How to improve long-term outcome after liver transplantation?

Long-Term Outcomes of Liver Transplant Recipients. What Do Patients Die From?

BACKGROUND

Several advances in liver transplantation (LT) have provided an increased rate in 1-year patient survival, currently reported between 84.5% and 91.4%. However, this significant improvement is not widely maintained after the 1-year of follow-up. In this study, we analyze short-term and long-term results in LT recipients.

METHODS

A retrospective observational cohort study, including patients who underwent LT between 1990 and 2009 and were followed for a minimum 15-year period, analyzing the causes and risk factors of mortality and patient and graft survival from LT up to the last outpatient visit.

RESULTS

A total of 594 patients with LT were included (median age, 53-year and 69.7% male). The most common indications for LT were HCV-cirrhosis (267 patients), alcoholic cirrhosis (250 patients), and hepatocellular carcinoma (HCC) (144 patients). Post-LT complications were acute rejection in 44.1%, cardiovascular in 40.6%, chronic kidney disease in 40.1%, hypertension in 22.6%, and de novo tumors in 25.6%. Retransplantation was performed in 40 (6.7%) patients. A total of 388 (65.3%) patients died during a follow-up over 20 years: 106 (17.8%) in the first year post-LT; 76 (12.8%) between 2 and 5 years; 75 (12.6%) between 6 and 10 years; 73 (812.3%) between 11 and 15 years; 30 (5%) between 16 and 20 years; and 28 (4.7%) after 20 years. The overall causes of death were infection in 69 (11.6%) patients, cardiovascular complications in 58 (9.8%) patients, pulmonary complications in 8 (1.3%) patients, liver graft failure in 126 (21.2%) patients, HCC recurrence in 15 (2.6%) patients, de novo tumors in 72 (12.1%) patients, and miscellaneous in 40 (6.7%) patients. Rates of actuarial patient survival at 1-, 3-, 5-, 10-, 15-, and 20-year after LT were 82.7%, 75.6%, 70%, 58.6%, 45.2%, and 37.6%, respectively, and actuarial graft survival were 80%, 72.5%, 67.1%, 54.8%, 42.6%, and 34.6%, respectively. Advanced recipient age, blood transfusion, and infection were the main risk factors for patient mortality.

CONCLUSIONS

The highest mortality rate was within the first year of LT, and the most common causes of death were hepatic failure, de novo tumors, infection, cardiovascular disease, and HCC recurrence.

AI Innovations in Liver Transplantation: From Big Data to Better Outcomes

Artificial intelligence (AI) has emerged as a transformative field in computational research with diverse applications in medicine, particularly in the field of liver transplantation (LT) given its ability to analyze and build upon complex and multidimensional data. This literature review investigates the application of AI in LT, focusing on its role in pre-implantation biopsy evaluation, development of recipient prognosis algorithms, imaging analysis, and decision-making support systems, with the findings revealing that AI can be applied across a variety of fields within LT, including diagnosis, organ allocation, and surgery planning. As a result, algorithms are being developed to assess steatosis in pre-implantation biopsies and predict liver graft function, with AI applications displaying great accuracy across various studies included in this review. Despite its relatively recent introduction to transplantation, AI demonstrates potential in delivering cost and time-efficient outcomes. However, these tools cannot replace the role of healthcare professionals, with their widespread adoption demanding thorough clinical testing and oversight.

Association of transplant recipient status with clinical and financial outcomes among patients undergoing major surgery

BACKGROUND

Transplant recipients undergoing surgery may represent a vulnerable population because of transplant-related comorbidities as well as reliance on immunosuppressive medications. We sought to characterize the association of prior transplant status on postoperative outcomes among patients undergoing major non-transplant-related surgical procedures.

METHODS

Data on patients who underwent a major surgical procedure (pneumonectomy, coronary artery bypass graft, abdominal aortic aneurysm repair, Whipple, colectomy) between 2016 and 2020 were obtained from the Nationwide Readmission Database. After balancing the 2 cohorts using entropy balancing, multivariable regression models were used to assess the relationship between post-transplant status and patient outcomes.

RESULTS

Among 1,818,973 patients, 0.45% (n = 8,212) had a history of solid organ transplantation (liver: n = 1,773, 21.6%; heart/lung: n = 1,087, 13.2%; kidney/pancreas: n = 4,891, 59.6%; and multiple: n = 461, 5.6%). In the unmatched cohort, patients who had a history of organ transplant were more likely to be male (64.1% vs 57.7%) and have Medicare insurance (71.7% vs 59.3%) (both P < .001). On multivariable analysis, prior transplant recipient status was associated with higher odds of postoperative complications (odds ratio 1.30, 95% confidence interval 1.22-1.38), 30-day readmission (odds ratio 1.42, 95% confidence interval 1.31-1.54), and in-hospital mortality (odds ratio 1.20, 95% confidence interval 1.03-1.40) (all P < .05). Moreover, organ transplantation was associated with higher index hospitalization costs (14.4% difference, 95% confidence interval 14.1%-14.6%) and 30-day postdischarge costs (16.2% difference, 95% confidence interval 15.3%-17.0%) (both P < .001).

CONCLUSIONS

Prior transplant recipient status was associated with adverse clinical and financial outcomes following subsequent major surgery. Prior history of transplant may be an important factor to incorporate into risk stratification of patients undergoing subsequent major surgical procedures.

Comparison of time-to-event machine learning models in predicting biliary complication and mortality rate in liver transplant patients

Post-Liver transplantation (LT) survival rates stagnate, with biliary complications (BC) as a major cause of death. We analyzed longitudinal data with a median 19-month follow-up. BC was diagnosed with ultrasounds and MRCP. Missing data was imputed using mean and median. Data preprocessing involved feature scaling and one-hot encoding. Survival analysis used filter (Cox-P, Cox-c) and embedded (RSF, LASSO) feature selection methods. Seven survival machine learning algorithms were used: LASSO, Ridge, RSF, E-NET, GBS, C-GBS, and FS-SVM. Model development employed 5-fold cross-validation, random oversampling, and hyperparameter tuning. Random oversampling addressed data imbalance. Optimal hyperparameters were determined based on average C-index. Features importance was assessed using standardized regression coefficients and permutation importance for top models. Stability was evaluated using 5-fold cross-validation standard deviation. Finally, 1799 observations with 40 outcome predictors were included. RSF with Ridge achieved the highest performance (C-index: 0.699) for BC prediction, while RSF with RSF had the highest performance (C-index: 0.784) for mortality prediction. Top BC predictors were LT graft types, IBD in recipients, recipient's BMI, recipient's history of PVT, and previous LT history. For mortality, they were post-transplant AST, creatinine, recipient's age, post-transplant ALT, and tacrolimus consumption. We identified BC and mortality risk factors, improving decision-making and outcomes.

Prostaglandin E1 administration post liver transplantation and renal outcomes: A retrospective single center experience

BACKGROUND

Prostaglandin E1 (PGE1), or alprostadil, is a potent vasodilator that improves hepatic blood flow and reduces ischemia-reperfusion injury post-liver transplantation (LT). However, the benefits of PGE1 on renal function after LT have not yet been well described.

AIM

To assess the impact of PGE1 administration on renal function in patients who underwent liver or liver-kidney transplant.

METHODS

This retrospective study included all patients who underwent liver or liver-kidney transplant at our institution from January, 2011 to December, 2021. Patients were classified based on whether they received PGE1. PGE1 was administered post-LT to those with transaminases > 1000 U/L in the immediate postoperative period. Demographics, post-LT treatments and/or complications, renal function, and survival were analyzed. Multivariable logistic regression analysis was performed, and a two-tailed P value < 0.05 was considered statistically significant.

