Protein-losing enteropathy after the Fontan operation

Protein-losing enteropathy after fontan surgery: insights from Vietnamese clinical experience and the need for global collaboration

Protein-losing enteropathy remains a formidable and underrecognised complication following Fontan surgery, contributing significantly to morbidity and mortality among affected patients. Despite substantial progress in managing single-ventricle CHDs, protein-losing enteropathy persists as a major clinical challenge, particularly in resource-constrained environments where specialised diagnostic modalities are scarce. This manuscript discusses the prevalence, clinical presentation, diagnostic hurdles, and management of protein-losing enteropathy in post-Fontan patients, drawing from clinical experiences in Vietnam. Among 95 post-Fontan patients reviewed, the prevalence of protein-losing enteropathy was 4.2%, with considerable morbidity necessitating invasive interventions and, in some cases, resulting in mortality. Diagnostic limitations, including restricted access to alpha-1-antitrypsin clearance testing, highlight the urgent need for heightened clinical suspicion and pragmatic diagnostic approaches. We advocate for integrating low-cost, widely accessible screening measures, such as routine serum protein monitoring, into standard post-Fontan care protocols to enhance early detection and management of protein-losing enteropathy. Furthermore, we underscore the critical importance of global collaboration and multicentre research initiatives to address the worldwide burden of protein-losing enteropathy, facilitate resource-sharing, and develop evidence-based interventions. Coordinated international efforts are essential to closing diagnostic and treatment gaps, ultimately improving survival and quality of life for patients living with the Fontan circulation.

How cardiac output is controlled in a Fontan circulation: an update

After creating a Fontan circuit, control of the circulation is shifted upstream from the ventricle to the newly created Fontan portal system. The goal of this review was to illustrate that the customary laws of biventricular cardiac output no longer apply and explain why standardized cardiac failure treatment regimens have little or no effect on a failing Fontan patient. A Fontan circulation is, in effect, a circulation in series regulated by the basic rules of any hydrodynamic circuit. We developed a formula that elucidates how flow through the critical bottleneck, and therefore through the whole circuit, is controlled. The critical bottleneck in a hydrodynamic model is the prime determinant of overall flow; other (less critical) bottlenecks may control local upstream congestion, but not overall flow. Once relieved, control of flow shifts to the next most significant bottleneck. The available options for improving flow in a hydrodynamic model are identical to those applicable to any dam: tackle the obstruction (the most impactful approach), push harder upstream (the easiest action) or pull/suck further downstream of the bottleneck (the least efficient strategy). In the early stages, the Fontan neo-portal circulation plays a pivotal role in the pathophysiology. The ventricle has little effect and has an impact only at a late stage. The Fontan formula in the present article stands as a valuable tool, aiding physicians in comprehending the pathophysiological and hydrodynamic intricacies of the Fontan circuit within the context of everyday clinical practice.

Fontan-associated liver disease: the importance of multidisciplinary teamwork in its management

The Fontan operation, which directly connects the superior and inferior vena cava to the pulmonary artery, is a palliative surgery for children with a functional or anatomic single ventricle. This procedure leads to hemodynamic changes (Fontan circulation) in patients, who tend to develop congestive hepatic fibrosis characterized by sinusoidal fibrosis and dilatation beginning approximately 10 years after the procedure. In addition, in the context of severe fibrosis and cirrhosis, hepato-gastrointestinal complications including hepatocellular carcinoma, focal nodular hyperplasia, and portal hypertension can arise. Fontan-associated liver disease (FALD) encompasses the broad spectrum of liver alterations secondary to postoperative hemodynamic changes, and the effective management of FALD requires contributions from specialists in hepatology, gastroenterology, surgery, radiology, histopathology, and pediatric and adult cardiology. In this article, we outline the pathogenesis of FALD and discuss the importance of a multidisciplinary collaborative approach to its management.

Combined Percutaneous Transhepatic Lymphatic Embolization and Peroral Duodenal Mucosal Radiofrequency Ablation to Manage Protein-Losing Enteropathy

Percutaneous transhepatic lymphatic embolization (PTLE) and peroral esophagogastroduodenoscopy (EGD) duodenal mucosal radiofrequency (RF) ablation were performed to manage protein-losing enteropathy (PLE) in patients with congenital heart disease. Five procedures were performed in 4 patients (3 men and 1 woman; median age, 49 years; range, 31-71 years). Transhepatic lymphangiography demonstrated abnormal periduodenal lymphatic channels. After methylene blue injection through transhepatic access, subsequent EGD evaluation showed methylene blue extravasation at various sites in the duodenal mucosa. Endoscopic RF ablation of the leakage sites followed by PTLE using 3:1 ethiodized oil-to-n-butyl cyanoacrylate glue ratio resulted in improved symptoms and serum albumin levels (before procedure, 2.6 g/dL [SD ± 0.2]; after procedure, 3.5 g/dL [SD ± 0.4]; P = .004) over a median follow-up of 16 months (range, 5-20 months). Transhepatic lymphangiography and methylene blue injection with EGD evaluation of the duodenal mucosa can help diagnose PLE. Combined PTLE and EGD-RF ablation is an option to treat patients with PLE.

Contemporary Management of the Failing Fontan

Adult patients with congenital heart disease have now surpassed the pediatric population due to advances in surgery and improved survival. One such complex congenital heart disease seen in adult patients is the Fontan circulation. These patients have complex physiology and are at risk for several complications, including thrombosis of the Fontan pathway, pulmonary vascular disease, heart failure, atrial arrhythmias, atrioventricular valve regurgitation, and protein-losing enteropathy. This review discusses the commonly encountered phenotypes of Fontan circulatory failure and their contemporary management.

Are dynamic measurements of central venous pressure in Fontan circulation during exercise or volume loading superior to resting measurements?

BACKGROUND

The main objective measure to assess the health of the Fontan circulation is the pressure measurement of the superior vena cava or pulmonary arteries. We reviewed the literature for benefits of measuring resting pressure in the Fontan circuit and explored whether dynamic measurement by volume loading or exercise has the potential to refine this diagnostic tool.

METHODS

PubMed was searched for articles showing a relationship between resting post-operative central venous pressure or pulmonary artery pressure and Fontan failure. Relationships between post-operative central venous pressure or pulmonary artery pressure and volume loading changes, such as during exercise or volume loading during cardiac catheterization, were also queried.

RESULTS

A total of 44 articles mentioned relationships between resting central venous pressure or pulmonary artery pressure and Fontan failure. Only 26 included an analysis between the variables and only seven of those articles found pressure to be predictive of Fontan failure. Ten articles examined the relationship between exercise or volume loading and outcomes and demonstrated a large individual variation of pressures under these dynamic conditions.

