Results of transcatheter Fontan fenestration to treat protein losing enteropathy

Implantation of atrial flow regulator devices in patients with congenital heart disease and children with severe pulmonary hypertension or cardiomyopathy-an international multicenter case series

Background

The Occlutech Atrial Flow Regulator (AFR) is a self-expandable double-disc nitinol device with a central fenestration. Its use has been approved in the adult population with heart failure and described for pulmonary hypertension (PH). Only case reports and small series have been published about its use in the paediatric population and for congenital heart disease (CHD).

Objectives

The authors sought to investigate the feasibility, safety, and short-term follow-up of AFR implantation in patients with CHD or children with PH or cardiomyopathy.

Methods

This is a multicenter retrospective study involving 10 centers worldwide. Patients of any age with CHD or patients aged < 18 years with PH or cardiomyopathy needing AFR implantation were included.

Results

A total of 40 patients underwent AFR implantation. The median age of the population at the time of the procedure was 58.5 months (IQR: 31.5-142.5) and the median weight was 17 kg (IQR: 10-46). A total of 26 (65.0%) patients had CHD, nine (22.5%) children, a cardiomyopathy, and five (12.5%), a structurally normal heart. The implantation success rate was 100%. There were two early and one late device thrombosis. Two patients (5.0%) with dilated cardiomyopathy on extracorporeal membrane oxygenator (ECMO) died during the hospital stay. At a median follow-up of 330 days (IQR: 125-593), 37 (92.5%) patients were alive. At follow-up, 20 patients improved their New York Heart Association (NYHA) class, 12 patients did not change their NYHA class, and one patient with idiopathic PH worsened.

Conclusions

AFR implantation in patients with CHD and children with severe PH or cardiomyopathy is promising and seems to have beneficial effects at short-term follow-up.

Versatility of Atrial Flow Regulator Device in Congenital Heart Disease: A Case Series

The Atrial Flow Regulator (AFR) is a self-expandable double-disk device with a central fenestration, intended to maintain a calibrated communication across the interatrial septum. Only case reports and small case series have been published about its use in the pediatric and congenital heart disease (CHD) population. We described AFR implantation in three congenital patients with different anatomies and indications. In the first case, the AFR was deployed to create a stable fenestration in a Fontan conduit, while in the second, it was used to reduce a Fontan fenestration. In the third case, we implanted an AFR to decompress the left atrium of an adolescent with complex CHD in natural history, with complete mixing, ductal-dependent systemic circulation and combined pulmonary hypertension. This case series demonstrates the great potential of the AFR device in the CHD field, showing versatility, efficacy, and safety in establishing a calibrated and stable shunt, with promising hemodynamic and symptomatic benefits.

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

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

Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

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.

Impact on clinical outcomes from transcatheter closure of the Fontan fenestration: A systematic review and meta-analysis

BACKGROUND

Meta-analysis of the impact on clinical outcome from transcatheter closure of Fontan fenestration.

METHODS

Cochrane, Embase, MEDLINE, and Open-Gray were searched. Parameters such as changes in oxygen saturation, cavo-pulmonary pressure, maximum heart rate during exercise, exercise duration, and oxygen saturation after fenestration closure were pooled and statistical analysis performed.

RESULTS

Among 922 publications, 12 retrospective observational studies were included. The included studies involved 610 patients, of which 552 patients (90.5%) had a fenestration. Of those patients, 505 patients (91.5%) underwent attempt at trans-catheter closure. When it could be estimated, the pooled overall mean age at trans-catheter fenestration closure was 6.6 ± 7.4 years, and the mean follow-up time was 34.4 ± 10.7 months. There were 32 minor (6.3%) and 20 major (4.0%) complications during or after trans-catheter Fontan fenestration closure. The forest plots demonstrate that following fenestration closure, there was a significant increase in the mean arterial oxygen saturation of 7.9% (95% CI 6.4-9.4%, p < 0.01). There was also a significant increase in the mean cavo-pulmonary pressure of 1.4 mmHg (95% CI 1.0-1.8 mmHg, p < 0.01) following fenestration closure. The exercise parameters reported in 3 studies also favored closing the fenestration as well, yet the exercise duration increase of 1.7 min (95% CI 0.7-2.8 min, p < 0.01) after fenestration closure is probably clinically insignificant.