RESULTS

A total of 145 patients underwent LT, with 44 (30%) receiving PGE1. Baseline patient characteristics were comparable, except the PGE1 group had significantly higher aspartate aminotransferase (AST) (1961.9 U/L ± 1862.3 U/L vs 878 U/L ± 741.4 U/L, P = 0.000), alanine aminotransferase (1070.6 U/L ± 895 U/L vs 547.7 U/L ± 410 U/L, P = 0.000), international normalized ratio on post-LT day 1 (2 ± 0.74 vs 1.8 ± 0.4, P = 0.03), a longer intensive care unit stay (8.1 days ± 11.8 days vs 3.8 days ± 4.6 days, P = 0.003), more vasopressor use (55.53 hours ± 111 hours vs 16.33 hours ± 26.3 hours, P = 0.002), and higher immediate postoperative complications (18.6% vs 4.9%, P = 0.04). The PGE1 group also had a significantly higher 90-day readmission rate (29.6% vs 13.1%, P = 0.02) and lower 1-year liver graft survival (87.5% vs 98.9%, P = 0.005). However, 30-day readmission (31.6% vs 27.4%, P = 0.64), LT complications (hepatic artery thrombosis, biliary complications, rejection of liver graft, cardiomyopathy), 1-year patient survival (96.9% vs 97.8%, P = 0.77), overall liver graft survival, and overall patient survival were similar between the two groups (95.4% vs 93.9%, P = 0.74 and 88.4% vs 86.9%, P = 0.81 respectively). Although the PGE1 group had a significantly lower glomerular filtration rate (eGFR) on post-LT day 7 (46.3 mL/minute ± 26.7 mL/minute vs 62.5 mL/minute ± 34 mL/minute, P = 0.009), the eventual need for renal replacement therapy (13.6% vs 5.9%, P = 0.09), the number of dialysis sessions (0.91 vs 0.27, P = 0.13), and eGFR at 1-month (37.2 mL/minute ± 35.9 mL/minute vs 42 mL/minute ± 36.9 mL/minute, P = 0.49), 6-months (54.8 mL/minute ± 21.6 mL/minute vs 62 mL/minute ± 21.4 mL/minute, P = 0.09), and 12-months (63.7 mL/minute ± 20.7 mL/minute vs 62.8 mL/minute ± 20.3 mL/minute, P = 0.85) post-LT were similar to those in the non-PGE1 group.

CONCLUSION

In patients who received PGE1 for ischemia-reperfusion injury, despite immediate acute renal injury post-LT, the renal function at 1-month, 6-months, and 12-months post-LT was similar compared to those without ischemia-reperfusion injury. Prospective clinical trials are needed to further elucidate the benefits of PGE1 use in renal function.

The impact of macro- and micro-steatosis on the outcomes of patients who undergo liver transplant: Analysis of the UNOS-STAR database

BACKGROUND AND AIMS

The presence of steatosis in a donor liver and its relation to post-transplantation outcomes are not well defined. This study evaluates the effect of the presence and severity of micro- and macro-steatosis of a donor graft on post-transplantation outcomes.

METHODS

The UNOS-STAR registry (2005-2019) was used to select patients who received a liver transplant graft with hepatic steatosis. The study cohort was stratified by the presence of macro- or micro-vesicular steatosis, and further stratified by histologic grade of steatosis. The primary endpoints of all-cause mortality and graft failure were compared using sequential Cox regression analysis. Analysis of specific causes of mortality was further performed.

RESULTS

There were 9184 with no macro-steatosis (control), 150 with grade 3 macro-steatosis, 822 with grade 2 macro-steatosis and 12 585 with grade 1 macro-steatosis. There were 10 320 without micro-steatosis (control), 478 with grade 3 micro-steatosis, 1539 with grade 2 micro-steatosis and 10 404 with grade 1 micro-steatosis. There was no significant difference in all-cause mortality or graft failure among recipients who received a donor organ with any evidence of macro- or micro-steatosis, compared to those receiving non-steatotic grafts. There was increased mortality due to cardiac arrest among recipients of a grade 2 macro-steatosis donor organ.

CONCLUSION

This study shows no significant difference in all-cause mortality or graft failure among recipients who received a donor liver with any degree of micro- or macro-steatosis. Further analysis identified increased mortality due to specific aetiologies among recipients receiving donor organs with varying grades of macro- and micro-steatosis.

MASH Continues as a Significant Burden on Metabolic Health of Liver Recipients

BACKGROUND

Metabolic complications are a recognized health concern in liver transplant recipients that result in inferior patient-reported outcomes. Patients with MASH are known to be disproportionately affected by metabolic diseases compared to other indications for transplantation.

PURPOSE

The aim of this study was to investigate the incidence of metabolic abnormalities in liver recipients with specific focus on differences between patients transplanted for MASH and non-MASH-causes.

PATIENTS AND METHODS

An observational, monocentric, and retrospective analysis was performed. Patients who received a cadaveric-donor-liver transplant between 2010 and 2019 were eligible.

RESULTS

282 patients were enrolled with a median age of 52 years (66.7% males). Metabolic dysfunction-associated steatohepatitis (MASH) led to liver transplant in 8.2% of cases. De-novo metabolic syndrome was diagnosed in 36% of the study population. Patients that underwent transplant owing to MASH showed significantly higher incidence of metabolic complications in both pre- and post-transplant period. Considerable differences were noted in the pattern of weight gain between patients transplanted for MASH and non-MASH patients. The MASH etiology (OR: 5.5; 95% CI: 1.624-22.868; P = .010), higher BMI at 1-year post-transplant (OR: 1.321; 95% CI: 1.214-1.449; P = <.001), and older age at transplant (OR: 1.038; 95% CI: 1.006-1.074; P = .022) were independently associated with new-onset metabolic syndrome in liver recipients.

CONCLUSION

Metabolic complications were prevalent in liver recipients. Liver recipients with underlying MASH significantly surpassed patients transplanted for other indications in terms of metabolic complications incidence and demonstrated an unfavorable trajectory of weight gain post-transplant.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Use of machine learning models for the prognostication of liver transplantation: A systematic review

BACKGROUND

Liver transplantation (LT) is a life-saving intervention for patients with end-stage liver disease. However, the equitable allocation of scarce donor organs remains a formidable challenge. Prognostic tools are pivotal in identifying the most suitable transplant candidates. Traditionally, scoring systems like the model for end-stage liver disease have been instrumental in this process. Nevertheless, the landscape of prognostication is undergoing a transformation with the integration of machine learning (ML) and artificial intelligence models.

AIM

To assess the utility of ML models in prognostication for LT, comparing their per formance and reliability to established traditional scoring systems.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, we conducted a thorough and standardized literature search using the PubMed/MEDLINE database. Our search imposed no restrictions on publication year, age, or gender. Exclusion criteria encompassed non-English stu dies, review articles, case reports, conference papers, studies with missing data, or those exhibiting evident methodological flaws.

RESULTS

Our search yielded a total of 64 articles, with 23 meeting the inclusion criteria. Among the selected studies, 60.8% originated from the United States and China combined. Only one pediatric study met the criteria. Notably, 91% of the studies were published within the past five years. ML models consistently demonstrated satisfactory to excellent area under the receiver operating characteristic curve values (ranging from 0.6 to 1) across all studies, surpassing the performance of traditional scoring systems. Random forest exhibited superior predictive capa bilities for 90-d mortality following LT, sepsis, and acute kidney injury (AKI). In contrast, gradient boosting excelled in predicting the risk of graft-versus-host disease, pneumonia, and AKI.

CONCLUSION

This study underscores the potential of ML models in guiding decisions related to allograft allocation and LT, marking a significant evolution in the field of prognostication.

Post Liver Transplant Renal Dysfunction-Evaluation, Management and Immunosuppressive Practice

Liver transplantation (LT) is an effective and lifesaving treatment for patients with end-stage liver disease and hepatocellular carcinoma. Significant improvement in intermediate and long-term survival has been possible due to advancements in immunosuppressive therapy, perioperative care, and surgical techniques. Despite these advances, metabolic complications, including diabetes mellitus, cardiovascular diseases, malignancies, and renal dysfunction, are challenging issues after LT. Acute kidney injury (AKI) and chronic kidney disease (CKD) after LT are common and result in significant morbidity and mortality. Early diagnosis of kidney injury after LT is challenging, and no technique has yet proven effective in prediction of renal dysfunction. The methods for assessing renal function range from formulas that predict glomerular filtration rate to non-invasive biomarkers. The universal adoption of the model for end-stage liver disease has a direct impact on the incidence of peri-transplant AKI and development of CKD in the long-term. Post-LT renal dysfunction is multifactorial and is usually a result of pre-transplantation comorbidities, occurrence of renal dysfunction on the waiting list, perioperative events, and post-transplant nephrotoxic immunosuppressive medication use. Early identification of patients at risk for renal dysfunction and adoption of preventive measures are crucial in the pre-transplant period. No data are currently available to suggest a surgical technique that reliably demonstrates renal protection. Nephroprotective strategies during LT follow accepted surgical practice guidelines, such as maintenance of intravascular volume and mean arterial pressure. The management of kidney disease following LT is challenging, as by the time the serum creatinine is significantly elevated, few interventions impact the course of progression. Early nephroprotective measures are strongly advised and they mostly center on delaying the administration of calcineurin inhibitors (CNIs) during the initial postoperative period, lowering CNI dosage and combining CNI with mycophenolate mofetil and everolimus. The reasons for renal failure following LT, the techniques used to diagnose it, and the therapies designed to preserve renal function both immediately and late after LT are all critically evaluated in this review.