CONCLUSIONS

Based on current literature, there is not a lot of strong evidence to show that elevated resting central venous pressure or pulmonary artery pressure is predictive of Fontan failure. Some individuals experience dramatic increases in central venous pressure or pulmonary artery pressure under increased loading conditions with exercise or bolus fluid infusion, while others experience increases closer to that of a healthy control population. Further studies are needed to examine whether more dynamic and continuous monitoring of systemic venous pressures might better predict outcomes in patients with Fontan circulation.

Dysbiosis of gut microbiota in patients with protein-losing enteropathy after the Fontan procedure

BACKGROUND

There is a lack of predictive biomarkers for the onset or activity of protein-losing enteropathy (PLE), a Fontan procedure-associated complication. Here, we aimed to identify the gut microbiota composition of patients with active PLE and investigate its relationship with PLE activity.

METHODS

This multicenter case-control study involved patients who developed PLE (n = 16) after the Fontan procedure and those who did not (non-PLE; n = 20). Patients with PLE who maintained a serum albumin level of ≥3 g/dL for >1 year were included in the remissive-stage-PLE group (n = 9) and those who did not maintain this level were included in the active-PLE group (n = 7). 16S rRNA gene sequencing analysis of fecal samples was performed using QIIME2 pipeline. Alpha (Shannon and Faith's phylogenetic diversity indices) and beta diversity was assessed using principal coordinate analysis based on unweighted UniFrac distances.

RESULTS

Shannon and Faith's phylogenetic diversity indices were lower in the active-PLE group than in the remissive-stage- (q = 0.028 and 0.025, respectively) and non-PLE (q = 0.028 and 0.017, respectively) groups. Analysis of beta diversity revealed a difference in the microbiota composition between the active-PLE and the other two groups. Linear discriminant effect size analysis demonstrated differences in the relative abundance of Bifidobacterium and Granulicatella spp., and Ruminococcus torques between patients with active- and those with remissive-stage-PLE.

CONCLUSIONS

Gut microbiota dysbiosis was observed in patients with active PLE. Changes in the bacterial composition of the gut microbiota and decreased diversity may be associated with the severity of PLE.

Anorexia nervosa in a postoperative patient with Ebstein's anomaly

Background

Along with the improved prognosis of patients with congenital heart disease, the associated diverse complications are under scrutiny. Due to various medical restrictions on their upbringing, patients with congenital heart disease often have coexisting mental disorders. However, reports on patients with congenital heart disease and coexisting eating disorders are rare. Here, we report the case of a patient who developed anorexia nervosa (AN) following surgery for Ebstein's anomaly.

Case Presentation

A 21-year-old female with Ebstein's anomaly who underwent Fontan surgery was transferred to our institution with suspected AN after >2 years of intermittent stays at a medical hospital for decreased appetite. Initially, she did not desire to lose weight or fear obesity, and we suspected that she was suffering from appetite loss due to a physical condition associated with Fontan circulation. However, the eating disorder pathology gradually became more apparent.

Conclusion

Our experience suggests that patients with congenital heart disease are more likely to have a psychological background and physical problems that might contribute to eating disorders than the general population.

Protein-Losing Enteropathy and Plastic Bronchitis Following the Total Cavopulmonary Connections

BACKGROUND

We aimed to evaluate incidence, outcomes, and predictors of protein-losing enteropathy (PLE) and plastic bronchitis (PB) in a cohort of total cavopulmonary connection (TCPC).

METHODS

We included 620 consecutive patients undergoing TCPC between 1994 and 2021. Prevalence and predictors for onset of PLE/PB were evaluated. Death and heart transplantation after onset of PLE/PB were examined.

RESULTS

A total of 41 patients presented with PLE/PB (31 with PLE, 15 with PB, and 5 developed both PLE and PB). Their median age at TCPC was 2.2 (interquartile ranges [IQRs], 1.7-3.7) years, and time period to onset for PLE was 2.6 (IQR: 1.0-6.6) years and for PB was 1.1 (IQR: 0.3-4.1) years after TCPC. Independent factors for developing PLE/PB were dominant right ventricle (RV, hazard ratio [HR], 2.243; 95% confidence interval [CI], 1.129-4.458, P = .021) and prolonged pleural effusion after TCPC (HR, 2.101; 95% CI, 1.090-4.049, P = .027). In PLE/PB population, freedom from death or transplantation after PLE/PB diagnosis at 5 and 10 years were 88.7% and 76.4%, respectively. Eleven surgical interventions were performed in 10 patients, comprising atrioventricular valve repairs (n = 4), Fontan pathway revisions (n = 2), pacemaker implantation (n = 2), secondary fenestration (n = 1), diaphragm plication (n = 1), and ventricular assist device implantation (n = 1). In nine patients, a recovery from PLE with the resolution of PLE symptoms and normal protein levels was achieved. Eight patients died and the remaining continued to have challenging protein loss.

CONCLUSIONS

Protein-losing enteropathy and PB remain severe complications in the cohort of TCPC. Patients with dominant RV, and prolonged pleural effusions, were at risk for PLE/PB.

Five decades of Fontan palliation: What have we learned? What should we expect?

The Fontan procedure is the final palliative surgery in a series of staged surgeries to reroute the systemic venous blood flow directly to the lungs, with the ventricle(s) pumping oxygenated blood to the body. Advances in medical and surgical techniques have improved patients' overall survival after the Fontan procedure. However, Fontan-associated chronic comorbidities are common. In addition to chronic cardiac dysfunction and arrhythmias, complications involving other organs such as the liver, lungs, intestine, lymphatic system, brain, and blood frequently occur. This narrative review focuses on the immediate and late consequences in children, pregnant women, and other adults with Fontan circulation. In addition, we describe the technical advancements that might change the way single-ventricle patients are managed in future.

27 years of experience with the Fontan procedure: characteristics and clinical outcomes of children in a tertiary referral hospital

BACKGROUND

The Fontan operation has improved the survival of children born with congenital heart disease with single ventricle physiology. The most widely adopted variations of the Fontan procedure are the extracardiac conduit, the lateral tunnel ve the intra/extracardiac conduit with fenestration. Despite advances in the treatment and prevention of early and late complications that may develop after Fontan surgery, morbidity still remains an important problem.

METHODS

304 patients who underwent Fontan surgery in our center between 1995 and 2022 were included in our study. The complications that developed in patients who underwent primary Fontan or lateral tunnel surgery and extracardiac conduit Fontan application were compared.

