Fontan-Associated Liver Disease

Cardiac and Liver Fibrosis Assessed by Multiparametric MRI in Patients with Fontan Circulation

The abnormal hemodynamics in Fontan circulation due to persistently increased systemic venous pressure results in hepatic venous congestion and Fontan-associated liver disease. Combined assessment of cardiac and liver fibrosis and cardiac remodeling using multiparametric MRI in this context have not been fully explored. To evaluate cardiac and liver fibrosis and cardiac remodeling using multiparametric MRI in patients who have undergone Fontan procedures. Thirty-eight patients and 23 controls underwent cardiac and liver MRI examinations in a 3.0-T scanner. Mann-Whitney, Fisher exact test, and Spearman's correlation were applied to evaluate myocardial volumes, function, native cardiac and liver T1 mapping, ECVs and liver stiffness. The mean native cardiac T1 value (p = 0.018), cardiac ECV (p < 0.001), liver native T1 (p < 0.001), liver ECV (p < 0.001), and liver stiffness (p < 0.001) were higher in patients than controls. The indexed end-diastolic volume (EDVi) correlated with the myocardial ECV (r = 0.356; p = 0.033), native liver T1 (r = 0.571; p < 0.001), and with liver stiffness (r = 0.391; p = 0.015). In addition, liver stiffness correlated with liver ECV (r = 0.361; p = 0.031) and native liver T1 (r = 0.458; p = 0.004). An association between cardiac remodeling and cardiac and liver fibrosis were found in this population. The usefulness of MRI to follow cardiac and liver involvement in these patients is critical to improve treatment strategies and to prevent the need for combined liver and heart transplantation.

Characteristics and Survival Outcomes of Hepatocellular Carcinoma After the Fontan Operation

BACKGROUND

The Fontan operation is a surgical procedure to palliate single ventricle congenital heart disease. Hepatocellular carcinoma (HCC) is a rare complication of Fontan-associated liver disease (FALD).

OBJECTIVES

The authors aim to examine characteristics of individuals with Fontan circulation diagnosed with HCC and to describe tumor characteristics, treatment, and survival outcomes of these patients.

METHODS

This was a multicenter retrospective case-control study of adults with Fontan circulation between 2005 and 2021. HCC cases were included based on histology or imaging-based diagnosis. Controls were randomly selected in a 3:1 ratio from the center in which the case was derived. Descriptive statistics were used to compare groups and Kaplan-Meier survival analysis was performed.

RESULTS

There were 58 cases of HCC diagnosed at a median age of 31 (IQR: 26-38) years. Diagnosis was made at very early or early stage disease in 68%. Compared to controls, cases had higher prevalence of advanced FALD including varices, ascites, splenomegaly, and decreased platelets. Treatment with curative intent (combined heart-liver transplantation, resection, or ablation) was performed in 41%. Survival at 1 year was 78.9% and highest among those diagnosed at very early or early stage. Over half were undergoing active surveillance at diagnosis, which showed a nonsignificant trend toward higher survival (P = 0.088).

CONCLUSIONS

We describe the clinical characteristics, treatment, and survival in patients with FALD-HCC. Results suggest that adults with FALD-HCC diagnosed with early stage disease may have survival benefit. Our findings underscore the importance of HCC screening for early detection in individuals after the Fontan operation.

Prevalence, Risk Factors, and Prognosis for Fontan-Associated Liver Disease: A Systematic Review and Exploratory Meta-Analysis

BACKGROUND

Patients with Fontan circulation are at risk of progressive liver disease, but the prevalence and risk factors for Fontan-associated liver disease (FALD) remain unclear.

OBJECTIVES

The aim of the study was to review unbiased data on FALD prevalence, diagnostic methods, risk factors, and prognostic significance, and to undertake exploratory meta-analysis on available data.

METHODS

This systematic review included studies with unselected FALD screening. Outcomes were imaging or biopsy-proven cirrhosis, advanced fibrosis, portal hypertension, and hepatocellular carcinoma. Exploratory meta-analysis was performed, as well as subgroup analyses and meta-regression to explore contributors towards outcome heterogeneity.

RESULTS

Thirty-seven studies comprising 5,701 patients were included, with a median of 17 years of follow-up post-Fontan completion. All estimates of FALD were highly heterogeneous, reflecting variable patient factors and institutional practices. Cirrhosis was diagnosed in 21% of patients, but ranged from 0% to 76%. Advanced fibrosis without cirrhosis was noted in 30%, portal hypertension in 17%, and hepatocellular carcinoma in 2%, also with significant heterogeneity. Subgroup analysis and meta-regression highlighted several factors that contributed to such heterogeneity. It was found that cirrhosis was less commonly diagnosed by biopsy than by imaging (10% vs 26%). Other risk factors for cirrhosis included years post-Fontan completion, atriopulmonary Fontan, moderate or greater ventricular dysfunction, and higher pulmonary capillary wedge pressure. Qualitative synthesis noted FALD to be associated with elevated risk of cardiovascular and all-cause mortality.

CONCLUSIONS

Liver disease is common post-Fontan completion, though prevalence varies widely. Several risk factors should guide patient screening. A universal, prognostically meaningful FALD definition is needed to advance research and clinical care.

Gut microbiota community and metabolic profiles in direct total cavopulmonary connection and Fontan circulation: a cross-sectional study in the single center

Background

This study aimed to evaluate the impact of the direct total cavopulmonary connection (dTCPC) procedure on the gut microbiome and metabolome. It also sought to elucidate the features of the gut microbiota community and metabolic profiles in Fontan circulation.

Methods

We randomly recruited 45 participants above 14 years old undergoing Fontan procedure by typical extracardiac conduit (TCPC group, n = 15), direct total cavopulmonary connection (dTCPC group, n = 16) procedure and healthy control (control group, n = 14) in our institution between May 2023 and October 2023. 16S rRNA amplicon sequencing and untargeted metabolites measurement were performed on their fecal sample.

Results

The four alpha diversity indexes showed no statistical significance between the dTCPC and TCPC groups (p > 0.05). Orthogonal partial least squares discriminant analysis (OPLS-DA) followed by permutation testing indicated an overfitting effect in the model between the dTCPC and TCPC groups. We observed significant differences in the Chao1 index (p = 0.0236), the ACE index (p = 0.0236), and the unweighted beta diversity (p = 0.0099) between the Fontan group and healthy control group. Strains of Fusobacterium were significantly overrepresented in the Fontan group [with linear discriminant analysis (LDA) scores exceeding (log10) >3]. Functional enrichment analysis revealed a significant overrepresentation of several metabolic pathways. These pathways predominantly included those related to amino acid metabolism, such as histidine metabolism, glycine, serine, and threonine metabolism, and cysteine and methionine metabolism. Additionally, the biosynthesis of unsaturated fatty acids was also notably enriched.

Conclusion

The dTCPC procedure demonstrated similar gut microbiota composition and metabolic profiles to the traditional ECC procedure in Fontan patients. Notably, the increased abundance of Fusobacterium, reduced microbial biodiversity, and altered metabolic profiles of amino acids and unsaturated fatty acids in the alimentary canal may serve as distinctive characteristics of patients who have undergone Fontan circulation. These findings provide valuable insights into the long-term physiological consequences of Fontan procedure and may inform future clinical management strategies.

Fontan-Associated Liver Disease (FALD) in the EUROFontan Experience. An Insight into European Awareness

Fontan-Associated Liver Disease (FALD) is a dramatically emerging problem even if not precisely defined in term of debated diagnosis and surveillance protocols. We analyze FALD prevalence, clinical impact and implications in a European cohort of patients. It's a retrospective observational multicenter study including Fontan patients operated between 1990 and 2022. Anatomical, clinical, surgical and liver-related data were collected, defining FALD as a spectrum of time-related structural-functional liver modifications due to congestive hepatopathy (from mild liver fibrosis to liver cirrhosis and hepatocellular carcinoma) diagnosed through multiparametric evaluations. 14 centers routinely conducted liver assessment after Fontan completion. Out of 2141 patients, 343 (16%) were diagnosed with FALD (M/F = 198/145; median age 18 years, IQR 15-26) with a median follow-up time of 14 years (IQR 9-20) from Fontan surgery. Among these, there were 19 (5.5%) deaths, 5 (26.3%) of whom related to advanced liver disease/cancer. FALD showed no significant association with gender (p = 0.4, adjusted p-value = 0.5), dominant ventricular morphology (p = 0.060, adjusted p-value = 0.086) nor surgery type (p = 0.3, adjusted p-value = 0.4). Significant association emerged between FALD and fenestration absence (p < 0.001, adjusted p-value < 0.001), systemic ventricular (p < 0.001, adjusted p-value < 0.001) and atrio-ventricular valve (p < 0.001) dysfunction, III-IV NYHA classes (p < 0.001, adjusted p-value < 0.001), tachyarrhythmias (p < 0.001) and liver stiffness ≥ 22 kPa on transient elastography (p < 0.001, adjusted p-value < 0.001). The analysis demonstrated no significant association between FALD and abnormal liver function tests (p = 0.2), heart transplantation (p = 0.6, adjusted p-value = 0.6), worse survival (p = 0.38). This study shows significant mortality related to FALD, which is also associated to clinical signs of failing Fontan circulation, stressing the pressing need of universally shared diagnostic criteria and surveillance protocols, to prevent and/or early-identify FALD and its more lethal complications.

