) and control limit (CL) for an in-control process over 5 years, were calculated. Results: D-MELD AUC was 0.618, BAR AUC was 0.648 and DL model AUC was 0.857. CL with BAR adjustment was 2.3 with an ARL of 326.31. D-MELD reached an ARL of 303.29 with a CL of 2.4. DL prediction resulted in a CL of 1.8 to reach an ARL of 332.67. Conclusions: This work introduces the first use of an automated DL-CUSUM system to monitor postoperative in-hospital mortality after liver transplantation. It allows for the real-time risk-adjusted monitoring of process quality.

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.

L-GrAFT7 has High Accuracy in Predicting Early Allograft Failure after Liver Transplantation: A Multicenter Cohort Study in China

Background and Aims

Increasing utilization of extended criteria donor leads to an increasing rate of early allograft failure after liver transplantation. However, consensus of definition of early allograft failure is lacking.

Methods

A retrospective, multicenter study was performed to validate the Liver Graft Assessment Following Transplantation (L-GrAFT) risk model in a Chinese cohort of 942 adult patients undergoing primary liver transplantation at three Chinese centers. L-GrAFT (L-GrAFT7 and L-GrAFT10) was compared with existing models: the Early Allograft Failure Simplified Estimation (EASE) score, the model of early allograft function (MEAF), and the Early Allograft Dysfunction (EAD) model. Univariate and multivariate logistic regression were used to find risk factors of L-GrAFT high-risk group.

Results

L-GrAFT7 had an area under the curve of 0.85 in predicting 90-day graft survival, significantly superior to MEAF [area under the curve (AUC=0.78, p=0.044)] and EAD (AUC=0.78, p=0.006), while there was no statistical significance between the predicting abilities of L-GrAFT7 and EASE (AUC=0.84, p>0.05). Furthermore, L-GrAFT7 maintains good predicting ability in the subgroup of high-donor risk index (DRI) cases (AUC=0.83 vs. MEAF, p=0.007 vs. EAD, p=0.014) and recipients of donors after cardiac death (AUC=0.92 vs. EAD, p<0.001). Through multivariate analysis, pretransplant bilirubin level, units of packed red blood cells, and the DRI score were selected as independent risk factors of a L-GrAFT7 high-risk group.

Conclusions

The accuracy of L-GrAFT7 in predicting early allograft failure was validated in a Chinese multicenter cohort, indicating that it has the potential to become an accurate endpoint of clinical practice and transitional study of machine perfusion.

Indocyanine green clearance tests to assess liver transplantation outcomes: a systematic review

BACKGROUND

Liver transplantation (LT) is the gold standard for end-stage liver disease, yet postoperative complications challenge patients and physicians. Indocyanine green (ICG) clearance, a quantitative dynamic test of liver function, is a rapid, reproducible, and reliable test of liver function. This study aimed to systematically review and summarize current literature analyzing the association between ICG tests and post-LT outcomes.

METHODS

This systematic review was conducted according to PRISMA guidelines. MEDLINE and Cochrane Library, as main databases, and other sources were searched until August 2022 to identify articles reporting the prognostic value of postoperative ICG tests associated with outcomes of adult LT recipients.Risk of bias of included articles was assessed using Quality In Prognosis Studies tool. Methodological quality varied from low to high across risk of bias domains.

RESULTS

Six studies conducted between 1994 and 2018 in Europe, America, and Asia were included. The study population ranged from 50 to 332 participants. ICG clearance on the first postoperative day was associated with early allograft dysfunction, graft loss, 1-month and 3-month patient survival probability, prolonged ICU, and hospital stay. The dichotomized ICG plasma disappearance rate (PDR) provided a strong association with medium-term and long-term outcomes: PDR less than 10%/min with 1-month mortality or re-transplantation (odds ratio: 7.89, 95% CI 3.59-17.34, P <0.001) and PDR less than 16.0%/min with 3-month patient survival probability (hazard ratio: 13.90, 95% CI 4.67-41.35, P <0.01). The preoperative model for end-stage liver disease and body mass index were independent prognostic factors for early allograft dysfunction, early complications, and prolonged ICU stay; post-LT prothrombin time and INR were independently associated with graft loss and bilirubin with a prolonged hospital stay.

CONCLUSION

This review shows that ICG clearance tests are associated with graft function recovery, suggesting that a potential prognostic role of ICG test, as an aid in predicting the post-LT course, could be considered.

Early predictors of prolonged intensive care utilization following liver transplantation

INTRODUCTION

Creatinine, bilirubin, and fibrinolysis resistance are associated with multi-organ dysfunction and likely risk factors for prolonged intensive care unit (pICU) stay following liver transplantation (LT). We hypothesize postoperative day-1 (POD-1) labs will predict pICU.

METHODS

LT recipients had clinical laboratories and viscoelastic testing with tissue plasminogen activator thrombelastography (tPA TEG) to quantify fibrinolysis resistance (LY30) on POD-1. pICU was defined as one week or longer in the ICU. Logistic regression was used to identify the relationship between POD-1 labs and pICU.

RESULTS

Of 304 patients, 50% went to the ICU, with 15% experiencing pICU. Elevated creatinine (OR 6.6, P ​< ​0.001) and low tPA TEG LY30 (OR 3.7, P ​= ​0.004) were independent predictors of pICU after controlling for other risk factors. A 9-fold increase in the rate of 90-day graft loss (19% vs 2% p ​< ​0.001) was observed patients who had these risk factors for pICU.

CONCLUSION

Elevated creatine and fibrinolysis resistance are associated with pICU and poor outcomes following LT.

Ventilator support in the pretransplant period predisposes early graft failure after deceased donor liver transplantation

Purpose

Deceased donor liver transplantation (DDLT) recipients in Korea are generally sicker due to an increasing organ shortage. In the present study, the risk factors for early 30-day liver graft failure after DDLT were identified.

Methods

From August 2017 to February 2021, 265 adult DDLTs were performed. The characteristics of patients with and without 30-day graft failure were compared.

Results

Liver graft failure occurred in 11 patients (17.7%) after DDLT. Baseline and perioperative characteristics of donors and recipients were not statistically significantly different between the 2 groups. The cumulative graft and overall survival rates at 6 months were 83.9% and 88.7%, respectively. Multivariate analysis showed ventilator support in the pretransplant period was a predisposing factor for 30-day graft failure after DDLT.

Conclusion

Present study indicates that cautious decision is required when allocating DDLT in critically ill patients on mechanical ventilatory support.

Evaluation of the Trend of Biochemical Functions in the Early Period After Cadaveric Liver Transplantation

BACKGROUND

Monitoring biochemical parameters to detect early complications after liver transplantation (LT) is important. Thus, we aimed to investigate parameter trends indicating liver function in patients who did not develop complications after cadaveric LT.

METHODS

A total of 266 cadaveric LT operations performed by a single center between 2007-2022 were included in the study. Patients with any early complications were excluded from the study. During the first 15 days, the parameters reflecting the patients' liver integrity and synthesis functions were evaluated. All parameters studied were evaluated at the same time of day and by a single laboratory.

RESULTS

Regarding synthesis functions, the coagulation parameters (prothrombin time and international normalized ratio) peaked on the first day and then decreased. Regarding tissue hypoxia, there was no significant change in lactate values. Total and direct bilirubin values also decreased after peaking on the first day. No significant change was observed in albumin, another liver synthesis value.

CONCLUSIONS

Although an increase in aspartate aminotransferase, alanine aminotransferase, total and direct bilirubin, prothrombin time, and international normalized ratio, which was especially seen on the first day, is considered normal, values that do not decrease after the second day or lactate values that increase gradually should be a warning in terms of possible early complications.

Machine Learning Model Validated to Predict Outcomes of Liver Transplantation Recipients with Hepatitis C: The Romanian National Transplant Agency Cohort Experience

BACKGROUND AND OBJECTIVES

In the early period after liver transplantation, patients are exposed to a high rate of complications and several scores are currently available to predict adverse postoperative outcomes. However, an ideal, universally accepted and validated score to predict adverse events in liver transplant recipients with hepatitis C is lacking. Therefore, we aimed to establish and validate a machine learning (ML) model to predict short-term outcomes of hepatitis C patients who underwent liver transplantation.

