Protein-losing enteropathy: integrating a new disease paradigm into recommendations for prevention and treatment

Small Bowel Lymphangiectasia Leading to Massive Gastrointestinal Bleeding: A Case Report

Lymphangiomas are benign lymphatic system abnormalities that can appear anywhere on the skin and mucous membranes. Lymphangiomas are caused by congenital or acquired lymphatic system disorders. In the congenital form, although the cause is unknown it is said that it is formed by the incorrect attachment of lymphatic channels to the main lymphatic drainage duct before the age of 5 years. lymphangiectasia as a subgroup of lymphangioma occurs seldom in the small bowel, especially in adults. If that happens, protein-losing enteropathy will be the most common presenting sign. In the present study, we introduce a case of a 40-year-old man without a history of any congenital or acquired diseases who was admitted to the emergency room due to long-lasting obscure overt gastrointestinal (GI) bleeding. Normal upper and lower GI endoscopies were suggestive of GI bleeding originating from the small intestine. Despite receiving iron supplements, he continued to have melena and remained anemic. Further evaluation of the small intestine by deep enteroscopy revealed multiple white spots histologically consistent with dilated lymphatics. Intestinal lymphangiectasia was eventually introduced to be the final diagnosis of the patient.

Nutritional Management of Patients with Fontan Circulation: A Potential for Improved Outcomes from Birth to Adulthood

Fontan circulation (FC) is a surgically achieved palliation state offered to patients affected by a wide variety of congenital heart defects (CHDs) that are grouped under the name of univentricular heart. The procedure includes three different surgical stages. Malnutrition is a matter of concern in any phase of life for these children, often leading to longer hospital stays, higher mortality rates, and a higher risk of adverse neurodevelopmental and growth outcomes. Notwithstanding the relevance of proper nutrition for this subset of patients, specific guidelines on the matter are lacking. In this review, we aim to analyze the role of an adequate form of nutritional support in patients with FC throughout the different stages of their lives, in order to provide a practical approach to appropriate nutritional management. Firstly, the burden of faltering growth in patients with univentricular heart is analyzed, focusing on the pathogenesis of malnutrition, its detection and evaluation. Secondly, we summarize the nutritional issues of each life phase of a Fontan patient from birth to adulthood. Finally, we highlight the challenges of nutritional management in patients with failing Fontan.

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.

Reaching consensus for unified medical language in Fontan care

Aims

The Fontan operation has resulted in improved survival in patients with single‐ventricle congenital heart disease. As a result, there is a growing population of teenagers and adults with a Fontan circulation. Many co‐morbidities have been increasingly recognized in this population due to the unique features of the Fontan circulation. Standardization of how Fontan co‐morbid conditions are defined will help facilitate understanding, consistency and interpretability of research and clinical experience. Unifying common language usage in Fontan is a critical precursor step for data comparison of research findings and clinical outcomes and ultimately accelerating improvements in management for this growing group of patients. This manuscript aimed to create unified definitions for morbidities seen after the Fontan palliation.

Methods

In association of many congenital heart disease organizations, this work used Delphi methodology to reach a broad consensus among recognized experts regarding commonly used terms in Fontan care and research. Each definition underwent at least three rounds of revisions to reach a final definition through surveys sent to experts in the field of single‐ventricle care.

Results

The process of reaching a consensus on multiple morbidities associated with the Fontan procedure is summarized in this manuscript. The different versions that preceded reaching the consensus are also presented in the Supporting Information. Table 1 represents the final definitions according to the consensus.

Conclusions

We propose the use of these definitions for clinical care, future research studies, registry development and clinical trials.

Innominate Vein Turn-down Procedure for Failing Fontan Circulation

After the Fontan, systemic venous hypertension induces pathophysiologic changes in the lymphatic system that can result in complications of pleural effusion, ascites, plastic bronchitis, and protein losing enteropathy. Advances in medical therapy and novel interventional approaches have not substantially improved the poor prognosis of these complications. A more physiological approach has been developed by decompression of the thoracic duct to the lower pressure common atrium with a concomitant increase of preload. Diverting the innominate vein to the common atrium increases the transport capacity of the thoracic duct, which in most patients enters the circulation at the left subclavian-jugular vein junction. Contrary to the fenestrated Fontan circulation, in which the thoracic duct is drained into the high pressure Fontan circulation, turn down of the innominate vein to the common atrium effectively decompresses the thoracic duct to the lower pressure system with "diastolic suctioning" of lymph. Innominate vein turn-down may be considered for medical-refractory post-Fontan lymphatic complications of persistent chylothorax, plastic bronchitis, and protein losing enteropathy. Prophylactic innominate vein turn-down may also be considered at time of the Fontan operation for patients that are higher risk for lymphatic complications.