Novel immunologic mechanisms for Fontan-associated liver disease

Introduction

Single ventricle congenital heart disease resulting in Fontan palliation has led to improved survival, however, Fontan-associated liver disease (FALD) is ubiquitous in this population by adulthood. While lymphopenia has been associated with the degree of FALD, potential immunologic mechanisms remain unstudied, and were the focus of this study.

Methods

Single-nuclei RNA-seq (snRNA-seq) data from liver samples of adolescent Fontan and control patients were analyzed with specific focus on lymphocytes and natural killer (NK) and T-cell fractions.

Results

Liver samples from Fontan patients demonstrated upregulation of endothelial cells (ECs: 4.2 ± 1.0 vs. 13.6 ± 3.4 %, p = 0.037) and total lymphocytes (0.7 ± 0.1 vs. 3.6 ± 0.7 %, p = 0.007), more specifically in NK and T-cells (NK: 0.29 ± 0.16 vs. 1.40 ± 0.64 %, p = 0.028 and T-cell: 0.28 ± 0.04 vs. 1.80 ± 1.01 %, p = 0.034). Enhanced genes important in T-cell activation and differentiation were demonstrated, as well as those involved in cell-to-cell adhesion and lymphocyte migration. Supporting lymphocyte trafficking, ECs demonstrated amplification of critical chemotactic and lymphocyte recruitment genes. Increased time from Fontan palliation was associated with more dramatic lymphocytic transcriptomic changes.

Conclusions

Hepatic changes in adolescent Fontan patients suggest that T-cells are contributing to the early development and possible progression of FALD.

Fontan-Associated Liver Disease

Fontan-associated liver disease (FALD) occurs in all patients who have undergone Fontan palliation for functional single ventricle congenital heart defects. While liver fibrosis is universal in patients who have undergone Fontan palliation, FALD may lead to more serious consequences including portal hypertension, cirrhosis, and hepatocellular carcinoma. Scientific studies of the pathophysiology and clinical management of FALD have been limited to date by the heterogeneous nature of the disease, relatively small population of patients with Fontan physiology, and inaccuracy of noninvasive staging tests. As survival after the Fontan procedure improves, the population of adults with Fontan physiology is growing, leading to more severe extracardiac complications related to the Fontan circulation and growing demand for heart and liver transplantation. The accurate evaluation, staging, and management of FALD comprises a clinical challenge which requires expert multidisciplinary input.

Native liver T1 mapping on magnetic resonance imaging for an evaluation of congestive liver injury in children with congenital heart disease

Fontan-associated liver disease (FALD) may be caused by chronic liver congestion due to high central venous pressure (CVP). Recently, the usefulness of liver native T1 mapping in magnetic resonance imaging (MRI) in adulthood has been reported. To evaluate the usefulness of native liver T1 mapping in children with congenital heart disease (CHD), we investigated the utility of native liver T1 relaxation time (LT1) in pediatric Fontan patients in comparison to other CHDs. Correlations between LT1 and laboratory biomarkers or hemodynamic data were also assessed. A total of 155 patients with CHD (biventricular repair, n = 42; bidirectional Glenn circulation, n = 38; and Fontan circulation, n = 75) underwent blood tests, cardiac catheterization, and cardiac MRI within 48 h. Both CVP and LT1 levels were higher in Fontan patients than in bidirectional Glenn and biventricular patients. There were significant correlation in the overall population and weak correlation in Fontan patients between CVP and LT1(correlation coefficient 0.644 [0.541-0.728] and 0.244 [0.0179-0.446], P < 0.001 and 0.035, respectively). Among the laboratory data, the multiple linear regression analysis revealed that the fibrosis-4 index and alanine aminotransferase were significantly correlated with LT1 in the overall population (P = 0.008,0.012), and the fibrosis-4 index was correlated with LT1 in Fontan patients (P = 0.019). LT1 might have some role to predict elevated CVP and liver injury in children with CHD.

Does High-Intensity Exercise Cause Acute Liver Injury in Patients with Fontan Circulation? A Prospective Pilot Study

The Fontan procedure results in chronic hepatic congestion and Fontan-associated liver disease (FALD) characterized by progressive liver fibrosis and cirrhosis. Exercise is recommended in this population, but may accelerate the progression of FALD from abrupt elevations in central venous pressure. The aim of this study was to assess if acute liver injury occurs after high-intensity exercise in patients with Fontan physiology. Ten patients were enrolled. Nine had normal systolic ventricular function and one had an ejection fraction < 40%. During cardiopulmonary exercise testing, patients had near-infrared spectroscopy (NIRS) to measure oxygen saturation of multiple organs, including the liver, and underwent pre- and post-exercise testing with liver elastography, laboratory markers, and cytokines to assess liver injury. The hepatic and renal NIRS showed a statistically significant decrease in oxygenation during exercise, and the hepatic NIRS had the slowest recovery compared to renal, cerebral, and peripheral muscle NIRS. A clinically significant increase in shear wave velocity occurred after exercise testing only in the one patient with systolic dysfunction. There was a statistically significant, albeit trivial, increase in ALT and GGT after exercise. Fibrogenic cytokines traditionally associated with FALD did not increase significantly in our cohort; however, pro-inflammatory cytokines that predispose to fibrogenesis did significantly rise during exercise. Although patients with Fontan circulation demonstrated a significant reduction in hepatic tissue oxygenation based on NIRS saturations during exercise, there was no clinical evidence of acute increase in liver congestion or acute liver injury following high-intensity exercise.

Epidemiology of Fontan-associated liver disease in Japan: Results from a nationwide survey in 2021

AIM

Although the Fontan procedure has improved the survival of patients with single-ventricle heart disease, the long-term consequences of the procedure have been a concern. This study aimed to explore the patients' postoperative clinical characteristics, including a diagnosis of Fontan-associated liver disease (FALD).

METHODS

A nationwide Japanese epidemiological survey of post-Fontan patients was undertaken in 2021. The survey targets were selected from all departments of pediatrics, pediatric surgery, cardiology, cardiovascular surgery, and gastroenterology using stratified random sampling by the number of beds. Each department was asked to complete a mail-back questionnaire on the numbers of patients and their clinical characteristics. The diagnosis of FALD was made by each attending physician.

RESULTS

The estimated number of post-Fontan patients was 7810 (95% confidence interval, 5430-10 200) in 2020, with a period prevalence of 61.9 per million. During the follow-up of 13.8 years after the Fontan procedure, 40% of patients were diagnosed with FALD. An elevated γ-glutamyl transpeptidase level was the most common finding leading to the FALD diagnosis (41%), and 45% of the patients also showed liver fibrosis. Compared with non-FALD patients, FALD patients were older, had longer duration since the Fontan procedure, and had more severe cardiac or liver conditions. However, more than half of the non-FALD patients had elevated liver enzyme levels, suggesting underestimation of the number of FALD patients.

CONCLUSIONS

In 2020, approximately 40% of post-Fontan patients underwent follow-up with a diagnosis of FALD, although the lack of established diagnostic criteria for FALD could affect the reported prevalence of FALD.

Perioperative considerations for non-cardiac procedures in patients with congenital heart disease: A practical overview

Providing thorough care for children with congenital heart disease (CHD) undergoing non-cardiac surgery requires a strong understanding of common heart defects and the procedures used to treat them. To care for these patients, multidisciplinary teams must consider the severity of the underlying cardiac disease, comorbid conditions, and preoperative severity of illness. The American Heart Association's Scientific Statement on Perioperative Considerations for Pediatric Patients with Congenital Heart Disease Presenting for Noncardiac Procedures offers valuable guidance.