RESULTS

Classic Fontan surgery and lateral tunnel surgery were performed in 26 of the patients, and extracardiac Fontan surgery was performed in 278 patients. 218 of 304 cases were patients with single ventricular pathology. 86 cases were patients with two ventricular morphologies but complex cardiac pathology. Fenestration was performed in only 6 patients, other patients did not require fenestration. The mean follow-up period of our patients was 12 years (3 months-27 years). When the complications between Fontan procedures were compared in our study, it was found that the length of hospital stay and mortality were statistically significantly reduced in patients who underwent extracardiac Fontan surgery. There was no significant difference in terms of complications that can be seen after Fontan surgery and the length of stay in the intensive care unit.

CONCLUSION

Fontan complex is a palliative surgery for children with complex heart disease. Palliative surgical operations aimed at the preparation of the Fontan circulation lead to the preparation of the pulmonary vascular bed and the preservation of ventricular function. The techniques applied in Fontan surgery affect the early and long-term complications and the survival of the patients. In our study, when we examined the patients who extracardiac conduit Fontan procedure for the non-cardiac route, we found that mortality and morbidity were minimal.

Pathophysiology, Diagnosis, and Management of Canine Intestinal Lymphangiectasia: A Comparative Review

Intestinal lymphangiectasia was first described in the dog over 50 years ago. Despite this, canine IL remains poorly understood and challenging to manage. Intestinal lymphangiectasia is characterized by variable intestinal lymphatic dilation, lymphatic obstruction, and/or lymphangitis, and is a common cause of protein-losing enteropathy in the dog. Breed predispositions are suggestive of a genetic cause, but IL can also occur as a secondary process. Similarly, both primary and secondary IL have been described in humans. Intestinal lymphangiectasia is definitively diagnosed via intestinal histopathology, but other diagnostic results can be suggestive of IL. Advanced imaging techniques are frequently utilized to aid in the diagnosis of IL in humans but have not been thoroughly investigated in the dog. Management strategies differ between humans and dogs. Dietary modification is the mainstay of therapy in humans with additional pharmacological therapies occasionally employed, and immunosuppressives are rarely used due to the lack of a recognized immune pathogenesis. In contrast, corticosteroid and immunosuppressive therapies are more commonly utilized in canine IL. This review aims toward a better understanding of canine IL with an emphasis on recent discoveries, comparative aspects, and necessary future investigations.

Fontan failure: phenotypes, evaluation, management, and future directions

OBJECTIVES

Management of "failing" and "failed" Fontan circulation, particularly the indications, timing, and type of re-intervention, currently remains nebulous. Factors contributing to pathogenesis and mortality following Fontan procedure differ between children and adults.

METHODS

Since organ systems in individual patients are affected differently, we searched the extant literature for a "failing" and "failed" Fontan reviewing the clinical phenotypes, diagnostic modalities, pharmacological, non-pharmacological, and surgical techniques employed, and their outcomes.

RESULTS

A total of 410 investigations were synthesised. Although proper candidate selection, thoughtful technical modifications, timely deployment of mechanical support devices, tissue-engineered conduits, and Fontan takedown have decreased the peri-operative mortality from 9 to 15% and 1 to 3% per cent in recent series, pernicious changes in organ function are causing long-term patient attrition. In the setting of a failed Fontan circulation, literature documents three surgical options: Fontan revision, Fontan conversion, or cardiac transplantation. The reported morbidity of 25% and mortality of 8-10% among Fontan conversion continue to improve in select institutions. While operative mortality following cardiac transplantation for Fontan failure is 30% higher than for other CHDs, there is no difference in long-term survival with actuarial 10-year survival of around 54%. Mechanical circulatory assistance, stem cells, and tissue-engineered Fontan conduit for destination therapy or as a bridge to transplantation are in infancy for failing Fontan circulation.

CONCLUSIONS

An individualised management strategy according to clinical phenotypes may delay the organ damage in patients with a failing Fontan circulation. At present, cardiac transplantation remains the last stage of palliation with gradually improving outcomes.

Optimal Fenestration of the Fontan Circulation

In this paper, we develop a pulsatile compartmental model of the Fontan circulation and use it to explore the effects of a fenestration added to this physiology. A fenestration is a shunt between the systemic and pulmonary veins that is added either at the time of Fontan conversion or at a later time for the treatment of complications. This shunt increases cardiac output and decreases systemic venous pressure. However, these hemodynamic benefits are achieved at the expense of a decrease in the arterial oxygen saturation. The model developed in this paper incorporates fenestration size as a parameter and describes both blood flow and oxygen transport. It is calibrated to clinical data from Fontan patients, and we use it to study the impact of a fenestration on several hemodynamic variables, including systemic oxygen availability, effective oxygen availability, and systemic venous pressure. In certain scenarios corresponding to high-risk Fontan physiology, we demonstrate the existence of a range of fenestration sizes in which the systemic oxygen availability remains relatively constant while the systemic venous pressure decreases.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Protein-losing enteropathy in Fontan circulation: Pathophysiology, outcome and treatment options of a complex condition

Protein-losing enteropathy (PLE) represents a rare but severe and potentially life-threatening complication following Fontan operation in patients with a functional single ventricle. PLE is characterized by enteric protein loss, leading to devastating multiorgan involvement with increased morbidity and mortality. In spite of remarkable advances in the care of congenital heart disease in recent years, treatment of PLE is still one of the most challenging tasks due to limited understanding of the underlying mechanisms and lack of high-quality evidence from large scale, controlled studies to test the real efficacy of the several treatment strategies, which have been proposed. For this reason, we herewith aim to discuss the pathogenesis and diagnosis of PLE in Fontan patients as well as provide a comprehensive overview on potential advantages and disadvantages of the currently available therapeutic strategies, in order to propose a stepwise approach for the management of this unique condition.

Management of circulatory failure after Fontan surgery

With improvement in survival after Fontan surgery resulting in an increasing number of older survivors, there are more patients with a Fontan circulation experiencing circulatory failure each year. Fontan circulatory failure may have a number of underlying etiologies. Once Fontan failure manifests, prognosis is poor, with patient freedom from death or transplant at 10 years of only about 40%. Medical treatments used include traditional heart failure medications such as renin-angiotensin-aldosterone system blockers and beta-blockers, diuretics for symptomatic management, antiarrhythmics for rhythm control, and phosphodiesterase-5 inhibitors to decrease PVR and improve preload. These oral medical therapies are typically not very effective and have little data demonstrating benefit; if there are no surgical or catheter-based interventions to improve the Fontan circulation, patients with severe symptoms often require inotropic medications or mechanical circulatory support. Mechanical circulatory support benefits patients with ventricular dysfunction but may not be as useful in patients with other forms of Fontan failure. Transplant remains the definitive treatment for circulatory failure after Fontan, but patients with a Fontan circulation face many challenges both before and after transplant. There remains significant room and urgent need for improvement in the management and outcomes of patients with circulatory failure after Fontan surgery.