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.

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.

Magnetic Resonance Imaging Assessment of Blood Flow Distribution in Fenestrated and Completed Fontan Circulation with Special Emphasis on Abdominal Blood Flow

Objective

To investigate the regional flow distribution in patients with Fontan circulation by using magnetic resonance imaging (MRI).

Materials and Methods

We identified 39 children (18 females and 21 males; mean age, 9.3 years; age range, 3.3–17.0 years) with Fontan circulation in whom flow volumes across the thoracic and abdominal arteries and veins were measured by using MRI. The patients were divided into three groups: fenestrated Fontan circulation group with MRI performed under general anesthesia (GA) (Group 1, 15 patients; average age, 5.9 years), completed Fontan circulation group with MRI performed under GA (Group 2, 6 patients; average age, 8.7 years), and completed Fontan circulation group with MRI performed without GA (Group 3, 18 patients; average age, 12.5 years). The patient data were compared with the reference ranges in healthy controls.

Results

In comparison with the controls, Group 1 showed normal cardiac output (3.92 ± 0.40 vs. 3.72 ± 0.69 L/min/m², p = 0.30), while Group 3 showed decreased cardiac output (3.24 ± 0.71 vs. 3.96 ± 0.64 L/min/m², p = 0.003). Groups 1 and 3 showed reduced abdominal flow (1.21 ± 0.28 vs. 2.37 ± 0.45 L/min/m², p < 0.001 and 1.89 ± 0.39 vs. 2.64 ± 0.38 L/min/m², p < 0.001, respectively), which was mainly due to the diversion of the cardiac output to the aortopulmonary collaterals in Group 1 and the reduced cardiac output in Group 3. Superior mesenteric and portal venous flows were more severely reduced in Group 3 than in Group 1 (ratios between the flow volumes of the patients and healthy controls was 0.26 and 0.37 in Group 3 and 0.63 and 0.53 in Group 1, respectively). Hepatic arterial flow was decreased in Group 1 (0.11 ± 0.22 vs. 0.34 ± 0.38 L/min/m², p = 0.04) and markedly increased in Group 3 (0.38 ± 0.22 vs. −0.08 ± 0.29 L/min/m², p < 0.0001). Group 2 showed a mixture of the patterns seen in Groups 1 and 3.

Conclusion

Fontan circulation is associated with reduced abdominal flow, which can be attributed to reduced cardiac output and portal venous return in completed Fontan circulation, and diversion of the cardiac output to the aortopulmonary collaterals in fenestrated Fontan circulation.

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.

Resolution of Protein-Losing Enteropathy after Congenital Heart Disease Repair by Selective Lymphatic Embolization

With improving survival of children with complex congenital heart disease (CCHD), postoperative complications, like protein-losing enteropathy (PLE) are increasingly encountered. A 3-year-old girl with surgically corrected CCHD (ventricular inversion/L-transposition of the great arteries, ventricular septal defect, pulmonary atresia, post-double switch procedure [Rastelli and Glenn]) developed chylothoraces. She was treated with pleurodesis, thoracic duct ligation and subsequently developed chylous ascites and PLE (serum albumin ≤0.9 g/dL) and was malnourished, despite nutritional rehabilitation. Lymphangioscintigraphy/single-photon emission computed tomography showed lymphatic obstruction at the cisterna chyli level. A segmental chyle leak and chylous lymphangiectasia were confirmed by gastrointestinal endoscopy, magnetic resonance (MR) enterography, and MR lymphangiography. Selective glue embolization of leaking intestinal lymphatic trunks led to prompt reversal of PLE. Serum albumin level and weight gain markedly improved and have been maintained for over 3 years. Selective interventional embolization reversed this devastating lymphatic complication of surgically corrected CCHD.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

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).