Isosorbide DiNitrate Effect on Hemodynamic Profile, Liver Stiffness, and Exercise Tolerance in Fontan Circulation (The NEET Clinical Trial)

After Fontan operation, decreased venous capacitance and venoconstriction are adaptive mechanisms to maintain venous return and cardiac output. The consequent higher venous pressure may adversely impact end-organ function, exercise capacity and result in worse clinical outcomes. This pilot study evaluated the safety and effect of isosorbide dinitrate (ISDN), a venodilator, on exercise capacity, peripheral venous pressure (PVP), and liver stiffness in patients with Fontan circulation. In this prospective single-arm trial, 15 individuals with Fontan circulation were evaluated at baseline and after 4 weeks of therapeutic treatment with ISDN. Primary aims were to assess the safety of ISDN and the effect on maximal exercise. We also aimed to evaluate the effect of ISDN on ultrasound-assessed liver stiffness, markers of submaximal exercise, and PVP at rest and peak exercise. Repeated measures t-tests were used to assess change in variables of interest in response to ISDN. Mean age was 23.5 ± 9.2 years (range 11.2-39.0 years), and 10/15 (67%) were male. There was no statistically significant change in peak VO2 (1401 ± 428 to 1428 ± 436 mL/min, p = 0.128), but VO2 at the anaerobic threshold increased (1087 ± 313 to 1115 ± 302 mL/min, p = 0.03). ISDN was also associated with a lower peak exercise PVP (22.5 ± 4.5 to 20.6 ± 3.0 mmHg, p = 0.015). Liver stiffness was lower with ISDN, though the difference was not statistically significant (2.3 ± 0.4 to 2.1 ± 0.5 m/s, p = 0.079). Of the patients completing the trial, mild headache was common (67%), but there were no major adverse events. Treatment with ISDN for 4 weeks is well-tolerated in patients with a Fontan circulation. ISDN is associated with an increase in VO2 at anaerobic threshold, lower peak PVP, and a trend toward lower liver stiffness. Larger, longer duration studies will be necessary to define the impact of ISDN on clinical outcomes in the Fontan circulation.Clinical Trial Registration: URL: https://clinicaltrials.gov . Unique identifier: NCT04297241.

Cytokeratin-18 is Elevated Prior to Conventional Measures of Liver Disease in Fontan-Associated Liver Disease

The Fontan procedure is used to palliate complex forms of congenital heart disease. This results in adverse hepatic sequelae now known as Fontan-associated liver disease (FALD). Conventional laboratory measures of liver disease do not correlate well with FALD severity. Cytokeratin-18 (CK-18) is a measure of cell death and is sensitive in detecting other causes of liver disease. Our aim was to assess the use of a novel measure of liver disease, CK-18, in Fontan patients. This is a single-center, prospective, cross-sectional study of Fontan patients aged 8-21 years old. We performed ultrasound elastography, echocardiography, magnetic resonance imaging, and serum laboratory testing. Novel laboratory test CK-18 levels in Fontan subjects were compared to healthy age-matched controls. Thirteen Fontan patients were evaluated with a median age 15 years (10, 14), 4 Hypoplastic left heart syndrome, 11 were male, and 5 were symptomatic. Fontan patients had normal AST/ALT, but a significantly elevated liver stiffness by elastography (median 13.4 kPa). Hepatic stiffness by elastography was associated with diastolic-indexed (rho = 0.58, p = 0.04) ventricular volumes. Compared to 10 aged-matched controls, CK-18 was higher in the Fontan group-cleaved CK-18 protein (p < 0.01) and full CK-18 protein, (p = 0.02). CK-18 was positively associated with AST and ALT. Elevated CK-18 levels were found in Fontan patients compared to controls suggesting hepatic cell death even in these relatively healthy Fontan patients. CK-18 was elevated prior to changes in traditional testing. CK-18 may be a useful sensitive marker of liver disease in FALD.

Invasive Implanted Hemodynamic Monitoring in Patients With Complex Congenital Heart Disease: State-of-the-Art Review

As the number of patients with congenital heart disease (CHD) continues to increase, the burden of heart failure (HF) in this population requires innovative strategies to individualize management. Given the success of implanted invasive hemodynamic monitoring (IHM) with the CardioMEMSTM HF system in adults with acquired HF, this is often suggested for use in patients with CHD, though published data are limited to case reports and case series. Therefore, this review summarizes the available published reports on the use of IHM in patients with complex CHD, describes novel applications, and highlights future directions for study. In patients with CHD, IHM has been used across the lifespan, from age 3 years to adulthood, with minimal device-related complications reported. IHM uses include (1) prevention of HF hospitalizations; (2) reassessment of hemodynamics after titration of medical therapy without repeated cardiac catheterization; (3) serial monitoring of at-risk patients for pulmonary hypertension to optimize timing of heart transplant referral; (4) and hemodynamic assessment with exercise (5) or after ventricular assist device placement. IHM has the potential to reduce the number of cardiac catheterizations in anatomically complex patients and, in patients with Fontan circulation, IHM pressures may have prognostic implications. In conclusion, though further studies are needed, as patients with CHD age and HF is more prevalent, this tool may assist CHD physicians in caring for this complex patient population.

Transfemoral-Transcaval Liver Biopsy (TFTC) and Transjugular Liver Biopsy (TJLB) in Patients with Fontan-Associated Liver Disease (FALD)

PURPOSE

To describe our experience in performing transfemoral-transcaval liver biopsy (TFTC) and transjugular liver biopsy (TJLB) in patients with Fontan-associated liver disease (FALD).

METHODS

A single-center, retrospective review of 23 TFTC and seven TJLB performed between August 2011 and May 2023 on patients who previously underwent the Fontan procedure (median age 23.1 years, ranging 11-43 years, 48% female). Patient demographics, laboratory values, pathology, radiology, and cardiology reports were reviewed. Liver explants were correlated with histopathological evaluation to determine sampling accuracy when available.

RESULTS

All biopsies achieved technical success (accurate targeting and safe tissue sample extraction) and histopathological success (yielding sufficient tissue for accurate diagnosis). Liver biopsies were performed during simultaneous cardiac catheterization in 28 of 30 (93%) procedures. There was no statistically significant change in hemoglobin, hematocrit, platelet count post-procedure, and fluoroscopy times. There was one major complication within the TJLB group and one minor complication within the TFTC group.

CONCLUSION

Transvenous liver biopsies, whether via transfemoral or transjugular route, may be safely performed in FALD patients while yielding samples with technical and histopathological success. The transfemoral approach, which is our preferred method; its compatibility with simultaneous cardiac catheterization and its potentially increased safety profile stemming from the avoidance of transversing the Fontan shunt-makes it a particular advantageous option in the management of FALD.

Lymphatic failure and lymphatic interventions: Knowledge gaps and future directions for a new frontier in congenital heart disease

Lymphatic failure is a broad term that describes the lymphatic circulation's inability to adequately transport fluid and solutes out of the interstitium and into the systemic venous circulation, which can result in dysfunction and dysregulation of immune responses, dietary fat absorption, and fluid balance maintenance. Several investigations have recently elucidated the nexus between lymphatic failure and congenital heart disease, and the associated morbidity and mortality is now well-recognized. However, the precise pathophysiology and pathogenesis of lymphatic failure remains poorly understood and relatively understudied, and there are no targeted therapeutics or interventions to reliably prevent its development and progression. Thus, there is growing enthusiasm towards the development and application of novel percutaneous and surgical lymphatic interventions. Moreover, there is consensus that further investigations are needed to delineate the underlying mechanisms of lymphatic failure, which could help identify novel therapeutic targets and develop innovative procedures to improve the overall quality of life and survival of these patients. With these considerations, this review aims to provide an overview of the lymphatic circulation and its vasculature as it relates to current understandings into the pathophysiology and pathogenesis of lymphatic failure in patients with congenital heart disease, while also summarizing strategies for evaluating and managing lymphatic complications, as well as specific areas of interest for future translational and clinical research efforts.

Accuracy of elastography versus biopsy in assessing severity of liver fibrosis in young Fontan patients

OBJECTIVES

We performed a single-centre retrospective study comparing the accuracy of non-invasive elastography with liver biopsy in accurate assessment of Fontan-associated liver disease.

METHODS

Fontan patients who underwent combined assessment with a percutaneous liver biopsy and non-invasive elastography between January 2015 and December 2023 at our Children's hospital were included. Liver biopsies were classified using the Congestive Hepatic Fibrosis Score as early Fontan-associated liver disease (scores 1, 2) and advanced Fontan-associated liver disease (score 3/bridging fibrosis and score 4/cirrhosis). Elastography values were categorised as advanced Fontan-associated liver disease for liver elasticity >2.1 m/s by ultrasound and liver stiffness >5 KPa on magnetic resonance elastography.

