Orthotopic liver transplantation and what to do during follow-up: recommendations for the practitioner

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.

Lebertransplantation in der Schweiz 2020

Die Lebertransplantation ist in den letzten beinahe 40 Jahren zu einer etablierten Therapie der fortgeschrittenen Leberzirrhose, des akuten Leberversagens sowie gewisser auf die Leber beschränkter Tumorerkrankungen geworden und stellt somit für viele unserer Patientinnen und Patienten eine lebensrettende Behandlungsmöglichkeit dar. Leider jedoch ist der Zugang zu einer Lebertransplantation dadurch limitiert, dass nicht für alle Patientinnen und Patienten ausreichend Spenderorgane zur Verfügung stehen. Der folgende Artikel fasst die wichtigsten Punkte zur Indikation, Abklärung vor Transplantation sowie zum Management nach der Transplantation zusammen.

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.

Medical care of liver transplant patients

INTRODUCTION

Liver transplantation is a life-changing event for patients and survival following transplantation has improved significantly since the first transplantation in 1967. Following liver transplantation, patients face a unique set of healthcare management decisions including transplantation-specific complications, recurrence of primary liver disease, as well as metabolic and malignancy concerns related to immunosuppression. As more patients with liver disease receive transplantation and live longer, understanding and managing these patients will require not only transplant specialist but also local subspecialist and primary care physicians.

AREAS COVERED

This review covers common issues related to the management of patients following liver transplantation including immunosuppression, liver allograft dysfunction, metabolic complications, as well as routine health maintenance such as immunizations and cancer screening.

EXPERT OPINION

Optimizing medical care for patients following liver transplant will benefit from ensuring all providers, not just transplant specialist, have a basic understanding of the common issues encountered in the post-transplant patient. This review provides an overview of common healthcare concerns and management options for patients following liver transplantation.

Coupling AAV-mediated promoterless gene targeting to SaCas9 nuclease to efficiently correct liver metabolic diseases

Non-integrative AAV-mediated gene therapy in the liver is effective in adult patients, but faces limitations in pediatric settings due to episomal DNA loss during hepatocyte proliferation. Gene targeting is a promising approach by permanently modifying the genome. We previously rescued neonatal lethality in Crigler-Najjar mice by inserting a promoterless human uridine glucuronosyl transferase A1 (UGT1A1) cDNA in exon 14 of the albumin gene, without the use of nucleases. To increase recombination rate and therapeutic efficacy, here we used CRISPR/SaCas9. Neonatal mice were transduced with two AAVs: one expressing the SaCas9 and sgRNA, and one containing a promoterless cDNA flanked by albumin homology regions. Targeting efficiency increased ~26-fold with an eGFP reporter cDNA, reaching up to 24% of eGFP-positive hepatocytes. Next, we fully corrected the diseased phenotype of Crigler-Najjar mice by targeting the hUGT1A1 cDNA. Treated mice had normal plasma bilirubin up to 10 months after administration, hUGT1A1 protein levels were ~6-fold higher than in WT liver, with a 90-fold increase in recombination rate. Liver histology, inflammatory markers, and plasma albumin were normal in treated mice, with no off-targets in predicted sites. Thus, the improved efficacy and reassuring safety profile support the potential application of the proposed approach to other liver diseases.

Recent advances in understanding and managing liver transplantation

Liver transplantation (LT) has been established as the most effective treatment modality for end-stage liver disease over the last few decades. Currently, patient and graft survival after LT are excellent, with 1- and 5-year survival of 90% and 80%, respectively. However, the timing of referral to LT is crucial for improving survival benefit and outcome. The current shortage of donors and the increasing demand for LT currently lengthen the waiting time. Thus, waiting list mortality is about 10–15%, according to the geographical area. For this reason, over the last several years, alternatives to deceased donor LT and new options for prioritizing patients on the waiting list have been proposed.

Postoperative Delirium After Liver Transplantation is Associated With Increased Length of Stay and Lower Survival in a Prospective Cohort

Introduction:

Although postoperative delirium (POD) is a common in-hospital complication associated with negative outcomes, evidence in liver transplantation (LT) is scarce.

Objective:

We examined the incidence and duration of POD, its impact on outcomes and health-care utilization, and described predisposing and precipitating factors favoring POD development.

Design:

This prospective cohort study included adults undergoing transplantation in a tertiary hospital. Postoperative delirium was assessed 3 times daily until 24 days post-LT, with the Intensive Care Delirium Screening Checklist on the intensive care unit (ICU) and the Delirium Observation Screening Scale on the ward. Postoperative delirium was noted if any of the daily measurements was positive.