CONCLUSION

Late closure of a Fontan fenestration has the impact of improving resting oxygen saturation, exercise oxygen saturation, and a modest improvement of exercise duration. These clinical benefits, however, may be at the expense of tolerating slightly higher cavo-pulmonary mean pressures.

Current Treatment Options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations, where biventricular repair is unsuitable, the Fontan procedure has provided a long-term palliation strategy with improved outcomes compared to the initially developed procedures. Despite these improvements, several complications merely due to a failing Fontan circulation, including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein-losing enteropathy, hepatic dysfunction, plastic bronchitis, and thrombo-embolism, may occur, thereby limiting the life-expectancy in this patient cohort. This review provides an overview of the most common complications of Fontan circulation and the currently available treatment options.

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.

Protein-losing enteropathy managed with percutaneous enlargement of a restrictive atrial septal defect

Protein-losing enteropathy is one of the most feared complications of the Fontan circulation. The diagnosis of protein-losing enteropathy in this setting should prompt a thorough investigation for the presence of a treatable hemodynamic impairment. In this report, we describe a complete reversal of protein-losing enteropathy following percutaneous enlargement of a restrictive atrial septal defect in a patient with a fenestrated lateral tunnel Fontan and severe mitral stenosis.

Transcatheter creation of a pulmonary artery to left atrial fenestration in a failing Fontan circulation using the Atrial Flow Regulator (AFR)

Transcatheter creation of an interatrial communication using the Occlutech Atrial Flow Regulator Device for pulmonary hypertension or heart failure is well described. We report a case of an 8-year-old boy with a failing Fontan circulation, in whom the Atrial Flow Regulator was used to successfully create a fenestration between the pulmonary artery and left atrium, improving his clinical condition.

Diagnosis and Management of Lymphatic Disorders in Congenital Heart Disease

Purpose of Review

Lymphatic disorders have received an increasing amount of attention over the last decade. Sparked primarily by improved imaging modalities and the dawn of lymphatic interventions, understanding, diagnostics, and treatment of lymphatic complications have undergone considerable improvements. Thus, the current review aims to summarize understanding, diagnostics, and treatment of lymphatic complications in individuals with congenital heart disease.

Recent Findings

The altered hemodynamics of individuals with congenital heart disease has been found to profoundly affect morphology and function of the lymphatic system, rendering this population especially prone to the development of lymphatic complications such as chylous and serous effusions, protein-losing enteropathy and plastic bronchitis.

Summary

Although improved, a full understanding of the pathophysiology and targeted treatment for lymphatic complications is still wanting. Future research into pharmacological improvement of lymphatic function and continued implementation of lymphatic imaging and interventions may improve knowledge, treatment options, and outcome for affected individuals.

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.

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).

Long Term Consequences of the Fontan Procedure and How to Manage Them

In 1971, Fontan and Baudet described a surgical technique for successful palliation of patients with tricuspid atresia. Subsequently, this technique has been applied to treat most forms of functional single ventricles and has become the current standard of care for long-term palliation of all patients with single ventricle congenital heart disease. Since 1971, the Fontan procedure has undergone several variations. These patients require lifelong management including a thorough knowledge of their anatomic substrate, hemodynamic status, management of rhythm and ventricular function along with multi organ evaluation. As these patients enter middle age, there is increasing awareness regarding the long-term complications and mortality. This review highlights the long-term outcomes of the Fontan procedure and management of late sequelae.

Creation of a defined and stable Fontan fenestration with the new Occlutech Atrial Flow Regulator (AFR®)

This report describes the first clinical experience with the new Occlutech Atrial Flow Regulator (AFR®) device for implementation of a late Fontan fenestration. The AFR® device secured a defined diameter of the fenestration without spontaneous re-occlusion of this extra-anatomic perforation. This ensured a permanent clinical improvement of our failing Fontan patient.