MATERIALS AND METHODS

We conducted a retrospective observational two-center cohort study involving hepatitis C patients who underwent liver transplantation. Based on clinical and laboratory parameters, the dataset was used to train a deep-learning model for predicting short-term postoperative complications (within one month following liver transplantation). Adverse events prediction in the postoperative setting was the primary study outcome.

RESULTS

A total of 90 liver transplant recipients with hepatitis C were enrolled in the present study, 80 patients in the training cohort and ten in the validation cohort, respectively. The age range of the participants was 12-68 years, 51 (56,7%) were male, and 39 (43.3%) were female. Throughout the 85 training epochs, the model achieved a very good performance, with the accuracy ranging between 99.76% and 100%. After testing the model on the validation set, the deep-learning classifier confirmed the performance in predicting postoperative complications, achieving an accuracy of 100% on unseen data.

CONCLUSIONS

We successfully developed a ML model to predict postoperative complications following liver transplantation in hepatitis C patients. The model demonstrated an excellent performance for accurate adverse event prediction. Consequently, the present study constitutes the foundation for careful and non-invasive identification of high-risk patients who might benefit from a more intensive postoperative monitoring strategy.

Arterial Lactate Concentration at the End of Liver Transplantation is Independently Associated With One-Year Mortality

BACKGROUND

Liver transplant patients who develop hyperlactatemia are at increased risk of postoperative morbidity and short-term mortality, but there are few data on longer-term outcomes. We therefore investigated if arterial lactate concentration obtained immediately after surgery, at the time of admission to the intensive care unit (ICU), was associated with 1-year mortality.

METHODS

In this retrospective cohort study, all patients who underwent liver transplant surgery from a deceased donor between September 2013 and December 2019 were screened for inclusion. Patients who underwent combined transplantation surgery and those with a history of previous liver transplantation (ie, redo surgery) were not included. Logistic regression modeling included univariate and multivariate analyses. Receiver operating characteristic curves and areas under the curves were calculated. Lactate thresholds and association with outcome were analyzed for specificity, sensitivity, and Youden's index.

RESULTS

Of 226 patients included, 18.4% died within 1 year of liver transplantation. Immediate postoperative lactate concentration was independently associated with 1-year mortality with an adjusted odds ratio of 1.35 (95% CI 1.16-1.59; P < .001) per mmol/L increase in lactate and an area under the curve of 0.80 (95% CI 0.72-0.87; P < .001). A lactate concentration of 2.25 mmol/L (cutoff determined using Youden's index) was associated with increased 1-year mortality with a sensitivity of 0.71 and a specificity of 0.72.

CONCLUSIONS

Increased arterial lactate concentration on admission to the intensive care unit immediately after orthotopic liver transplantation is independently associated with increased 1-year mortality.

Is a Preservation Solution for Living Donor Liver Transplantation Needed? Adding a New Chapter in LDLT!

Preservation solutions are required for organ viability in deceased donor liver transplantation (LT). However, their role in live donor LT (LDLT) has not been standardized.

METHODS

Eighty adult recipients who underwent right lobe LDLT at the Department of Liver Transplantation Surgery, Gambat, Pakistan, were studied. Based on shorter cold ischemia time and no back table reconstruction work, recipients were assigned to receive "no preservation solution" (cases/non-histidine-tryptophan-ketoglutarate group; n = 40) or "HTK group" (controls; n = 40). Early allograft dysfunction (bilirubin, transaminases, and international normalized ratio), postoperative complications (biliary and vascular), hospital stay, and 1-y survival were reported. The direct cost was also reported.

RESULTS

Demographics and clinical characteristics were comparable in the 2 groups. Comparing cases versus controls, mean bilirubin, alanine aminotransferase, aspartate aminotransferase, and international normalized ratio on postoperative day 7 were similar in the 2 groups. Five (12.5%) cases and 4 (10%) controls developed early allograft dysfunction (P = 0.72). Post-LT complications (biliary leak 2.5% in cases versus 0 in control), strictures (15% in cases versus 17.5% in controls), hepatic artery thrombosis (2.5% versus 00%)' and portal vein thrombosis (0 versus 2.5%) were comparable. Mean hospital stay (10.80 + 2.36 and 11.78 + 2.91 d) and 30 d mortality (2.5% versus 5%) were also comparable. Finally, 1-y survival based on Kaplan-Meier analysis was comparable in both groups (ie, 92.5%; non-HTK group versus 90%; HTK group) (P = 0.71). The direct cost of using a non-HTK-based approach was less than the HTK solution.

CONCLUSION

In a selected cohort of right lobe LDLT recipients, preservation solutions can be avoided safely with comparable outcomes.

Decoding Single-cell Landscape and Intercellular Crosstalk in the Transplanted Liver

BACKGROUND

Liver transplantation (LT) is the most effective treatment for various end-stage liver diseases. However, the cellular complexity and intercellular crosstalk of the transplanted liver have constrained analyses of graft reconstruction after LT.

METHODS

We established an immune-tolerated orthotopic LT mouse model to understand the physiological process of graft recovery and intercellular crosstalk. We employed single-cell RNA sequencing and cytometry by time-of-flight to comprehensively reveal the cellular landscape.

RESULTS

We identified an acute and stable phase during perioperative graft recovery. Using single-cell technology, we made detailed annotations of the cellular landscape of the transplanted liver and determined dynamic modifications of these cells during LT. We found that 96% of graft-derived immune cells were replaced by recipient-derived cells from the preoperative to the stable phase. However, CD206 + MerTK + macrophages and CD49a + CD49b - natural killer cells were composed of both graft and recipient sources even in the stable phase. Intriguingly, the transcriptional profiles of these populations exhibited tissue-resident characteristics, suggesting that recipient-derived macrophages and natural killer cells have the potential to differentiate into 'tissue-resident cells' after LT. Furthermore, we described the transcriptional characteristics of these populations and implicated their role in regulating the metabolic and immune remodeling of the transplanted liver.

CONCLUSIONS

In summary, this study delineated a cell atlas (type-proportion-source-time) of the transplanted liver and shed light on the physiological process of graft reconstruction and graft-recipient crosstalk.

Integrative analysis of circulating microRNAs and the placental transcriptome in recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a major type of pathological pregnancy that still lacks reliable early diagnosis and effective treatment. The placenta is critical to fetal development and pregnancy success because it participates in critical processes such as early embryo implantation, vascular remodeling, and immunological tolerance. RPL is associated with abnormalities in the biological behavior of placental villous trophoblasts, resulting in aberrant placental function. MicroRNAs (miRNAs) are increasingly being recognized as essential regulators of placental development, as well as potential biomarkers. In this study, plasma miRNAs and placental messenger RNAs (mRNAs) from RPL patients and normal pregnant (NP) controls were sequenced and analyzed. Compared to those in NP controls, 108 circulating miRNAs and 1199 placental mRNAs were differentially expressed in RPL samples. A total of 140 overlapping genes (overlapping between plasma miRNA target genes and actual placental disorder genes) were identified, and functional enrichment analysis showed that these genes were mainly related to cell proliferation, angiogenesis, and cell migration. The regulatory network among miRNAs, overlapping genes, and downstream biological processes was analyzed by protein–protein interactions and Cytoscape. Moreover, enriched mRNAs, which were predictive targets of the differentially expressed plasma miRNAs miR-766-5p, miR-1285-3p, and miR-520a-3p, were accordingly altered in the placenta. These results suggest that circulating miRNAs may be involved in the pathogenesis of RPL and are potential noninvasive biomarkers for RPL.

Assessing the discriminative ability of the respiratory exchange ratio to detect hyperlactatemia during intermediate-to-high risk abdominal surgery

BACKGROUND

A mismatch between oxygen delivery (DO₂) and consumption (VO₂) is associated with increased perioperative morbidity and mortality. Hyperlactatemia is often used as an early screening tool, but this non-continuous measurement requires intermittent arterial line sampling. Having a non-invasive tool to rapidly detect inadequate DO₂ is of great clinical relevance. The respiratory exchange ratio (RER) can be easily measured in all intubated patients and has been shown to predict postoperative complications. We therefore aimed to assess the discriminative ability of the RER to detect an inadequate DO₂ as reflected by hyperlactatemia in patients having intermediate-to-high risk abdominal surgery.

