Abdominal imaging findings in adult patients with Fontan circulation

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.

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.

Congestive Hepatopathy: Pathophysiology, Workup, and Imaging Findings with Pathologic Correlation

Liver congestion is increasingly encountered in clinical practice and presents diagnostic pitfalls of which radiologists must be aware. The complex altered hemodynamics associated with liver congestion leads to diffuse parenchymal changes and the development of benign and malignant nodules. Distinguishing commonly encountered benign hypervascular lesions, such as focal nodular hyperplasia (FNH)-like nodules, from hepatocellular carcinoma (HCC) can be challenging due to overlapping imaging features. FNH-like lesions enhance during the hepatic arterial phase and remain isoenhancing relative to the background liver parenchyma but infrequently appear to wash out at delayed phase imaging, similar to what might be seen with HCC. Heterogeneity, presence of an enhancing capsule, washout during the portal venous phase, intermediate signal intensity at T2-weighted imaging, restricted diffusion, and lack of uptake at hepatobiliary phase imaging point toward the diagnosis of HCC, although these features are not sensitive individually. It is important to emphasize that the Liver Imaging Reporting and Data System (LI-RADS) algorithm cannot be applied in congested livers since major LI-RADS features lack specificity in distinguishing HCC from benign hypervascular lesions in this population. Also, the morphologic changes and increased liver stiffness caused by congestion make the imaging diagnosis of cirrhosis difficult. The authors discuss the complex liver macro- and microhemodynamics underlying liver congestion; propose a more inclusive approach to and conceptualization of liver congestion; describe the pathophysiology of liver congestion, hepatocellular injury, and the development of benign and malignant nodules; review the imaging findings and mimics of liver congestion and hypervascular lesions; and present a diagnostic algorithm for approaching hypervascular liver lesions. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Fontan-Associated Liver Disease: A Review

Fontan-associated liver disease (FALD) is a chronic complication of the Fontan procedure, a palliative surgery for patients with congenital heart disease that results in a single-ventricle circulation. The success of the Fontan procedure has led to a growing population of post-Fontan patients living well into adulthood. For this population, FALD is a major cause of morbidity and mortality. It encompasses a spectrum of hepatic abnormalities, ranging from mild fibrosis to cirrhosis and hepatocellular carcinoma. The pathophysiology of FALD is multifactorial, involving hemodynamic and inflammatory factors. The diagnosis and monitoring of FALD present many challenges. Conventional noninvasive tests that use liver stiffness as a surrogate marker of fibrosis are unreliable in FALD, where liver stiffness is also a result of congestion due to the Fontan circulation. Even invasive tissue sampling is inconsistent due to the patchy distribution of fibrosis. FALD is also associated with both benign and malignant liver lesions, which may exhibit similar imaging features. There is therefore a need for validated diagnostic and surveillance protocols to address these challenges. The definitive treatment of end-stage FALD is also a subject of controversy. Both isolated heart transplantation and combined heart-liver transplantation have been employed, with the latter becoming increasingly preferred in the US. This article reviews the current literature on the epidemiology, pathophysiology, diagnosis, and management of FALD, and highlights knowledge gaps that require further research.

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.

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.

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.

Combined hepatocellular carcinoma-cholangiocarcinoma in a patient with Fontan-associated liver disease

We present a rare case of combined hepatocellular carcinoma-cholangiocarcinoma in a woman with a history of univentricular congenital heart disease requiring multiple corrective operations including Fontan procedure. During workup for elevated alpha fetal protein, a right hepatic lobe lesion was identified with biopsy showing poorly differentiated hepatocellular carcinoma. She underwent successful segment 5 liver resection. Final pathology demonstrated combined hepatocellular carcinoma-cholangiocarcinoma. She was treated with gemcitabine/oxaliplatin adjuvant chemotherapy and had no evidence of recurrent disease at her 12-month follow-up. To our knowledge, this is the first case reported in of successful treatment of this rare malignancy in the setting of Fontan-associated liver disease and highlights the importance of a robust screening protocol in this patient population. Semiannual screening for the development of primary liver malignancy should start by 10 years post-Fontan and continue until heart-liver transplantation may be performed. It is important to note that cirrhosis is not a pre-requisite for the development of hepatocellular carcinoma or cholangiocarcinoma in these patients.