Results:

Forty-two patients (69% male, mean age 55 years, median Model for End-Stage Liver Disease score 15 [interquartile range 8-26]) were included. The incidence of POD was 45.2%, with a median duration of 5 days. Patients with POD had longer ICU (median 8 vs 2 days, P = .000) and hospital stays (median 32 vs 14 days, P = .000) as well as shorter survival (Breslow test P = .045, log-rank test P = .150). Pre-LT comorbidities and perioperative factors might be related to POD development.

Conclusion:

Nurses are key persons in the detection of POD in the daily clinical routine. The high incidence of POD and its negative association with patient outcomes highlight not only the relevance of systematic assessment of POD after LT but also the need for preventive interventions.

Cost-effectiveness of everolimus plus reduced tacrolimus in de novo liver-recipients in the Italian setting

INTRODUCTION

Long-term exposure to calcineurin inhibitor-based immunosuppressant (IS) therapy in liver transplant (LT) recipients is associated with renal complications. In the randomized trial H2304, everolimus + reduced-dose tacrolimus (EVR + rTAC) demonstrated equivalent efficacy and superior renal function compared to standard-dose tacrolimus.

METHODS

To evaluate the cost-effectiveness of EVR + rTAC vs TAC, in de novo LT patients, a Markov model simulating both liver and kidney function was developed and estimated the long-term outcomes of IS following LT. The analysis used the Italian healthcare payer perspective.

RESULTS

Patients treated with EVR + rTAC gained on average 1.92 years and 1.62 quality-adjusted life years (QALYs). The incremental cost-effectiveness ratios (ICER) were €35,851 and €42,567 for LY gained and QALY gained, respectively. For the hepatitis-c sub-population, the ICERs decreased to €22,519 and €30,658, respectively.

CONCLUSION

EVR + rTAC improves survival and quality-of-life and is a cost-effective alternative to calcineurin-inhibitor monotherapy for patients requiring LT.

Cystic fibrosis related liver disease--another black box in hepatology

Due to improved medical care, life expectancy in patients with cystic fibrosis (CF) has veritably improved over the last decades. Importantly, cystic fibrosis related liver disease (CFLD) has become one of the leading causes of morbidity and mortality in CF patients. However, CFLD might be largely underdiagnosed and diagnostic criteria need to be refined. The underlying pathomechanisms are largely unknown, and treatment strategies with proven efficacy are lacking. This review focuses on current invasive and non-invasive diagnostic standards, the current knowledge on the pathophysiology of CFLD, treatment strategies, and possible future developments.

Care of the liver transplant patient

OBJECTIVE

To provide an approach to the care of liver transplant (LT) patients, a growing patient population with unique needs.

METHODS

A literature search of PubMed for guidelines and review articles using the keywords "liver transplantation", "long term complications" and "medical management" was conducted, resulting in 77 articles.

RESULTS

As a result of being on immunosuppression, LT recipients are at increased risk of infections and must be screened regularly for metabolic complications and malignancies.

DISCUSSION

Although immunosuppression is key to maintaining allograft health after transplantation, it comes with its own set of medical issues to follow. Physicians following LT recipients must be aware of the greater risk for hypertension, diabetes, dyslipidemia, renal failure, metabolic bone disease and malignancies in these patients, all of whom require regular monitoring and screening. Vaccination, quality of life, sexual function and pregnancy must be specifically addressed in transplant patients.

Evolution and trends in reconstructive facial surgery: an update

Surgical correction of congenital and acquired facial deformities has transcended the primitive era of using non biologic materials to current attempts at own face growing through biotechnology. A summative account of this trend is still lacking in the literature. The objective of this article is to present an update on current knowledge in the strides to achieve functionally and aesthetically perfect facial reconstruction. It highlights the impact of advancements in 3D imaging, stereolithographic biomodelling, microvascular surgical tissue transplantation and tissue biotechnology in the surgical efforts to solve the problems of facial disfigurement whether congenital or acquired.

Long-term medical management of the liver transplant recipient: what the primary care physician needs to know

Recognition, management, and prevention of medical complications and comorbidities after liver transplant is the key to improved long-term outcomes. Beyond allograft-related complications, metabolic syndrome, cardiovascular disease, renal dysfunction, and malignancies are leading causes of morbidity and mortality in this patient population. Primary care physicians have an important role in improving outcomes of liver transplant recipients and are increasingly relied on for managing these complex patients. This review serves to assist the primary care physician in the long-term management issues of liver transplant recipients.