METHODS

This historical cohort study included all consecutive patients who underwent intermediate-to-high risk surgery from January 1st, 2014, to April 30th, 2019 except those who did not have RER and/or arterial lactate measured. Blood lactate levels were measured routinely at the beginning and end of surgery and RER was calculated at the same moment as the blood gas sampling. The present study tested the hypothesis that RER measured at the end of surgery could detect hyperlactatemia at that time. A receiver operating characteristic (ROC) curve was constructed to assess if RER calculated at the end of the surgery could detect hyperlactatemia. The chosen RER threshold corresponded to the highest value of the sum of the specificity and the sensitivity (Youden Index).

RESULTS

Among the 996 patients available in our study cohort, 941 were included and analyzed. The area under the ROC curve was 0.73 (95% CI: 0.70 to 0.76; p < 0.001), with a RER threshold of 0.75, allowing to discriminate a lactate > 1.5 mmol/L with a sensitivity of 87.5% and a specificity of 49.5%.

CONCLUSION

In mechanically ventilated patients undergoing intermediate to high-risk abdominal surgery, the RER had moderate discriminative abilities to detect hyperlactatemia. Increased values should prompt clinicians to investigate for the presence of hyperlactatemia and treat any potential causes of DO₂/VO₂ mismatch as suggested by the subsequent presence of hyperlactatemia.

Noninvasive imaging of hepatic dysfunction: A state-of-the-art review

Hepatic dysfunction represents a wide spectrum of pathological changes, which can be frequently found in hepatitis, cholestasis, metabolic diseases, and focal liver lesions. As hepatic dysfunction is often clinically silent until advanced stages, there remains an unmet need to identify affected patients at early stages to enable individualized intervention which can improve prognosis. Passive liver function tests include biochemical parameters and clinical grading systems (e.g., the Child-Pugh score and Model for End-Stage Liver Disease score). Despite widely used and readily available, these approaches provide indirect and limited information regarding hepatic function. Dynamic quantitative tests of liver function are based on clearance capacity tests such as the indocyanine green (ICG) clearance test. However, controversial results have been reported for the ICG clearance test in relation with clinical outcome and the accuracy is easily affected by various factors. Imaging techniques, including ultrasound, computed tomography, and magnetic resonance imaging, allow morphological and functional assessment of the entire hepatobiliary system, hence demonstrating great potential in evaluating hepatic dysfunction noninvasively. In this article, we provide a state-of-the-art summary of noninvasive imaging modalities for hepatic dysfunction assessment along the pathophysiological track, with special emphasis on the imaging modality comparison and selection for each clinical scenario.

Postreperfusion Liver Biopsy as Predictor of Early Graft Dysfunction and Survival After Orthotopic Liver Transplantation

BACKGROUND

Postreperfusion liver biopsy (PRB) can assess the degree of ischemia/reperfusion injury (IRI) after orthotopic liver transplantation (OLT). The influence of IRI on graft outcomes and overall survival is controversial.

AIM

To determine the correlation between the severity of IRI in PRB and overall graft and patient survival and, secondarily, to identify factors on PRB that predict poor graft outcomes.

METHODS

This is a retrospective analysis of all patients who underwent OLT using donation after brain death (DBD) with PRB. The severity of IRI in PRB was graded. Predictors of IRI were assessed using univariate and multivariate analysis and the Kaplan-Meier with log rank test for the graft and overall survival, respectively.

RESULTS

We included 280 OLTs (64.7%). The histopathological assessment of IRI severity was as follows: no IRI (N = 96, 34.3%), mild IRI (N = 65; 23.2%), moderate IRI (N = 101; 36.1%), and severe IRI (N = 18; 6.4%). The incidence rates of initial good graft function (IGGF), primary nonfunction and early allograft dysfunction (EAD) were 32.5%, 3.9%, and 18.6%, respectively. Severe IRI was associated with a lower incidence of IGGF (OR: 0.34, 95% CI 0.12-0.92; P = 0.03). Patients with severe IRI tended to have a higher incidence of EAD (33.2% vs. 18.6, P = 0.23). The cold ischemia time was an independent predictor of severe IRI on the multivariate analysis. Severe IRI was associated with poor 1- and 5-year overall survival rates (67% and 44%, respectively, compared with 84 and 68% in nonsevere IRI). Patients with severe IRI exhibited worse graft and overall survival.

CONCLUSIONS

Cold ischemia time predicts the development of severe IRI. Patients with severe IRI show worse graft and overall survival and a lower incidence of IGGF, suggesting that histopathological findings could be useful for identifying patients at high risk of worse outcomes after OLT.

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.

Early postoperative mortality in liver transplant recipients involving indications other than hepatocellular carcinoma. A retrospective cohort study

AIMS

To analyze the perioperative differences in a consecutive cohort of liver transplant recipients (LTRs) classified according to the indication of transplantation, and assess their impact upon early mortality 90 days after transplantation.

DESIGN

A retrospective cohort study was carried out.

SCOPE

A single university hospital.

PATIENTS

A total of 892 consecutive adult LTRs were included from January 1995 to December 2017. Recipients with acute liver failure, retransplantation or with grafts from non-brain death donors were excluded. Two cohorts were analyzed according to transplant indication: hepatocellular carcinoma (HCC-LTR) versus non-carcinoma (non-HCC-LTR).

MAIN VARIABLES OF INTEREST

Recipient early mortality was the primary endpoint. The pretransplant recipient and donor characteristics, surgical time data and postoperative complications were analyzed as independent predictors.

RESULTS

The crude early postoperative mortality rate related to transplant indication was 13.3% in non-HCC-LTR and 6.6% in HCC-LTR (non-adjusted HR=2.12, 95%CI=1.25-3.60; p=0.005). Comparison of the perioperative features between the cohorts revealed multiple differences. Multivariate analysis showed postoperative shock (HR=2.02, 95%CI=1.26-3.24; p=0.003), early graft vascular complications (HR=4.01, 95%CI=2.45-6.56; p<0.001) and multiorgan dysfunction syndrome (HR=18.09, 95%CI=10.70-30.58; p<0.001) to be independent predictors of mortality. There were no differences in early mortality related to transplant indication (adjusted HR=1.60, 95%CI=0.93-2.76; p=0.086).

CONCLUSIONS

The crude early postoperative mortality rate in non-HCC-LTR was higher than in HCC-LTR, due to a greater incidence of postoperative complications with an impact upon mortality (shock at admission to intensive care and the development of multiorgan dysfunction syndrome).

Complications and safety of the transplanted organ after upper extremity surgery in patients receiving immunosuppressant therapy after solid organ transplantation

PURPOSE

The purpose of this study was to evaluate the complications and safety of transplanted organs after upper extremity surgery in patients taking immunosuppressants after solid organ transplantation (SOT).

METHODS

Seventy-two transplant recipients underwent 99 upper extremity surgeries while on immunosuppressants after SOT at our institution between January 2009 and December 2018. We retrospectively reviewed the clinical data of these patients, including their demographic information and data related to the SOT and upper extremity surgery.

RESULTS

Trigger/tendon release (n = 31, 31.3%) was the most frequently performed upper extremity surgery, followed by incision and drainage for an infection (n = 16, 16.2%). Post-operative complications occurred after ten upper extremity operative procedures (10.1%), among which uncontrolled infection after surgery for an infection (n = 4) was the most common. According to the Clavien-Dindo classification, the complications of three surgical procedures were grade I, three were grade II, and four were grade III, and all were treatable. The occurrence rate of the complications was not significantly different between emergent and elective surgery. All transplanted organ-specific indicators did not worsen significantly after emergent or elective upper extremity surgery.

CONCLUSIONS

Since the function of the transplanted organ was well-preserved after emergent or elective upper extremity surgery, common upper extremity procedures do not seem to be a worrisome practice for SOT patients. However, when treating hand and upper extremity infections in SOT patients, surgeons should explain the possible need for multiple operations  and the high complication rate.

Intraoperative Factors Associated With Early Recipient Death After Adult-to-Adult Living Donor Liver Transplant

OBJECTIVES

Living donor liver transplant is the gold standard therapy for patients with terminal hepatic disorders for whom no alternative therapy is available. The primary aim was to assess different intraoperative factors that may predict early death after adult-to-adult living donor liver transplant. The secondary aim was to assess the effect of small-for-size syndrome on mortality.