Noninvasive graft monitoring using donor-derived cell-free DNA in Japanese liver transplantation

AIM

To evaluate the use of donor-derived cell-free DNA (dd-cfDNA) in diagnosing graft injuries in Japanese liver transplantation (LTx), including family-related living donors.

METHODS

A total of 321 samples from 10 newly operated LTx recipients were collected to monitor the early dynamics of dd-cfDNA levels after LTx. Fifty-five samples from 55 recipients were collected during protocol biopsies (PB), whereas 36 samples from 27 recipients were collected during event biopsies, consisting of 11 biopsy-proven acute rejection (AR), 20 acute dysfunctions without rejection (ADWR), and 5 chronic rejections. The levels of dd-cfDNA were quantified using a next-generation sequencer based on single nucleotide polymorphisms.

RESULTS

The dd-cfDNA levels were elevated significantly after LTx, followed by a rapid decline to the baseline in patients without graft injury within 30 days post-LTx. The dd-cfDNA levels were significantly higher in the 11 samples obtained during AR than those obtained during PB (p < 0.0001), which decreased promptly after treatment. The receiver operator characteristic curve analysis of diagnostic ability yielded areas under the curve of 0.975 and 0.897 for AR (rejection activity index [RAI] ≥3) versus PB and versus non-AR (ADWR + PB). The dd-cfDNA levels during AR were elevated earlier and correlated more strongly with the RAI (r = 0.740) than aspartate aminotransferase/alanine aminotransferase. The dd-cfDNA levels were neither associated with graft fibrosis based on histology nor the status of donor-specific antibodies in PB samples.

CONCLUSIONS

Donor-derived cell-free DNA serves as a sensitive biomarker for detecting graft injuries in LTx. Further large-scale cohort studies are warranted to optimize its use in differentiating various post-LTx etiologies.

Liver transplantation meets gastrointestinal cancer

Liver transplantation (LT) has emerged as a standard of care for patients with end-stage liver disease, providing a life-saving intervention for patients with severely compromised liver function in both the acute and chronic setting. While LT has also become a routine procedure for early-stage hepatocellular carcinoma (HCC), offering a potential cure by treating both the tumor and the underlying liver disease, its relevance in the context of other malignancies such as cholangiocellular carcinoma (CCA), combined hepatocellular-cholangiocarcinoma (cHCC-CCA) or liver metastases is still the subject of intense debate and no definite recommendations have yet been established. This review summarizes the current therapeutic standards in the context of LT for gastrointestinal malignancies and provides a reflection and outlook on current scientific and clinical developments.

Primary Care Utilization, Preventative Screening, and Control of Metabolic Syndrome in Metabolic Dysfunction-Associated Steatohepatitis Liver Transplant Recipients

OBJECTIVES

Patients with pre-transplant metabolic dysfunction-associated steatohepatitis (MASH) are at high risk of metabolic syndrome (MetS) after liver transplant. While many patients are co-managed by a transplant team, most preventative screening and MetS management may occur in the primary care setting. We aimed to evaluate primary care utilization by MASH liver transplant recipients as well as MetS screening and control.

METHODS

We conducted a retrospective chart review that included adults who underwent liver transplant for MASH or cryptogenic cirrhosis at a single institution from January 2010 to December 2016, had available primary care data, and at least 36-months of follow-up post-transplant. Measures included primary care utilization, adherence to screening guidelines, and control of MetS. We used Fischer's exact test to explore the association of primary care utilization with screening and control.

RESULTS

A total of 37 patients met inclusion criteria with 366 visits reviewed. The median time to first visit was 68 days post-transplant and patients had a median of 9 total visits. Few patients met screening guidelines for diabetes (8.1%) or hyperlipidemia (10.8%). The percentage of patients with control of obesity, hypertension, diabetes, and hyperlipidemia decreased over the 36-month follow-up period. Primary care utilization was not associated with adherence to screening recommendations for diabetes (P = .141) or hyperlipidemia (P = .103). Higher primary care utilization was not associated with control of hypertension (P = .107), diabetes (P = .871), or hyperlipidemia (P = .999).

CONCLUSION

More research is needed to investigate barriers to screening and management of MetS conditions in this high-risk patient population in the primary care setting as well as to optimize post-transplant care coordination.

Short-Term and Long-Term Effects of Ischemic Conditioning on Liver Transplantation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Although liver transplantation (LT) is one of the definitive treatments for patients with end-stage liver failure, it inevitably results in ischemic reperfusion injury. It is known that prognosis is improved when temporary ischemic conditioning (IC) is applied to patients with ischemic reperfusion injury. The objective of this meta-analysis was to determine the short-term and long-term effects of IC on the clinical outcomes of LT recipients.

METHODS

Randomized controlled studies on IC in patients with LTs were included. Patients were compared between an IC group and a sham group. Studies were retrieved from PubMed, Embase, and Cochrane Library. The risk of bias was evaluated using RoB 2.0. Mortality, graft function, and major complications were synthesized using RevMan 5.4.1.

RESULTS

Among 316 papers, 17 articles (1196 patients) were included. There was an insignificant increase in short-term mortality (risk ratio [RR]: 3.00, 95% CI: 0.32-28.14, P = .34). However, long-term mortality was lower in the IC group than in the sham group, but not significantly (RR: 0.75; 95% CI: 0.47-1.20, P = .23). Short-term graft function (acute graft rejection and primary graft non-function) was not improved by IC. One-year graft loss tended to show better results in the IC group (RR: 0.53, 95% CI: 0.26-1.07, P = .08).

CONCLUSION

Ischemic conditioning did not have a beneficial effect on LT. Although long-term outcomes appear to be better in the IC group than in the sham group, further randomized controlled trials are needed.

Perioperative Decision-Making in Pulmonary Hypertension

Pulmonary hypertension (PH) is a haemodynamic manifestation of cardiorespiratory and non-cardiorespiratory pathologies. Cardiorespiratory pathologies account for nearly three-fourths of patients with PH. It is now increasingly being recognised due to routine requests for transthoracic echocardiographic examination in the perioperative setting in patients undergoing intermediate- to high-risk non-cardiac surgery. The increased risks of perioperative morbidity and mortality attributed to PH have been widely acknowledged in the literature. The importance of PH in perioperative decision-making and postoperative outcomes has had little mention in all the guidelines. Understanding the complexity of the pathophysiology of PH may help in anaesthetic and surgical decision-making. Preoperative evaluation and risk assessment are guided by the nature, extent, invasiveness, and duration of surgery. Surgical decision-making and anaesthetic management involve preoperative risk stratification, understanding the interactions between surgical procedures and PH, and understanding the interactions between anaesthetic procedures, PH, and cardiopulmonary interactions. Intraoperative and postoperative monitoring is crucial for maintaining the haemodynamic parameters and helps titrate anaesthetic agents and medication. This narrative review focusses on all issues related to anaesthetic and surgical challenges in patients with PH. This review aimed to suggest a preoperative evaluation plan, surgical decision-making, anaesthetic plan, and anaesthetic management based on the evidence available in the literature.

Management of cardiac diseases in liver transplant recipients: Comprehensive review and multidisciplinary practice-based recommendations

Cardiac diseases are one of the most common causes of morbidity and mortality following liver transplantation (LT). Prior studies have shown that cardiac diseases affect close to one-third of liver transplant recipients (LTRs) long term and that their incidence has been on the rise. This rise is expected to continue as more patients with advanced age and/or non-alcoholic steatohepatitis undergo LT. In view of the increasing disease burden, a multidisciplinary initiative was developed to critically review the existing literature (between January 1, 1990 and March 17, 2021) surrounding epidemiology, risk assessment, and risk mitigation of coronary heart disease, arrhythmia, heart failure, and valvular heart disease and formulate practice-based recommendations accordingly. In this review, the expert panel emphasizes the importance of optimizing management of metabolic syndrome and its components in LTRs and highlights the cardioprotective potential for the newer diabetes medications (e.g., sodium glucose transporter-2 inhibitors) in this high-risk population. Tailoring the multidisciplinary management of cardiac diseases in LTRs to the cardiometabolic risk profile of the individual patient is critical. The review also outlines numerous knowledge gaps to pave the road for future research in this sphere with the ultimate goal of improving clinical outcomes.