Diagnosis and Management of Noncardiac Complications in Adults With Congenital Heart Disease: A Scientific Statement From the American Heart Association

Life expectancy and quality of life for those born with congenital heart disease (CHD) have greatly improved over the past 3 decades. While representing a great advance for these patients, who have been able to move from childhood to successful adult lives in increasing numbers, this development has resulted in an epidemiological shift and a generation of patients who are at risk of developing chronic multisystem disease in adulthood. Noncardiac complications significantly contribute to the morbidity and mortality of adults with CHD. Reduced survival has been documented in patients with CHD with renal dysfunction, restrictive lung disease, anemia, and cirrhosis. Furthermore, as this population ages, atherosclerotic cardiovascular disease and its risk factors are becoming increasingly prevalent. Disorders of psychosocial and cognitive development are key factors affecting the quality of life of these individuals. It is incumbent on physicians who care for patients with CHD to be mindful of the effects that disease of organs other than the heart may have on the well-being of adults with CHD. Further research is needed to understand how these noncardiac complications may affect the long-term outcome in these patients and what modifiable factors can be targeted for preventive intervention.

A computational study of the Fontan circulation with fenestration or hepatic vein exclusion

Fontan patients may undergo additional surgical modifications to mitigate complications like protein-losing enteropathy, liver cirrhosis, and other issues in their splanchnic circulation. Recent case reports show promise for several types of modifications, but the subtle effects of these surgeries on the circulation are not well understood. In this paper, we employ mathematical modeling of blood flow to systematically quantify the impact of these surgical changes on extracardiac Fontan hemodynamics. We investigate two modifications: (1) the fenestrated Fontan and (2) the Fontan with hepatic vein exclusion. Closed-loop hemodynamic models are used, which consist of one-dimensional networks for the major vessels and zero-dimensional models for the heart and organ beds. Numerical results suggest the hepatic vein exclusion has the greatest overall impact on the hemodynamics, followed by the largest sized fenestration. In particular, the hepatic vein exclusion drastically lowers portal venous pressure while the fenestration decreases pulmonary artery pressure. Both modifications increase flow to the intestines, a finding consistent with their utility in clinical practice for combating complications in the splanchnic circulation.

Fenestration closure with Amplatzer Duct Occluder II in patients after total cavo-pulmonary connection

INTRODUCTION

Creation of a fenestration during completion of a total cavopulmonary connection (TCPC) has been associated with a reduction in early mortality and morbidity. However, the long-term benefits are negated by an associated limitation in exercise tolerance and the potential risks of thrombo-embolic complications. We sought to describe the safety and efficacy of an Amplatzer Duct Occluder II (ADO II) for transcatheter fenestration closure following TCPC.

MATERIAL AND METHODS

Between January 2000 and July 2014, 102 patients underwent percutaneous closure of extra-cardiac TCPC fenestrations with a range of devices. Patients in whom fenestration closure was performed with an ADO II and who had at least 6 months of follow-up were included in this study.

RESULTS

Forty-seven patients had successful fenestration occlusion with an ADO II. The mean oxygen saturation and mean systemic venous pressures increased from 84.8 ±6.1% before to 97.6 ±2.9% (p < 0.001) after and from 14.2 ±2.15 mm Hg before to 15.6 ±2.2 mm Hg after closure (p < 0.001). Eight patients developed heart failure symptoms, managed by optimization of medical therapy, with 1 patient requiring device removal to reopen the fenestration. Color Doppler transthoracic echocardiography demonstrated residual flow across the device in 18 (38%), 10 (22%), 5 (11%) and 4 (9%) patients before discharge, at 1 and 6 months, and at the latest outpatient visit, respectively.

CONCLUSIONS

The ADO II can be safely and effectively used to close fenestrations in extra-cardiac type Fontan completions. Many of the design features of this device confer potential benefit in this population.

Unusual method of creation of a transcatheter fenestration in an extracardiac conduit Fontan circulation

Failing Fontan physiology in univentricular hearts manifest with protein-losing enteropathy, plastic bronchitis, low cardiac output, and recurrent effusions. Transcatheter creation of fenestration in a failing Fontan may be useful in alleviating the symptoms by improving the cardiac output. It is traditionally achieved by puncturing through the conduit from femoral or jugular venous access. In the absence of good venous path, transhepatic access provides a direct route for needle puncture of the conduit. If marked intimal ingrowth into the conduit results in increasing rigidity and makes the conduit nonyielding, alternative approaches may be needed. A successful creation of pulmonary artery to atrial roof communication through the potential space of transverse sinus using a covered stent is presented.