MATERIALS AND METHODS

This retrospective multicenter cohort study was performed on records from 145 adults with cirrhosis who had received a right lobe living donor liver transplant. Patients were divided according to the occurrence of short-term mortality (death within the first month after transplant). The primary intraoperative parameters included graft weight, surgical duration, mean blood pressure, serum lactate and sodium bicarbonate, transfusions, durations of cold and warm ischemia and anhepatic phase, input and output during surgery, and portal venous pressures.

RESULTS

There were statistically significant variations between both cohorts for number of units of packed red blood cells, durations of cold and warm ischemia and anhepatic phase, preclamp and postreperfusion portal venous pressures, average urine output, mean serum lactate, mean blood pressure, and surgical duration (P ⟨ .001). Also, there were significant differences in the number of platelets, units of fresh frozen plasma, and mean sodium bicarbonate (P = .025, .003, and .035, respectively). Of the 25 patients who died within the early postoperative period, 20 had developed small-for-size syndrome (P ⟨ .001).

CONCLUSIONS

A variety of intraoperative risk factors may affect early posttransplant mortality, which suggests the high complexity of living donor liver transplants and the need for well-trained experienced teams to perform these surgeries.

An evaluation of the safety and preliminary efficacy of peri- and post-operative treprostinil in preventing ischemia and reperfusion injury in adult orthotopic liver transplant recipients

Background

Orthotopic liver transplantation (OLT) is the only treatment option for various end‐stage liver diseases. Ischemia and reperfusion (I/R) injury is one of the unavoidable complications/conditions in OLT. In 2019, a total of 8896 livers were transplanted of which >94% organs were procured from deceased donors. An increase in the use of extended criteria donor (ECD) livers for transplantation further unraveled the role of hepatic I/R injury on short‐term and long‐term graft outcomes. Despite promising outcomes with the use of antioxidants, free radical scavengers, and vasodilators; I/R‐mediated liver injury persists and significantly influences the overall clinical outcomes. Treprostinil, a synthetic prostacyclin I₂ (PGI₂) analog, due to its vasodilatory property, antiplatelet activity, and its ability to downregulate pro‐inflammatory cytokines can potentially minimize I/R injury.

Aim

We investigated the safety and preliminary efficacy of continuous intravenous infusion of treprostinil in liver transplant recipients in a prospective, single‐center, non‐randomized, interventional study.

Material and methods

This was a dose escalation (3 + 3 design) phase 1/2 study. Deceased donor liver transplant recipients received 5 ng/kg/min for two days, or 2.5, 5, and 7.5 ng/min/kg for 5 days as a continuous infusion. Multiple blood samples were collected for biochemical parameter assessment and for measuring treprostinil levels. Indocyanine green plasma disappearance rate was used as a measure of hepatic functional capacity.

Results

Subjects tolerated continuous infusion of treprostinil up to 5 ng/kg/min for 120 h with no occurrence of primary graft non‐function (PNF), minimized need for ventilation support, reduced hospitalization time, 100% graft and patient survival, and improved hepatobiliary excretory function comparable to normal healthy adults.

Discussion

Treprostinil can be administered to liver transplant patients safely during the perioperative period.

Conclusion

Based on this phase 1/2 study, further efficacy studies of treprostinil in preventing I/R injury of liver should be conducted to potentially increase the number of livers available for transplantation.

Design, Analysis, and Pitfalls of Clinical Trials Using Ex Situ Liver Machine Perfusion: The International Liver Transplantation Society Consensus Guidelines

BACKGROUND

Recent trials in liver machine perfusion (MP) have revealed unique challenges beyond those seen in most clinical studies. Correct trial design and interpretation of data are essential to avoid drawing conclusions that may compromise patient safety and increase costs.

METHODS

The International Liver Transplantation Society, through the Special Interest Group "DCD, Preservation and Machine Perfusion," established a working group to write consensus statements and guidelines on how future clinical trials in liver perfusion should be designed, with particular focus on relevant clinical endpoints and how different techniques of liver perfusion should be compared. Protocols, abstracts, and full published papers of clinical trials using liver MP were reviewed. The use of a simplified Grading of Recommendations Assessment, Development, and Evaluation working group (GRADE) system was attempted to assess the level of evidence. The working group presented its conclusions at the International Liver Transplantation Society consensus conference "DCD, Liver Preservation, and Machine Perfusion" held in Venice, Italy, on January 31, 2020.

RESULTS

Twelve recommendations were proposed with the main conclusions that clinical trials investigating the effect of MP in liver transplantation should (1) make the protocol publicly available before the start of the trial, (2) be adequately powered, and (3) carefully consider timing of randomization in function of the primary outcome.

CONCLUSIONS

There are issues with using accepted primary outcomes of liver transplantation trials in the context of MP trials, and no ideal endpoint could be defined by the working group. The setup of an international registry was considered vital by the working group.

An Italian survey on the use of T-tube in liver transplantation: old habits die hard!

There is enough clinical evidence that a T-tube use in biliary reconstruction at adult liver transplantation (LT) does not significantly modify the risk of biliary stricture/leak, and it may even sustain infective and metabolic complications. Thus, the policy on T-tube use has been globally changing, with progressive application of more restrictive selection criteria. However, there are no currently standardized indications in such change, and many LT Centers rely only on own experience and routine. A nation-wide survey was conducted among all the 20 Italian adult LT Centers to investigate the current policy on T-tube use. It was found that 20% of Centers completely discontinued the T-tube use, while 25% Centers used it routinely in all LT cases. The remaining 55% of Centers applied a selective policy, based on criteria of technical complexity of biliary reconstruction (72.7%), followed by low-quality graft (63.6%) and high-risk recipient (36.4%). A T-tube use > 50% of annual caseload was not associated with high-volume Center status (> 70 LT per year), an active pediatric or living-donor transplant program, or use of DCD grafts. Only 10/20 (50%) Centers identified T-tube as a potential risk factor for complications other than biliary stricture/leak. In these cases, the suspected pathogenic mechanism comprised bacterial colonization (70%), malabsorption (70%), interruption of the entero-hepatic bile-acid cycle (50%), biliary inflammation due to an indwelling catheter (40%) and gut microbiota changes (40%). In conclusion, the prevalence of T-tube use among the Italian LT Centers is still relatively high, compared to the European trend (33%), and the potential detrimental effect of T-tube, beyond biliary stricture/leak, seems to be somehow underestimated.

Predictive value of serum cytokine level in the assessment of complications after liver transplantation

Introduction. One of the urgent tasks in modern transplantology is the search of biomarkers for predicting and early diagnosis of graft dysfunction.Objective. The study objective was to determine the biomarkers of liver graft dysfunction.Material and methods. We have examined 19 recipients who underwent liver transplantation and 36 healthy blood donors. Levels of 7 serum cytokines were measured by multiparametric fluorescence analysis with magnetic microspheres (xMAP technology, Luminex 200, USA). Statistical analysis was carried out by methods of nonparametric statistics. To determine the predictive value of the test, a ROC-analysis was performed.Results and discussion. We found that the interleukin-8 level was 3.6 times higher in recipients with liver graft dysfunction compared to those who had an uneventful postoperative course. The diagnostic sensitivity of the test was 75%, the specificity was 91%, and negative predictive value was 84.6.Conclusion. Serum interleukin-8 measurement provides a biomarker for early predicting a post-transplant liver graft dysfunction development

Impact of Graft Weight Change During Perfusion on Hepatocellular Carcinoma Recurrence After Living Donor Liver Transplantation

BACKGROUNDS

Inadequate liver volume and weight is a major source of morbidity and mortality after adult living donor liver transplantation (LDLT). The purpose of our study was to investigate HCC recurrence, graft failure, and patient survival according to change in right liver graft weight after histidine-tryptophan-ketoglutarate (HTK) solution perfusion in LDLT.

METHODS

Two hundred twenty-eight patients underwent LDLT between 2013 and 2017. We calculated the change in graft weight by subtracting pre-perfusion graft weight from post-perfusion graft weight. Patients with increased graft weight were defined as the positive group, and patients with decreased graft weight were defined as the negative group.

RESULTS

After excluding patients who did not meet study criteria, 148 patients underwent right or extended right hepatectomy. The negative group included 89 patients (60.1%), and the positive group included 59 patients (39.9%). Median graft weight change was -28 g (range; -132-0 g) in the negative group and 21 g (range; 1-63 g) in the positive group (P<0.001). Median hospitalization time was longer for the positive group than the negative group (27 days vs. 23 days; P=0.048). There were no statistical differences in tumor characteristics, postoperative complications, early allograft dysfunction, or acute rejection between the two groups. Disease-free survival, death-censored graft survival, and patient survival were lower in the positive group than the negative group. Additionally, the positive group showed strong association with HCC recurrence, death-censored graft survival, and patient survival in multivariate analysis.