Focal Nodular Hyperplasia and Focal Nodular Hyperplasia-like Lesions

Focal nodular hyperplasia (FNH) is a benign lesion occurring in a background of normal liver. FNH is seen most commonly in young women and can often be accurately diagnosed at imaging, including CT, MRI, or contrast-enhanced US. In the normal liver, FNH frequently must be differentiated from hepatocellular adenoma, which although benign, is managed differently because of the risks of hemorrhage and malignant transformation. When lesions that are histologically identical to FNH occur in a background of abnormal liver, they are termed FNH-like lesions. These lesions can be a source of diagnostic confusion and must be differentiated from malignancies. Radiologists' familiarity with the imaging appearance of FNH-like lesions and knowledge of the conditions that predispose a patient to their formation are critical to minimizing the risks of unnecessary intervention for these lesions, which are rarely symptomatic and carry no risk for malignant transformation. FNH is thought to form secondary to an underlying vascular disturbance, a theory supported by the predilection for formation of FNH-like lesions in patients with a variety of hepatic vascular abnormalities. These include abnormalities of hepatic outflow such as Budd-Chiari syndrome, abnormalities of hepatic inflow such as congenital absence of the portal vein, and hepatic microvascular disturbances, such as those that occur after exposure to certain chemotherapeutic agents. Familiarity with the imaging appearances of these varied conditions and knowledge of their association with formation of FNH-like lesions allow radiologists to identify with confidence these benign lesions that require no intervention. Online supplemental material is available for this article. ^©RSNA, 2022.

Semiquantitative characterization of dynamic magnetic resonance perfusion of the liver in pediatric Fontan patients

BACKGROUND

Dynamic contrast-enhanced magnetic resonance imaging (MRI) of the liver in pediatric Fontan patients often shows peripheral reticular areas of hypoenhancement, which has not been studied in detail.

OBJECTIVE

To semiquantitatively score the hepatic MR perfusion abnormality seen in pediatric Fontan patients, and to correlate the perfusion abnormality with functional clinical and hemodynamic parameters.

MATERIALS AND METHODS

All children (< 18 years old) after Fontan palliation with combined clinical cardiac and liver MRI performed between May 2017 and April 2019 were considered for inclusion. A semiquantitative perfusion score was used to assess the severity of the hepatic reticular pattern seen on dynamic contrast-enhanced liver imaging. The liver was divided into four sections: right posterior, right anterior, left medial and left lateral. Each liver section was assigned a score from 0 to 4 depending on the amount of abnormal reticular hypoenhancement. Scoring was assigned for each section of the liver across eight successive dynamic contrast-enhanced modified spoiled gradient echo runs. Scores were correlated with clinical and hemodynamic parameters.

RESULTS

All Fontan children showed hepatic reticular hypoenhancement by MRI, most severe in the early portal venous phase with a median maximum total perfusion abnormality score of 12 (range: 9-14). All perfusion abnormalities progressively resolved during the hepatic venous phase. Perfusion abnormality scores were greatest in the right compared to left hepatic lobes (7 range: [6-8] vs. 5 [range: 3-6], P < 0.01). The maximum left hepatic lobe perfusion abnormality scores were greatest in children with versus without imaging signs of portal hypertension (8 [range: 7-8] vs. 4 [range: 3-5], P < 0.01). High unconjugated bilirubin and low platelets correlated with greater perfusion abnormality (R = 0.450, P = 0.024, and R =  - 0.458, P < 0.01, respectively). Age at MRI, time from Fontan, focal liver lesions and cardiac MRI hemodynamic parameters did not show significant correlations with the severity of the liver perfusion abnormality.

CONCLUSION

All Fontan children have hepatic reticular hypoenhancement abnormalities seen with MRI that are most severe in the right hepatic lobe and universally show gradual resolution through the hepatic venous phase. Perfusion abnormality in the left hepatic lobe is worse in children with portal hypertension.