Fontan-associated protein-losing enteropathy and post‒heart transplant outcomes: A multicenter study

BACKGROUND

The influence of Fontan-associated protein-losing enteropathy's (PLE) severity, duration, and treatment on heart transplant (HTx) outcomes is unknown. We hypothesized that long-standing PLE and PLE requiring more intensive therapy are associated with increased post-HTx mortality.

METHODS

This 12-center, retrospective cohort study of post-Fontan patients with PLE referred for HTx from 2003 to 2015 involved collection of demographic, medical, surgical, and catheterization data, as well as PLE-specific data, including duration of disease, intensity/details of treatment, hospitalizations, and complications. Factors associated with waitlist and post-HTx outcomes and PLE resolution were sought.

RESULTS

Eighty patients (median of 5 per center) were referred for HTx evaluation. Of 68 patients listed for HTx, 8 were removed due to deterioration, 4 died waiting, and 4 remain listed. In 52 patients undergoing HTx, post-HTx 1-month survival was 92% and 1-year survival was 83%. PLE-specific factors, including duration of PLE pre-HTx, pre-HTx hospitalizations, need for/frequency of albumin replacement, PLE therapies, and growth parameters had no association with post-HTx mortality. Immunosuppressant regimen was associated with mortality; standard mycophenolate mofetil immunotherapy was used in 95% of survivors compared with only 44% of non-survivors (p = 0.03). Rejection (53%) and infection (42%) post-HTx were common, but not associated with PLE-specific factors. PLE resolved completely in all but 1 HTx survivor at a median of 1 month (interquartile range 1 to 3 months); resolution was not affected by PLE-specific factors.

CONCLUSIONS

PLE severity, duration, and treatment do not influence post-HTx outcome, but immunosuppressive regimen may have an impact on survival. PLE resolves in nearly all survivors.

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.

Prevalence of Subclinical Enteric Alpha-1-Antitrypsin Loss in Children with Univentricular Circulation Following Total Cavopulmonary Connection

Protein-Losing Enteropathy post Fontan palliation is associated with significant morbidity and mortality. To date, very little research has been carried out to improve early identification of enteric protein loss in these patients. We hypothesise that subclinical enteric protein loss may occur in patients post Fontan surgery. A cross-sectional study was performed on 43 patients post Fontan surgery. We collected specimens of stool and blood from patients with no symptoms of protein-losing enteropathy post Fontan. Stool samples were assessed for alpha one antitrypsin. The stool samples of two patients were discarded, leaving 41 stool samples. Blood samples were also collected to review albumin, C-reactive protein, liver and renal function. Twenty-eight (65%) of those enrolled were male. The median (IQR) age between Fontan and collection of study specimens was 3.5 (2-7) years. Two (5%) patients had elevated levels of alpha-1-antitrypsin. There was no correlation between blood biochemistry and elevated stool alpha-1-antitrypsin. Subclinical protein loss is rare in asymptomatic children after Fontan procedure with only 5% of patients having elevated stool alpha-1-antitrypsin but no other symptoms. These findings may relate to our small cohort size and the time to testing post cardiac surgery. Future longitudinal follow-up studies should assess the ability of alpha-1-antitrypsin to provide earlier detection of protein-losing enteropathy in asymptomatic patients post Fontan. Given the serious prognosis of protein-losing enteropathy in this patient group, further work is warranted.

Protein losing enteropathy: comprehensive review of the mechanistic association with clinical and subclinical disease states