CONCLUSION

This study suggests that positive graft weight change during HTK solution perfusion indicates poor prognosis in LDLT.

Double-blind placebo-controlled randomized trial of N-acetylcysteine infusion following live donor liver transplantation

BACKGROUND

The role of N-acetylcysteine (NAC) in improving outcomes following live donor liver transplantation (LDLT) is not well established. We designed a randomized double-blind placebo-controlled trial to study the role of NAC infusion in recipients undergoing LDLT.

METHODS

We assigned 150 patients who underwent LDLT by computer-generated random sequence on 1:1 ratio to either NAC group or placebo group. Patients in the NAC group received NAC infusion which was started at beginning of graft implantation at an initial loading dose of 150 mg/kg/h over 1 h, followed by 12.5 mg/kg/h for 4 h and then at 6.25 mg/kg/h continued for 91 h. Placebo group received normal saline. The primary endpoint was composite occurrence of acute kidney injury (AKI) and early allograft dysfunction (EAD) in the recipient. Secondary endpoints included levels of bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, INR, primary graft non-function, intraoperative bleeding, post-transplant hospital stay and in-hospital mortality.

RESULTS

The composite endpoint did not show any significant difference between the NAC and placebo group (21.3% vs 29.3%, p = 0.35). Peak AST (425.65 IU/L vs 702.24 IU/L, p = 0.02) and peak ALT (406.65 IU/L vs 677.99 IU/L, p = 0.01) levels were significantly lower in the study group. Time to normalization of transaminases was also significantly low in the study group.

CONCLUSIONS

Perioperative NAC infusion following LDLT resulted in significantly lower postoperative AST and ALT levels. Rapid normalization of transaminases was also observed. This, however, did not translate to improvement in AKI or EAD.

Nutrition Support in Liver Transplantation and Postoperative Recovery: The Effects of Vitamin D Level and Vitamin D Supplementation in Liver Transplantation

Vitamin D plays an important role in the arena of liver transplantation. In addition to affecting skeletal health significantly, it also clinically exerts immune-modulatory properties. Vitamin D deficiency is one of the nutritional issues in the perioperative period of liver transplantation (LT). Although vitamin D deficiency is known to contribute to higher incidences of acute cellular rejection (ACR) and graft failure in other solid organ transplantation, such as kidneys and lungs, its role in LT is not well understood. The aim of this study was to investigate the clinical implication of vitamin D deficiency in LT. LT outcomes were reviewed in a retrospective cohort of 528 recipients during 2014-2019. In the pre-transplant period, 55% of patients were vitamin-D-deficient. The serum vitamin D level was correlated with the model for end-stage liver disease (MELD-Na) score. Vitamin D deficiency in the post-transplant period was associated with lower survival after LT, and the post-transplant supplementation of vitamin D was associated with a lower risk of ACR. The optimal vitamin D status and vitamin D supplementation in the post-transplant period may prolong survival and reduce ACR incidence.

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.

Clinical significance of personalized tacrolimus dosing by adjusting to donor CYP3A-status in liver transplant recipients

Donor's CYP3A-status (CYP3A5 genotype and CYP3A4 expression) can provide prognostic information regarding tacrolimus-metabolizing capacity of the liver graft and initial tacrolimus dosing for therapeutic blood concentrations in liver transplants. The present work prospectively investigated whether CYP3A-status guided tacrolimus therapy has any potential clinical benefit for recipients in the early postoperative period.

METHODS

The contribution of preliminary assaying of donor CYP3A-status to the optimization of initial tacrolimus therapy and to the reduction of adverse events (acute rejection, infection, nephrotoxicity) was investigated in 112 liver transplant recipients (CYPtest group) comparing to 101 control patients on tacrolimus concentration guided therapy.

RESULTS

The time for achieving therapeutic tacrolimus concentration was significantly reduced, confirming potential benefit of initial tacrolimus therapy adjusted to donor's CYP3A-status over classical clinical practice of tacrolimus concentration guided treatment (4 vs 8 days, P < 0.0001). Acute rejection episodes (3.6 vs 23.8%, P < 0.0001) and tacrolimus induced nephrotoxicity (8 vs 27%, P = 0.0004) were less frequent in CYPtest group than in control patients, whereas occurrence of infectious disease was not influenced by tacrolimus dosing strategy (3.6 vs 5.9% in CYPtest and control groups, P > 0.05). Acute rejection was often accompanied with tacrolimus blood concentrations lower than 10 ng mL^-1 (20/24 of control and 2/4 of CYPtest patients), while nephrotoxicity was associated with high tacrolimus concentrations (>20 ng mL^-1 ) in the first week after transplantation (13/27 of control and 2/9 of CYPtest patients).

CONCLUSION

CYP3A-status guided therapy significantly improved the risk of misdosing induced early adverse effects (acute rejection, nephrotoxicity).

NLRC3 alleviates hypoxia/reoxygenation induced inflammation in RAW264.7 cells by inhibiting K63-linked ubiquitination of TRAF6

BACKGROUND

NOD-like receptor family CARD domain containing 3 (NLRC3) plays an important role in both innate and adaptive immunity. This study was to explore the function and related mechanisms of NLRC3 in a hypoxia/reoxygenation (H/R)-induced inflammatory response in RAW264.7 cells.

METHODS

Liver ischemia-reperfusion (I/R) model in mice and H/R model in RAW264.7 cells were constructed. Western blotting was used to determine the protein expression level of NLRC3 in liver tissue and NLRC3, TRAF6, p-p65, p65, IκB-α, and the K63-linked ubiquitination level of TRAF6 in cells. The immunofluorescence assay was performed to evaluate the nuclear level of the NF-κB (p65). ELISA was conducted to measure the content of IL-1β in serum and cell supernatant. The interaction between NLRC3 and TRAF6 in cells was analyzed by the Co-IP assay.

RESULTS

The NLRC3 protein level in liver tissue was decreased with the prolongation of reperfusion time (P < 0.05). The expression of NLRC3 and IκB-α protein in RAW264.7 was decreased gradually, while the expression of p-p65 and TRAF6 proteins and K63-linked ubiquitination of TRAF6 were increased gradually with the prolongation of reoxgenation time (P < 0.05). The Co-IP assay revealed that NLRC3 and TRAF6 can bind to each other directly. However, NLRC3 had no effect on the expression of TRAF6 protein. The ubiquitination test results showed that the K63-linked ubiquitination level of TRAF6 in H/R + Lv-NLRC3 group was significantly lower than that in the H/R + negative control (NC) group (P < 0.05). Moreover, the activation of NF-κB in H/R + Lv-NLRC3 group was inhibited compared with that in the H/R + NC group, and the level of the inflammatory factor IL-1β in the cell culture supernatant was also decreased accordingly (P < 0.05).

CONCLUSIONS

NLRC3 might alleviate H/R-induced inflammation in RAW264.7 cells by inhibiting K63-linked ubiquitination of TRAF6.

Indocyanine Green Fluorescence Imaging to Predict Graft Survival After Orthotopic Liver Transplantation: A Pilot Study

The incidence of primary nonfunction (PNF) after liver transplantation (LT) remains a major concern with the increasing use of marginal grafts. Indocyanine green (ICG) fluorescence is an imaging technique used in hepatobiliary surgery and LT. Because few early predictors are available, we aimed to quantify in real time the fluorescence of grafts during LT to predict 3-month survival. After graft revascularization, ICG was intravenously injected, and then the fluorescence of the graft was captured with a near infrared camera and postoperatively quantified. A multiparametric modeling of the parenchymal fluorescence intensity (FI) curve was proposed, and a predictive model of graft survival was tested. Between July 2017 and May 2019, 76 LTs were performed, among which 6 recipients underwent retransplantation. No adverse effects of ICG injection were observed. The parameter a₁₅₀ (temporal course of FI) was significantly higher in the re-LT group (0.022 seconds^-1 (0.0011-0.059) versus 0.012 seconds^-1 (0.0001-0.054); P = 0.01). This parameter was the only independent predictive factor of graft survival at 3 months (OR, 2.4; 95% CI, 1.05-5.50; P = 0.04). The best cutoff for the parameter a₁₅₀ (0.0155 seconds^-1 ) predicted the graft survival at 3 months with a sensitivity (Se) of 83.3% and a specificity (Spe) of 78.6% (area under the curve, 0.82; 95% CI, 0.67-0.98; P = 0.01). Quantitative assessment of intraoperative ICG fluorescence on the graft was feasible to predict graft survival at 3 months with a good Se and Spe. Further prospective studies should be undertaken to validate these results over larger cohorts and evaluate the clinical impact of this tool.