Albuminuria as a predictor of mortality in type II diabetic patients after living-donor liver transplantation

PURPOSE

Diabetes mellitus (DM) increases the risk of morbidity and mortality after liver resection. Albuminuria is associated with a higher risk for all-cause and cardiovascular mortality. This study evaluated albuminuria as a predictor of the outcome of living donor liver transplantation (LDLT) in patients with pre-existing DM.

METHODS

This retrospective study involved 103 type II diabetic patients with end-stage liver disease who received LDLT. Preoperative spot urine albumin: creatinine ratio was used to determine the degree of albuminuria. The primary outcome measure was the impact of urinary albumin excretion on the 3-year mortality rate after LDLT in this diabetic cohort.

RESULTS

Hepatitis C virus infection was the main cause of cirrhosis. Albuminuria was detected in 41 patients (39.8%); 15 had macroalbuminuria, while 26 had microalbuminuria. Patients with microalbuminuria were significantly older than those with macroalbuminuria and normal albumin in urine. After 3 years, twenty-four patients (23.3%) died within 3 years after LT. Myocardial infarction was the leading cause of death (25%). Albuminuria was an independent factor affecting 3-year mortality with an odds ratio of 5.17 (95% CI: 1.86-14.35).

CONCLUSION

Preoperative albuminuria is an independent factor affecting mortality within 3 years after LDLT in type II diabetic patients. Myocardial infarction was the leading cause of death in 25% of cases, followed by hepatocellular carcinoma recurrence, sepsis, and graft failure.KEY MESSAGESDiabetes mellitus (DM) increases the risk of morbidity and mortality after liver resection.Albuminuria is associated with a higher risk for all-cause and cardiovascular mortality.Preoperative albuminuria is a significant predictor of mortality within 3 years after LDLT in diabetic patients.

A Reduction of Calcineurin Inhibitors May Improve Survival in Patients with De Novo Colorectal Cancer after Liver Transplantation

Background and Objectives: After liver transplantation (LT), long-term immunosuppression (IS) is essential. IS is associated with de novo malignancies, and the incidence of colorectal cancer (CRC) is increased in LT patients. We assessed course of disease in patients with de novo CRC after LT with focus of IS and impact on survival in a retrospective, single-center study. Materials and Methods: All patients diagnosed with CRC after LT between 1988 and 2019 were included. The management of IS regimen following diagnosis and the oncological treatment approach were analyzed: Kaplan−Meier analysis as well as univariate and multivariate analysis were performed. Results: A total of 33 out of 2744 patients were diagnosed with CRC after LT. Two groups were identified: patients with restrictive IS management undergoing dose reduction (RIM group, n = 20) and those with unaltered regimen (maintenance group, n = 13). The groups did not differ in clinical and oncological characteristics. Statistically significant improved survival was found in Kaplan−Meier analysis for patients in the RIM group with 83.46 (8.4−193.1) months in RIM and 24.8 (0.5−298.9) months in the maintenance group (log rank = 0.02) and showed a trend in multivariate cox regression (p = 0.054, HR = 14.3, CI = 0.96−213.67). Conclusions: Immunosuppressive therapy should be reduced further in patients suffering from CRC after LT in an individualized manner to enable optimal oncological therapy and enable improved survival.

Safety of Tacrolimus Monotherapy within 12 Months after Liver Transplantation in the Era of Reduced Tacrolimus and Mycophenolate Mofetil: National Registry Study

Tacrolimus monotherapy is accepted as a feasible option during early post-liver transplantation as per current international consensus guidelines. However, its effects in the recent era of reduced tacrolimus (TAC) and mycophenolate mofetil (MMF) remain unclear. Liver recipients who either received TAC monotherapy from the treatment onset or switched from TAC/MMF to TAC-mono within 12 months (TAC-mono group; n = 991) were chronologically matched to patients who continued to receive TAC/MMF (TAC/MMF group; n = 991) at the corresponding time points on time-conditional propensity scores. Outcomes within 12 months after matched time points were compared. Biopsy-proven rejection (TAC/MMF: 3.5% vs. TAC-mono: 2.6%; p = 0.381) and graft failure (0.2% vs. 0.7%; p = 0.082) were similar in both groups. However, the decline in eGFR was 3.1 mL/min/1.73 m2 (95% CI: 0.8-5.3) greater at six months (p = 0.008) and 2.4 mL/min/1.73 m2 (95% CI: -0.05-4.9) greater at 12 months (p = 0.048) after the matched time points in TAC-mono group than that in TAC/MMF group. TAC trough levels were also higher in the TAC-mono group throughout the study period. TAC-mono within 12 months after liver transplantation is immunologically safe. However, it can increase the required TAC dose and the decline in renal function than that in TAC/MMF combination therapy.

Mortality and Causes of Death After Liver Transplantation: Analysis of Sex Differences in a Large Nationwide Cohort

In the last few years, several studies have analyzed sex and gender differences in liver transplantation (LT), but none have performed a disaggregated analysis of both mortality and causes of death. Data from 15,998 patients, 11,914 (74.5%) males and 4,069 (25.5%) females, transplanted between 2000 and 2016 were obtained from the Liver Transplantation Spanish Registry. Survival analysis was applied to explore recipient sex as a risk factor for death. The causes of death at different follow-up duration were disaggregated by recipient sex for analysis. Short-term survival was higher in males, whereas long-term survival was higher in females. Survival at 1, 5 and 10 years post-transplant was 87.43%, 73.83%, and 61.23%, respectively, in males and 86.28%, 74.19%, and 65.10%, respectively, in females (p = 0.05). Post-LT mortality related to previous liver disease also presented sex differences. Males had 37% increased overall mortality from acute liver failure (p = 0.035) and 37% from HCV-negative cirrhosis (p < 0.001). Females had approximately 16% increased mortality when the liver disease was HCV-positive cirrhosis (p = 0.003). Regarding causes of death, non-malignancy HCV+ recurrence (6.3% vs. 3.9% of patients; p < 0.001), was more frequently reported in females. By contrast, death because of malignancy recurrence (3.9% vs. 2.2% of patients; p = 0.003) and de novo malignancy (4.8% vs. 2.5% of patients; p < 0.001) were significantly more frequent in male recipients. Cardiovascular disease, renal failure, and surgical complications were similar in both. In summary, male patients have lower short-term mortality than females but higher long-term and overall mortality. In addition, the post-LT mortality risk related to previous liver disease and the causes of mortality differ between males and females.

Liver transplantation as a treatment for Wilson's disease with neurological presentation: a systematic literature review

Introduction

Wilson’s disease (WD) is a potentially treatable, genetic disorder of copper metabolism, with survival similar to healthy populations if controlled. However, in almost 50% of WD patients, neurological symptoms persist despite treatment, and in up to 10% of patients, neurological deterioration is irreversible. International guidelines on WD treatment do not recommend liver transplantation (LT) as a treatment for neurological symptoms in WD. However, such treatment has been assessed in retrospective analyses, case and series reports. We aimed to systematically assess all available evidence on the effectiveness and safety of LT in WD patients with neurological presentation.

Methods

This systematic literature review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies were identified by searching the PubMed database (up to 6 April 2021) and by screening reference lists.

Results

Based on the systematic literature review, 48 articles were identified, showing outcomes of LT in 302 WD patients with neurological symptoms. Of these patients, major improvement was found in 215 cases (71.2%), with no difference in neurological status before and after LT in 21 cases (6.9%). There were 29 deaths (9.6%), neurological worsening in 24 cases (7.9%), and 13 cases (4.3%) were lost to follow-up.

Conclusions

The results suggest that LT is a promising method of WD management in patients with severe, neurological symptoms, particularly if the patient has not responded to pharmacological de-coppering treatment. Further studies of LT in these patients are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13760-022-01872-w.