Blood test assessment of liver ultrasound findings in patients with Fontan surgery

Hepatic complications are common in patients with Fontan surgery. The objective of this observational study is to compare demographic, clinical and blood test data in patients older than 14 years old with a Fontan procedure (cases) and asymptomatic patients with single non-operated restrictive ventricular septal defect (VSD) (controls) and to determine whether there are differences in blood collection and liver disease scores according to the liver ultrasound findings in the group of Fontan patients. The liver findings were classified as mild (normal or heterogeneous echogenicity) and significant (nodular surface, small hyperechoic nodules or hepatocarcinoma). 74 patients (14 patients with a Fontan procedure and 60 patients with a restrictive VSD) were included in the study. Median age was 18 (14-45) years old and 41 patients were males. Fontan patients had significantly lower platelet count, lower mean platelet volume (MPV) and lower glucose levels than patients with single non-operated restrictive VSD. On the contrary, Fontan patients showed higher liver enzymes [aspartate aminotransferase (AST) and alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT)], N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and thyroid-stimulating hormone (TSH) concentrations than patients with restrictive VSD. 4 out of 14 (29%) patients with Fontan operation and significant liver ultrasound findings showed greater number of cardiac surgeries, lower MPV values and higher GGT and TSH levels than Fontan patients with mild findings. In conclusion, Fontan patients showed higher liver enzymes (AST, ALT and GGT) than controls and Fontan patients with significant liver ultrasound findings had higher GGT and TSH concentrations than Fontan patients with mild findings.

Platelet count and abdominal dynamic CT are useful in predicting and screening for gastroesophageal varices after Fontan surgery

OBJECTIVE

Patients who undergo Fontan surgery for complex cardiac anomalies are prone to developing liver and gastrointestinal complications. In particular, gastroesophageal varices (GEVs) can occur, but their prevalence is unknown. We aimed to elucidate the occurrence of GEVs and the predicting parameters of GEVs in these patients.

MATERIALS AND METHODS

Twenty-seven patients (median age, 14.8 years; median time since surgery, 12.9 years) who had undergone the Fontan surgery and were examined by abdominal dynamic computed tomography (CT) for the routine follow-up were included in the study. Radiological findings including GEVs and extraintestinal complications were retrospectively evaluated by experienced radiologists in a blinded manner. Relationships between blood-biochemical and demographic parameters and the presence of GEVs were statistically analyzed.

RESULTS

Dynamic CT revealed gastric varices (n = 3, 11.1%), esophageal varices (n = 1, 3.7%), and gastrorenal shunts (n = 5, 18.5%). All patients with gastric varices had gastrorenal shunts. All gastric varices were endoscopically confirmed as being isolated and enlarged, with indications for preventive interventional therapy. A platelet count lower than 119 × 109 /L was identified as a predictor of GEV (area under the receiver operating curve, 0.946; sensitivity, 100%; and specificity, 87%).

CONCLUSIONS

GEVs are important complications that should not be ignored in patients who have undergone a Fontan procedure. Platelet counts lower than 119 × 109 /L may help to prompt patient screening by using abdominal dynamic CT to identify GEVs and their draining collateral veins in these patients.

Role of Transient Elastography to Stage Fontan-Associated Liver Disease (FALD) in Adults with Single Ventricle Congenital Heart Disease Correction

Fontan-associated liver disease (FALD) is an arising clinical entity that can occur long after a successful Fontan operation for correction of single ventricle (SV) congenital heart disease (CHD). Occurrence of FALD is characterized by liver cirrhosis and other hepatic complications, and determinates an increased morbidity and mortality. Currently, there is no consensus on how to stage FALD. We report here our experience by an observational study in 52 patients with SV-CHD after Fontan operation that were recruited through a period of 36 ± 9.3 months. All cases underwent lab tests and liver and cardiac imaging evaluation, including liver stiffness (LS) measurement by transient elastography (TE) (FibroScan®). According to selective criteria for liver disease, we identified 23/43 (53.5%) cases with advanced FALD that showed: older age (p < 0.05), larger hepatic and cava veins diameter (p < 0.05), worsened NYHA class (p < 0.05), abnormal lymphocytes (p < 0.01), platelet count (p < 0.05), and GGT, prothrombin time (INR), albumin and cystatin C levels (p < 0.05), with respect to cases without advanced FALD. LS values were significantly increased in cases with advanced FALD, at cut-off values higher than 22 kPa (p < 0.001). LS, and its combined score with spleen diameter and platelet count (LSPS) successfully helped to detect 100% of cases with portal hypertension (p < 0.001). In conclusion, LS can be effective to stage FALD and to uncover cases with severe risk of complications, avoiding higher morbidity and mortality related to advanced FALD.

Spectrum of Fontan-associated liver disease assessed by MRI and US in young adolescents

Purpose

Patients with Fontan circulation are at risk of developing hepatic fibrosis/cirrhosis. The mechanisms and disease development are unclear and early secondary liver cancer is a concern. This study will describe hepatic imaging findings in a national cohort of adolescents with Fontan circulation.