Metabonomic Profile of Macrosteatotic Allografts for Orthotopic Liver Transplantation in Patients With Initial Poor Function: Mechanistic Investigation and Prognostic Prediction

BACKGROUND

Our previous study revealled amplified hazardous effects of macrosteatosis (MaS) on graft failure (GF) in recipients with severe liver damage in short post-operative days, with vague mechanism inside.

AIM

We aimed to uncover the molecular mechanism of donor MaS on GF, and construct the predictive model to monitor post-transplant prognosis based on "omics" perspective.

METHODS

Ultra-performance liquid chromatography coupled to mass spectrometry metabolomic analysis was performed in allograft tissues from 82 patients with initial poor function (IPF) from multi-liver transplant (LT) centers. Pathway analysis was performed by on-line toolkit Metaboanalyst (v 3.0). Predictive model was constructed based on combinative metabonomic and clinical data extracted by stepwised cox proportional analysis.

RESULTS

Principle component analysis (PCA) analysis revealled stratification on metabolic feature in organs classified by MaS status. Differential metabolits both associated with MaS and GF were significantly enriched on pathway of glycerophospholipid metabolism (P < 0.05). Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) involved in glycerophospholipid metabolism was significantly decreased in cases with MaS donors and GF (P < 0.05). Better prediction was observed on graft survival by combinative model (area under the curve = 0.91) and confirmed by internal validation.

CONCLUSION

Metabonomic features of allografts can be clearly distinguished by MaS status in patients with IPF. Dysfunction on glycerophospholipid metabolism was culprit to link donor MaS and final GF. Decrement on PC and PE exerted the fatal effects of MaS on organ failure. Metabonomic data might help for monitoring long-term graft survival after LT.

Approach to the liver transplant early postoperative period: an institutional standpoint

The liver transplant program in our center started in 1992, and post-liver transplant patients are still admitted to the intensive care unit. For the intensive care physician, a learning curve started then, skills were acquired, and a specific practice was established. Throughout this time, several concepts changed, improving the care of these patients. The practical approach varies between liver transplant centers, according to local specificities. Hence, we wanted to present our routine practice to stimulate the debate between dedicated teams, which can allow the introduction of new ideas and potentially improve each local standard of care.

Patients with Alcoholic Liver Disease Have Worse Functional Status at Time of Liver Transplant Registration and Greater Waitlist and Post-transplant Mortality Which Is Compounded by Older Age

BACKGROUND

Worse functional status correlates with increased mortality on the liver transplant (LT) waitlist. Whether functional status affects LT outcomes equally across cirrhosis etiologies is unclear.

AIMS

We evaluate the impact of functional status on waitlist and post-LT mortality stratified by etiology and age.

METHODS

Functional status among US adults from 2005 to 2017 United Network for Organ Sharing LT registry data was retrospectively evaluated using Karnofsky Performance Status Score (KPS-1 = functional status 80-100%, KPS-2 = 60-70%, KPS-3 = 40-50%, KPS-4 = 10-30%). Waitlist and post-LT survival were stratified by KPS and cirrhosis etiology, including alcoholic liver disease (ALD), nonalcoholic steatohepatitis (NASH), hepatitis C (HCV), and HCV/ALD, and evaluated using Kaplan-Meier and multivariate Cox proportional hazard models.

RESULTS

Among 94,201 waitlist registrants (69.4% men, 39.5% HCV, 26.7% ALD, 23.2% NASH), ALD patients had worse functional status compared to HCV (KPS-4: 17.2% vs. 8.3%, p < 0.001). Worse functional status at time of waitlist registration was associated with higher 90-day waitlist mortality with the greatest effect in ALD (KPS-4 vs. KPS-1: ALD HR 2.16, 95% CI 1.83-2.55; HCV HR 2.17, 95% CI 1.87-2.51). Similar trends occurred in 5-year post-LT survival with ALD patients the most harmed. Compared to patients < 50 years, patients ≥ 65 years had increased waitlist mortality at 90-days if they had HCV or HCV/ALD, and 5-year post-LT mortality regardless of cirrhosis etiology with ALD patients most severely affected.

CONCLUSIONS

In a retrospective cohort study of patients, US ALD patients had disparately worse functional status at time of LT waitlist registration. Worse functional status correlated with higher risk of waitlist and post-LT mortality, affecting ALD and HCV patients the most.

Arterial Lactate Concentration at the End of Liver Transplantation Is an Early Predictor of Primary Graft Dysfunction

BACKGROUND

Although many prognostic factors of primary graft dysfunction after liver transplantation (LT) are available, it remains difficult to predict failure in a given recipient.

OBJECTIVE

We aimed to determine whether the intraoperative assay of arterial lactate concentration at the end of LT (LCEOT) might constitute a reliable biological test to predict early outcomes [primary nonfunction (PNF), early graft dysfunction (EAD)].

METHODS

We reviewed data from a prospective database in a single center concerning patients transplanted between January 2015 and December 2016 (n = 296).

RESULTS

There was no statistical imbalance between the training (year 2015) and validation groups (year 2016) for epidemiological and perioperative feature. Ten patients (3.4%) presented with PNF, and EAD occurred in 62 patients (20.9%); 9 patients died before postoperative day (POD) 90. LCEOT ≥5 mmol/L was the best cut-off point to predict PNF (Se=83.3%, SP=74.3%, positive likelihood ratio (LR+)=3.65, negative likelihood ratio (LR-)=0.25, diagnostic odds ratio (DOR)=14.44) and was predictive of PNF (P = 0.02), EAD (P = 0.05), and death ≤ POD90 (P = 0.06). Added to the validated BAR-score, LCEOT improved its predictive value regarding POD 90 survival with a better AUC (0.87) than BAR score (0.74). The predictive value of LCEOT was confirmed in the validation cohort.

CONCLUSION

As a reflection of both hypoperfusion and tissue damage, the assay of arterial LCEOT ≥5 mmol/L appears to be a strong predictor of early graft outcomes and may be used as an endpoint in studies assessing the impact of perioperative management. Its accessibility and low cost could impose it as a reliable parameter to anticipate postoperative management and help clinicians for decision-making in the first PODs.

Effects of pre-transplant L-carnitine supplementation on primary graft dysfunction in liver transplant recipients: a pilot, randomized, placebo-controlled clinical trial

Primary graft dysfunction (PGD) and non-function (PNF) happen in 8.7-24.7% and 0.9-7.2% of liver transplant recipients, respectively. These phenomena increase treatment cost and patients’ death. This study assessed the effect of L-carnitine supplementation on the incidences of PNF/PGD in liver transplant recipients. This randomized, placebo-controlled, clinical trial was performed on adult liver transplant recipients. Patients took L-carnitine syrup 500 mg three times daily or placebo from the time of including in transplant waiting list until the day of transplant surgery (median 14 days, 1-192 days). Thirty-three patients in L-carnitine and 39 patients in placebo group completed the study. Although not statistically significant, PNF and PGD happened less frequently among recipients in L-carnitine compared with placebo group (3% vs. 12.8% for PNF; 15.2% vs. 30.8% for PGD). Alanine aminotransferase (ALT) and aspartate aminotransferase were lower in L-carnitine group at day 3 after transplantation. ALT declined more significantly within 48 h after transplantation in L-carnitine arm (median 120.50 vs. 79 IU/L; P = 0.03). One-month patients’ survival was significantly higher in L-carnitine versus placebo group (97% vs. 74.4%; P = 0.008). The rates of PNF and PGD in L-carnitine group were approximately one-fourth and one-half of placebo group respectively. One-month patients’ survival was higher in L-carnitine group.