Current aspects of renal dysfunction after liver transplantation

The development of chronic kidney disease (CKD) after liver transplantation (LT) exerts a severe effect on the survival of patients. The widespread adoption of the model for end-stage liver disease score strongly impacted CKD incidence after the procedure, as several patients are transplanted with previously deteriorated renal function. Due to its multifactorial nature, encompassing pre-transplantation conditions, perioperative events, and nephrotoxic immunosuppressor therapies, the accurate identification of patients under risk of renal disease, and the implementation of preventive approaches, are extremely important. Methods for the evaluation of renal function in this setting range from formulas that estimate the glomerular filtration rate, to non-invasive markers, although no option has yet proved efficient in early detection of kidney injury. Considering the nephrotoxicity of calcineurin inhibitors (CNI) as a factor of utmost importance after LT, early nephroprotective strategies are highly recommended. They are based mainly on delaying the application of CNI during the immediate postoperative-period, reducing their dosage, and associating them with other less nephrotoxic drugs, such as mycophenolate mofetil and everolimus. This review provides a critical assessment of the causes of renal dysfunction after LT, the methods of its evaluation, and the interventions aimed at preserving renal function early and belatedly after LT.

Current state of clinical trials regarding liver transplant rejection

BACKGROUND

Liver transplant (LT) is the second most common transplant intervention. The rate of acute cellular rejection (ACR) is 15-25% after LT, while being higher in chronic rejection (CR). Clinical trials had a major role in getting more potent and selective immunosuppressive medications. Our study plays an important role by evaluating and tracking clinical trials related to liver transplant rejection, focusing on interventional therapeutic trials.

METHODS

On October 28, we searched Clinicaltrials.gov for interventional clinical trials related to liver transplant rejection. A total of 27 clinical trials included in this study. Characteristics on each trial were collected, and availability of linked publications was searched using Medline/PubMed and Embase/Scopus. Content of publications was reviewed and main findings were summarized.

RESULTS

Majority of trials were completed (15 out of 27). Eleven trials had between 11 and 50 participants, and 10 had above 100. The study duration was between 1 and 4 years for the majority of trials (16 trials), with an average of 3.77 years. Most of the trials were done in Europe/UK/Russia (n = 12). The results were provided in 9 trials but published in 4, showing the possible tolerogenic efficacy of MSC in liver transplantation, increased success of immunosuppression (IS) withdrawal after sirolimus addition, efficacy of Alemtuzumab, normal graft function and stability within 1 year of immunosuppression withdrawal.

CONCLUSION

This study revealed a low number of trials, lack of variety in location and low publishing rates. The focus of trials was mainly towards side effects and safety of immunosuppressants, and their withdrawal. These trials reached results that must be built on to reach definitive guidelines and treatment strategies. This highlights the need for better management of human and financial resources, in order to reach new and more effective therapeutic strategies, leading to the decrease in rate of LTR.

Evaluation of rejection, infection, and malignancy outcomes in elderly liver transplant recipients receiving a similar level of immunosuppression compared to a younger group

Elderly liver transplant (LTx) recipients at a lower risk of acute rejection compared to younger recipients due to immunosenescence. As such, they may benefit from reduced immunosuppression (IS) to minimize infectious and malignant complications. We aimed to evaluate outcomes in LTx recipients ≥60 years compared to a younger group of LTx recipients aged 18-59 years maintained on a similar level of IS. This was a single-center retrospective evaluation of adult LTx recipients from 2013 to 2018 who received methylprednisolone induction and were maintained on tacrolimus, mycophenolate mofetil (MMF), and a prednisone taper. A total of 143 LTx recipients were evaluated. Mean age in the older group was 65 ± 3.8 compared to 49 ± 10.4 years in the younger group (p < 0.0001). Mean tacrolimus levels and the duration of MMF and steroids were comparable. Both groups had a similar incidence of first rejection within 1 year (19.2% in the elderly group vs. 23.1% in the younger group, p = 0.57). There were no statistical difference in terms of infection, malignancy, or patient survival. In conclusion, our data suggests that elderly LTx recipients, when treated with a similar level of IS, had similar 1 year incidence of rejection, infection, malignancy, and patient survival as younger LTx recipients.

Liver transplantation in malignant disease

Liver transplantation for malignant disease has gained increasing attention as part of transplant oncology. Following the implementation of the Milan criteria, hepatocellular carcinoma (HCC) was the first generally accepted indication for transplantation in patients with cancer. Subsequently, more liberal criteria for HCC have been developed, and research on this topic is still ongoing. The evident success of liver transplantation for HCC has led to the attempt to extend its indication to other malignancies. Regarding perihilar cholangiocarcinoma, more and more evidence supports the use of liver transplantation, especially after neoadjuvant therapy. In addition, some data also show a benefit for selected patients with very early stage intrahepatic cholangiocarcinoma. Hepatic epithelioid hemangioendothelioma is a very rare but nonetheless established indication for liver transplantation in primary liver cancer. In contrast, patients with hepatic angiosarcoma are currently not considered to be optimal candidates. In secondary liver tumors, neuroendocrine cancer liver metastases are an accepted but comparability rare indication for liver transplantation. Recently, some evidence has been published supporting the use of liver transplantation even for colorectal liver metastases. This review summarizes the current evidence for liver transplantation for primary and secondary liver cancer.

Designing and Psychometric Properties of Appraisal Adherence to Care and Treatment Scale in Liver Transplantation Recipients

Background: Care and treatment adherence are important factors for given good liver transplantation outcomes. Objectives: Design and validate an instrument to appraise adherence to care and treatment in liver transplantation recipients. Methods: A mixed-methods sequential exploratory study was conducted in two phases from 2017 to 2019, in the Liver Transplantation Clinic Tehran, Iran. In the qualitative phase, the concept of care and treatment adherence in liver transplantation recipients extracted by a conventional content analysis was performed on semi-structural interviews that were conducted on 18 liver transplantation recipients that were recruited through purposive sampling technique. Also, two physicians, one nurse coordinator of the liver transplantation team, and two family members were interviewed. The scale was developed based on operational definitions extracted from the qualitative phase. The validity was assessed by face, content, construct validity, and confirmatory factor analysis. The reliability was also evaluated by calculating test-retest intraclass correlation coefficient and Cronbach's alpha. The exploratory factor analysis was carried out with 286 filled the questionnaire. Results: Four factors were extracted in factor analysis. These factors explained 45.622% of the variance. The final version of the scale consisted of 20 items. The Cronbach's alpha coefficient reported as 0.889 for the total scale and the intraclass correlation coefficient was reported as 0.912. The confirmatory factor analysis led to a fitting model. Chi-square indices were reported as CMIN/DF = 2.34, NFI = 0.94, CFI = 0.96, and RAMSEA = 0.067. Conclusions: With a four factors structure, validity and reliability of adherence to care and treatment scale are acceptable; therefore, it can be used for appraisal care and treatment adherence in liver transplant recipients.

Outcomes after liver transplantation in Korea: Incidence and risk factors from Korean transplantation registry

BACKGROUND/AIMS

To analyze the incidence and risk factors of outcomes after liver transplantation (LT) in the Korean population.

METHODS

This study analyzed data from the liver cohort of Korean Organ Transplantation Registry (KOTRY) who had LT between May 2014 and December 2017. Study measures included the incidence of post-LT outcomes in recipients of living donor LT (LDLT) and deceased donor LT (DDLT). Cox multivariate proportional hazards model was used to determine the potential risk factors predicting the outcomes.

RESULTS

A total of 2,563 adult recipients with LT (LDLT, n=1,956; DDLT, n=607) were included, with mean±standard deviation age of 53.9±8.9 years, and 72.2% were male. The post-LT outcomes observed in each LDLT and DDLT recipients were death (4.0% and 14.7%), graft loss (5.0% and 16.1%), rejection (7.0% and 12.0%), renal failure (2.7% and 13.8%), new onset of diabetes (12.5% and 15.4%), and hepatocellular carcinoma (HCC) recurrence (both 6.7%). In both LDLT and DDLT recipients, the most common post-LT complications were renal dysfunction (33.6% and 51.4%), infection (26.7% and 48.4%), and surgical complication (22.5% and 23.9%). Incidence of these outcomes were generally higher among recipients of DDLT than LDLT. Multivariate analysis indicated recipient age and DDLT as significant risk factors associated with death and graft loss. DDLT and ABO incompatible transplant were prognostic factors for rejection, and HCC beyond Milan criteria at pre-transplant was a strong predictor of HCC recurrence.

CONCLUSION

This study is a good indicator of the post-LT prognosis in the Korean population and suggests a significant burden of post-LT complications.