RESULTS

We included 130 patients (116 children, 89%, mean age at biopsy: 14.6 years ± 3.6) who underwent liver biopsy at a mean duration of 11.1 years (±0.3) following Fontan surgery. Advanced Fontan-associated liver disease was noted in 41 (31.5%) patients with 13 (10%) showing frank cirrhosis. Pre-biopsy ultrasound showed advanced liver fibrosis in 18/125 (14%), with low sensitivity (23%), high specificity (90%), and low accuracy (68%, k = 0.1) in diagnosing advanced Fontan-associated liver disease. Similarly, pre-biopsy magnetic resonance elastography showed advanced fibrosis in 23/86 (27%) of patients, with low sensitivity (30%), fair specificity (75%), and low accuracy (63%, k = 0.1). Interestingly, advanced Fontan-associated liver disease was missed by ultrasound in 29% and by magnetic resonance elastography in 25% of patients. Advanced Fontan-associated liver disease was associated with lower platelet count (p = 0.02) and higher Gamma-glutamyl Transferase levels (p = 0.02).

CONCLUSION

Advanced hepatic fibrosis is common among paediatric Fontan patients. Non-invasive elastography may overestimate and underestimate the degree of liver fibrosis, and therefore, liver biopsy may be required for confirming disease severity.

Meta-analysis: Incidence of cirrhosis and hepatocellular carcinoma in patients with Fontan palliation

BACKGROUND AND AIMS

The Fontan palliation is the final stage of surgery for many children born with univentricular physiology. Almost all Fontan patients develop liver fibrosis which may eventually lead to cirrhosis and hepatocellular carcinoma (HCC). These are important causes of morbidity and mortality in these patients. We performed a systematic review and meta-analysis to assess the incidence of cirrhosis and HCC in Fontan patients and stratify it based on time since surgery.

METHODS

A literature search of seven databases identified 1158 records. Studies reporting the number of cirrhosis and HCC cases in Fontan patients and time since Fontan surgery were included. In the cirrhosis cohort, we included only those studies where all patients underwent liver biopsy.

RESULTS

A total of 23 studies were included: 12 and 13 studies in the cirrhosis and HCC cohorts, respectively, with two studies included in both cohorts. The incidence of cirrhosis was 0.97 per 100 patient-years (95% CI 0.57-1.63), with the incidence and cumulative incidence ≥20 years post Fontan surgery being 1.61 per 100 patient-years (95% CI 1.24-2.08) and 32.2% (95% CI 25.8%-39.4%), respectively. The incidence of HCC was 0.12 per 100 patient-years (95% CI 0.07-0.21), with the incidence and cumulative incidence ≥20 years post Fontan surgery being 0.20 per 100 patient-years (95% CI 0.12-0.35) and 3.9% (95% CI 2.2%-6.8%), respectively. Only about 70% of patients with HCC (20/28) had underlying cirrhosis.

CONCLUSION

The incidence of cirrhosis and HCC increases over time, especially at ≥20 years post Fontan surgery. Studies are needed to further identify at-risk patients in order to streamline surveillance for these highly morbid conditions.

Cardiac MRI-Derived Inferior Vena Cava Cross-Sectional Area Correlates with Measures of Fontan-Associated Liver Disease

There is currently no clear consensus on screening techniques to evaluate the presence or severity of Fontan-associated liver disease (FALD). Cardiac MRI (CMR) is used routinely for post-Fontan surveillance, but CMR-derived measures that relate to the severity of FALD are not yet defined. This was a cross-sectional single-center study of post-Fontan patients who underwent a CMR. CMR exams were re-analyzed by a single pediatric cardiologist. Surrogates of FALD included Gamma-Glutamyl Transferase (GGT), Fibrosis-4 laboratory score (FIB-4), and imaging findings. Findings consistent with cirrhosis on liver ultrasound included increased liver echogenicity and/or nodularity. Statistical analyses were performed to investigate potential relationships between CMR parameters and markers of FALD. Sixty-one patients were included. A larger inferior vena cava cross-sectional area (IVC-CSA) indexed to height was significantly associated with a higher FIB-4 score (Spearman's ρ = 0.28, p = 0.04), a higher GGT level (Spearman's ρ = 0.40, p = 0.02), and findings consistent with cirrhosis on liver ultrasound (OR 1.17, 95% CI: (1.01, 1.35), p = 0.04). None of the other CMR parameters were associated with markers of FALD. A larger indexed IVC-CSA was associated with higher systemic ventricle end-diastolic pressure (EDP) on cardiac catheterization (Spearman's ρ = 0.39, p = 0.018) as well as older age (Spearman's ρ = 0.46, p =  < 0.001). Indexed IVC-CSA was the only CMR parameter that was associated with markers of FALD. This measure has the potential to serve as an additional non-invasive tool to improve screening strategies for FALD.

Mortality and morbidity after combined heart and liver transplantation in the failing Fontan: An updated dual center retrospective study

INTRODUCTION

As the adult Fontan population with Fontan associated liver disease continues to increase, more patients are being referred for transplantation, including combined heart and liver transplantation.

METHODS

We report updated mortality and morbidity outcomes after combined heart and liver transplant in a retrospective cohort series of 40 patients (age 14 to 49 years) with Fontan circulation across two centers from 2006-2022.

RESULTS

The 30-day, 1-year, 5-year and 10-year survival rate was 90%, 80%, 73% and 73% respectively. Sixty percent of patients met a composite comorbidity of needing either post-transplant mechanical circulatory support, renal replacement therapy or tracheostomy. Cardiopulmonary bypass time > 283 min (4.7 h) and meeting the composite comorbidity were associated with mortality by Kaplan Meier analysis.

CONCLUSION

Further study to mitigate early mortality and the above comorbidities as well as the high risk of bleeding and vasoplegia in this patient population is warranted.

Histopathological Spectrum and Molecular Characterization of Liver Tumors in the Setting of Fontan-Associated Liver Disease

PURPOSE

Univentricular heart is corrected with the Fontan procedure (FP). In the long term, so-called Fontan-associated liver diseases (FALDs) can develop. The aim of this study is to analyze the molecular profile of FALDs.

METHODS

FALDs between January 1990 and December 2022 were reviewed for histology and immunohistochemistry, laboratory data, and images. Targeted next generation sequencing (NGS), performed on the DNA and RNA of both neoplastic and non-lesional liver tissue, was applied.

RESULTS

A total of 31/208 nodules > 1 cm in diameter were identified on imaging, but a liver biopsy was available for five patient demonstrating the following: one hepatocellular adenoma (HA), two hepatocellular carcinomas (HCCs), one fibrolamellar carcinoma (FLC), and one intrahepatic cholangiocarcinoma (ICC). Molecular analysis showed a copy number alteration involving FGFR3 in three cases (two HCCs and one ICC) as well as one HCC with a hotspot mutation on the CTNNB1 and NRAS genes. Tumor mutational burden ranged from low to intermediate. A variant of uncertain significance in GNAS was present in two HCCs and in one ICC. The same molecular profile was observed in a non-lesional liver. A DNAJB1-PRKACA fusion was detected only in one FLC.

CONCLUSIONS

Neoplastic FALDs show some unusual molecular profiles compared with non-Fontan ones. The presence of the same alterations in non-lesional cardiac cirrhosis could contribute to the development of FALD.

Early Experience and Lessons Learned Using Implanted Hemodynamic Monitoring in Patients With Fontan Circulation

BACKGROUND

Data on the use of implanted hemodynamic monitoring (IHM) in patients with Fontan circulation are limited. This study reports our experience using the CardioMEMS HF system in adults with Fontan circulation.

METHODS AND RESULTS

This single-center, retrospective study evaluated heart failure hospitalizations, procedural complications, and device-related complications in patients with Fontan circulation referred for IHM placement (2015-2022). The association of pulmonary artery pressure (by most recent catheterization and median IHM pressure within 30 days of placement) with both death and follow-up Model for End-Stage Liver Disease Excluding International Normalized Ratio score were evaluated. Of 18 patients referred for IHM placement, 17 were successful (median age, 30 [range 21-48] years, 6 women). Procedural complications (access site hematomas, pulmonary artery staining) occurred in 3 patients, without device-related procedural complications. In follow-up (median, 35 [range, 6-83] months), 1 patient developed a pulmonary embolism (possibly device-related). Heart failure hospitalizations/year were similar before and after IHM (median, 1 [interquartile range, 0-1.0] versus 0.6 [0-2.3]; P=0.268), though only 46% of heart failure hospitalizations had associated IHM transmissions. IHM pressures were associated with Model for End-Stage Liver Disease Excluding International Normalized Ratio scores (R2=0.588, P<0.001), though catheterization pressures were not (R2=0.140, P=0.139). The long-term mortality rate was 53% in this cohort. On unadjusted survival analysis, IHM pressures ≥18 mm Hg were associated with mortality (log rank P=0.041), which was not reproduced with catheterization pressures (log rank P=0.764).

CONCLUSIONS

In patients with Fontan circulation, IHM did not reduce heart failure hospitalizations, though patient adherence to transmission was low. Device-related complications were low. IHM pressures may better represent real-life conditions compared with catheterization given associations with mortality and Model for End-Stage Liver Disease Excluding International Normalized Ratio score.