Serum Factor V Is a Continuous Biomarker of Graft Dysfunction and a Predictor of Graft Loss After Liver Transplantation

BACKGROUND

Factor V has never been compared to a validated early allograft dysfunction (EAD) definition. We aimed to assess factor V as a biomarker of EAD and a predictor of graft loss after liver transplantation (LT).

METHODS

We retrospectively assessed the serum factor V levels on postoperative day 1 after LT. Patients were divided according to their factor V levels into the ≤36.1 U/mL and > 36.1 U/mL groups. The primary outcome was graft loss within 1, 3, and 6 months. The secondary outcome was EAD, as defined by Olthoff et al. Predictors of outcomes were identified by multivariable logistic regression.

RESULTS

Two hundred twenty-seven patients were included in the study: 74 with factor V of 36.1 U/mL or less and 153 with factor V >36.1 U/mL. EAD was diagnosed in 41 (55.4%) of 74 patients with factor V of 36.1 U/mL or less and in 20/153 (13.1%) patients with factor V >36.1 U/mL (P < 0.001). According to the multivariable regression model, factor V was a continuous marker of EAD (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.94-0.98 per U/mL). Among the study groups, the 1-, 3-, and 6-month graft survival rates were 82%, 74%, and 74%, respectively, for patients with factor V of 36.1 U/mL or less and 98%, 95%, and 95%, respectively, for patients with factor V >36.1 U/mL (P = 0.001). Factor V was a continuous predictor for 3- and 6-month graft losses (OR, 0.96; 95% CI, 0.94-0.99 and OR, 0.97; 95% CI, 0.94-0.99 per U/mL), whereas EAD was not significant when adjusted for factor V.

CONCLUSION

Factor V is an early marker for EAD and is a continuous predictor of short-term graft loss after LT.

Platelet and liver regeneration after liver surgery

The success of liver surgery, including resection and transplantation, is largely dependent on the ability of the liver to regenerate. Despite substantial improvement in surgical techniques and perioperative care, one of the main concerns is post-hepatectomy liver failure and early allograft dysfunction, both of which are associated with impaired liver regeneration. Recent studies have demonstrated the positive role of platelets in promoting liver regeneration and protecting hepatocytes; however, the underlying mechanisms responsible for these effects are not fully understood. In this review, we updated the accumulated evidence of the role of platelets in promoting liver regeneration, with a focus on liver resection and liver transplantation. The goal of these studies was to support the clinical implementation of platelet agents, such as thrombopoietin receptor agonists, to augment liver regeneration after liver surgery. This "platelet therapy" may become a treatment choice for post-hepatectomy liver failure and early allograft dysfunction.

More Severe Deficits in Performance Status at Time of Liver Transplant is Associated With Significantly Higher Risk of Death Following Liver Transplantation

GOAL

To evaluate the impact of Karnofsky Performance Status score (KPSS) at the time of liver transplantation (LT) on post-LT survival.

BACKGROUND

While the Model for End-Stage Liver Disease (MELD) score is used to prioritize individuals for LT, it does not specifically incorporate functional status into patient assessment for LT.

METHODS

Using 2005 to 2016 United Network for Organ Sharing data, all adults (age 18 y and above) undergoing LT were identified. The association of KPSS at the time of LT (KPSS 1: functional status 80% to 100%, KPSS 2: 60% to 70%, KPSS 3: 40% to 50%, KPSS 4: 10% to 30%) with post-LT survival was evaluated using Kaplan-Meier methods and adjusted multivariate logistic regression models.

RESULTS

Among 66,397 LT recipients (68% male, 72% non-Hispanic white, 22% hepatocellular carcinoma, median age: 55 to 57), women were more likely to be KPSS 4 at the time of LT compared with men (27.95% vs. 22.79%; P<0.001) and African Americans (25.43% vs. 23.03%; P<0.001) and Hispanics (31.69% vs. 23.03%; P<0.001) were more likely to be KPSS 4 than non-Hispanic whites. Worse KPSS at LT correlated with higher post-LT mortality [compared with KPSS 1: Hazard Ratio (HR) for KPSS 2: 1.16, 95% confidence interval (CI): 1.10-1.22; HR for KPSS 3: 1.40; 95% CI: 1.32-1.49; HR for KPSS 4: 1.67; 95% CI: 1.55-1.79]. This increased mortality seen with worse KPSS was observed among all liver disease etiologies and in patients with and without hepatocellular carcinoma.

CONCLUSIONS

Worse functional status at the time of LT is strongly associated with higher risk of mortality following LT, emphasizing the importance of optimizing performance status in the preoperative period.

Peri-transplant lactate levels and delayed lactate clearance as predictive factors for poor outcomes after liver transplantation: A propensity score-matched study

This study aimed to investigate risk factors for early allograft dysfunction (EAD) and outcomes after liver transplantation (LT), focusing on peri-transplant lactate clearance. We reviewed patients who underwent deceased donor LTs between 2011 and 2014. Lactate levels were checked at reperfusion and at the time of intensive care unit admission. Early lactate clearance was defined as reduction rate of lactate between the times of reperfusion and immediately after LT. Patients were categorized into the normal and delayed clearance groups. We used propensity score matching (PSM) between these two groups to estimate an impact of lactate clearance on incidence of EAD and graft survival. A total of 256 recipients were eligible for this study. Cut-off value of lactate clearance to predict occurrence of EAD was determined at 0.2 mmol/L/h. After PSM, 120 patients in the normal clearance and 36 patients in the delayed clearance group were matched. Delayed lactate clearance was considered as an independent risk factor for EAD (Odds ratio 3.49, P = 0.002). The adjusted hazard of one-year graft loss was significantly increased in the delayed clearance group (hazard ratio 6.69, P = 0.001). In conclusion, peri-transplant delayed lactate clearance may be a strong predictor for EAD and poor liver graft outcomes.

Postoperative Risk Factors and Outcome of Patients With Liver Transplantation Who Were Admitted to Pediatric Intensive Care Unit: A 10-Year Single-Center Review in China

INTRODUCTION

The aim of this study was to present our 10-year experience of pediatric intensive care unit (PICU) management with pediatric liver recipients and to understand the importance of close interdisciplinary cooperation in 2 hospitals.

METHODS

A retrospective chart review study was performed according to our hospital's medical records and the pediatric liver transplant database of Renji hospital.

RESULTS

A total of 767 patients received liver transplantation (LT) performed in Renji hospital between October 2006 and December 2016, of which 97 of them were admitted to PICU in our center for various complications developed after transplantation. 8.8% (16/208) and 14.4% (81/559) of patients were transferred to PICU in stages I and II, respectively, and was comparable in the 2 stages (P = .017). The majority of patients was late postoperative children (median 185 post-LT days) in stage I. More patients were transferred to PICU directly in stage II. PICU admitted more younger (median 8.2 months) and early postoperative patients in stage II. The median length of PICU stay was 11.0 (6.0-20.5) days. The median length of mechanical ventilation was 5.0 (0.0-12.0) days. The most frequent complications were pulmonary complications (52 [53.6%] patients), surgical complications (22 [22.7%] patients), sepsis (7 [7.2%]), and other miscellaneous complications (16 [16.5%] patients). The overall 28-day PICU mortality was 25.8% (n = 25) and 64.0% (n = 16) of the deaths happened in the early postoperative period. There was significant difference concerning mortality in children with surgical complications and medical problems (54.5% [12/22] vs 17.3% [13/75], P = .001). Multivariate analysis by regression showed that the pediatric risk of mortality III score was the only independent prognostic factor (P = .031).

CONCLUSIONS

Multiple complications occur in children with LT. Although challenging, interdisciplinary cooperation between different hospitals is an effective mean to enable children to maximize the benefit gained from LT in China.

Ischaemia reperfusion injury in liver transplantation: Cellular and molecular mechanisms

Liver disease causing end organ failure is a growing cause of mortality. In most cases, the only therapy is liver transplantation. However, liver transplantation is a complex undertaking and its success is dependent on a number of factors. In particular, liver transplantation is subject to the risks of ischaemia-reperfusion injury (IRI). Liver IRI has significant effects on the function of a liver after transplantation. The cellular and molecular mechanisms governing IRI in liver transplantation are numerous. They involve multiple cells types such as liver sinusoidal endothelial cells, hepatocytes, Kupffer cells, neutrophils and platelets acting via an interconnected network of molecular pathways such as activation of toll-like receptor signalling, alterations in micro-RNA expression, production of ROS, regulation of autophagy and activation of hypoxia-inducible factors. Interestingly, the cellular and molecular events in liver IRI can be correlated with clinical risk factors for IRI in liver transplantation such as donor organ steatosis, ischaemic times, donor age, and donor and recipient coagulopathy. Thus, understanding the relationship of the clinical risk factors for liver IRI to the cellular and molecular mechanisms that govern it is critical to higher levels of success after liver transplantation. This in turn will help in the discovery of therapeutics for IRI in liver transplantation - a process that will lead to improved outcomes for patients suffering from end-stage liver disease.