Methods

The patients prospectively underwent abdominal contrast enhanced magnetic resonance imaging (MRI) including diffusion-weighted imaging. Images were assessed for criteria of fibrosis/cirrhosis including characterization of hepatic nodules. These nodules were in addition, assessed by ultrasonography (US). Nodules ≥ 1 cm were investigated and monitored to evaluate malignant transformation. Clinical and hepatic serological data were recorded.

Results

Forty-six patients, median age of 16.5 years (15.4–17.9 years) were enrolled. All patients underwent US examination and MRI was performed in 35/46 patients. On MRI, 60% had hepatomegaly and 37% had signs of fibrosis/cirrhosis. Seven patients had together 13 nodules ≥ 1 cm in diameter. Only 4/13 (17%) where seen on US. Nodules had variable MRI signal characteristics including hepatobiliary contrast enhancement and two nodules revealed portal venous phase ‘wash-out’ on the first examination. No further imaging signs of malignancy were revealed during the follow-up period of median 24.4 (7–42) months.

Conclusion

The majority of adolescents with Fontan circulation had imaging findings of fibrosis/cirrhosis of varying severity. US had low detection rate of hepatic nodules compared to MRI. The imaging work-up before transition to adult cardiology care did not reveal findings suggestive of malignancy. However, the high prevalence of Fontan-associated liver disease calls for surveillance strategies even in childhood.

Supplementary Information

The online version of this article (10.1007/s00261-021-02994-0) contains supplementary material, which is available to authorized users.

Abdominal Imaging of Children and Young Adults With Fontan Circulation: Pathophysiology and Surveillance

OBJECTIVE. The Fontan procedure has significantly improved the survival in children with a functional single ventricle, but it is associated with chronically elevated systemic venous pressure that leads to multisystemic complications. Imaging plays an important role in assessing these complications and guiding management. The pathophysiology, imaging modalities, and current surveillance recommendations are discussed and illustrated. CONCLUSION. Significant improvement in survival of patients with Fontan circulation is associated with ongoing cardiac and extracardiac comorbidities and multisystemic complications. The liver and intestines are particularly vulnerable to damage. In addition, this patient population has been shown to be at increased risk of certain malignancies such as hepatocellular carcinoma and neuroendocrine tumors. Familiarity with imaging findings of Fontan-associated liver disease and other abdominal complications of the Fontan circulation is essential for radiologists because we are likely to encounter these patients in our general practice.

Prognostic Value of Liver and Spleen Stiffness in Patients with Fontan Associated Liver Disease (FALD): A Case Series with Histopathologic Comparison

The Fontan operation is the current surgical procedure to treat single-ventricle congenital heart disease, by splitting the systemic and pulmonary circulations and thus permitting lifespan to adulthood for the majority of newborns. However, emerging data are showing that Fontan-associated liver disease (FALD) is an increasing related cause of morbidity and mortality in patients with the Fontan circuit. We described the clinical, laboratory, and transient elastography (TE) findings in a case series of adults with the Fontan circuit, and also correlated data with post-mortem histological features, aimed to define the prognostic value of TE in the staging of FALD. All patients presented signs of a long-standing Fontan failure, characterized by reoperation need, systemic ventricle dysfunction, and FALD stigmata (liver and spleen enlargement, portal vein and inferior vena cava dilation, and abnormal liver function tests). Liver and spleen stiffness (LS and SS) values were indicative of significant liver fibrosis/cirrhosis and the presence of suggestive portal hypertension (LS mean 35.9; range 27.3–44.7 kPa; SS mean 42.1, range 32.2–54.5 kPa). Post-mortem evaluations confirmed a gross hepatic architecture distortion in all cases. All patients died from severe complications related to liver dysfunction and bleeding. TE correlated well with pathological findings and FALD severity. We propose this validated and harmless technique to monitor liver fibrosis extension and portal hypertension over time in Fontan patients, and to identify the optimal timing for surgical reoperations or orthotopic-heart transplantation (OHT), avoiding a higher risk of morbidity and mortality in cases with severe FALD.

Fontan-associated liver disease

OBJECTIVE

To review the pathophysiology of Fontan-associated liver disease, its histologic changes, and its radiologic manifestations.