EASL-ERN position paper on liver involvement in patients with Fontan-type circulation

Fontan-type surgery is the final step in the sequential palliative surgical treatment of infants born with a univentricular heart. The resulting long-term haemodynamic changes promote liver damage, leading to Fontan-associated liver disease (FALD), in virtually all patients with Fontan circulation. Owing to the lack of a uniform definition of FALD and the competitive risk of other complications developed by Fontan patients, the impact of FALD on the prognosis of these patients is currently debatable. However, based on the increasing number of adult Fontan patients and recent research interest, the European Association for The Study of the Liver and the European Reference Network on Rare Liver Diseases thought a position paper timely. The aims of the current paper are: (1) to provide a clear definition and description of FALD, including clinical, analytical, radiological, haemodynamic, and histological features; (2) to facilitate guidance for staging the liver disease; and (3) to provide evidence- and experience-based recommendations for the management of different clinical scenarios.

Liver Biopsy Leads to Serendipitous Diagnosis of Glycogen Storage Disease Type IX in a Patient With Fontan-Associated Liver Disease

Fontan-associated liver disease (FALD) is a form of congestive hepatopathy resulting from Fontan palliation procedures in patients with single ventricle physiology. Although there is variation between pediatric centers, the surveillance for FALD may include liver biopsies for assessment of degree of fibrosis. Our report describes a 7-year-old girl with hypoplastic left heart syndrome who underwent Fontan palliation at age 2, and presented with disproportionate hepatomegaly, elevated liver enzymes, and increased stiffness on liver elastography. Liver biopsy showed diffuse hepatocellular cytoplasmic glycogenation, leading to the diagnosis of glycogen storage disease IX. This case demonstrates the importance of investigating unexpected physical exam findings and the potential for serendipitous benefit of liver biopsy in FALD.

Severe Fontan-Associated Liver Disease and Its Association With Mortality

Background Data are rare about the incidence of severe Fontan-associated liver disease (FALD) and its association with mortality. We sought to: (1) estimate the probability of developing severe FALD in patients who undergo the Fontan procedure (Fontan patients), compared with severe liver complications in patients with a ventricular septal defect; (2) assess the severe FALD-mortality association; and (3) identify risk factors for developing severe FALD. Methods and Results Using the Quebec Congenital Heart Disease database, a total of 512 Fontan patients and 10 232 patients with a ventricular septal defect were identified. Kaplan-Meier curves demonstrated significantly higher cumulative risk of severe FALD in Fontan patients (11.95% and 52.24% at 10 and 35 years, respectively), than the risk of severe liver complications in patients with a ventricular septal defect (0.50% and 2.75%, respectively). At 5 years, the cumulative risk of death was 12.60% in patients with severe FALD versus 3.70% in Fontan patients without FALD (log-rank P=0.0171). Cox proportional hazard models identified significant associations between the development of severe FALD and congestive heart failure and supraventricular tachycardia, with hazard ratios (HRs) of 2.36 (95% CI, 1.38-4.02) and 2.45 (95% CI, 1.37-4.39), respectively. More recent Fontan completion was related to reduced risks of severe FALD, with an HR of 0.95 (95% CI, 0.93-0.97) for each more recent year. Conclusions This large-scale population-based study documents that severe FALD in Fontan patients was associated with a >3-fold increase in mortality. The risk of FALD is time-dependent and can reach >50% by 35 years after the Fontan operation. Conditions promoting poor Fontan hemodynamics were associated with severe FALD development.

Liver Fibrosis Scores Are Associated With Resting and Exercise Fontan and Pulmonary Artery Wedge Pressures: Insights Into FALD

BACKGROUND

Alterations in liver perfusion and venous hypertension have been implicated in the pathophysiology of Fontan-associated liver disease (FALD). However, the correlation between exercise hemodynamics and markers of FALD have not been studied.

METHODS

We performed a retrospective review of 32 consecutive adults undergoing exercise catheterisation at the Mayo Clinic, Minnesota. Invasive hemodynamics were correlated with aspartate transaminase to platelet ratio index (APRI) and the Fibrosis-4 (Fib-4) score, well validated surrogates of liver fibrosis.

RESULTS

The mean age was 30.9 ± 7 years. The mean APRI was 0.5 ± 0.2 and the mean Fib-4 score 1.3 ± 0.8. Fib-4 scores correlated with spleen size on abdominal imaging (r = 0.40; P = 0.03). Resting Fontan pressure was 13.9 ± 3.9 mm Hg and pulmonary artery wedge pressure (PAWP) 10.0 ± 3.5 mm Hg. At peak exercise (69.4 ± 23.2 W), Fontan pressures increased to 26.5 ± 6.2 mm Hg and PAWP to 22.4 ± 7.1 mm Hg. APRI and Fib-4 score were directly related to Fontan pressure and PAWP at rest and during exercise, and inversely related to exercise arterial O2 saturation. Fib-4 inversely correlated with O2 delivery indices. Similarly, when categorising patients according to high APRI (> 0.5 vs ≤ 0.5) or Fib-4 score (≥ 1.45 vs < 1.45) according to previously proposed cutoffs for diagnosis of liver fibrosis, those with elevated scores had higher resting and exercise Fontan and PAWP pressure with lower O2 arterial saturation.

CONCLUSIONS

APRI and Fib-4 score correlated with resting and exercise Fontan pressure and PAWP. In addition, Fib-4 scores were inversely related to O2 delivery indices. These findings support a role played by hepatic venous hypertension and reduced O2 supply in patients with FALD.

Transient liver elastography in the follow-up of Fontan patients: results of a nation wide survey in Germany

Introduction

Fontan-palliated patients are at risk for the development of Fontan-associated liver disease (FALD). Currently, there is no consensus on how to stage FALD. Transient elastography (TE) is a rapid, non-invasive method to assess FALD and liver fibrosis.

Method

To assess the availability and conditions of using TE to monitor liver disease in Fontan patients in german centers for pediatric cardiology and to propose the introduction of a standardized national protocol for the monitoring of liver disease, we developed a questionnaire.

Results

In total, 95 valid questionnaires were collected. Only 20% of the centers offer the TE investigation directly. Most of the centers transfer the patients to another department or center (40%) or didńt offer TE (40%). In only 2.6% of the centers TE is performed directly by the cardiologist. Most of the centers transfer the patients to a other department. In 29.2% TE is performed only at a certain age of the patients and in 27.7% it is performed if the patients present symptoms of failing Fontan. In only 13.9% of the centers TE is proposed in all the Fontan patients on a routine basis. Most often TE is performed only from the beginning of the adolescence. In the majority of answers it was not known if the patients are fasting for the examination (68%) or not and if the TE examination had to be performed in a specific breathing phase during TE (Inspiration/Expiration, 90%). In the majority, TE is not offered routinely (46.9%).

Discussion

To date in Germany, TE is only used in a few numbers of centers specialized in Fontan follow-up. A standardized protocol to use TE is currently not existing. With regard to the feasibility of the examination, it is evident that TE is a quick, cheap and easy method to distinguish between cases with and without progressive FALD. This makes TE a useful and prognostic tool for screening of liver disease and to failing Fontan circulation.

Conclusion

We propose a systematic TE evaluation of possible liver congestion and fibrosis, as a part of the routine follow-up of Fontan patients.

In Silico Evaluation of a Self-powered Venous Ejector Pump for Fontan Patients

PURPOSE

The Fontan circulation carries a dismal prognosis in the long term due to its peculiar physiology and lack of a subpulmonic ventricle. Although it is multifactorial, elevated IVC pressure is accepted to be the primary cause of Fontan's high mortality and morbidity. This study presents a self-powered venous ejector pump (VEP) that can be used to lower the high IVC venous pressure in single-ventricle patients.

METHODS

A self-powered venous assist device that exploits the high-energy aortic flow to lower IVC pressure is designed. The proposed design is clinically feasible, simple in structure, and is powered intracorporeally. The device's performance in reducing IVC pressure is assessed by conducting comprehensive computational fluid dynamics simulations in idealized total cavopulmonary connections with different offsets. The device was finally applied to complex 3D reconstructed patient-specific TCPC models to validate its performance.

RESULTS

The assist device provided a significant IVC pressure drop of more than 3.2 mm Hg in both idealized and patient-specific geometries, while maintaining a high systemic oxygen saturation of more than 90%. The simulations revealed no significant caval pressure rise (< 0.1 mm Hg) and sufficient systemic oxygen saturation (> 84%) in the event of device failure, demonstrating its fail-safe feature.

CONCLUSIONS

A self-powered venous assist with promising in silico performance in improving Fontan hemodynamics is proposed. Due to its passive nature, the device has the potential to provide palliation for the growing population of patients with failing Fontan.

