Lymphatic interventions in congenital heart disease

Congenital heart disease affects 1/100 live births and is one of the most common congenital abnormalities. The relationship between congenital heart disease and lymphatic abnormalities and/or dysfunction is well documented and can be grossly divided into syndromic and non-syndromic etiologies. In patients with genetic syndromes (as examples listed above), there are known primary abnormal lymphatic development leading to a large pleiotropic manifestation of lymphatic dysfunction. Non-syndromic patients, or those without clear genetic etiologies for their lymphatic dysfunction, are often thought to be secondary to physiologic abnormalities as sequelae of congenital heart disease and palliative surgeries. Patients with congenital heart disease and lymphatic dysfunction have a wide variety of clinical manifestations for which there were not many therapeutic interventions available. The development of new imaging techniques allows us to understand better the pathophysiology of these problems and to develop different percutaneous interventions aiming to restore normal lymphatic function.

Pulmonary Complications in Patients With Fontan Circulation: JACC Review Topic of the Week

The Fontan operation has resulted in significant improvement in survival of patients with single ventricle physiology. As a result, there is a growing population of individuals with Fontan physiology reaching adolescence and adulthood. Despite the improved survival, there are long-term morbidities associated with the Fontan operation. Pulmonary complications are common and may contribute to both circulatory and pulmonary insufficiency, leading ultimately to Fontan failure. These complications include restrictive lung disease, sleep abnormalities, plastic bronchitis, and cyanosis. Cyanosis post-Fontan procedure can be attributed to multiple causes including systemic to pulmonary venous collateral channels and pulmonary arteriovenous malformations. This review presents the unique cardiopulmonary interactions in the Fontan circulation. Understanding the cardiopulmonary interactions along with improved recognition and treatment of pulmonary abnormalities may improve the long-term outcomes in this growing patient population. Interventions focused on improving pulmonary function including inspiratory muscle training and endurance training have shown a promising effect post-Fontan procedure.

Current diagnostic and therapeutic strategies for the management of lymphatic insufficiency in patients with hypoplastic left heart syndrome

Children with hypoplastic left heart syndrome share unique hemodynamic features that alter lymphatic integrity at all stages of palliation. Lymphatic congestion is almost universal in this patient group to some extent. It may lead to reversal of lymphatic flow, the development of abnormal lymphatic channels and ultimately decompression and loss of protein rich lymphatic fluid into extra lymphatic compartments in prone individuals. Some of the most devastating complications that are associated with single ventricle physiology, notably plastic bronchitis and protein losing enteropathy, have now been proven to be lymphatic in origin. Based on the new pathophysiologic concept new diagnostic and therapeutic strategies have recently been developed. Dynamic contrast magnetic resonance lymphangiography is now mainstay in diagnosis of lymphatic insufficiency and allows a thorough assessment of anatomy and function of the main lymphatic compartments through intranodal, intrahepatic and intramesenteric lymphatic imaging. Contrast enhanced ultrasound can evaluate thoracic duct patency and conventional fluoroscopic lymphangiography has been refined for evaluation of patients where magnetic resonance imaging cannot be performed. Novel lymphatic interventional techniques, such as thoracic duct embolization, selective lymphatic duct embolization and liver lymphatic embolization allow to seal abnormal lymphatic networks minimally invasive and have shown to resolve symptoms. Innominate vein turn-down procedures, whether surgical or interventional, have been designed to reduce lymphatic afterload and increase systemic preload effectively in the failing Fontan circulation. Outflow obstruction can now be managed with new microsurgical techniques that create lympho-venous anastomosis. Short term results for all of these new approaches are overall promising but evidence is sparse and long-term outcome still has to be defined. This review article aims to summarize current concepts of lymphatic flow disorders in single ventricle patients, discuss new emerging diagnostic and therapeutic strategies and point out lacks in evidence and needs for further research on this rapidly growing topic.

Transconduit approach for pulmonary vein stenting in an extracardiac Fontan and plastic bronchitis case

Plastic bronchitis (PB) is a rare but severe complication in patients following the Fontan operation, the final palliative procedure for single ventricle heart disease. PB is characterised by the formation of rubbery casts of the tracheobronchial tree that may cause cough, wheezing, dyspnoea and hypoxia. Progressive airway obstruction may lead to asphyxia and death, and the overall mortality rate is 15.2%. Most patients receive a combination therapy from three different treatment strategies, that is, therapy for relief of airway obstruction, anti-inflammatory treatment and treatment to improve haemodynamics of the Fontan physiology. Therapy improving haemodynamics consists of optimising the Fontan circulation or cardiac function, antiarrhythmic therapy, inhibition of lymph leakage/production, decompression of the Fontan circulation and heart transplantation.We present the case of a child with PB after extracardiac Fontan operation, who was refractory to balloon angioplasty and surgical release for pulmonary vein (PV) stenosis. We decided to perform stent implantation for the right PVs through transconduit puncture instead of fenestration because the position of fenestration was too high to access the PVs. After PV stenting via the transconduit approach, she experienced improvement in cough, wheezing and breathlessness, and a significant reduction in airway cast formation.

Fontan circulation has improved life expectancy for infants born with complex heart disease over the last 50 years but has also resulted in significant morbidity

The prognosis for infants born with complex heart disease improved dramatically with the introduction of the Fontan circulation 50 years ago. With today's carefully designed and staged operations to a Fontan circulation, life expectancy has increased and most children will survive into adult life. The Fontan circulation entails an unphysiological circulation with high risk for multiple organ system dysfunction. Neurodevelopmental disabilities with adverse psychosocial effects are prevalent. The Fontan circulation may eventually fail and necessitate heart transplantation. CONCLUSION: Fifty years development of the Fontan circulation to today's staged surgical procedures has improved survival but also revealed the burden of a high morbidity for a growing number of patients.