Rapamycin treated tol-dendritic cells derived from BM-MSCs reversed graft rejection in a rat liver transplantation model by inducing CD8+CD45RC-Treg

OBJECTIVE

To investigate the influence of tolerance dendritic cells (tolDCs), generated from Bone marrow mesenchymal stem cells (BM-MSCs) treated with rapamycin (Rapa) on liver allograft survival in a rat acute liver transplantation model.

METHODS

Different GM-CSF induction project was used to obtain immature DCs (imDCs), mature DCs (matDCs) or tolDCs from BM-MSCs. First, MLR was performed to analyze the activity of tolDCs on polyclonaly stimulated total T cells. Then, co-cultured imDCs, matDCs and tolDCs with CD8⁺T cells isolated by magnetic activated cell sorting to analyze the influence on its regulatory characteristic. Last, the established rat acute liver transplantation model were adoptive transfused with imDCs, matDCs or tolDCs isolated by anti-CD11c immunomagnetic beads. The phenotype of DC cells and level of CD8⁺Treg in the culture system and in vivo, the expression of CD8 and CD45RC in the tissues were analyzed by flow cytometry and immunohistochemistry, respectively.

RESULTS

The loGM-CSF plus IL-4 decreased the costimulatory molecules of CD80/86 and MHC class II of DCs comparison with hiGM-CSF from BM-MSCs no matter whether stimulation by LPS (P<0.05). Rapa treated not only reduced the expression of CD80/86 and MHC class II but also down-regulated the expression of CD11c after LPS stimulation which was more obviously in tolDCs by loGM-CSF project (P<0.05). Moreover, tolDCs displayed a rather higher level of IL-10 and low level of IL-12p70 than others (P<0.01), which shown a rather lower stimulative effect on the proliferation of T cells comparison with matDCs and imDCs. Co-cultured with CD8⁺Treg showed an improvement on induction of CD8⁺TCR⁺CD45RC^-T cells (CD8⁺Treg) in ex vivo. The rats transfused with tolDCs has a delayed survival benefits with high level of CD8⁺Tregs (P<0.01) and high expression of CD45RC in liver tissue (P<0.01) and spleen when comparison with other groups. The infused tolDCs improved a mean survival time (MST) of 32 days comparison with a MTS of 9.5 days and 15.75 days displayed by rat that per-infused with matDCs and imDCs, respectively.

CONCLUSION

Rapa modified tolDCs derived from BM-MSCs reversed graft rejection by improve tolerance characteristics of CD8⁺CD45RC^-Treg in acute liver rat transplantation.

Long-term mortality risk stratification of liver transplant recipients: real-time application of deep learning algorithms on longitudinal data

BACKGROUND

Survival of liver transplant recipients beyond 1 year since transplantation is compromised by an increased risk of cancer, cardiovascular events, infection, and graft failure. Few clinical tools are available to identify patients at risk of these complications, which would flag them for screening tests and potentially life-saving interventions. In this retrospective analysis, we aimed to assess the ability of deep learning algorithms of longitudinal data from two prospective cohorts to predict complications resulting in death after liver transplantation over multiple timeframes, compared with logistic regression models.

METHODS

In this machine learning analysis, model development was done on a set of 42 146 liver transplant recipients (mean age 48·6 years [SD 17·3]; 17 196 [40·8%] women) from the Scientific Registry of Transplant Recipients (SRTR) in the USA. Transferability of the model was further evaluated by fine-tuning on a dataset from the University Health Network (UHN) in Canada (n=3269; mean age 52·5 years [11·1]; 1079 [33·0%] women). The primary outcome was cause of death, as recorded in the databases, due to cardiovascular causes, infection, graft failure, or cancer, within 1 year and 5 years of each follow-up examination after transplantation. We compared the performance of four deep learning models against logistic regression, assessing performance using the area under the receiver operating characteristic curve (AUROC).

FINDINGS

In both datasets, deep learning models outperformed logistic regression, with the Transformer model achieving the highest AUROCs in both datasets (p<0·0001). The AUROC for the Transformer model across all outcomes in the SRTR dataset was 0·804 (99% CI 0·795-0·854) for 1-year predictions and 0·733 (0·729-0·769) for 5-year predictions. In the UHN dataset, the AUROC for the top-performing deep learning model was 0·807 (0·795-0·842) for 1-year predictions and 0·722 (0·705-0·764) for 5-year predictions. AUROCs ranged from 0·695 (0·680-0·713) for prediction of death from infection within 5 years to 0·859 (0·847-0·871) for prediction of death by graft failure within 1 year.

INTERPRETATION

Deep learning algorithms can incorporate longitudinal information to continuously predict long-term outcomes after liver transplantation, outperforming logistic regression models. Physicians could use these algorithms at routine follow-up visits to identify liver transplant recipients at risk for adverse outcomes and prevent these complications by modifying management based on ranked features.

FUNDING

Canadian Donation and Transplant Research Program, CIFAR AI Chairs Program.

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Machine learning in liver transplantation: a tool for some unsolved questions?

Machine learning has recently been proposed as a useful tool in many fields of Medicine, with the aim of increasing diagnostic and prognostic accuracy. Models based on machine learning have been introduced in the setting of solid organ transplantation too, where prognosis depends on a complex, multidimensional and nonlinear relationship between variables pertaining to the donor, the recipient and the surgical procedure. In the setting of liver transplantation, machine learning models have been developed to predict pretransplant survival in patients with cirrhosis, to assess the best donor-to-recipient match during allocation processes, and to foresee postoperative complications and outcomes. This is a narrative review on the role of machine learning in the field of liver transplantation, highlighting strengths and pitfalls, and future perspectives.

Perioperative management of patients with pulmonary hypertension undergoing non-cardiothoracic, non-obstetric surgery: a systematic review and expert consensus statement

BACKGROUND

The risk of complications, including death, is substantially increased in patients with pulmonary hypertension (PH) undergoing anaesthesia for surgical procedures, especially in those with pulmonary arterial hypertension (PAH) and chronic thromboembolic PH (CTEPH). Sedation also poses a risk to patients with PH. Physiological changes including tachycardia, hypotension, fluid shifts, and an increase in pulmonary vascular resistance (PH crisis) can precipitate acute right ventricular decompensation and death.

METHODS

A systematic literature review was performed of studies in patients with PH undergoing non-cardiac and non-obstetric surgery. The management of patients with PH requiring sedation for endoscopy was also reviewed. Using a framework of relevant clinical questions, we review the available evidence guiding operative risk, risk assessment, preoperative optimisation, and perioperative management, and identifying areas for future research.

RESULTS

Reported 30 day mortality after non-cardiac and non-obstetric surgery ranges between 2% and 18% in patients with PH undergoing elective procedures, and increases to 15-50% for emergency surgery, with complications and death usually relating to acute right ventricular failure. Risk factors for mortality include procedure-specific and patient-related factors, especially markers of PH severity (e.g. pulmonary haemodynamics, poor exercise performance, and right ventricular dysfunction). Most studies highlight the importance of individualised preoperative risk assessment and optimisation and advanced perioperative planning.

CONCLUSIONS

With an increasing number of patients requiring surgery in specialist and non-specialist PH centres, a systematic, evidence-based, multidisciplinary approach is required to minimise complications. Adequate risk stratification and a tailored-individualised perioperative plan is paramount.

Long-Term Tacrolimus Blood Trough Level and Patient Survival in Adult Liver Transplantation

Tacrolimus is the most widely used immunosuppressant in liver transplant (LT) patients. However, the ideal long-term target level for these patients is unknown. This retrospective study aimed to investigate the impact of tacrolimus blood concentration five years after LT on long-term patient survival outcomes in adult LT recipients. Patients who underwent LT between January 2004 and July 2014 at a tertiary medical center were included in this study (n = 189). The mean tacrolimus blood concentrations of each patient during the fifth year after LT were recorded and the overall survival rate was determined. A multivariate analysis of factors associated with long-term survival was conducted using a Cox’s model. The median follow-up period was 9.63 years, and 144 patients (76.2%) underwent live donor LT. Sixteen patients died within 5 years of LT. In the Cox’s model, patients with a mean tacrolimus blood trough level of 4.6–10.2 ng/mL had significantly better long-term survival than those with a mean tacrolimus blood trough level outside this range (estimated hazard ratio = 4.76; 95% confidence interval: 1.34–16.9, p = 0.016). Therefore, a tacrolimus level no lower than 4.6 ng/mL would be recommended in adult LT patients.