Long-term Outcome of Fontan-Associated Protein-Losing Enteropathy: Treatment Modality and Predictive Factor of Mortality

We conducted the first retrospective study on Fontan-associated protein-losing enteropathy (PLE) in Korea. Fontan-associated PLE is still challenging to treat, although the survival rate has improved. There is no best treatment for PLE, and relapse occurs frequently. However, selected patients show promising results after various treatments. It would be helpful to identify the risk factors of mortality in patients with Fontan-associated PLE. High-risk patients should undergo comprehensive evaluations and receive more aggressive therapies for PLE. This study emphasizes the necessity for developing aggressive and individually targeted treatment strategies by sharing our long-term experience on Fontan-associated PLE in the current era.

Background and Objectives

Protein-losing enteropathy (PLE) is a devastating complication after the Fontan operation. This study aimed to investigate the clinical characteristics, treatment response, and outcomes of Fontan-associated PLE.

Methods

We reviewed the medical records of 38 patients with Fontan-associated PLE from 1992 to 2018 in 2 institutions in Korea.

Results

PLE occurred in 4.6% of the total 832 patients after the Fontan operation. After a mean period of 7.7 years after Fontan operation, PLE was diagnosed at a mean age of 11.6 years. The mean follow-up period was 8.9 years. The survival rates were 81.6% at 5 years and 76.5% at 10 years. In the multivariate analysis, New York Heart Association Functional classification III or IV (p=0.002), low aortic oxygen saturation (<90%) (p=0.003), and ventricular dysfunction (p=0.032) at the time of PLE diagnosis were found as predictors of mortality. PLE was resolved in 10 of the 38 patients after treatment. Among medical managements, an initial heparin response was associated with survival (p=0.043). Heparin treatment resulted in resolution in 4 patients. We found no evidence on pulmonary vasodilator therapy alone. PLE was also resolved after surgical Fontan fenestration (2/6), aortopulmonary collateral ligation (1/1), and transplantation (1/1).

Conclusions

The survival rate of patients with Fontan-associated PLE has improved with the advancement of conservative care. Although there is no definitive method, some treatments led to the resolution of PLE in one-fourth of the patients. Further investigations are needed to develop the best prevention and therapeutic strategies for PLE.

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.

Intrahepatic Dynamic Contrast-Enhanced Magnetic Resonance Lymphangiography: Potential Imaging Signature for Protein-Losing Enteropathy in Congenital Heart Disease

Background

Protein‐losing enteropathy (PLE) is a significant cause of morbidity and mortality in congenital heart disease patients with single ventricle physiology. Intrahepatic dynamic contrast‐enhanced magnetic resonance lymphangiography (IH‐DCMRL) is a novel diagnostic technique that may be useful in characterizing pathologic abdominal lymphatic flow in the congenital heart disease population and in diagnosing PLE. The objective of this study was to characterize differences in IH‐DCMRL findings in patients with single ventricle congenital heart disease with and without PLE.

Methods and Results

This was a single‐center retrospective study of IH‐DCMRL findings and clinical data in 41 consecutive patients, 20 with PLE and 21 without PLE, with single ventricle physiology referred for lymphatic evaluation. There were 3 distinct duodenal imaging patterns by IH‐DCMRL: (1) enhancement of the duodenal wall with leakage into the lumen, (2) enhancement of the duodenal wall without leakage into the lumen, and (3) no duodenal involvement. Patients with PLE were more likely to have duodenal involvement on IH‐DCMRL than patients without PLE (P<0.001).

Conclusions

IH‐DCMRL findings of lymphatic enhancement of the duodenal wall and leakage of lymph into the duodenal lumen are associated with PLE. IH‐DCMRL is a useful new modality for characterizing pathologic abdominal lymphatic flow in PLE and might be useful as a risk‐assessment tool for PLE in at‐risk patients.

Impact of Protein-Losing Enteropathy on Inflammatory Biomarkers and Vascular Dysfunction in Fontan Circulation

Fontan palliation has improved survival for single ventricle patients, but long-term complications persist including cardiovascular dysfunction, neurohormonal abnormalities, and protein-losing enteropathy (PLE). Although chronic inflammation contributes to morbidity, an association between inflammation and vascular dysfunction has not been studied. We assessed inflammation and vascular function in 31 Fontan-palliated patients (52% male, median age 14.3 years), including 10 PLE+. Fontan circulation was associated with altered inflammatory cytokines (TNF-α: mean 2.5 ± 1.4 vs. 0.7 ± 0.2 pg/ml, p < 0.0001; sTNFR2: 371 ± 108 vs. 2694 ± 884 pg/ml, p < 0.0001) and vascular dysfunction [log-transformed reactive hyperemia index (lnRHI) 0.28 ± 0.19 vs. 0.47 ± 0.26, p < 0.01; augmentation index (AI) -2.9 ± 13.8 vs. -16.3 ± 12.0, p = 0.001; circulating endothelial progenitor cells (cEPCs) 5.0 ± 8.1 vs. 22.8 ± 15.9, p = 0.0002)]. Furthermore, PLE+ patients showed greater inflammation (IFN-γ 6.3 ± 2.2 vs. 11.5 ± 7.9 pg/ml, p = 0.01; sTNFR1: 1181 ± 420 vs. 771 ± 350 pg/ml, p = 0.01) and decreased arterial compliance (AI: 5.4 ± 17.1 vs. -6.8 ± 10.2, p = 0.02) than PLE- patients. Circulating EPCs, but not inflammatory cytokines, were inversely associated with arterial stiffness in Fontan patients. In conclusion, chronic inflammation and vascular dysfunction are observed after Fontan operation, with greater inflammation and arterial stiffness in Fontan patients with active PLE. However, there is no clear association between inflammatory cytokines and vascular dysfunction, suggesting these pathophysiologic processes are not mechanistically linked.

Overview of Albumin Physiology and its Role in Pediatric Diseases

PURPOSE OF REVIEW

Albumin plays a critical role in a wide range of disease processes; however, the role of albumin in pediatric patients has not been well described. This article aims to review albumin physiology and kinetics in children, albumin's impact on pediatric diseases, and the utility of albumin as a predictor of clinical outcome.

RECENT FINDINGS

Hypoalbuminemia is seen in a wide range of conditions, including protein-losing enteropathy, hepatic synthetic failure, malnutrition, inflammatory states, and renal disease. While the impact of hypoalbuminemia has been more extensively studied in adult patients, there is a relative paucity of literature in the pediatric population. Hypoalbuminemia is a marker of poor outcome in critically ill children and those undergoing a wide range of medical interventions. Albumin infusions may be an effective therapy for fluid resuscitation and for patients with severe hypoalbuminemia.