Protein losing enteropathy (PLE) has been associated with more than 60 different conditions, including nearly all gastrointestinal diseases (Crohn’s disease, celiac, Whipple’s, intestinal infections, and so on) and a large number of non-gut conditions (cardiac and liver disease, lupus, sarcoidosis, and so on). This review presents the first attempt to quantitatively understand the magnitude of the PLE in relation to the associated pathology for three different disease categories: 1) increased lymphatic pressure (e.g., lymphangiectasis); 2) diseases with mucosal erosions (e.g., Crohn’s disease); and 3) diseases without mucosal erosions (e.g., celiac disease). The PLE with lymphangiectasis results from rupture of the mucosal lymphatics, with retrograde drainage of systemic lymph into the intestinal lumen with the resultant loss of CD4 T cells, which is diagnostic. Mucosal erosion PLE results from macroscopic breakdown of the mucosal barrier, with the epithelial capillaries becoming the rate-limiting factor in albumin loss. The equation derived to describe the relationship between the reduction in serum albumin (C_P) and PLE indicates that gastrointestinal albumin clearance must increase by at least 17 times normal to reduce the C_P by half. The strengths and limitations of the two quantitative measures of PLE (⁵¹Cr-albumin or α₁-antitrypsin [αAT] clearance) are reviewed. αAT provides a simple quantitative diagnostic test that is probably underused clinically. The strong, unexplained correlation between minor decreases in C_P and subsequent mortality in seemingly healthy individuals raises the question of whether subclinical PLE could account for the decreased C_P and, if so, could the mechanism responsible for PLE play a role in the increased mortality? A large-scale study correlating αAT clearance with serum albumin concentrations will be required in order to determine the role of PLE in the regulation of the serum albumin concentration of seemingly healthy subjects.

Thoracic Duct Decompression for Protein-Losing Enteropathy in Failing Fontan Circulation

An infrequent but devastating late complication of Fontan circulation is protein-losing enteropathy (PLE), which results from unbalanced lymphatic homeostasis. Surgical decompression of the thoracic duct by redirecting its drainage to the pulmonary venous atrium has been introduced recently as a possible treatment. This report describes a single-institution experience with this innovative procedure in 2 patients with failing Fontan circulation with PLE refractory to optimized medical therapy.

Immune Abnormalities in Fontan Protein-Losing Enteropathy: A Case-Control Study

OBJECTIVE

To comprehensively characterize the immunologic characteristics of patients with protein-losing enteropathy (PLE) post-Fontan and compare them with patients without PLE post-Fontan.

STUDY DESIGN

Patients with PLE post-Fontan and age-matched controls post-Fontan were prospectively studied with laboratory markers of immune function. Infectious history was obtained by interview and chart review. The groups' demographics, cardiac history, immune characteristics, and infection history were compared using appropriate 2-group statistics.

RESULTS

A total of 16 patients enrolled (8 patients with PLE and 8 controls). All patients with PLE had lymphopenia compared with 25% of controls (P = .01). All patients with PLE had markedly depressed CD4 T cell counts (median 58 cells/μL) compared with controls (median 450 cells/μL, P = .0002); CD4% was also low in the PLE group (12.3%) and normal in control (36.9%, P = .004). Both groups had mildly depressed CD8 T cells and normal to slightly elevated natural killer and B-cell subsets. A majority of patients with PLE (62.5%) had negative titers to measles, mumps, and rubella vaccination, compared with no control Fontan with a negative titer (P = .03). Despite profoundly low CD4 counts, the frequency of infection was not different between groups with no reported opportunistic infections.

CONCLUSIONS

Patients with Fontan-associated PLE have extensive quantitative immune abnormalities, particularly CD4 deficiency. These immune abnormalities are similar to those found in non-Fontan patients with PLE caused by intestinal lymphangiectasia.

Fontan-associated protein-losing enteropathy and plastic bronchitis

OBJECTIVE

To characterize the medical history, disease progression, and treatment of current-era patients with the rare diseases Fontan-associated protein-losing enteropathy (PLE) and plastic bronchitis.

STUDY DESIGN

A novel survey that queried demographics, medical details, and treatment information was piloted and placed online via a Facebook portal, allowing social media to power the study. Participation regardless of PLE or plastic bronchitis diagnosis was allowed. Case control analyses compared patients with PLE and plastic bronchitis with uncomplicated control patients receiving the Fontan procedure.