Identification of peripheral CD154+ T cells and HLA-DRB1 as biomarkers of acute cellular rejection in adult liver transplant recipients

Decreasing graft rejection and increasing graft and patient survival are great challenges facing liver transplantation (LT). Different T cell subsets participate in the acute cellular rejection (ACR) of the allograft. Cell-mediated immunity markers of the recipient could help to understand the mechanisms underlying acute rejection. This study aimed to analyse different surface antigens on T cells in a cohort of adult liver patients undergoing LT to determine the influence on ACR using multi-parametric flow cytometry functional assay. Thirty patients were monitored at baseline and during 1 year post-transplant. Two groups were established, with (ACR) and without (NACR) acute cellular rejection. Leukocyte, total lymphocyte, percentages of CD4+ CD154+ and CD8+ CD154+ T cells, human leukocyte antigen (HLA) mismatch between recipient-donor and their relation with ACR as well as the acute rejection frequencies were analysed. T cells were stimulated with concanavalin A (Con-A) and surface antigens were analysed by fluorescence activated cell sorter (FACS) analysis. A high percentage of CD4+ CD154+ T cells (P = 0·001) and a low percentage of CD8+ CD154+ T cells (P = 0·002) at baseline were statistically significant in ACR. A receiver operating characteristic analysis determined the cut-off values capable to stratify patients at high risk of ACR with high sensitivity and specificity for CD4+ CD154+ (P = 0·001) and CD8+ CD154+ T cells (P = 0·002). In logistic regression analysis, CD4+ CD154+ , CD8+ CD154+ and HLA mismatch were confirmed as independent risk factors to ACR. Post-transplant percentages of both T cell subsets were significantly higher in ACR, despite variations compared to pretransplant. These findings support the selection of candidates for LT based on the pretransplant percentages of CD4+ CD154+ and CD8+ CD154+ T cells in parallel with other transplant factors.

Current Challenges in the Post-Transplant Care of Liver Transplant Recipients in Germany

Improving long-term patient and graft survival after liver transplantation (LT) remains a major challenge. Compared to the early phase after LT, long-term morbidity and mortality of the recipients not only depends on complications immediately related to the graft function, infections, or rejection, but also on medical factors such as de novo malignancies, metabolic disorders (e.g., new-onset diabetes, osteoporosis), psychiatric conditions (e.g., anxiety, depression), renal failure, and cardiovascular diseases. While a comprehensive post-transplant care at the LT center and the connected regional networks may improve outcome, there is currently no generally accepted standard to the post-transplant management of LT recipients in Germany. We therefore described the structure and standards of post-LT care by conducting a survey at 12 German LT centers including transplant hepatologists and surgeons. Aftercare structures and form of cost reimbursement considerably varied between LT centers across Germany. Further discussions and studies are required to define optimal structure and content of post-LT care systems, aiming at improving the long-term outcomes of LT recipients.

Effective dose for multiple and repeated radiation examinations in donors and recipients of adult-to-adult living donor liver transplants at a single center

PURPOSE

To evaluate the effective doses received by donors and recipients, identify effective dose contributions, and make risk assessments.

MATERIALS AND METHODS

It was a retrospective study. 100 Donors and 100 recipients were enrolled with an operative day from March 2016 to August 2017. The dose was analyzed for all radiation-related examinations over a period of 2 years, 1 year before and 1 year after the LDLT procedure. The effective doses of plain X-rays, CT, fluoroscopy, and nuclear medicine per patient were simulated by a Monte Carlo software, evaluated by the dose-length product conversion factors, evaluated by the dose-area product conversion factors, and evaluated by the activity conversion factors, respectively. The risks of radiation-induced cancer were assessed on the basis of the ICRP risk model.

RESULTS

The median effective doses were 71 (range: 30-186) mSv for donors and 147 (32-423) mSv for recipients. The radiation examinations were mainly performed in the last three months of preoperative period to first month of postoperative period for recipients and donors. The HCC recipients received a higher effective dose, 195 (64-423) mSv, than those with other indications. The median radiation-induced cancer risk was 0.38 % in male and 0.48 % in female donors and was 0.50 % in male and 0.58 % in female recipients.

CONCLUSION

Donors and recipients received a large effective dose, mainly from the CT scans. To reduce effective doses should be included in future challenges in some living donor liver transplants centers that often use CT examinations.

Medical management of metabolic and cardiovascular complications after liver transplantation

Liver transplantation represents the only curative option for patients with end-stage liver disease, fulminant hepatitis and advanced hepatocellular carcinoma. Even though major advances in transplantation in the last decades have achieved excellent survival rates in the early post-transplantation period, long-term survival is hampered by the lack of improvement in survival in the late post transplantation period (over 5 years after transplantation). The main etiologies for late mortality are malignancies and cardiovascular complications. The latter are increasingly prevalent in liver transplant recipients due to the development or worsening of metabolic syndrome and all its components (arterial hypertension, dyslipidemia, obesity, renal injury, etc.). These comorbidities result from a combination of pre-liver transplant features, immunosuppressive agent side-effects, changes in metabolism and hemodynamics after liver transplantation and the adoption of a sedentary lifestyle. In this review we describe the most prevalent metabolic and cardiovascular complications present after liver transplantation, as well as proposing management strategies.

Post Liver Transplantation Survival and Related Prognostic Factors among Adult Recipients in Tehran Liver Transplant Center; 2002-2019

BACKGROUND

Liver transplantation is a standard treatment for patients with end-stage liver disease (ESLD). However, with increasing demand for this treatment and limited resources, it is available only to patients who are more likely to survive. The primary aim was to determine prognostic factors for survival.

METHODS

We collected data from 597 adult patients with ESLD, who received a single organ and initial orthotopic liver transplantation (OLT) in our center between 20 March 2008 and 20 March 2018. In this historical cohort study, univariate and multiple Cox model were used to determine prognostic factors of survival after transplantation.

RESULTS

After a median follow-up of 825 (0-3889) days, 111 (19%) patients died. Survival rates were 88%, 85%, 82% and 79% at 90 days, 1 year, 3 years, and 5 years, respectively. Older patients (HR = 1.27; 95% CI: 1.01-1.59), presence of pre-OLT ascites (HR = 2.03; 95% CI: 1.16-3.57), pre-OLT hospitalization (HR = 1.88; 95% CI:1.02-3.46), longer operative time (HR = 1.006; 95% CI: 1.004-1.008), post-OLT dialysis (HR = 3.51; 95% CI: 2.07-5.94), cancer (HR = 2.69; 95% CI: 1.23-5.89) and AID (HR = 2.04; 95% CI: 1.17-3.56) as underlying disease versus hepatitis, and higher pre-OLT creatinine (HR = 1.67; 95% CI: 1.10-2.52) were associated with decreased survival.

CONCLUSION

In this center, not only are survival outcomes excellent, but also younger patients, cases with better pre-operative health conditions, and those without complications after OLT have superior survival.

Preoperative cardiac assessment in liver transplant candidates

New and extended indications, older age, higher cardiovascular risk, and the long-standing cirrhosis-associated complications mandate specific skills for an appropriate preoperative assessment of the liver transplant (LT) candidate. The incidence of cardiac diseases (dysrhythmias, cardiomyopathies, coronary artery disease, valvular heart disease) are increasing among LT recipients: however, no consensus exists among clinical practice guidelines for cardiovascular screening and risk stratification. In spite of different "transplant center-centered protocols", basic "pillars" are common (electrocardiography, baseline echocardiography, functional assessment). Owing to intrinsic limitations, yields and relevance of noninvasive stress tests, under constant scrutiny even if used, are discussed, focusing the definition of the "high risk" candidate and exploring noninvasive imaging and new forms of stress imaging. The aim is to find an appropriate and rational stepwise algorithm. The final commitment is to select the right candidate for a finite resource, the graft, able to save (and change) lives.

Liver transplantation in Jehovah's witnesses: 13 consecutive cases at a single institution

Background

Jehovah’s Witnesses represent a tremendous clinical challenge when indicated to liver transplantation because they refuse blood transfusion on religious grounds and the procedure is historically associated with potential massive peri-operative blood loss. We herein describe a peri-operative management pathway with strategies toward a transfusion-free environment with the aim not only of offering liver transplant to selected Jehovah’s Witnesses patients but also, ultimately, of translating this practice to all general surgical procedures.