Venous Properties in a Fontan Patient with Successful Remission of Protein-Losing Enteropathy

We present the case of a 1-year-old boy who developed protein-losing enteropathy (PLE) within 2 months of a fenestrated Fontan procedure. His fenestration rapidly closed despite bilateral pulmonary stenosis (BPS). Subsequent to PLE onset, both fenestration and the bilateral pulmonary artery were reconstructed, and the patient's PLE had been in remission, with additive use of medications, for more than 2 years. Notably, although fenestration closed again and central venous pressure (CVP) reduction was minimal, the surrogates of venous return resistance were markedly suppressed as shown by increased blood volume, reduced estimated mean circulatory filling pressure, and suppressed CVP augmentation against a contrast agent. Taken together, dynamic characteristics of venous stagnation, rather than the absolute value of CVP, were ameliorated by the pulmonary reconstruction and use of medications, suggesting a significant role of venous property in the physiology of PLE. In addition, simultaneous measures of CVP and ventricular end-diastolic pressure during the abdominal compression procedure suggested a limited therapeutic role of fenestration against PLE in this patient.

Heart Failure in Adult Congenital Heart Disease

As the population of adult congenital heart disease patients ages and grows, so too does the burden of heart failure in this population. Despite the advances in medical and surgical therapies over the last decades, heart failure in adult congenital heart disease remains a formidable complication with high morbidity and mortality. This review focuses on the challenges in determining the true burden and management of heart failure in adult congenital heart disease. There is a particular focus on the need for developing a common language for classifying and reporting heart failure in adult congenital heart disease, the clinical presentation and prognostication of heart failure in adult congenital heart disease, the application of hemodynamic evaluation, and advanced heart failure treatment. A common case study of heart failure in adult congenital heart disease is utilized to illustrate these key concepts.

Perioperative Management of the Fontan Patient for Cardiac and Noncardiac Surgery

The Fontan circulation is the single-ventricle approach to surgical palliation of complex congenital heart disease wherein biventricular separation and function cannot be safely achieved. Incremental improvements in this surgical technique, along with improvements in the long-term medical management of these patients, have led to greater survival of these patients and a remarkably steady increase in the number of adults living with this unusual circulation and physiology. This has implications for healthcare providers who now have a greater chance of encountering Fontan patients during the course of their practice. This has particularly important implications for anesthesiologists because the effects of their interventions on the finely balanced Fontan circulation may be profound. The American Heart Association and American College of Cardiology recommend that, when possible, elective surgery should be performed in an adult congenital heart disease center, although this may not be feasible in the provision of true emergency care. This review article summarizes the pathophysiology pertinent to the provision of anesthesia in this complex patient group and describes important modifications to anesthetic technique and perioperative management.

Lymphatic pathway evaluation in congenital heart disease using 3D whole-heart balanced steady state free precession and T2-weighted cardiovascular magnetic resonance

BACKGROUND

Due to passive blood flow in palliated single ventricle, central venous pressure increases chronically, ultimately impeding lymphatic drainage. Early visualization and treatment of these malformations is essential to reduce morbidity and mortality. Cardiovascular magnetic resonance (CMR) T2-weighted lymphangiography (T2w) is used for lymphatic assessment, but its low signal-to-noise ratio may result in incomplete visualization of thoracic duct pathway. 3D-balanced steady state free precession (3D-bSSFP) is commonly used to assess congenital cardiac disease anatomy. Here, we aimed to improve diagnostic imaging of thoracic duct pathway using 3D-bSSFP.

METHODS

Patients underwent CMR during single ventricle or central lymphatic system assessment using T2w and 3D-bSSFP. T2w parameters included 3D-turbo spin echo (TSE), TE/TR = 600/2500 ms, resolution = 1 × 1 × 1.8 mm, respiratory triggering with bellows. 3D-bSSFP parameters included electrocardiogram triggering and diaphragm navigator, 1.6 mm isotropic resolution, TE/TR = 1.8/3.6 ms. Thoracic duct was identified independently in T2w and 3D-bSSFP images, tracked completely from cisterna chyli to its drainage site, and classified based on severity of lymphatic abnormalities.

RESULTS

Forty-eight patients underwent CMR, 46 of whom were included in the study. Forty-five had congenital heart disease with single ventricle physiology. Median age at CMR was 4.3 year (range 0.9-35.1 year, IQR 2.4 year), and median weight was 14.4 kg (range, 7.9-112.9 kg, IQR 5.2 kg). Single ventricle with right dominant ventricle was noted in 31 patients. Thirty-eight patients (84%) were status post bidirectional Glenn and 7 (16%) were status post Fontan anastomosis. Thoracic duct visualization was achieved in 45 patients by T2w and 3D-bSSFP. Complete tracking to drainage site was attained in 11 patients (24%) by T2w vs 25 (54%) by 3D-bSSFP and in 28 (61%) by both. Classification of lymphatics was performed in 31 patients.

CONCLUSION

Thoracic duct pathway can be visualized by 3D-bSSFP combined with T2w lymphangiography. Cardiac triggering and respiratory navigation likely help retain lymphatic signal in the retrocardiac area by 3D-bSSFP. Visualizing lymphatic system leaks is challenging on 3D-bSSFP images alone, but 3D-bSSFP offers good visualization of duct anatomy and landmark structures to help plan interventions. Together, these sequences can define abnormal lymphatic pathway following single ventricle palliative surgery, thus guiding lymphatic interventional procedures.

Association of Lymphatic Abnormalities with Early Complications after Fontan Operation

Background  Increased central venous pressure is inherent in Fontan circulation but not strongly related to Fontan complication. Abnormalities of the lymphatic circulation may play a crucial role in early Fontan complications.

Methods  This was a retrospective, single-center study of patients undergoing Fontan operation from 2008 to 2015. The primary outcome was significant early Fontan complication defined as secondary in-hospital treatment due to peripheral edema, ascites, pleural effusions, protein-losing enteropathy, or plastic bronchitis. All patients received T2-weighted magnetic resonance images to assess abdominal and thoracic lymphatic perfusion pattern 6 months after Fontan completion with respect to localization, distribution, and extension of lymphatic perfusion pattern (type 1–4) and with application of an area score (0–12 points).