RESULTS

The survey was completed by 671 subjects, including 76 with PLE, 46 with plastic bronchitis, and 7 with both. Median PLE diagnosis was 2.5 years post-Fontan. Hospitalization for PLE occurred in 71% with 41% hospitalized ≥ 3 times. Therapy varied significantly. Patients with PLE more commonly had hypoplastic left ventricle (62% vs 44% control; OR 2.81, 95% CI 1.43-5.53), chylothorax (66% vs 41%; OR 2.96, CI 1.65-5.31), and cardiothoracic surgery in addition to staged palliation (17% vs 5%; OR 4.27, CI 1.63-11.20). Median plastic bronchitis diagnosis was 2 years post-Fontan. Hospitalization for plastic bronchitis occurred in 91% with 61% hospitalized ≥ 3 times. Therapy was very diverse. Patients with plastic bronchitis more commonly had chylothorax at any surgery (72% vs 51%; OR 2.47, CI 1.20-5.08) and seasonal allergies (52% vs 36%; OR 1.98, CI 1.01-3.89).

CONCLUSIONS

Patient-specific factors are associated with diagnoses of PLE or plastic bronchitis. Treatment strategies are diverse without clear patterns. These results provide a foundation upon which to design future therapeutic studies and identify a clear need for forming consensus approaches to treatment.

Clinical outcomes and improved survival in patients with protein-losing enteropathy after the Fontan operation

BACKGROUND

Patients with protein-losing enteropathy (PLE) following the Fontan operation have a reported 50% mortality at 5 years after diagnosis.

OBJECTIVES

The aim of this study was to review outcomes in patients with PLE following the Fontan operation.

METHODS

From 1992 to 2010, 42 patients (55% male) with PLE following the Fontan operation were identified from clinical databases at the Mayo Clinic. Data were collected retrospectively.

RESULTS

Mean age at PLE diagnosis was 18.9 ± 11.0 years. Initial Fontan operation was performed at 10.1 ± 10.8 years of age. Mean time from Fontan operation to PLE diagnosis was 8.4 ± 14.2 years. Survival was 88% at 5 years. Decreased survival was seen in patients with high Fontan pressure (mean >15 mm Hg; p = 0.04), decreased ventricular function (ejection fraction <55%; p = 0.03), and New York Heart Association functional class >2 at diagnosis (p = 0.04). Patients who died had higher pulmonary vascular resistance (3.8 ± 1.6 Wood units [WU] vs. 2.1 ± 1.1 WU; p = 0.017), lower cardiac index (1.6 ± 0.4 l/min/m(2) vs. 2.7 ± 0.7 l/min/m(2); p < 0.0001), and lower mixed venous saturation (53% vs. 66%; p = 0.01), compared with survivors. Factors were assessed at the time of PLE diagnosis. Treatments used more frequently in survivors with PLE included spironolactone (21 [68%]), octreotide (7 [21%]), sildenafil (6 [19%]), fenestration creation (15 [48%]), and relief of Fontan obstruction (7 [23%]).

CONCLUSIONS

PLE remains difficult to treat; however, in the current era, survival has improved with advances in treatment. Further study is needed to better understand the mechanism of disease and ideal treatment strategy.

Treatment of children with protein - losing enteropathy after fontan and other complex congenital heart disease procedures in condition with limited human and technical resources

BACKGROUND

Protein-losing enteropathy (PLE) is a disorder characterized by abnormal and often profound enteric protein loss. It's relatively uncommon complication of Fontan and other complex congenital heart disease (CCHD) procedures. Because of the complexity and rarity of this disease process, the pathogenesis and pathophysiology of protein-losing enteropathy remain poorly understood, and attempts at treatment seldom yield long-term success.

AIM OF PRESENTATION

is to describe single centre experience in diagnosis, evaluation, management and treatment of children with protein-losing enteropathy after Fontan and other CCHD procedures in the current era and in centre with limited human and technical resources, follows with a comprehensive review of protein-losing enteropathy publications, and concludes with suggestions for prevention and treatment.

MATERIAL AND METHODOLOGY

Retrospectively we analyzed patients with CCHD and protein-losing enteropathy in our institution, starting from January 2000 to December 2012. The including criteria were age between two and 17 years, to have a complex congenital heart disease and available complete documentation of cardiac surgery under cardiopulmonary bypass.