Modified Technique to Create Diabolo Stent Configuration

Diabolo stent configuration aids in stent positioning, stability, and creating a controlled defect with a predetermined size. A number of techniques to create the diabolo configuration have been previously described. The indications for creating a controlled "defect" are rapidly growing and include the Fontan circulation, patients with severe end-stage pulmonary hypertension, restrictive atrial communication in the setting of hypoplastic right or left heart syndrome, and diastolic left heart failure. We describe an alternative technique using a prefabricated readily available tool (gooseneck snare) to create a diabolo stent configuration. The chosen balloon expandable stent is mounted on a 5-mm gooseneck snare centered on an angioplasty catheter larger than 5 mm diameter. When deployed, the snare restricts the central waist to 5 mm and both ends expand to a larger diameter creating a dumbbell/diabolo configuration. A total of six diablo stent configurations were successfully implanted in four patients with failing Fontan physiology; five to create a transcatheter fenestration and one to relieve atrial septal restriction. Data expressed as median and IQR. Their weight was 24.8 kg (19.6-46.95), and age years was 9.2 (6.28-13.23). There were no complications and a consistent diabolo configuration with a 5-mm central waist was created in all patients. The snare serves as a sterile, preconfigured, radiopaque, readily available tool of adequate length and strength, to create consistent diabolo stent configuration without any modifications. This technique is a simple, reproducible, and easy to learn.

Is Four Stage Management the Future of Univentricular Hearts? Destination Therapy in the Young

For the child born with a functionally univentricular heart, multi-stage surgical palliation culminating in the Fontan operation is now well established as the standard of care. Though this is an effective approach, there are several inherent disadvantages to the Fontan circulation: subnormal resting cardiac output, impaired exercise capacity, increased risk of thromboembolism, and increased risk of arrhythmia. Perhaps most importantly, the long-term deleterious effects of substantial systemic venous hypertension, which is necessary to "drive" blood through the pulmonary vascular bed, include progressive dysfunction of other organ systems, particularly renal, lymphatic, gastrointestinal, and hepatic systems. When such dysfunction is advanced, heart transplantation or even heart-liver transplantation may be a reasonable option. However, because the syndrome seems to be increasingly widespread and there is already a significant donor shortage, alternative solutions are required. Because many patients with "failing Fontan" physiology have preserved systemic ventricular function, application of a systemic ventricular assist device is unlikely to be effective. However, for such patients, a right-sided sub-pulmonary ventricular assist device is an intellectually appealing solution. Several such devices have been proposed or are in varying stages of evaluation. The lack of economic incentive for development of right-sided pumps may be partially ameliorated both by recognition of the size of the cohort of Fontan patients now surviving into adulthood as well as by the increasing recognition of important right-sided heart failure in adults with biventricular hearts supported only with durable left-sided ventricular assist devices.

Heart Failure in Adult Congenital Heart Disease: Nonpharmacologic Treatment Strategies

In early stages, heart failure (HF) in adult congenital heart disease (ACHD) remains an elusive diagnosis. Many ACHD patients seem well-compensated owing to chronic physical and psychological adaptations. HF biomarkers and cardiopulmonary exercise tests are often markedly abnormal, although patients report stable health and good quality of life. Treatment differs from acquired HF. Evidence for effective drug therapy in ACHD-related HF is lacking. Residual ventricular, valvular, and vascular abnormalities contribute to HF pathophysiology, leading to an emphasis on nonpharmacologic treatment strategies. This article reviews emerging perspectives on nonpharmacologic treatment strategies, including catheter-based interventions, surgical correction, and palliative care.

Bronchial compression following pulmonary artery stenting in single ventricle lesions: how to prevent, and how to decompress

OBJECTIVES

To assess airway compression during pulmonary artery (PA) intervention in single ventricle (SV) palliation.

BACKGROUND

SV lesions with a prominent neo-aortic root are considered a high risk for branch PA and/or bronchial stenosis. PA stenting is well established, but may result in ipsilateral bronchial compression.

METHODS

Single-centre retrospective analysis of 19 palliated SV patients with branch PA stenosis and close proximity to the ipsilateral main bronchus who underwent cardiac catheterisation at a median age and weight of 8.5 years (0.5-25) and 16.5 kg (6-82) between 12/2011 and 05/2015.