Results  Nine out of 42 patients developed early Fontan complication. Patients with complication had longer chest tube drainage (mean 28 [interquartile range [IQR]: 13–60] vs. 13 [IQR: 2–22] days, p  = 0.01) and more often obstructions in the Fontan circuit 6 months after surgery (56 vs. 15%, p  = 0.02). Twelve patients showed little or no abnormalities of lymphatic perfusion (lymphatic perfusion pattern type 1). Most frequently magnetic resonance imaging showed lymphatic congestion in the supraclavicular region (24/42 patients). Paramesenteric lymphatic congestion was observed in eight patients. Patients with early Fontan complications presented with higher lymphatic area score (6 [min–max: 2–10] vs. 2 [min–max: 0–8]), p  = 0.001) and greater distribution and extension of thoracic lymphatic congestion (type 3–4: n  = 5/9 vs. n  = 1/33, p  = 0.001).

Conclusion  Early Fontan complication is related to hemodynamic factors such as circuit obstruction and to the occurrence and extent of lymphatic congestion.

Long-term Outcomes of Extracardiac Total Cavopulmonary Connection for Apicocaval Juxtaposition

BACKGROUND

The long-term outcomes of a total cavopulmonary connection (TCPC) with an extracardiac conduit (ECC) for patients with apicocaval juxtaposition (ACJ) remain unclear.

METHODS

A total of 38 patients with ACJ who underwent TCPC with ECC between 1998 and 2014 were enrolled in this study. For 19 patients with a superior vena cava - inferior vena cava contralateral position, a long-curved route rounding the opposite side of the apex was selected (CC group). For 11 patients with a superior vena cava-inferior vena cava ipsilateral position, a long-curved route was principally selected (IC group); however, a short, straight route was selected for 8 patients because there was sufficient space behind the ventricular apex (IS group).

RESULTS

Follow-up was completed in all patients, with a mean follow-up duration of 13.2 ± 4.9 years. The angles of the caudal conduit anastomosis site measured from the frontal view of cineangiography had significantly straightened in the CC group from 1 year to 15 years (P < .05) and in the IC group from 1 year to 10 years (P < .05). There were 2 late mortalities and 6 reoperations during follow-up. Overall survival and freedom from reoperation rates at 15 years were 95% and 82%, respectively. There were no conduit-related or route-related complications such as death, reoperations, pulmonary venous obstructions, conduit obstructions, or pulmonary arteriovenous malformations in any of the groups.

CONCLUSIONS

Even though chronologic geometric changes of curved ECCs were observed, TCPC with ECC for patients with ACJ can be safely applied without conduit- or route-related complications in long-term follow-up.

Impact of protein-losing enteropathy in children who underwent the Fontan operation

Previous reports have identified risk factors associated with development of post-Fontan protein-losing enteropathy. Less is known about the economic impact and resource utilisation required for post-Fontan protein-losing enteropathy in the current era. We conducted a single-centre retrospective study to assess the impact of post-Fontan protein-losing enteropathy on transplant-free survival. We also described resource utilisation and treatment variations among post-Fontan protein-losing enteropathy patients. Children who received care at our centre between 2009 and 2017 after the Fontan surgery were eligible. Initial admissions for the Fontan operative procedure were excluded. Demographics, hospital admissions, resource utilisation, medications and charges were reviewed. Patients were divided into two groups based on the presence of post-Fontan protein-losing enteropathy. Of the 343 patients screened, 147 met the eligibility criteria. Of these, 28 (19%) developed protein-losing enteropathy. After adjusting for follow-up duration, the protein-losing enteropathy group had higher number of encounters (2.15 ± 2.16 versus 1.47 ± 2.56, p 0.002), hospital length of stay (days) (25 ± 51.3 versus 11.4 ± 41.7, p < 0.0001) and total charges (2018US$) (388,489 ± 759,859 versus 202,725 ± 1,076,625, p < 0.0001). Encounters for patients with protein-losing enteropathy utilised more therapies. Among those with protein-losing enteropathy, use of digoxin was associated with slightly decreased odds for mortality and/or transplant (0.95, confidence interval 0.90-0.99, p 0.021). The 10-year transplant-free survival for patients with/without protein-losing enteropathy was 65.7/97.3% (p 0.002), respectively. Post-Fontan protein-losing enteropathy is associated with reduced 10-year transplant-free survival, higher resource utilisation, charges and medication use compared with the non-protein-losing enteropathy group. Practice variation among post-Fontan protein-losing-enteropathy patients is common. Further larger studies are needed to assess the impact of standardisation on the well-being of children with post-Fontan protein-losing enteropathy.

Protein-losing enteropathy and plastic bronchitis after the Fontan procedure

OBJECTIVES

Protein losing enteropathy and plastic bronchitis are severe complications in Fontan circulation, with 5-year survival ranging from 46% to 88%. We report risk factors and outcomes of protein losing enteropathy and plastic bronchitis in patients undergoing the Fontan.

METHODS

We performed a retrospective analysis of 1561 patients from the Australia New Zealand Fontan Registry. Two end points were death and cardiac transplantation examined with Cox regression (if no competing risks) or cumulative incidence curves and cause-specific Cs regression.

RESULTS

A total of 55 patients with protein losing enteropathy/plastic bronchitis were included. Their median age at the Fontan was 5.7 years, and time to onset after the Fontan for protein losing enteropathy was 5.0 years and plastic bronchitis was 1.7 years. Independent predictors for developing protein losing enteropathy/plastic bronchitis were right-ventricular morphology with hypoplastic left-heart syndrome (hazard ratio, 2.30; confidence interval, 1.12-4.74), older age at Fontan (hazard ratio, 1.13; confidence interval, 1.03-1.23), and pleural effusions after Fontan (hazard ratio, 2.43; confidence interval, 1.09-5.41); left-ventricular morphology was protective (hazard ratio, 0.36; confidence interval, 0.18-0.70). In the protein losing enteropathy/plastic bronchitis population, freedom from death or transplantation after protein losing enteropathy/plastic bronchitis diagnosis at 5, 10, and 15 years was 70% (confidence interval, 58-85), 65% (confidence interval, 51-83), and 43% (confidence interval, 26-73), respectively; only older age (hazard ratio, 1.23; confidence interval, 1.01-1.52) was an independent predictor. Twenty-six surgical interventions were performed in 20 patients, comprising Fontan revisions (n = 5), fenestrations (n = 11), Fontan conversions (n = 5), atrioventricular valve repairs (n = 3), and hepatic vein diversion (n = 2).

CONCLUSIONS

Protein losing enteropathy and plastic bronchitis remain severe complications, preferably affecting patients with dominant right single ventricle, with older age at Fontan being a predictor of developing protein losing enteropathy/plastic bronchitis and poorer prognosis. Heart transplantation remains the ultimate treatment, with 30% dying or requiring transplantation within 5 years, and the remaining being stable for long periods.