CONCLUSIONS

Fontan-associated liver disease is the result of a set of structural and functional changes in the liver that occur secondary to hemodynamic changes brought about by Fontan surgery. The radiologic manifestations of Fontan-associated liver disease consist of changes in the size and shape of the liver, alterations in the signal intensity or pattern of enhancement, abnormalities in the vascular structures, and focal lesions, which include benign nodules with intense uptake in the arterial phase and hepatocellular carcinoma. Radiologists need to be familiar with this disease and its complications, because the number of patients who undergo Fontan surgery continues to increase, and these patients undergo an increasing number of imaging tests.

Fontan-associated liver disease and hepatocellular carcinoma in adults

The Fontan operation creates a unique circulation, and is a palliative therapy for patients with single-ventricle congenital heart disease. Increased venous pressure and decreased cardiac output and hepatic venous drainage result in sinusoidal dilatation around the central veins. This causes congestion and hypoxia in the liver, leading to Fontan-associated liver disease (FALD). Non-invasive and invasive markers enable diagnosis and evaluation of the fibrosis status in chronic liver disease; however, these markers have not been validated in FALD. Additionally, regenerative nodules such as focal nodular hyperplasia (FNH) are frequently found. The severity of fibrosis correlates with the duration of the Fontan procedure and the central venous pressure. Cirrhosis is a risk factor for hepatocellular carcinoma (HCC), the annual risk of which is 1.5–5.0%. HCC is frequently difficult to diagnose and treat because of cardiac complications, coagulopathy, and congenital abnormalities. The mortality rate of FALD with liver cirrhosis and/or FALD-HCC was increased to ~ 29.4% (5/17 cases) in a nationwide survey. Although there is no consensus on the surveillance of patients with FALD, serial monitoring of the alpha fetoprotein level and imaging at 6-month intervals is required in patients with cirrhosis.

Transarterial chemoembolization for hepatocellular carcinoma in Fontan surgery patient

We describe the case of a 41‐year‐old woman who developed a liver neoplasm due to previous Fontan surgery for a single ventricle anomaly and pacemaker implantation. She was admitted to our hospital for moderate ascites and she was affected by hepatocellular carcinoma treated by trans-arterial chemoembolization (TACE). Computed tomography showed features of chronic liver disease and 4 cm hepatic nodules with arterial enhancement. Laboratory analyses documented preserved liver function and increased levels of alpha-fetoprotein. TACE was performed obtaining complete necrosis at 4 weeks of follow up and significant reduction of alpha-fetoprotein after 2 months. The patient is currently in follow-up, being evaluated for further treatments and/or combined liver/heart transplantation. TACE is a therapeutic option for the treatment of patients with unresectable HCC and with severe heart disease, like those submitted to FS.

Imaging of Fontan-associated liver disease

The Fontan operation has dramatically altered the natural history of functionally single ventricle congenital heart disease. Patients who have undergone the Fontan operation are living longer and, thus, noncardiac morbidity resulting from the Fontan operation is increasingly being recognized. Fontan-associated liver disease (FALD), one of the chief morbidities following the Fontan operation, is believed to be a multifactorial process that manifests as hepatic congestion and fibrosis, portal hypertension, and development of focal liver lesions, including malignant tumors. This article reviews the imaging findings of FALD in the pediatric and young adult population, reviews the literature related to the imaging of FALD and discusses possible screening algorithms for this population. The need for further research to better understand the causes of FALD, to establish if early liver stiffness measurements (or their change over time) predict long-term outcomes and complications, and to define optimal liver screening procedures is highlighted.

Fontan-Associated Liver Disease: Screening, Management, and Transplant Considerations

Surgical innovation and multidisciplinary management have allowed children born with univentricular physiology congenital heart disease to survive into adulthood. An estimated global population of 70 000 patients have undergone the Fontan procedure and are alive today, most of whom are <25 years of age. Several unexpected consequences of the Fontan circulation include Fontan-associated liver disease. Surveillance biopsies have demonstrated that virtually 100% of these patients develop clinically silent fibrosis by adolescence. As they mature, there are increasing reports of combined heart-liver transplantation resulting from advanced liver disease, including bridging fibrosis, cirrhosis, and hepatocellular carcinoma, in this population. In the absence of a transplantation option, these young patients face a poor quality of life and overall survival. Acknowledging that there are no consensus guidelines for diagnosing and monitoring Fontan-associated liver disease or when to consider heart transplantation versus combined heart-liver transplantation in these patients, a multidisciplinary working group reviewed the literature surrounding Fontan-associated liver disease, with a specific focus on considerations for transplantation.