Regional Elevation of Liver T1 in Fontan Patients

Background

Fontan-associated liver disease (FALD) is characterized by hepatic congestion and progressive hepatic fibrosis in patients with the Fontan operation. This condition is generally clinically silent until late, necessitating techniques for early detection. Liver T1 mapping has been used to screen for FALD, but without consideration of regional variations in T1 values.

Methods

Liver T1 measured with a liver-specific T1 mapping sequence (PROFIT1) in Fontan patients was compared with cohorts of patients with biventricular congenital heart disease (BiV-CHD) and controls with normal cardiac function and anatomy.

Results

Liver T1 was significantly elevated in the Fontan cohort (n = 20) compared with patients with BiV-CHD (n = 12) and controls (n = 9) (781, 678, and 675 milliseconds, respectively; P < 0.001), with a consistent pattern of significantly elevated T1 values in the peripheral compared with central liver regions (ΔT1 = 54, 2, and 11 milliseconds; P < 0.001). PROFIT1 also yielded simultaneous T2∗ maps and fat fraction values that were similar in all groups. Fontan liver T1 values were also significantly elevated as compared with BiV-CHD and controls as measured with the cardiac (modified Look-Locker inversion) acquisitions (728, 583, and 583 milliseconds, respectively; P < 0.001) and values correlated with PROFIT1 liver T1 (R = 0.87, P < 0.001).

Conclusions

Fontan patients have globally increased liver T1 values and consistent spatial variations, with higher values in the peripheral liver regions as compared with spatially uniform values in BiV-CHD and controls. The spatial patterns may provide insight into the progression of FALD. Liver T1 mapping studies should include uniform spatial coverage to avoid bias based on slice locations in this population.

Young Adult Case of Fontan-associated Liver Disease with Hepatocellular Carcinoma During the Transition from Pediatric to Internal Medicine Care and Follow-up

In recent years, the outcomes of the Fontan procedure have been good, but Fontan-associated liver disease (FALD), which causes congestive hepatopathy due to elevated central venous pressure (CVP), has become a serious problem when considering patients' long-term prognosis. A 28-year-old woman with Emanuel syndrome was admitted to our hospital for the treatment of hepatocellular carcinoma (HCC). She was diagnosed with pulmonary atresia and underwent a bidirectional pulmonary artery shunt at the age of 1 year and 10 months and the Fontan procedure at 4 years of age. Blood tests showed an increase in γ-glutamyltransferase in her early 20s and a marked increase in alfa-fetoprotein levels at age 27 years. She was diagnosed as having HCC in the S7 region by contrast-enhanced computed tomography and underwent hepatectomy. There were no serious adverse events, and the patient has survived 18 months after surgery without recurrence. In this report, the optimal time for the transition from the pediatrics department to adult healthcare units is also discussed, along with the management system for FALD in our hospital.

Haemodynamic and prognostic associations of liver fibrosis scores in Fontan-associated liver disease

OBJECTIVES

Fontan-associated liver disease (FALD) is universal post-Fontan palliation; however, its impact on survival remains controversial and current diagnostic tools have limitations. We aimed to assess the prognostic role of liver fibrosis scores (aminotransferase to platelet ratio [APRI] and fibrosis-4 [FIB-4]) and their association with haemodynamics and other markers of liver disease.

METHODS

159 adults (age ≥18 years) post-Fontan undergoing catheterisation at Mayo Clinic, Minnesota, between 1999 and 2017 were included. Invasive haemodynamics and FALD-related laboratory, imaging and pathology data were documented.

RESULTS

Mean age was 31.5±9.3 years, while median age at Fontan procedure was 7.5 years (4-14). Median APRI score (n=159) was 0.49 (0.33-0.61) and median FIB-4 score (n=94) was 1.12 (0.71-1.65). Correlations between APRI and FIB-4 scores and Fontan pressures (r=0.30, p=0.0002; r=0.34, p=0.0008, respectively) and pulmonary arterial wedge pressure (r=0.25, p=0.002; r=0.30, p=0.005, respectively) were weak. Median average hepatic stiffness by magnetic resonance elastography was 4.9 kPa (4.3-6.0; n=26) and 24 (77.4%) showed stage 3 or 4 liver fibrosis on biopsy; these variables were not associated with APRI/FIB-4 scores. On multivariable analyses, APRI and FIB-4 scores were independently associated with overall mortality (HR 1.31 [1.07-1.55] per unit increase, p=0.003; HR 2.15 [1.31-3.54] per unit increase, p=0.003, respectively).

CONCLUSIONS

APRI and FIB-4 scores were associated with long-term all-cause mortality in Fontan patients independent of other prognostic markers. Correlations between haemodynamic status and liver scores were weak; furthermore, most markers of liver fibrosis failed to correlate with non-invasive indices, underscoring the complexity of FALD.

Fontan-associated liver disease: Diagnosis, surveillance, and management

The Fontan operation is a lifesaving procedure for patients with functional single-ventricle congenital heart disease, where hypoplastic left heart syndrome is the most frequent anomaly. Hemodynamic changes following Fontan circulation creation are now increasingly recognized to cause multiorgan affection, where the development of a chronic liver disease, Fontan-associated liver disease (FALD), is one of the most important morbidities. Virtually, all patients with a Fontan circulation develop liver congestion, resulting in fibrosis and cirrhosis, and most patients experience childhood onset. FALD is a distinctive type of congestive hepatopathy, and its pathogenesis is thought to be a multifactorial process driven by increased nonpulsatile central venous pressure and decreased cardiac output, both of which are inherent in the Fontan circulation. In the advanced stage of liver injury, complications of portal hypertension often occur, and there is a risk of developing secondary liver cancer, reported at young age. However, FALD develops with few clinical symptoms, a surprisingly variable degree of severity in liver disease, and with little relation to poor cardiac function. The disease mechanisms and modifying factors of its development are still not fully understood. As one of the more important noncardiac complications of the Fontan circulation, FALD needs to be diagnosed in a timely manner with a structured monitoring scheme of disease development, early detection of malignancy, and determination of the optimal time point for transplantation. There is also a clear need for consensus on the best surveillance strategy for FALD. In this regard, imaging plays an important role together with clinical scoring systems, biochemical workups, and histology. Patients operated on with a Fontan circulation are generally followed up in cardiology units. Ultimately, the resulting multiorgan affection requires a multidisciplinary team of healthcare personnel to address the different organ complications. This article discusses the current concepts, diagnosis, and management of FALD, with special emphasis on the role of different imaging techniques in the diagnosis and monitoring of disease progression, as well as current recommendations for liver disease surveillance.

A Review of Biventricular Repair for the Congenital Cardiac Anesthesiologist

The management of children with a borderline ventricle has been debated for many years. The pursuit of a biventricular repair in these children aims to avoid the long-term sequelae of single ventricle palliation. There is a lack of anesthesia literature relating to the care of this complex heterogenous patient population. Anesthesiologists caring for these patients should have an understanding on the many different forms of physiology and the impact on provision of anesthesia and hemodynamic parameters, the goals of biventricular staging and completion as well as the pre-operative, intra-operative, and post-operative considerations relating to this high-risk group of patients.

Hepatocellular carcinoma and focal nodular hyperplasia in patients with Fontan-associated liver disease: characterisation using dynamic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI

AIM

To identify the characteristic diagnostic features of hepatocellular carcinoma (HCC) and focal nodular hyperplasia (FNH) in Fontan-associated liver disease (FALD) patients using dynamic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Thirty-one FALD patients (mean age, 28.3 ± 7.2 years) with liver nodules who underwent dynamic Gd-EOB-DTPA-enhanced MRI were enrolled prospectively. Twenty-five patients (mean age, 72.8 ± 11.4 years) with hepatitis C virus (HCV)-related HCC constituted the control group. The tumour-to-liver signal intensity (SI) ratio was measured at 30, 60, 100, 180 seconds and 15 minutes, and the SI ratio was compared among FALD-HCC, FALD-FNH, and HCV-HCC.

RESULTS

FALD-HCC exhibited weak early enhancement with mild washout in late phases. FALD-FNH exhibited marked early enhancement that continued until the late phases. The SI ratio was significantly lower for FALD-HCC than for FALD-FNH in all phases. The SI ratio was significantly lower for FALD-HCC than for HCV-HCC only at 30 seconds (p<0.05), whereas poorer washout was seen in FALD-HCC than HCV-HCC in other phases. In 15 minutes, FALD-HCC had a significantly lower SI ratio compared to FALD-FNH (p<0.001).

CONCLUSIONS

The time course of Gd-EOB-DTPA-enhanced MRI signal intensity in FALD-HCC was different from that in FALD-FNH or HCV-HCC. This imaging finding may be useful adjunctive information to distinguish FALD-HCC from FALD-FNH.