Steroid-Refractory Protein-Losing Enteropathy with Gastrointestinal Bleeding in a Patient with Fontan Circulation

Protein-losing enteropathy (PLE) is one of the major complications after a Fontan operation. Some PLE patients suffer from concurrent gastrointestinal bleeding. An effective treatment regimen for such patients has not been established yet. Further, it remains unknown whether PLE and gastrointestinal bleeding coexist independently, or protein losing is associated with gastrointestinal bleeding. We report a 7-year-old steroid-refractory post-Fontan PLE case suggesting the latter pathogenesis together with a literature review.

Treatment strategies for protein-losing enteropathy in Fontan-palliated patients

OBJECTIVE

Protein-losing enteropathy is an infrequent but severe condition occurring after Fontan procedure. The multifactorial pathogenesis remains unclear and no single proposed treatment strategy has proven universally successful. Therefore, we sought to describe different treatment strategies and their effect on clinical outcome and mortality.

MATERIAL AND METHODS

We performed a retrospective observational study. From the total cohort of 439 Fontan patients treated in our institution during the study period 1986-2019, 30 patients (6.8%) with protein-losing enteropathy were identified. Perioperative, clinical, echocardiographic, laboratory, and invasive haemodynamic findings and treatment details were analysed.

RESULTS

Median follow-up after disease onset was 13.1 years [interquartile range 10.6]. Twenty-five patients received surgical or interventional treatment for haemodynamic restrictions. Medical treatment, predominantly pulmonary vasodilator and/or systemic anti-inflammatory therapy with budesonide, was initiated in 28 patients. In 15 patients, a stable remission could be achieved by medical or surgical procedures (n = 3 each), by combined multimodal therapy (n = 8), or ultimately by cardiac transplantation (n = 1). Phrenic palsy, bradyarrhythmia, Fontan pathway stenosis, and absence of a fenestration were significantly associated with development of protein-losing enteropathy (p = 0.001-0.48). Ten patients (33.3%) died during follow-up; 5-year survival estimate was 96.1%. In unadjusted analysis, medical therapy with budesonide and pulmonary vasodilator therapy in combination was associated with improved survival.

CONCLUSIONS

Protein-losing enteropathy is a serious condition limiting survival after the Fontan procedure. Comprehensive assessment and individual treatment strategies are mandatory to achieve best possible outcome. Nevertheless, relapse is frequent and long-term mortality substantial. Cardiac transplantation should be considered early as treatment option.

The failing Fontan

Nearly 50 years back, Francis Fontan pioneered an operation for tricuspid atresia that bears his name today. The operation has since undergone numerous modifications and continues to be widely applied to an array of single ventricles. Despite restoring normal oxygen levels in the body, the operation creates a neoportal system where adequate cardiac output can be generated only at the expense of increased systemic venous congestion. This results in slow but relentless damage to the end organ systems especially the liver. Continuous surveillance of the patient to monitor this circulation, that will ultimately fail, is of paramount importance. Timely medical and cardiac catheterization and surgical intervention can extend the life span of Fontan patients. Ultimately a change of the hemodynamic circuit in the form of heart transplantation or ventricular assist device will be required to salvage the failing Fontan circuit.

Evidence of Systemic Absorption of Enteral Budesonide in Patients with Fontan-Associated Protein-Losing Enteropathy

To evaluate for evidence of systemic glucocorticoid absorption in cases of Fontan-associated protein-losing enteropathy (PLE) treated with enteral budesonide, we reviewed the charts of 27 patients with Fontan-associated PLE followed at Children's Hospital Colorado from 2005 to 2018. Cases were excluded for lack of budesonide thserapy or a treatment duration of less than 6 months. Charts were examined by two endocrinologists for review of prior biochemical endocrine evaluations, alterations in linear growth, and physical exam findings consistent with steroid excess. Twelve patients met inclusion criteria. Eight had prior documented cortisol screening. Three patients were tested while on treatment with a median fasting AM cortisol of 0.9 mcg/dL; two of these had a concomitantly measured ACTH, both below the detectable limit. Five patients were tested while weaning or having discontinued budesonide, with a median fasting AM cortisol of 9.1 mcg/dL. Eleven patients had decreases in height velocity associated with starting budesonide. Six patients had documentation of cushingoid features by an endocrinologist. In this cohort of children treated with budesonide for PLE following Fontan, clinical signs of systemic glucocorticoid absorption were frequent. Cortisol secretion was suppressed while on therapy, with adrenal recovery noted once budesonide was discontinued. Growth failure and cushingoid features were common findings. While these findings should be confirmed in larger cohorts, we recommend that the evaluation for systemic absorption of exogenous steroids be considered in patients treated with long-term enteral budesonide given the potential risk for adrenal crisis in times of physiologic stressors.

Review on Mechanical Support and Cell-Based Therapies for the Prevention and Recovery of the Failed Fontan-Kreutzer Circulation

Though the current staged surgical strategy for palliation of single ventricle heart disease, culminating in a Fontan circulation, has increased short-term survival, mounting evidence has shown that the single ventricle, especially a morphologic right ventricle (RV), is inadequate for long-term circulatory support. In addition to high rates of ventricular failure, high central venous pressures (CVP) lead to liver fibrosis or cirrhosis, lymphatic dysfunction, kidney failure, and other comorbidities. In this review, we discuss the complications seen with Fontan physiology, including causes of ventricular and multi-organ failure. We then evaluate the clinical use, results, and limitations of long-term mechanical assist devices intended to reduce RV work and high CVP, as well as biological therapies for failed Fontan circulations. Finally, we discuss experimental tissue engineering solutions designed to prevent Fontan circulation failure and evaluate knowledge gaps and needed technology development to realize a more robust single ventricle therapy.

Budesonide for Protein Losing Enteropathy in Patients with Fontan Circulation: A Systematic Review and Meta-Analysis

Background:

Recent studies have shown that oral budesonide can be used to improve albumin level in patients with protein-losing enteropathy (PLE) following Fontan procedure. However, there has never been a systematic review and meta-analysis to confirm this finding. We performed a systematic review and meta-analysis to explore the therapeutic effect of budesonide in patients with PLE post-Fontan procedure.

Methods:

We searched the databases of MEDLINE and EMBASE from inception to January 2019. Included studies were published studies that evaluate albumin level before and after budesonide therapy in patients with PLE following Fontan procedure. Data from each study were combined using the random-effects model.

Results:

Five studies with 36 post-Fontan operation patients with PLE were included. In random-effects model, there was a statistically significant difference in albumin level between before and after budesonide treatment (weighted mean difference = 1.28, 95% confidence interval: 0.76-1.79). No publication bias was observed on a funnel plot and Egger test with a P value of .676.