Fontan-associated liver disease: pathophysiology, investigations, predictors of severity and management

Cardiac hepatopathy is the liver injury resulting from congestion and ischaemia associated with acute or chronic heart failure. The improved longevity of adults with operated congenital heart disease who develop heart failure as an increasingly late event makes this form of liver injury increasingly clinically relevant. Patients with congenital heart disease with a single ventricle anomaly, who require creation of a Fontan circulation, are particularly vulnerable as they have elevated venous filling pressures with chronic liver congestion. Progression to liver fibrosis and eventually cirrhosis may occur, with its associated risks of liver failure and hepatocellular carcinoma. This risk likely increases over the patient's lifetime, related to the duration post-surgical repair and reflects the chronicity of congestion. Liver biopsy is rarely performed due to a higher risk of complications in the setting of elevated venous pressures, and the frequent use of anticoagulation. Non-invasive methods of liver assessment are poorly validated and different factors require consideration compared to other chronic liver diseases. This review discusses the current understanding of cardiac hepatopathy in congenital heart disease patients with a Fontan circulation. This entity has recently been called Fontan Associated Liver Disease in the literature, with the term useful in recognising that the pathophysiology is incompletely understood, and that long-standing venous pressure elevation and hypoxaemia are presumed to play an additional significant role in the pathogenesis of the liver injury.

Portal vein thrombosis in Fontan-associated liver disease

A 25-year-old patient with signs of cirrhosis on ultrasound and CT presented with portal vein thrombosis on routine follow-up examinations; retrograde hepatic wedge angiography demonstrated only the right-sided portal vein branch. Development of a portosystemic collateral vessel to the left-sided renal vein prevented signs of hypersplenism. This unique complication of portal vein thrombosis should be considered during long-term surveillance.

Prevalence, features and predictive factors of liver nodules in Fontan surgery patients: The VALDIG Fonliver prospective cohort

BACKGROUND & AIMS

Fontan surgery is used to treat a variety of congenital heart malformations, and may lead to advanced chronic liver disease in the long-term. This study examines the prevalence, characteristics and predictors of liver nodules in patients following Fontan surgery.

METHODS

This was a prospective, cross-sectional, observational study conducted at 8 European centres. Consecutive patients who had undergone Fontan surgery underwent blood tests, abdominal ultrasonography (US), transient elastography (Fibroscan®), echocardiography, haemodynamic assessments, and abdominal MRI/CT scan. The primary outcome measure was liver nodules detected in the MRI/CT scan. Predictors of liver nodules were identified by multivariate logistic regression.

RESULTS

One hundred and fifty-two patients were enrolled (mean age 27.3 years). The mean time elapsed from surgery to inclusion was 18.3 years. Liver nodule prevalences were 29.6% (95% CI 23-37%) on US and 47.7% (95% CI 39-56%) on MRI/CT. Nodules were usually hyperechoic (76.5%), round-shaped (>80%), hyperenhancing in the arterial phase (92%) and located in the liver periphery (75%). The sensitivity and specificity of US were 50% (95% CI 38-62%) and 85.3% (95% CI 75-92%), respectively. Inter-imaging test agreement was low (adjusted kappa: 0.34). In the multivariate analysis, time since surgery >10 years was the single independent predictor of liver nodules (odds ratio 4.18; p = 0.040). Hepatocellular carcinoma was histologically diagnosed in 2 of the 8 patients with hypervascular liver nodules displaying washout.

CONCLUSION

While liver nodules are frequent in Fontan patients, they may go unnoticed in US. Liver nodules are usually hyperechoic, hypervascular and predominantly peripheral. This population is at risk of hepatocellular carcinoma, the diagnosis of which requires confirmatory biopsy.

LAY SUMMARY

Fontan surgery is the standard of care for many patients with univentricular congenital cardiopathies. Recent advances have improved the survival of Fontan patients, and nowadays most of them reach adulthood. In this setting, Fontan-associated liver disease (FALD) is increasingly recognised, and has become a significant prognostic factor. Liver nodules are considered a component of FALD yet their prevalence, imaging features and predictors have hardly been evaluated. In this study, we observed that liver nodules are frequent, typically hyperechoic, hypervascular and predominantly peripheral in patients with FALD. This population is at risk of hepatocellular carcinoma, the diagnosis of which must be confirmed by biopsy.