Methods

This is a retrospective review of prospective medical records of JW patients who underwent LT at our Institution. The peri-operative multimodal strategy to liver transplantation in Jehovah’s Witnesses includes a pre-operative red cell mass optimization package and the intra-operative use of normovolemic haemodilution, veno-venous bypass and low central venous pressure.

Results

In a 9-year period, 13 Jehovah’s Witness patients received liver transplantation at our centre representing the largest liver transplant program from deceased donors in Jehovah’s Witnesses patients reported so far. No patient received blood bank products but 3 had fibrinogen concentrate and one tranexamic acid to correct ongoing hyper-fibrinolysis. There were 4 cases of acute kidney injury (one required extracorporeal renal replacement treatment) and one patient needed vasoactive medications to support blood pressure for the first 2 postoperative days. Two patients underwent re-laparotomy. Finally, of the 13 recipients, 12 were alive at the 1 year follow-up interview and 1 died due to septic complications.

Conclusions

Our experience confirms that liver transplantation in selected Jehovah’s Witnesses patients can be feasible and safe provided that it is carried out at a very experienced centre and according to a multidisciplinary approach.

Comprehensive characterization of ureagenesis in the spfash mouse, a model of human ornithine transcarbamylase deficiency, reveals age-dependency of ammonia detoxification

The most common ureagenesis defect is X-linked ornithine transcarbamylase (OTC) deficiency which is a main target for novel therapeutic interventions. The spf ^ash mouse model carries a variant (c.386G>A, p.Arg129His) that is also found in patients. Male spf ^ash mice have a mild biochemical phenotype with low OTC activity (5%-10% of wild-type), resulting in elevated urinary orotic acid but no hyperammonemia. We recently established a dried blood spot method for in vivo quantification of ureagenesis by Gas chromatography-mass spectrometry (GC-MS) using stable isotopes. Here, we applied this assay to wild-type and spf ^ash mice to assess ureagenesis at different ages. Unexpectedly, we found an age-dependency with a higher capacity for ammonia detoxification in young mice after weaning. A parallel pattern was observed for carbamoylphosphate synthetase 1 and OTC enzyme expression and activities, which may act as pacemaker of this ammonia detoxification pathway. Moreover, high ureagenesis in younger mice was accompanied by elevated periportal expression of hepatic glutamine synthetase, another main enzyme required for ammonia detoxification. These observations led us to perform a more extensive analysis of the spf ^ash mouse in comparison to the wild-type, including characterization of the corresponding metabolites, enzyme activities in the liver and plasma and the gut microbiota. In conclusion, the comprehensive enzymatic and metabolic analysis of ureagenesis performed in the presented depth was only possible in animals. Our findings suggest such analyses being essential when using the mouse as a model and revealed age-dependent activity of ammonia detoxification.

Posttransplant Calcineurin Inhibitors Levels and Intrapatient Variability Are Not Associated With Long-term Outcomes Following Liver Transplantation

BACKGROUND

There is an interest in understanding the association between early calcineurin inhibitors exposure post-liver transplantation (LT) and long-term outcomes. We aimed to analyze this association exploring median calcineurin inhibitor levels and intrapatient variability (IPV) in a multicenter, retrospective cohort.

METHODS

Tacrolimus (Tac) and Cyclosporine (CsA) levels obtained during the first 15 days post-LT were collected. High immunosuppression (IS) was considered as a median of Tac, CsA blood trough levels 12 hours after drug administration, or blood levels 2 hours after drug administration higher than 10, 250, or 1200 ng/mL, respectively, or a peak of Tac >20 ng/mL. Optimal IS was defined as a median of Tac, CsA blood trough levels 12 hours after drug administration, or blood levels 2 hours after drug administration levels between 7 and 10, 150 and 250, or 800 and 1200 ng/mL. Low IS was defined as below the thresholds of optimal IS. IPV was estimated during the first 15 days post-LT.

RESULTS

The study included 432 patients with a median follow-up of 8.65 years. IS regimen was based on either Tac or CsA in 243 (56.3%) and 189 (43.8%), respectively. There were no differences in terms of graft loss among low versus optimal and high IS groups (P = 0.812 and P = 0.451) nor in high versus low IPV (P = 0.835). Only viral hepatitis and arterial hypertension were independently associated with higher graft loss (hazard ratio = 1.729, P = 0.029 and hazard ratio = 1.570, P = 0.021).

CONCLUSIONS

In contrast to what has previously been reported, no association was found between very early postoperative over IS or high IPV and long-term outcome measures following LT. Strategies aimed at reducing these long-term events should likely focus on other factors or on a different IS time window.

Liver transplantation for unresectable malignancies: Beyond hepatocellular carcinoma

Indications for liver transplantation have expanded over the past few decades owing to improved outcomes and better understanding of underlying pathologies. In particular, there has been a growing interest in the field of transplant oncology in recent years that has led to considerable developments which have pushed the boundaries of malignant indications for liver transplantation beyond hepatocellular carcinoma (HCC). In this article, we review and summarise the published evidence for liver transplantation in non-HCC primary and metastatic liver malignancies and highlight ongoing clinical trials that address unresolved questions therein. We also examine the current technical, immunological and oncological challenges that face liver transplantation in this growing field and explore potential approaches to overcome these barriers.

Is everolimus linked to metabolic syndrome in liver transplant recipients?

BACKGROUND

As the mortality rates after liver transplantation (LT) have been reduced, the attention has shifted to additional conditions which still compromise the quality of life and the survival of these patients, such as the post-LT metabolic syndrome (MS). In order to determine the prevalence and the factors associated with the post-LT MS, we carried out the present study.

METHODS

One hundred and six LT recipients, after completing at least 1 year follow up after LT, were included in the study. Data on clinical, laboratory parameters and immunosuppressive therapy before and after LT were recorded. MS was defined as per current diagnostic criteria.

RESULTS

MS was prevalent in 47.2% (50 of 106 patients) and was not associated with the LT indications and the time period after LT. Univariate analysis showed that history of diabetes mellitus before (odds ratio [OR] 3.2, 95% confidence interval [CI] 1.046-9.918, p = 0.042) and after LT (OR 6.03, 95% CI 2.18-16.67, p = 0.001), the age at the time of baseline visit (OR 1.077, 95% CI 1.033-1.124, p = 0.001) and the everolimus-based immunosuppression (OR 1.23, 95% CI 1.003-1.33, p = 0.019) were significantly associated with MS. Notably, everolimus administration was the only factor independently associated with the presence of post-LT MS (OR 1.026, 95% CI 1.004-1.047, p = 0.019). More specifically, everolimus was linked to the presence of arterial hypertension (OR 1.02, 95% CI 1.0-1.03, p = 0.05) and hyperlipidemia (OR 2.87, 95% CI 1.28-6.56, p = 0.011).

CONCLUSIONS

Our study demonstrated for the first time that everolimus was independently associated with post-LT MS. Nevertheless, more robust studies are required to confirm these findings.

D-dopachrome tautomerase predicts outcome but not the development of acute kidney injury after orthotopic liver transplantation

BACKGROUND

Elevated concentrations of D-dopachrome tautomerase (D-DT) were associated with adverse outcome in various clinical settings. However, no study assessed D-DT concentrations in patients requiring orthotopic liver transplantation (OLT). The aim of this observational study was to measure serum D-DT concentrations in patients undergoing OLT and associate D-DT with survival and acute kidney injury (AKI).

METHODS

Forty-seven adults with end-stage liver disease undergoing OLT were included. Areas under the receiver operating curves (AUC) were calculated to assess predictive values of D-DT for outcome and AKI after OLT. Survival was analyzed by Kaplan-Meier curves.

RESULTS

Serum D-DT concentrations were greater in non-survivors than in survivors prior to OLT (86 [50-117] vs. 53 [31-71] ng/ml, P = 0.008), and on day 1 (357 [238-724] vs. 189 [135-309] ng/ml, P = 0.001) and day 2 (210 [142-471] vs. 159 [120-204] ng/ml, P = 0.004) following OLT. Serum D-DT concentrations predicted lethal outcome when measured preoperatively (AUC = 0.75, P = 0.017) and on postoperative day 1 (AUC = 0.75, P = 0.015). One-year survival of patients with preoperative D-DT concentrations >85 ng/ml was 50%, whereas that of patients with preoperative D-DT concentrations <85 ng/ml was 83% (Chi² = 5.83, P = 0.016). In contrast, D-DT was not associated with AKI after OLT.

CONCLUSION

In patients undergoing OLT, serum D-DT might predict outcome after OLT.