Primary liver graft dysfunction and non-function: integrative literature review

Avoiding deaths in the waiting list for an organ is no longer the only focus of the transplant teams attention. Research and care in clinical practice has been increasingly focused on post transplant graft survival and functioning. In the present work, we performed an integrative literature review to identify the terminology used about liver graft dysfunction and non-function, as well as to investigate the incidence and risk factors of these clinical events. We chosen articles written in Portuguese, English and Spanish between 2012 and 2016, based on CINAHL, MEDLINE, Cochrane, LILACS, BDENF, IBECS, EMBASE and Web of Science. We selected 14 studies, in which we identified the incidence of hepatic graft dysfunction ranging from 7% to 27%. The terminology used to describe this clinical event was initial malfunction, graft hypofunction, marginal function or delay in function. The primary non-function of the liver graft was found in 1.4% to 8.4% of the patients, and the terminology used to describe the event was early dysfunction or graft loss. The risk factors found are related to donor, recipient, graft and transplant logistics variables. We conclude that knowledge of the different terminologies employed in the literature, related to dysfunction and primary non- function incidence, and of their risk factors are fundamental to qualify the control of the events, aiming to improve patients' survival after liver transplantation.

C-reactive protein at ICU admission as a marker of early graft dysfunction after liver transplant. A prospective, single-center cohort study

OBJECTIVE

To explore the behavior of C-reactive protein (CRP) after orthotopic liver transplantation (OLT) during the first postoperative days, and its usefulness as a marker of severe early allograft dysfunction (EAD).

DESIGN

A prospective, single-center cohort study was carried out.

SETTING

The Intensive Care Unit (ICU) of a regional hospital with a liver transplant program since 1997.

PATIENTS

The study comprised a total of 183 patients admitted to our ICU immediately after liver transplantation between 2009 and 2015.

VARIABLES OF INTEREST

C-reactive protein levels upon ICU admission and after 24 and 48h, severe EAD and hospital mortality.

RESULTS

The CRP levels after OLT were: upon ICU admission 57.5 (51.6-63.3)mg/L, after 24h 80.1 (72.9-87.3)mg/L and after 48h 69.9 (62.5-77.4)mg/L. Severe EAD patients (14.2%) had higher mortality (23.1 vs 2.5; OR 11.48: 2.98-44.19) and lower CRP upon ICU admission (39.3 [29.8-48.7]mg/L) than the patients without EAD (0.5 [53.9-67.0]; p<0.05] - the best cut-off point being 68mg/L (sensitivity 92.3%; specificity 40.1%; Youden index 0.33). Lower CRP upon ICU admission was correlated to higher mortality (24.5 [9.2-39.7] vs 59.4 [53.4-65.4]; p<0.01, AUC 0.79 [0.65-0.92]).

CONCLUSION

Liver transplant is a strong inflammatory stimulus accompanied by high levels of C-reactive protein. A blunted rise in CRP on the first postoperative day after OLT may be a marker of poor allograft function and is related to hospital mortality.

Low platelet count: Predictor of death and graft loss after liver transplantation

BACKGROUND

The impact of platelets on liver transplantation (LT) is well recognized, but not completely understood. Platelets exert dichotomous effects on the graft and on the patient. On the one hand, they are essential for primary hemostasis and tissue repair and regeneration. On the other hand, they support ischemia/reperfusion injury and inflammatory processes. Recent evidence has shown a new role for platelet count (PC) in predicting outcomes after LT.

AIM

To evaluate if low PC is a predictor of short- and long-term outcomes after LT.

METHODS

Four hundred and eighty consecutive LT patients were retrospectively assessed. PC from the preoperative to the seventh postoperative day (POD) were considered. C-statistic analysis defined the ideal cutoff point for PC. Cox regression was performed to check whether low PC was a predictor of death, retransplantation or primary changes in graft function within one year after LT.

RESULTS

The highest median PC was 86 × 10⁹/L [interquartile range (IQR) = 65–100 × 10⁹/L] on seventh POD, and the lowest was 51 × 10⁹/L (IQR = 38–71 × 10⁹/L) on third POD. The C-statistic defined a PC < 70 × 10⁹/L on fifth POD as the ideal cutoff point for predicting death and retransplantation. In the multivariate analysis, platelets < 70 × 10⁹/L on 5POD was an independent risk factor for death at 12 mo after LT [hazard ratio (HR) = 2.01; 95% confidence interval (CI) 1.06-3.79; P = 0.031]. In the Cox regression, patients with PC < 70 × 10⁹/L on 5POD had worse graft survival rates up to one year after LT (HR = 2.76; 95%CI 1.52-4.99; P = 0.001).

CONCLUSION

PC < 70 × 10⁹/L on 5POD is an independent predictor of death in the first year after LT. These results are in agreement with other studies that indicate that low PC after LT is associated with negative outcomes.

Early graft dysfunction after liver transplant: Comparison of different diagnostic criteria in a single-center prospective cohort

OBJECTIVE

Comparison of different diagnostic criteria for early liver allograft dysfunction (EAD) and their capability to predict mortality.

DESIGN

Single-center, prospective, cohort study.

SETTINGS

ICU in a Regional Hospital with a liver transplant program since 1997.

PATIENTS

253 consecutive patients admitted to our ICU immediately after liver transplantation between 2009 and 2015.

VARIABLES OF INTEREST

Differences in the incidence of EAD and its relation with ICU, Hospital and 2-year mortality depending on the definition applied using as comparator the UNOS (United Network for Organ Sharing) primary non-function criterion.

RESULTS

The incidence of early liver allograft dysfunction according to UNOS was 13.8%, to Makowka 6.3%, to Ardite 10.7%, to Nanashima 20.6%, to Dhillon 30.8% and to MEAF 13.4%. Kappa test did not show a good correlation among these criteria. EAD was related with ICU mortality for all diagnostic criteria except Dhillon but only UNOS, Makowka and MEAF were associated with 2-year mortality. Hospital mortality was poorly predicted by all criteria except for the MEAF score.

CONCLUSION

We found a poor agreement between different criteria analyzed for the diagnosis of EAD. In our population, the MEAF score showed the best relationship with short- and long-term mortality.

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.

New-onset hyperglycemia immediately after liver transplantation: A national survey from China Liver Transplant Registry

BACKGROUND

New-onset hyperglycemia (NOH) is a common phenomenon after liver transplantation (LT), but its impact on clinical outcomes has not yet been fully assessed. We aimed to evaluate the etiology and prognosis of NOH within 1 month after LT.

METHODS

The data of 3339 adult patients who underwent primary LT from donation after citizen death between January 2010 and June 2016 were extracted from China Liver Transplant Registry database and analyzed. NOH was defined as fasting blood glucose ≥7.0 mmol/L confirmed on at least two occasions within the first post-transplant month with or without hypoglycemic agent.

RESULTS

Of 3339 liver recipients, 1416 (42.4%) developed NOH. Recipients with NOH had higher incidence of post-transplant complications such as graft and kidney failure, infection, biliary stricture, cholangitis, and tumor recurrence in a glucose concentration-dependent manner as compared to non-NOH recipients (P < 0.05). The independent risk factors of NOH were donor warm ischemic time >10 min, cold ischemic time >10 h, anhepatic time >60 min, recipient model for end-stage liver disease score >30, moderate ascites and corticosteroid usage (P < 0.05). Liver enzymes (alanine aminotransferase and gamma-glutamyltranspeptidase) on post-transplant day 7 significantly correlated with NOH (P < 0.001).

CONCLUSIONS

NOH leads to increased morbidity and mortality in liver recipients. Close surveillance and tight control of blood glucose are desiderated immediately following LT particularly in those with delayed graft function and receiving corticosteroid. Strategic targeting graft ischemic injury may help maintain glucose homeostasis.