Hepatic pathology in patients after Fontan operation: A computed tomography imaging study

BACKGROUND

Hepatic dysfunction is an important long-term complication in Fontan patients. The purpose of this study was to evaluate the hepatic computed tomography (CT) findings after Fontan surgery and identify their association with clinical parameters.

METHODS

This study recruited 43 patients (23 male and 20 female patients aged 15.3 ± 6.8 years), who underwent Fontan surgery. Medical records were reviewed to collect their age, sex, congenital heart disease type, date of Fontan surgery, laboratory data, and hepatic CT findings. The relationship between hepatic findings and clinical parameters was analyzed.

RESULTS

The follow-up duration was 6.8 ± 4.1 years. Abnormal hepatic parenchymal enhancement was observed in 77% of the patients, with mild degree in 18, moderate degree in 10, and severe degree in 5 patients. According to the univariate analysis, risk factors for hepatic parenchymal enhancement were follow-up duration (odds ratio [OR]: 1.354 [95% confidence interval (CI): 1.024-2.078]; p = 0.042), hypoplastic left heart syndrome (HLHS) (OR: 3.262 [95% CI: 1.145-5.628]; p = 0.002), mean pulmonary artery pressure (OR: 1.598 [95% CI: 1.089-2.132]; p = 0.026), pulmonary vascular resistance index (OR: 1.263 [95% CI: 1.068-1.245]; p = 0.032), and brain natriuretic peptide (OR: 1.956 [95% CI: 1.085-2.673]; p = 0.045). According to the multivariate analysis, only HLHS (OR: 3.856 [95% CI: 1.389-5.863]; p = 0.001), mean pulmonary artery pressure (OR: 1.846 [95% CI: 1.362-2.549]; p = 0.015), and pulmonary vascular resistance index (OR: 1.185 [95% CI: 1.042-1.736]; p = 0.047) were significant risk factors for abnormal parenchymal enhancement.

CONCLUSION

Abnormal hepatic parenchymal enhancement detected through CT is common in Fontan patients. Regular liver function test in conjunction with imaging studies may be considered when following up Fontan patients.

Pheochromocytoma in Congenital Cyanotic Heart Disease

Studies on genome-wide transcription patterns have shown that many genetic alterations implicated in pheochromocytoma-paraganglioma (P-PGL) syndromes cluster in a common cellular pathway leading to aberrant activation of molecular response to hypoxia in normoxic conditions (the pseudohypoxia hypothesis). Several cases of P-PGL have been reported in patients with cyanotic congenital heart disease (CCHD). Patients affected with CCHD have an increased likelihood of P-PGL compared to those affected with noncyanotic congenital heart disease. One widely supported hypothesis is that chronic hypoxia represents the determining factor supporting this increased risk. We report the case of a 23-year-old woman affected with congenital tricuspid atresia surgically by the Fontan procedure. The patient was admitted to hospital with hypertensive crisis and dyspnea. Chest computed tomography revealed, incidentally, a 6-cm mass in the left adrenal lodge. Increased levels of noradrenaline (NA) and its metabolites were detected (plasma NA 5003.7 pg/ml, n.v.<480; urinary NA 1059.5 µg/24 h, n.v.<85.5; urinary metanephrine 489 µg/24 h, n.v.<320). The patient did not report any additional symptom related to catecholamine excess. The left adrenal tumor showed abnormal accumulation when 131I-metaiodobenzylguanidine scintigraphy was performed. A 18F-fluorodeoxyglucose positron emission tomography showed no significant metabolic activity in the left adrenal gland but intense uptake in the supra- and subdiaphragmatic brown adipose tissue, probably due to noradrenergic-stimulated glucose uptake. The patient underwent left open adrenalectomy after preconditioning with α- and β-blockers and histopathological examination confirmed the diagnosis of pheochromocytoma (Ki-67<5%). Screening for germline mutations did not show any genes mutation (investigated mutations: RET, TMEM127, MAX, SDHD, SDHC, SDHB, SDHAF2, SDHA, and VHL). Clinicians should consider P-PGL when an unexplained clinical deterioration occurs in CCHD patients, even in the absence of typical paroxysmal symptoms.