RESULTS

Of all patients we evaluated 18 cases with protein-losing enteropathy, aged 6 to 19 years (mean 14±9); there were three children who had undergone screening procedure for D-transposition, one Tetralogy of Fallot, and remaining 14 patients had undergone Fontan procedures; (anatomic diagnosis are: six with tricuspid atresia, seven with d-transposition, double outlet right ventricle and pulmonary atresia and two with hypoplastic left heart syndrome). The diagnosis of protein-losing enteropathy was made at median age of 5.6 years, ranging from 13 months to 15 years. Diagnosis was made using alpha 1-antitrypsin as a gold marker in stool. By physical examination in 14 patients edema was found, in three ascites, and six patients had pleural effusion. Laboratory findings at the time of diagnosis are: abnormal enteric protein loss was documented at the time of diagnosis in all 18 patients. At the time of diagnosis all patients receiving some form of anticoagulation, 17 patients receiving other medication: 17 - diuretics and ACE inhibitors, 12 digoxin, 9 antiarrhytmics. Cross-sectional echocardiography was performed for all patients and different abnormalities were registered. In 14 patients also magnetic resonance was performed. Therapeutic approach was based on the non-specific medication (diet, diuretics, digoxin, ACE inhibitors, and anticoagulants), heparin and corticosteroids therapy. Long-term response to this type of therapy was registered in three patients. Nine patients underwent treatment with heparin and corticosteroids and no one experienced long term benefit. Despite of needs for catheter therapy or surgical intervention in our study, in the absent of technical and human resources now any one had underwent those procedures. Six patients has been transferred abroad and in five of them surgical intervention was perform.

CONCLUSION

Protein-losing enteropathy remains a devastating complication of Fontan procedure and despite in advantages in surgical and medical therapy there is no evidence that protein-losing enteropathy is less common in the current area.

MR assessment of abdominal circulation in Fontan physiology

The Fontan operation allows for longer survival of those born with functionally single ventricle physiology. Although it effectively eliminates cyanosis, increased systemic venous pressure is an unavoidable consequence and low cardiac output is frequent. The abdomen is particularly vulnerable to these alterations in hemodynamics because the hepatic blood flow consists predominantly of portal venous flow, which relies on a low pressure gradient between the portal and hepatic veins. Therefore, any subtle increase in systemic venous pressure will adversely affect the hemodynamic balance of the liver as well as the intestine. As the clinical manifestations and routine laboratory findings of abdominal complications can lag behind the hemodynamic and pathologic changes in the abdominal organs, regular imaging surveillance is critical. Magnetic resonance (MR) provides excellent visualization of both cardiovascular and abdominal systems. It provides robust anatomic and hemodynamic data which can be used for timely implementation of treatment options. In this review paper, we discuss the pathogenesis and MR findings of abdominal complications following the Fontan operation. Specifically we explore the utility of phase-contrast MR for assessment of the abdominal circulation in children following the Fontan palliation.

Clinical research priorities in adult congenital heart disease

BACKGROUND

Adult congenital heart disease (ACHD) clinicians are hampered by the paucity of data to inform clinical decision-making. The objective of this study was to identify priorities for clinical research in ACHD.

METHODS

A list of 45 research questions was developed by the Alliance for Adult Research in Congenital Cardiology (AARCC), compiled into a survey, and administered to ACHD providers. Patient input was sought via the Adult Congenital Heart Association at community meetings and online forums. The 25 top questions were sent to ACHD providers worldwide via an online survey. Each question was ranked based on perceived priority and weighted based on time spent in ACHD care. The top 10 topics identified are presented and discussed.

RESULTS

The final online survey yielded 139 responses. Top priority questions related to tetralogy of Fallot (timing of pulmonary valve replacement and criteria for primary prevention ICDs), patients with systemic right ventricles (determining the optimal echocardiographic techniques for measuring right ventricular function, and indications for tricuspid valve replacement and primary prevention ICDs), and single ventricle/Fontan patients (role of pulmonary vasodilators, optimal anticoagulation, medical therapy for preservation of ventricular function, treatment for protein losing enteropathy). In addition, establishing criteria to refer ACHD patients for cardiac transplantation was deemed a priority.

CONCLUSIONS

The ACHD field is in need of prospective research to address fundamental clinical questions. It is hoped that this methodical consultation process will inform researchers and funding organizations about clinical research topics deemed to be of high priority.