RESULTS

Two of the 19 patients suffered an almost-closed left-main bronchus (LMB) following PA stenting. Fortunately, LMB decompression succeeded in both those patients by re-shaping the PA stents by compressing the chest while splinting the LMB with an inflated balloon. To prevent the other 17 patients from suffering this serious complication, we adopted a thorough preparation strategy: 13 patients underwent safe simultaneous bronchoscopy and cardiac catheterisation; in the remaining 4 patients CT-angiography enabled accurate risk evaluation prior to re-catheterisation.

CONCLUSIONS

In SV lesions accompanied by branch PA stenosis, thorough preparation via cross-sectional imaging is mandatory, including simultaneous bronchoscopy and cardiac catheterisation in selected cases, to rule out any airway compression before considering endovascular stent implantation. If a PA stent's compression has already caused severe bronchial obstruction, our balloon-splinted decompression technique should be considered.

Effect of Fontan fenestration on regional venous oxygen saturation during exercise: further insights into Fontan fenestration closure

Fontan fenestration closure is a topic of great debate. The body of data regarding the risks and benefits of fenestration closure is limited yet growing. Previous studies have demonstrated that Fontan patients have less exercise capacity than those with normal cardiovascular anatomy. Differences also have been noted within various subgroups of Fontan patients such as whether Fontan is fenestrated or not. This study aimed to compare trends in regional oxygen saturations using near-infrared spectroscopy (NIRS) in patients with Fontan circulations during ramping exercise to further delineate differences between patients with and without a fenestration. It was hypothesized that Fontan patients with fenestrations have better exercise times, higher absolute regional oxygen venous saturations, and smaller arteriovenous differences than Fontan patients without fenestrations. For this study, 50 consecutive Fontan patients and 51 consecutive patients with normal cardiovascular anatomy were recruited. Placement of NIRS probes was performed to obtain regional oxygen saturations from the brain and the kidney. Readings were obtained at 1-min intervals during rest, exercise, and recovery. A standard Bruce protocol was used with a 5-min recovery period. Absolute regional tissue oxygenation values (rSO2) and arterial-venous oxygen saturation differences (AVDO2) calculated as arterial oxygen saturation (SPO2)--rSO2 for normal versus Fontan patients and for fenestrated versus unfenestrated Fontan patients were compared using independent t tests. When normal and Fontan patients were compared, the Fontan patients had a significantly shorter duration of exercise (9.3 vs 13.2 min; p < 0.001). No statistically significant difference in rSO2 change or AVDO2 was evident at the time of peak exercise, at 2 min into the recovery, or at 5 min into the recovery. A small oxygen debt also was paid back to the brain in the Fontan patients after exercise, as evidenced by a narrower AVDO2 than at baseline. The comparison of Fontan patients with and without fenestration showed no statistically significant difference in exercise time, rSO2 change, or AVDO2. The Fontan patients were noted to have shorter exercise times than the normal patients and also appeared to have an alteration in postexertional regional blood flow. However, when the various Fontan subtypes were compared by presence or absence of a fenestration, no significant differences were noted with regard to change in regional oxygen saturation or arteriovenous oxygen saturation. Thus, for patients with Fontan physiology, closure of the fenestration does not seem to have an impact on the dynamics of regional oxygen extraction during exercise or recovery.

Contractility-afterload mismatch in patients with protein-losing enteropathy after the Fontan operation

This study aimed to clarify the relationship between onset of protein-losing enteropathy (PLE) and Fontan circulation, with special reference to the development of contractility-afterload mismatch. The PLE group comprised 9 patients who experienced PLE after undergoing the Fontan operation, and the control group consisted of 32 patients had did not experienced PLE more than 10 years after the Fontan operation. The study compared the pre- and postoperative values of arterial elastance (Ea), end-systolic elastance (Ees), and contractility-afterload mismatch (Ea/Ees). Furthermore, the variations in the values were examined during the preoperative, postoperative, and midterm postoperative periods in seven PLE patients who underwent cardiac catheterization at the onset of PLE and during the pre- and postintervention periods in three PLE patients who underwent surgical intervention to improve the Fontan circulation after the onset of PLE. Comparison of the values obtained before and after Fontan operations showed that the Ea values increased significantly in the PLE group. However, the pre- and postoperative Ees values did not differ in the two groups. During the postoperative period, Ea/Ees increased significantly, and the Ea and Ea/Ees values increased continuously until the onset of PLE in the PLE group. In the patients who underwent surgical intervention to improve the Fontan circulation after the onset of PLE, the Ea/Ees decreased significantly, and the serum albumin levels improved after the intervention. Contractility-afterload mismatch, mainly caused by the increase in the afterload of the systemic ventricle, may have an important role in the development of PLE after the Fontan operation.