Predictors of liver cirrhosis and hepatocellular carcinoma among perioperative survivors of the Fontan operation

OBJECTIVE

Fontan-associated liver disease (FALD) is widely recognised as a common complication in patients long after the Fontan operation. However, data on the predictors of FALD that can guide its screening and management are lacking. The present study aimed to identify the predictors of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) in post-Fontan patients.

METHODS

This was a multi-institutional retrospective cohort study. Clinical data of all perioperative survivors of Fontan operation before 2011 who underwent postoperative catheterisation were collected through a retrospective chart review.

RESULTS

A total of 1117 patients (538 women, 48.2%) underwent their first Fontan operation at a median age of 3.4 years. Postoperative cardiac catheterisation was conducted at a median of 1.0 year. During a median follow-up period of 10.3 years, 67 patients (6.0%) died; 181 (16.2%) were diagnosed with liver fibrosis, 67 (6.0%) with LC, 54 (4.8%) with focal nodular hyperplasia and 7 (0.6%) with HCC. On multivariable analysis, high central venous pressure (CVP) (HR, 1.28 (95% CI 1.01 to 1.63) per 3 mm Hg; p=0.042) and severe atrioventricular valve regurgitation (HR, 6.02 (95% CI 1.53 to 23.77); p=0.010) at the postoperative catheterisation were identified as independent predictors of LC/HCC.

CONCLUSIONS

Patients with high CVP and/or severe atrioventricular valve regurgitation approximately 1 year after the Fontan operation are at increased risk of developing advanced liver disease in the long term. Whether therapeutic interventions to reduce CVP and atrioventricular valve regurgitation decrease the incidence of advanced liver disease requires further elucidation.

Fontan Hepatopathy - Managing Unknowns

BACKGROUND AND AIMS

How to best monitor Fontan associated liver disease (FALD) remains unclear. We describe results from a prospective liver care pathway in adults (n=84) with a Fontan circulation.

METHODS

Routine assessment of the liver, by acoustic radiation force frequency and ultrasound was undertaken. Results, including liver biochemistry, systemic ventricular function (echocardiography), functional class, medication use and clinical endpoints (varices, hepatocellular carcinoma, heart transplantation and death) were collated.

RESULTS

Most individuals returned a cirrhotic range acoustic radiation force impulse imaging (ARFI) result. ARFI values were greater in the proportion of individuals with hepatic nodularity (p=0.024). Univariate analysis demonstrated moderate correlation with platelet number (Spearmans rho= -0.376, p=0.049). Patients with clinical endpoints had lower platelets (p=0.012) but only a trend to hepatic nodularity (p=0.057). Clinical endpoints were more common in those with ventricular dysfunction (p=0.011). Multivariate analysis revealed that age at Fontan and being on angiotensin converting enzyme inhibitors (ACEI) predicted ARFI score (β=0.06 (95% CI 0.01-0.09), p=0.007 and β=0.53 (95% CI 0.17-0.89), p=0.005, respectively). However, these associations were not significant once adjusted for Fontan type, age at ARFI, systemic ventricle morphology, ventricle function, or Model for End-stage Liver Disease (MELD-XI) excluding international normalised ratio (INR) (p>0.05 for all).

CONCLUSIONS

Ideal FALD monitoring remains unclear. ARFI has utility as a binary non-invasive indicator of cirrhosis, highlighting individuals who may need more frequent ongoing monitoring for hepatocellular carcinoma. However, no definite advantage to serial ARFI, once cirrhotic range ARFI results are present, has been identified.

Transcatheter Fontan Fenestration Closure: Sustained Improvements in Oxygen Saturation with Minimal Morbidity and Mortality

Fontan fenestration decreases central venous pressure and preserves cardiac output while decreasing systemic oxygen saturation. Transcatheter fenestration closure increases oxygen saturation, though the persistence of this increase and the long-term incidence of adverse outcomes such as death and heart transplant remain unknown. We describe immediate and long-term clinical and adverse outcomes following fenestration closure. Catheterization, echocardiogram, and clinic reports were reviewed following transcatheter Fontan fenestration closure. Data were reported as n (%) and median (IQR). Continuous variables were compared using Wilcoxon ranked sum test. 51 patients had fenestration closure 0.9 (0.7-1.5) years following extracardiac Fontan operation. Most (84%) were closed with Amplatzer Septal Occluders. Systemic O₂ saturation immediately increased from 87 (83-89) to 95 (94-97)%, P < 0.05. Cardiac index decreased from 4 (3-5) to 2.9 (2.6-3.5) L/min/m². Fontan pressure and pulmonary vascular resistance were not significantly changed. Clinical follow-up duration for all patients was 7.3 (range 1.3-16) years. Oxygen saturation at last follow-up was 94.5 (92-97)% and did not decrease over time (P < 0.05). One patient (2%) developed protein losing enteropathy, 1 (2%) had heart transplant, and 1 (2%) patient died 9.4 years following fenestration closure. No patient required fenestration re-creation following closure. Transcatheter Fontan fenestration closure leads to sustained increases in systemic oxygen saturation and a low incidence of adverse outcomes such as death and transplant. Further study comparing fenestration closure to non-closure and longer follow-up duration are required to determine if there is a survival benefit to fenestration closure.

T1 mapping of the myocardium and liver in the single ventricle population

BACKGROUND

Fontan associated liver disease (FALD) is an increasingly recognized complication of the single ventricle circulation characterized by hepatic venous congestion leading to hepatic fibrosis. Within the Fontan myocardium, fibrotic myocardial remodeling may occur and lead to ventricular dysfunction. Magnetic resonance imaging (MRI) T1 mapping can characterize both myocardial and liver properties.

OBJECTIVE

The aim of this study was to compare myocardial and liver T1 between single ventricle patients with and without a Fontan and biventricular controls.

MATERIALS AND METHODS

A retrospective study of 3 groups of patients: 16 single ventricle patients before Fontan (SV_pre 2 newborns, 9 pre-Glenn, 5 pre-Fontan, 31% single right ventricle [SRV]), 16 Fontans (56% SRV) and 10 repaired d-transposition of the great arteries (TGA). Native modified Look-Locker inversion T1 times were measured in the myocardium and liver. Cardiac MRI parameters, myocardial and liver T1 values were compared in the three groups. Correlations were assessed between liver T1 and cardiac parameters.

RESULTS

Myocardial T1 was higher in SV_pre (1,056 ± 48 ms) and Fontans (1,047 ± 41 ms) compared to TGA (1,012 ± 48 ms, P < 0.05). Increased liver T1 was found in both SV_pre (683 ± 82 ms) and Fontan (727 ± 49 ms) patients compared to TGA patients (587 ± 58 ms, P < 0.001). There was no difference between single left ventricle (SLV) versus SRV myocardial or liver T1. Liver T1 showed moderate correlations with myocardial T1 (r = 0.48, confidence interval [CI] 0.26-0.72) and ejection fraction (r = -0.36, CI -0.66-0.95) but not with other volumetric parameters.

CONCLUSION

Increased liver T1 at both pre- and post-Fontan stages suggests there are intrinsic liver abnormalities early in the course of single ventricle palliation. Increased myocardial T1 and its relationship to liver T1 suggest a combination of edema from passive venous congestion and/or myocardial fibrosis occurring in this population. Liver T1 may provide an earlier marker of liver disease warranting further study.

A Novel Strategy for the Mechanical Subpulmonary Support in Failing Fontan Patients

Background The number of single ventricle patients undergoing Fontan palliation and surviving to adulthood worldwide has steadily increased in recent years. Nevertheless, the Fontan circulation is destined to fail. Ultimately, heart transplantation (HTx) remains the definitive treatment option. Due a shortage of organs, mechanical circulatory support in the form of ventricular assist devices (VADs) is widely used to bridge heart failure patients to HTx, but these devices have been mainly developed to address the needs of normal anatomies. A novel venous cannula has been developed as part of the EXCOR® VAD to provide subpulmonary support in these patients. Its clinical application is investigated in the “Registry to Assess the Safety and Feasibility of the Subpulmonary Support with the Novel Venous Cannula in Patients with Failing/Absence of the Right Heart” (RegiVe study, NCT04782232).

Methods RegiVe is a multicenter, international, observational, prospective, non-randomized registry aiming to collect the routine clinical data of up to 20 patients. The primary endpoints address device performance and safety, while the secondary endpoints target organ status and overall safety (according to the Interagency Registry for Mechanically Assisted Circulatory Support – INTERMACS – definitions). Data analysis will be performed by means of descriptive statistics.

Results RegiVe has received the favorable opinion of an independent ethics committee and enrollment has recently started.