End-organ consequences of the Fontan operation: liver fibrosis, protein-losing enteropathy and plastic bronchitis

The Fontan operation, although part of a life-saving surgical strategy, manifests a variety of end-organ complications and unique morbidities that are being recognised with increasing frequency as patients survive into their second and third decades of life and beyond. Liver fibrosis, protein-losing enteropathy and plastic bronchitis are consequences of a complex physiology involving circulatory insufficiency, inflammation and lymphatic derangement. These conditions are manifest in a chronic, indolent state. Management strategies are emerging, which shed some light on the origins of these complications. A better characterisation of the end-organ consequences of the Fontan circulation is necessary, which can then allow for development of specific methods for treatment. Ideally, the goal is to establish systematic strategies that might reduce or eliminate the development of these potentially life-threatening challenges.

Haemodynamic characteristics before and after the onset of protein losing enteropathy in patients after the Fontan operation

OBJECTIVES

Determinant risk factors for developing protein losing enteropathy (PLE), including haemodynamics, remain unclear in patients after the Fontan operation.

METHODS

Our purpose was to characterize the serial PLE haemodynamics before and after the onset and to determine the risk factors based on the cardiac catheterization-based analysis.

RESULTS

Of 354 Fontan survivors who had undergone postoperative cardiac catheterizations, we experienced 26 PLE patients during the follow-up. Non-left ventricular morphology systemic ventricle, functional one-lung pulmonary circulation and an early postoperative high central venous pressure (CVP) were associated with the PLE onset and the high CVP (odds ratio (OR) = 1.19 per 1 mmHg, 95% confidence interval (CI) 1.04-1.37, especially ≥12 mmHg, OR = 3.09, 95% CI 1.25-7.64, P < 0.05 for both) and one-lung pulmonary circulation (OR = 10.0-10.5, P < 0.001) independently predicted the onset. At the time of the PLE onset, a Fontan route stenosis/obstruction, arrhythmias, ventricular dysfunction/heart failure and pulmonary arterio-venous fistulae were demonstrated in 10 (38%), 8 (31%), 4 (15%) and 3 (12%) patients, respectively. When compared with 56 excellent Fontan survivors, the high CVP, ventricular end-diastolic pressure, and pulmonary artery resistance, and the low arterial oxygen saturation, systemic artery pressure, and ventricular ejection fraction characterized the pre-PLE Fontan haemodynamics (P < 0.05-0.0001). However, the following intensive treatments reduced the CVP, systemic artery pressure and cardiac output (P < 0.05-0.01), resulting in haemodynamics no different from those of the excellent survivors, except for the low systemic pressure (P < 0.0001).

CONCLUSIONS

The pre-PLE haemodynamics was characterized by several impaired haemodynamics, while those after PLE only by a low systemic pressure. A high early postoperative CVP was the only haemodynamic predictor for a new onset of PLE. Strict selective criteria for the operation and strategies to eliminate CVP-raising factors are mandatory to prevent a new onset of PLE.

Stent therapy for acute and chronic obstructions in extracardiac Fontan conduits

We describe transcatheter therapy for early onset occlusion or stenoses of extracardiac conduits in three children who had undergone Fontan completion. Successful stent implantation was associated with complete resolution of symptoms.

Protein losing enteropathy secondary to a pulmonary artery stent

A 2-year-old patient with hypoplastic left heart syndrome presented 6 months following Fontan completion with protein-losing enteropathy (PLE). He had undergone stent implantation in the left pulmonary artery after the Norwood procedure, followed by redilation of the stent prior to Fontan completion. Combined bronchoscopic and catheterization studies during spontaneous breathing confirmed left bronchial stenosis behind the stent, and diastolic systemic ventricular pressure during expiration of 25 mm Hg. We postulate that the stent acts as a valve, against which the patient generates high expiratory pressures, which are reflected in the ventricular diastolic pressure. This may be the cause of PLE.

Protein-losing enteropathy associated with or without systemic autoimmune disease: what are the differences?

OBJECTIVE

The aim of our study was to compare protein-losing enteropathy (PLE) associated with or without systemic autoimmune (SA) diseases.

METHODS

Patients diagnosed with PLE were selected, and their clinical characteristics, laboratory, endoscopic and imaging characteristics, treatment, and outcome were analyzed.