Protein-losing enteropathy and the Fontan operation

Protein-losing enteropathy (PLE) is a complex disorder characterized by enteric protein loss and often is associated with cardiovascular abnormalities, particularly those with elevated central venous pressure. The Fontan operation is a surgical procedure used to palliate patients with a functional single ventricle. Although the Fontan operation eliminates cyanosis and decreases the workload of the functionally single ventricle, it also elevates central venous pressure. This can result in hepatic and enteric congestion as well as PLE. Despite the universal elevation in central venous pressure, only a fraction of patients who have had a Fontan operation develop PLE. However, PLE is associated with significant morbidity and mortality. Presenting signs and symptoms of PLE include abdominal bloating, diarrhea, edema, pleural effusions, ascites, and failure to thrive. In this review, the authors discuss the diagnosis and prevalence of PLE after the Fontan operation and review currently available therapeutic strategies.

Late catheter interventions in hypoplastic left heart syndrome

Interventional cardiology plays a key role in the diagnosis and management of patients with functionally univentricular physiology after the various stages of surgical palliation. The interventions performed are widely variable in type, including angioplasty of stenotic vessels and implantation of stents in stenotic vessels; closure of defects such as collaterals, leaks in baffles, and fenestrations; creation of fenestration; and more. In the setting of venous hypertension associated with stenosis at the Fontan baffle, conduit, or pulmonary arteries, stent implantation is often preferred, as the aim is to eliminate completely the narrowing, given that relatively mild stenosis can have a significant detrimental hemodynamic effect in patients with functionally univentricular circulation. The procedure is highly successful. In patients who fail after Fontan procedure, creation of a fenestration is often performed, with variable technique depending on the underlying anatomic substrate. To increase chances of patency of the fenestration, implantation of a stent is often required, particularly in the setting of an extracardiac conduit. For those patients with cyanosis and favorable Fontan hemodynamics, closure of the fenestration is performed using atrial septal occluder devices with high success rate. Coils compatible with magnetic resonance imaging are used widely to treat collateral vessels, although on occasion other specific embolization tools are required, such as particles or vascular plugs. Postoperative arch obstruction is successfully managed with angioplasty at a younger age, while implantation of a stent in the aorta is reserved for older patients. Specifics of these interventional procedures as applied to the population of patients with functionally univentricular hearts are described in this manuscript.

Oral budesonide as a therapy for protein-losing enteropathy in patients having undergone Fontan palliation

BACKGROUND

  Protein-losing enteropathy is associated with Fontan palliation for single-ventricle physiology and has been difficult to treat. Limited data suggest the successful use of oral budesonide (Entocort, AstraZeneca) as a palliative measure.

METHODS

  We examine our single-institution retrospective experience in eight patients who were treated with this therapy.

RESULTS

  Median pretherapy albumin level was 1.7 g/dL (range 1.0-2.7 g/dL), 3 months after therapy was 3.1 g/dL (range 2-4.8 g/dL), and by the end of the first year was 3.4 g/dL (range 2.1-5.3 g/dL). All patients had at least a transient improvement, and at latest follow-up (median 29 months, range 3-51 months) five patients remain on therapy. Five of eight patients had required pretherapy albumin transfusions; one patient required albumin infusions after therapy. Four patients had side effects associated with the medication.

CONCLUSIONS

  Oral budesonide is an additional therapy that has the potential to improve symptoms and delay need for heart transplantation in this patient population.