Depressive symptoms predict long-term mortality after liver transplantation

OBJECTIVE

Depressive symptoms are common after liver transplantation (LT). We studied whether depressive symptoms affect long-term survival after LT.

METHODS

In a prospective cohort study, 134 liver transplant patients were assessed for depressive symptoms using the Beck Depression Inventory-short form (BDI), focusing on the 3 months post-LT score and on the score change from the waiting list period. They were followed up for long-term survival. The median duration of the follow-up period was 43 months post-LT. None of the 134 patients was lost to follow-up for survival.

RESULTS

A total of 33.6% of the LT patients had mild to moderate depressive symptoms 3 months post-LT. Eighteen (13.4%) patients died during the follow-up. Using Cox proportional hazards analysis, depressive symptoms were significantly associated with mortality (hazard ratio [HR] 1.22, 95% confidence interval (CI) 1.07-1.40, P<.003), one more point in the BDI score being associated with a 17% increase in mortality risk. Other predictive factors of mortality were older age and hepatitis C virus with recurrence 3 months post-LT. Similarly, an increase in depressive symptoms between the waiting list and 3 months post-LT periods predicted mortality (HR 1.18, 95% CI 1.01-1.38, P=.03), especially for patients without depressive symptoms on waiting list (HR 1.56, 95% CI 1.16-2.12, P=.004).

CONCLUSION

Depressive symptoms after LT and an increase in depressive symptoms between the waiting list and post-LT are associated with an increased risk of long-term mortality. Interventions that could reduce depressive symptoms could potentially decrease long-term mortality after LT.

Long-term results of liver transplantation

Liver transplantation (LT) is an established therapy associated with a dramatic improvement in patients life expectancy. With improved early-term management, current 10-year patient survival rates in many indications exceed 70%. Life-long immunosuppressive therapy may, however, be accompanied by considerable longterm toxicity: most importantly, renal dysfunction, cardiovascular disease, and cancer, which, in addition to recurrence of the primary liver disease, emerge as key contributors to late mortality. Chronic kidney disease cumulatively affects up to 28% of patients by ten years after LT. Various factors can contribute to renal impairment, but perioperative acute kidney injury, calcineurin inhibitor toxicity, hypertension, and diabetes are considered most important. LT patients demonstrate 3-fold risk for cardiovascular events, which seems to result mostly from an excess of traditional risk factors, mainly hypertension and diabetes. The cumulative cancer incidence reaches 16-42% by 20 years after LT, and cancer rates are 2- to 4-fold higher among LT patients than among matched controls. Highest rates are for nonmelanoma skin cancer (3- to 70-fold) and lymphoma (8- to 29-fold). The liver graft usually displays uncomplicated function in the long term. Most common causes for chronic graft dysfunction include disease recurrence and biliary problems. LT generally restores patients quality of life to a level comparable with that of the general population, with only minor deficits in some areas. Thus, long-term survival after LT is impressive, and despite these long-term complications, patients quality of life remains comparable with that of the general population.

Reduction in functional ability is significant postliver transplantation compared with matched liver disease and community dwelling controls

We compared functional ability and symptom severity in liver transplant recipients and matched chronic liver disease (CLD) and community controls. A total of 103/140 consecutive liver transplant recipients from a single centre (73%) and matched controls completed the patient-reported functional outcome measure: Patient-Reported Outcomes Measurement Information System, Health Assessment Questionnaire (PROMIS HAQ). Symptoms frequently seen in CLD were quantified by (i) Fatigue Impact Scale (FIS), (ii) Orthostatic Grading Scale (OGS: autonomic dysfunction), (iii) Cognitive Failures Questionnaire (CFQ) and (iv) Epworth Sleepiness Scale (ESS: Daytime somnolence). Liver transplant recipients exhibited significant reduction in function (P<0.0001) across all domains of the PROMIS HAQ suggesting that functional impairment is broad-based. Seventy-seven per cent of all postliver transplants identified some difficulty with activities of daily living. There was no relationship between PROMIS HAQ and liver biochemistry (r²=0.04, P=NS) or time since transplant (r² =0.1, P=NS). Elevation in PROMIS HAQ (and therefore functional impairment) strongly associated with symptoms, particularly fatigue, cognitive impairment and daytime somnolence. Fatigue severity was independently associated with functional impairment (FIS) (Beta 0.727, P < 0.0001). Symptoms or functional ability was not different between liver transplant recipients and matched chronic liver disease controls. Although survival postliver transplantation is improving, our cross-sectional study suggests that functional ability may not improve postliver transplantation. Further study is warranted to address the mechanisms responsible for post-transplant functional impairment and to develop effective rehabilitation regimes to maximize function following liver transplantation.