RESULTS

From 2001 to 2010, 74 patients (60 patients with SA disease) with a female predominance were diagnosed with PLE. The SA group tended to be younger, presented early (4.3 vs. 7 weeks, P=0.08), and had significantly more mucocutaneous-articular involvement (16.7 vs. 0%, P<0.05; 50 vs. 0%, P<0.02; 43.3 vs. 0%, P<0.01), compared with the other group, which showed more weight loss (64.3 vs. 25%, P<0.01), malaise and fatigue (57.1 vs. 28.3%, P<0.02), and tended to have more gastrointestinal (GI) symptoms. The SA group was associated with lymphopenia (0.8 vs. 2.7 × 10⁹/l, P<0.01), hyperglobulinemia (43 vs. 31.2 IU/l, P<0.04), lactate dehydrogenase (511.1 vs. 393.5 IU/l, P<0.05), hematuria (48.3 vs. 7.1%, P<0.01), and pyuria (23.3 vs. 0%, P<0.03), whereas the non-SA group had a higher platelet count (402 vs. 262.5 × 10⁹/l, P<0.01) and alkaline phosphatase (111 vs. 78.2 IU/l, P<0.03) on admission. A subgroup analysis of patients with SA disease showed that more lupus patients had pericardial effusion (14.6 vs. 0%, P=0.08), polyarthritis (50 vs. 16.7%, P=0.02), lower C3 level (0.5 vs. 0.85 mg/l, P<0.01), antinuclear factors (89.6 vs. 58.3%, P<0.01), and antiextractable nuclear antigen antibody (73.3 vs. 37.5%, P<0.03), whereas nonlupus patients had higher C-reactive protein (87.9 vs. 40 mg/l, P<0.01) and more antineutrophil cytoplasmic antibody (ANCA) (60 vs. 3%, P=0.00). Thirty-seven (71%) patients with SA disease had diffuse nonerosive erythematous GI mucosa with chronic inflammatory cells in the lamina propria layer, and 12 (85.7%) patients without SA disease had focal lesions. The treatment response was comparable between the two groups. However, the time required to normalize the serum albumin level (6.3 vs. 12.3 months, P=0.02) of patients with SA disease was much shorter than that of the non-SA group and those of inflammatory markers, specifically, C-reactive protein and complement C3, of its own group (6.3 vs. 11.6 vs. 12.1 months, P<0.04). More patients without SA disease had infective episodes during the management period (14.3 vs. 1.7%, P<0.01).

CONCLUSION

Patients with PLE associated with SA disease tend to have a distinct clinical syndrome with regard to the extent of clinical manifestations and laboratory, endoscopic, and histological features compared with those without. Patients without SA disease are more prone to develop complications and mortality. However, both can be effectively treated with comparable treatment response.

Long-term serial aerobic exercise capacity and hemodynamic properties in clinically and hemodynamically good, "excellent", Fontan survivors

BACKGROUND

The serial hemodynamics and predictors of long-term, good Fontan survivors remain unknown.

METHODS AND RESULTS

Two hundred one patients who had undergone a Fontan operation before September 1998 were reviewed to compare their long-term clinical status with serial hemodynamics. During a mean follow-up of 18.7 years, 47 (30.1%) of the 156 survivors had no clinical events that required an unscheduled hospitalization. Of those, 18 survivors exhibited good serial hemodynamics and the respective mean values of central venous pressure (CVP, mmHg), cardiac index (CI, L·min(-1)·m(2)), and ventricular ejection fraction (EF, %) before and 1, 5, 10, and 15 years after the operation were as follows: 3.8, 9.0, 11.3, 10.6, and 10.1 (CVP); 3.6, 3.1, 2.8, 2.6, and 2.6, and 69 (CI); 57, 56, 58, 54, and 53 (EF). Serial values of CVP, ventricular end-diastolic pressure (EDP) and the grade of atrioventricular valve regurgitation (AVVR) were lower and the peak oxygen uptake was greater in the good patients (P<0.05 for all). A 1-year postoperative lower CVP and no history of AVVR repair during the Fontan operation independently predicted the good patients (P<0.05).

CONCLUSIONS

A lower CVP and EDP, better atrioventricular valvular function, and greater exercise capacity characterize good Fontan survivors and an early postoperative low CVP without an AVVR repair predicts good survivors.