Oral budesonide treatment for protein-losing enteropathy in Fontan-palliated patients

Protein-losing enteropathy (PLE) is a rare complication of Fontan palliation associated with significant morbidity and mortality. It is characterized by the loss of serum proteins into the intestinal lumen, and its pathophysiology likely involves enteral inflammation. Budesonide, an oral steroid, is an attractive treatment option because of its potent enteral activity and minimal systemic side effects. A single-center, retrospective review of Fontan-palliated PLE patients treated with oral budesonide for 6 months or longer was performed. The patient characteristics reviewed were demographics, anatomic diagnosis, budesonide treatment (dose and duration), other medications and therapeutic interventions, hospitalizations, serum albumin levels, medical complications, and patient status at the time of follow-up assessment. The study enrolled 10 patients representing 228 patient-months of on-therapy follow-up evaluation. Serum albumin levels increased after initiation of budesonide for 90% of the patients, and clinical evidence of fluid overload improved for 60% of them. Symptomatic improvement was reported in 80% of the cases. During the treatment period, 50% of the patients met the primary end point of death or cardiac transplantation. In this series of PLE patients, oral budesonide therapy was associated with significant symptomatic improvement and sustained increases in serum albumin. However, budesonide therapy may not alter the long-term outcome for patients with advanced PLE.

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

Protein-losing enteropathy is a relatively uncommon complication of Fontan procedures for palliation of complex congenital cardiac disease. However, the relative infrequency of protein-losing enteropathy belies the tremendous medical, psychosocial and financial burdens it places upon afflicted patients, their families and the healthcare system that supports them. Unfortunately, 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. The most comprehensive analyses of protein-losing enteropathy in this patient population are now over a decade old, and re-evaluation of the prevalence and progress in treatment of this disease is needed. This report describes a single institution experience with the evaluation, management, and treatment of protein-losing enteropathy in patients with congenital cardiac disease in the current era, follows with a comprehensive review of protein-losing enteropathy, focused upon what is known and not known about the pathophysiology of protein-losing enteropathy in this patient population, and concludes with suggestions for prevention and treatment.

The use of oral budesonide in adolescents and adults with protein-losing enteropathy after the Fontan operation

BACKGROUND

Approximately 5% to 15% of patients develop protein-losing enteropathy (PLE) after the Fontan operation. Oral controlled release (CR) budesonide has been used as a treatment strategy, but its use in the older Fontan population has not been described.

METHODS

Seven patients with refractory PLE after the Fontan operation were started on oral CR-budesonide at 9 mg. After 3 to 9 months, the dose was weaned to 3 mg. Response to treatment was assessed by clinical evaluation, serum albumin levels, and fecal α-1 antitrypsin clearance when available.

RESULTS

Median age at last evaluation was 20 years (range, 16 to 32 years). Six patients had increases in serum albumin levels but only 4 patients had symptomatic improvement. Systemic side effects included: cushingoid features (5), adrenal insufficiency (4), and new-onset type 2 diabetes mellitus (2). One patient had improvement in cushingoid features after weaning CR-budesonide to 3 mg. Older patients (ages 27 to 32 years) had the worst side effect profiles and were the most refractory to treatment. These patients had sonographic evidence of hepatic cirrhosis but normal serum liver function tests. Two deaths occurred: 1 from sepsis 1 month after CR-budesonide initiation and 1 from respiratory arrest 5 months after CR-budesonide discontinuation.

CONCLUSIONS

CR-budesonide can be used to treat PLE in certain patients, but careful assessment of hepatic function should be performed before initiation of therapy as systemic side effects can limit treatment. Normal serum liver function tests do not preclude hepatic dysfunction in the Fontan patient, and it is important to perform radiographic assessments as well.

The Fontan procedure: evolution in technique; attendant imperfections and transplantation for "failure"

Application of the Fontan procedure has allowed the survival of many patients with univentricular cardiac lesions into mid adulthood. Despite its ingenious design, implementation, and thoughtful modifications, its attendant hemodynamic perturbations persist; central venous hypertension and reduced cardiac output. These aberrations in physiology have led to pernicious changes in organ function. A more thorough understanding of these derangements and attempts at Fontan revision have temporized, yet the morbidity and patient attrition persists. Mechanical assistance to normalize the circulation is being investigated and holds some promise. At present, cardiac transplantation remains the last stage of palliation for many.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.