Conclusions:

The results of this systematic review and meta-analysis show that budesonide can be used to increase albumin level in patients with PLE following Fontan operation. Further studies may focus on the impact of outcome of budesonide in this population.

CHAPLE syndrome uncovers the primary role of complement in a familial form of Waldmann's disease

Primary intestinal lymphangiectasia (PIL) or Waldmann's disease was described in 1961 as an important cause of protein-losing enteropathy (PLE). PIL can be the sole finding in rare individuals or occur as part of a multisystemic genetic syndrome. Although genetic etiologies of many lymphatic dysplasia syndromes associated with PIL have been identified, the pathogenesis of isolated PIL (with no associated syndromic features) remains unknown. Familial cases and occurrence at birth suggest genetic etiologies in certain cases. Recently, CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and PLE (the CHAPLE syndrome) has been identified as a monogenic form of PIL. Surprisingly, loss of CD55, a key regulator of complement system leads to a predominantly gut condition. Similarly to other complement disorders, namely paroxysmal nocturnal and hemoglobinuria (PNH) and atypical hemolytic uremic syndrome (aHUS), CHAPLE disease involves pathogenic cross-activation of the coagulation system, predisposing individuals to severe thrombosis. The observation that complement system is overly active in CHAPLE disease introduced a novel concept into the management of PLE; anti-complement therapy. While CD55 deficiency constitutes a treatable subgroup in the larger pool of patients with isolated PIL, the etiology remains to be identified in the remaining patients with intact CD55.

Protein-Losing Enteropathy and Plastic Bronchitis After the Fontan Operation

Protein-losing enteropathy and plastic bronchitis remain challenging to treat despite recent treatment advances. Protein-losing enteropathy and plastic bronchitis have been diagnosed in patients with cardiomyopathy, constrictive pericarditis, and congestive heart failure. This article focuses on patients with protein-losing enteropathy or plastic bronchitis following the Fontan procedure. Patients with single-ventricle physiology who have undergone the Fontan procedure are at risk for these conditions. Fontan physiology predisposes patients to chronically low cardiac output, increased central venous pressure, and congestive heart failure. These altered hemodynamics lead to increased mesenteric vascular resistance, resulting in venous hypertension and congestion in protein-losing enteropathy. Plastic bronchitis is a complex disease in which chronic high lymphatic pressures from Fontan physiology cause acellular bronchial casts to develop. These entities may also occur in patients with normal Fontan hemodynamics. This article also covers medical and surgical interventions for protein-losing enteropathy and plastic bronchitis. (Critical Care Nurse 2018;38[6]:e5-e12).

Comparison of Clinical Profiles in Patients with Protein-Losing Enteropathy With and Without Fontan Circulation

Protein-losing enteropathy (PLE) is a life-threatening complication in patients following the Fontan operation. However, PLE also develops in some patients with congenital heart disease (CHD) after biventricular repair (BVR). This study compared clinical profiles of PLE patients following the Fontan operation with those after BVR. We retrospectively reviewed clinical charts of postoperative CHD patients with PLE. The study population comprised 42 PLE patients (14BVR, 28Fontan). Postoperative follow-up period until onset was significantly shorter in the Fontan group than in the BVR group (14 ± 2 vs. 8 ± 1 years, p = 0.02), while there was no difference in PLE onset age between groups. Furthermore, there were no differences in prevalence of clinically relevant arrhythmias, cardiac output, or central venous pressure between the two groups at PLE onset. Percentage of structural lesions (valve regurgitation and/or stenotic lesions) responsible for development of PLE and ventricular end-diastolic pressure were higher in the BVR group than in the Fontan group (93 vs. 50%, p < 0.01), (13.4 ± 6.3 vs. 7.5 ± 4.1, p < 0.0001). Catheter intervention was applied in 2Fontan and 6BVR patients, while surgical intervention was required in 8BVR and 7Fontan patients. Of these, catheter intervention was effective in 2 (25%, 1Fontan, 1BVR) and surgical intervention was effective in 4 (26.7%, 1Fontan, 3BVR). Only one patient (5.3%) improved without intervention. Complete PLE remission rate was higher in the BVR group than in the Fontan group (38 vs. 7%, p = 0.02). During follow-up, death of 2 BVR and 8 Fontan patients occurred. There were no group differences in 5- to 10-year survival rates after PLE onset (81 vs. 81%, BVR, 81 vs. 66%, Fontan). Although BVR patients may have greater chance of PLE remission when compared with those exhibiting Fontan pathophysiology, mortality in PLE-CHD patients was significantly high regardless of postoperative hemodynamics.

Pathophysiology of thrombosis and anticoagulation post Fontan surgery

The Fontan procedure has transformed the lives of children born with single-ventricle physiology, previously deemed inoperable. Worldwide, there are an increasing number of children with Fontan circulation, with the potential for survival into adulthood. Due to the abnormal circulation, Fontan patients have an increased risk of thromboembolic (TE) events, with up to 25% of events leading to death. Despite the importance of preventing TE events in this patient population, there is currently no clinical consensus on the optimal monitoring, thromboprophylaxis therapies, and treatment of these events. This paper reviews the available literature regarding anticoagulation in the pediatric and adult Fontan population, including the mechanisms for thrombosis and current antithrombotic therapies.

Abdominal imaging findings in adult patients with Fontan circulation

Abstract

The Fontan procedures, designed to treat paediatric patients with functional single ventricles, have markedly improved the patient’s survival into adulthood. The physiology of the Fontan circuit inevitably increases systemic venous pressure, which may lead to multi-system organ failure in the long-term follow-up. Fontan-associated liver disease (FALD) can progress to liver cirrhosis with signs of portal hypertension. Focal nodular hyperplasia-like nodules commonly develop in FALD. Imaging surveillance is often performed to monitor the progression of FALD and to detect hepatocellular carcinoma, which infrequently develops in FALD. Other abdominal abnormalities in post-Fontan patients include protein losing enteropathy and pheochromocytoma/paraganglioma. Given that these abdominal abnormalities are critical for patient management, it is important for radiologists to become familiar with the abdominal abnormalities that are common in post-Fontan patients on cross-sectional imaging.

Teaching points

• Fontan procedure for functional single ventricle has improved patient survival into adulthood.

• Radiologists should be familiar with unique imaging findings of Fontan-associated liver disease.

• Focal nodular hyperplasia-like nodules commonly develop in Fontan-associated liver disease.

• Hepatocellular carcinoma, protein-losing enteropathy, pheochromocytoma/paraganglioma may develop.

Electronic supplementary material

The online version of this article (10.1007/s13244-018-0609-2) contains supplementary material, which is available to authorized users.