Infectious complications more than 1 year after liver transplantation: a 3-decade nationwide experience

Because few reports have addressed infections late (≥1 year) after liver transplantation (LT), we evaluated the incidence, risk factors and pathogens involved. Infection data were from the Finnish LT registry, with starting date, type and relevant pathogens for 501 Finnish adult LT patients surviving ≥1 year post-transplant. Follow-up end points were end of study, death or retransplantation. Logistic regression to assess risk factors was adjusted for age, gender and follow-up time. With 3923 person-years of follow-up, overall infection incidence was 66/1000 person-years; 155 (31%) suffered 259 infections, and two-thirds experienced only one infection. Cholangitis (20%), pneumonia (19%) and sepsis (14%) were most common. The most frequent bacteria were Enterococcus spp. and Escherichia coli, and the most frequent viruses cytomegalovirus and varicella zoster virus. Fungal infections were rare (n = 7). With 13 fatal infections, 17% of all late deaths involved infection. Primary sclerosing cholangitis (PSC) and Roux-en-Y-type biliary anastomosis were associated with cholangitis; 18% of PSC patients suffered late cholangitis. Late acute rejection was associated with sepsis. Age, gender or cytomegalovirus did not significantly influence late infections. In conclusion, although infection risk under maintenance immunosuppression therapy is relatively low, particular vigilance regarding cholangitis, pneumonia and sepsis seems appropriate.

The perceived threat of the risk for graft rejection and health-related quality of life among organ transplant recipients

AIMS

This study was primarily aimed for developing and testing a valid and reliable instrument that measures perceived threat of the risk for graft rejection after organ transplantation. A second aim was to report descriptive data regarding graft rejection and Health-Related Quality of Life.

BACKGROUND

The most serious risk connected with transplantations besides infection is graft rejection.

DESIGN

Non experimental, descriptive involving instrument development and psychometric assessment.

METHOD

Questionnaires about perceived threat of the risk for graft rejection and Health-Related Quality of Life were mailed to 229 OTRs between 19-65 years old. The items were formed from a previous interview study. Patients were transplanted with a kidney, a liver or a heart and/or a lung. All patients with follow-up time of one year ± three months and three years ± three months were included.

RESULTS

With an 81% response rate, the study comprised of 185 OTRs, who had received either a kidney (n = 117), a liver (n = 39) or heart or lung (n = 29). Three homogenous factors of perceived threat for graft rejection were revealed, labelled 'intrusive anxiety', 'graft-related threat' and 'lack of control'. Tests of internal consistency showed good item-scale convergent and discriminatory validity. A majority of the OTRs scored low levels for 'intrusive anxiety'. The kidney transplant recipients experienced more 'graft-related threat' by acute graft rejection than those transplanted with a liver, heart or lung.

CONCLUSION

In conclusion, this study suggests that it is possible to measure the perceived threat of the risk for graft rejection in three homogenous factors. Relevance to clinical practice.  The instrument perceived threat of the risk for graft rejection, might be usable to measure the impact of fear of graft rejection, to predict needs of pedagogical intervention strategies to reduce fear and to improve Health-Related Quality of Life related to graft rejection.

Recurrent nonviral liver disease following liver transplantation

Recurrent disease after liver transplantation is well recognized and remains a potential cause of premature graft loss. The rates of recurrence are difficult to establish because of the lack of consistency in diagnostic criteria and approaches to diagnosis. Owing to the fact that recurrent parenchymal disease may occur in the presence of normal liver tests, those centers that use protocol biopsies will report greater rates of recurrence. It is important to recognize that rates of recurrence vary according to indication and show little correlation with rates of graft loss from recurrent disease. Recurrance rates are greatest for primary sclerosing cholangitis and autoimmune hepatitis, and low reccurrance rates are reported for alcoholic liver disease and recurrent primary biliary cirrhosis. The impact of recurrent nonalcoholic fatty liver disease is not yet clear. Patients and clinicians need to be aware of the possibility of recurrent disease in the differential diagnosis of abnormal liver tests, and management stategies may require alteration to reduce the impact of disease recurrence on outcome. Finally, an understanding of which diseases do recur after transplantation and identification of the risk factors may lead to a better understanding of the pathogenetic mechanisms of these conditions.