Conclusion RegiVe is the first study evaluating the use of a medical device specifically developed for subpulmonary support of failing Fontan patients. The study will provide important insight and further information on this cohort and help to improve a dedicated VAD strategy.

Fontan-associated Liver Disease in Adults: What a Cardiologist Needs to Know. A Comprehensive Review for Clinical Practitioners

Nowadays most patients with a univentricular heart after Fontan repair survive until adulthood. One of the hallmarks of Fontan circulation is permanently elevated central venous pressure, which leads to congestive hepatopathy. Subsequently, liver fibrosis, cirrhosis, or hepatocellular carcinoma may occur, all of them constituting an entity called Fontan-associated liver disease (FALD). Given that these complications convey poor prognosis, the need for life-long hepatic surveillance is not in doubt. Many serum biomarkers and sophisticated imaging techniques have been proposed to avoid invasive liver biopsy in this cohort, but none proved to be a relevant surrogate of liver fibrosis seen in histopathological specimens. The surveillance models proposed to date require an extensive diagnostic work-up, which can be problematic, particularly in resource-depleted countries. Moreover, the question of combined heart-liver transplant is gaining more attention in the Fontan cohort. The aim of this study is to provide practical information on the pathophysiology of FALD and to propose a simplified framework for the routine assessment of liver status in Fontan patients that would be helpful in the decision-making process.

Liver and spleen volume and stiffness in patients post-Fontan procedure and patients with ARPKD compared to normal controls

PURPOSE

Both congestive (patients post-Fontan hepatopathy) and congenital (patients with ARPKD) disease can lead to hepatic fibrosis and portal hypertension with eventual development of splenomegaly. We investigated liver and spleen stiffness as measured by MRE between post-Fontan, ARPKD patients and controls independent of organ volume.

METHODS

Our study included 122 subjects (70 Fontan patients, 14 ARPKD patients, and 38 controls). The mean MRE liver and spleen stiffness values of Fontan patients and patients with ARPKD were compared to controls. Similarly, the liver and spleen volumes of the Fontan patients and patients with ARPKD were then compared to the volumes of controls.

RESULTS

Post-Fontan and ARPKD patients, mean liver stiffness, mean liver volume as well as mean spleen stiffness and mean spleen volume were higher than mean liver stiffness, mean liver volume, mean spleen stiffness, and mean spleen volume of controls. While liver stiffness correlated to liver volume in controls, we found no correlation between stiffness and volume in either Fontan or ARPKD patients, which indicates MRE's ability to act as an independent biomarker. However, these findings are not true in the spleen, where there is significant association between volume and stiffness in patients with ARPKD, but not in Fontan patients or controls.

CONCLUSION

Liver and spleen stiffness and volumes are significantly different among Fontan patients, ARPKD patients, and controls. Our findings suggest that beyond diagnosing fibrosis, MRE cut-off values could be disease-specific since not only the severity but the underlying pathology causing organ congestion or fibrosis influences MRE results.

Care Pattern for Fontan-Associated Liver Disease by Academic Pediatric Hepatologists in Canada

Fontan-Associated Liver Disease (FALD) is a common extracardiac complication seen in patients following the Fontan procedure. There are no consensus guidelines on screening and management of children with FALD.

Objective

The current study aims to determine academic pediatric hepatologists' practices and identify variability in management provided to children with FALD in Canada.

Methods

Using the infrastructure of the Canadian Pediatric Hepatology Research Group, a nationwide survey was distributed electronically to all pediatric hepatologists practicing in university-affiliated hospitals.

Results

Twelve pediatric hepatologists from 12 of 13 academic centers (92%) responded to the survey. The institutions of only 2 (17%) physicians offer post-Fontan care with a multidisciplinary team, both from different provinces. The screening for other comorbidities, use of noninvasive modality, and timing of liver biopsy for estimation of liver fibrosis and screening for esophageal varices differ from program to program. The frequency of outpatient clinic follow-up varies significantly. Education and counseling concerning liver health are generally used as treatment; only 58% of academic centers have a formal adult care transition plan.

Conclusions

Significant discrepancies exist in the care provided to children with FALD by hepatologists practicing in academic centers across Canada. Future study is needed to develop a standardized protocol for managing and following children and youth with FALD.

Invasive Hemodynamic Evaluation of the Fontan Circulation: Current Day Practice and Limitations

PURPOSE OF REVIEW

Establishing the Fontan circulation has led to improved survival in patients born with complex congenital heart diseases. Despite early success, the long-term course of Fontan patients is complicated by multi-organ dysfunction, mainly due to a combination of low resting and blunted exercise-augmented cardiac output as well as elevated central venous (Fontan) pressure. Similarly, despite absolute hemodynamic differences compared to the normal population with biventricular circulation, the "normal" ranges of hemodynamic parameters specific to age-appropriate Fontan circulation have not been well defined. With the ever-increasing population of patients requiring Fontan correction, it is of utmost importance that an acceptable range of hemodynamics in this highly complex patient cohort is better defined.

RECENT FINDINGS

Multiple publications have described hemodynamic limitations and potential management options in patients with Fontan circulation; however, an acceptable range of hemodynamic parameters in this patient population has not been well defined. Identification of "normal" hemodynamic parameters among patients with Fontan circulation will allow physicians to more objectively define indications for intervention, which is a necessary first step to eliminate institutional and regional heterogeneity in Fontan management and potentially improve long-term clinical outcomes.

Relation of Liver Volume to Adverse Cardiovascular Events in Adolescents and Adults With Fontan Circulation

Elevated central venous pressure in those with Fontan circulation causes liver congestion and hepatomegaly. We assessed if liver volume by magnetic resonance imaging (MRI) is associated with adverse cardiovascular outcomes. Retrospective study of 122 patients with Fontan circulation who were >10 years old and had a liver MRI with magnetic resonance elastography. Liver volume (ml) was measured by manual segmentation from axial T2-weighted images and was indexed to body surface area. The composite outcome included death, heart transplant, ventricular assist device placement, or nonelective cardiovascular hospitalization. The median age at the time of MRI was 18.9 (interquartile range 15.8 to 25.9) years, and 47% of the patients were women. The mean indexed liver volume was 1,133 ± 180 ml/m². Indexed liver volume was not significantly associated with age, years since Fontan, or with liver stiffness (r = 0.15, p = 0.10), but was positively correlated with Fontan pressure (r = 0.32, p = 0.002). Over a median follow-up of 2.1 (0.8 to 4.2) years, 32 patients (26%) experienced the composite outcome. Higher indexed liver volume was associated with a greater hazard for the composite outcome (hazard ratio per 1 SD increase = 1.74, 95% confidence interval 1.27 to 2.35, p = 0.0004) but increased liver stiffness was not significantly associated with the composite outcome (hazard ratio per 1 SD increase 1.44, 95% confidence interval 0.90 to 2.21, p = 0.11). In conclusion, greater liver volume indexed to body surface area is associated with unfavorable hemodynamics and adverse outcomes in patients with Fontan circulation. Liver volume may be a useful, simple imaging biomarker in adolescents and adults with Fontan circulation.

Adult Combined Heart-Liver Transplantation: The United States Experience

Background: We aimed to review the indications and outcomes of adults undergoing combined heart-liver transplantation (CHLT) in the US using national registry data.

Methods: Adult (≥18 years) CHLT recipients in the United Network for Organ Sharing database were included (09/1987–09/2020; era 1 = 1989–2000, era 2 = 2001–2010, era 3 = 2011–2020). Survival analysis was conducted by means of Kaplan-Meier method, log-rank test, and Cox regression.

Results: We identified 369 adults receiving CHLT between 12/1989–08/2020. The number of adult CHLT recipients (R² = 0.75, p < 0.001) and centers performing CHLT (R² = 0.80, p < 0.001) have increased over the study period. The most common cardiac diagnosis in the first two eras was restrictive/infiltrative cardiomyopathy, while the most common in era 3 was congenital heart disease (p = 0.03). The 1-, 3-, and 5-years patient survival was 86.8, 80.1, and 77.9%, respectively. In multivariable analysis, recipient diabetes [adjusted hazard ratio (aHR) = 2.35, 95% CI: 1.23–4.48], CHLT between 1989-2000 compared with 2011–2020 (aHR = 5.00, 95% CI: 1.13–22.26), and sequential-liver first CHLT compared with sequential-heart first CHLT (aHR = 2.44, 95% CI: 1.15–5.18) were associated with increased risk of mortality. Higher left ventricular ejection fraction was associated with decreased risk of mortality (aHR = 0.96, 95% CI: 0.92–0.99).

Conclusion: CHLT is being increasingly performed with evolving indications. Excellent outcomes can be achieved with multidisciplinary patient and donor selection and surgical planning.