Lymphatic Morphology of Fontan Patients

The Fontan procedure has revolutionized the treatment of patients born with a congenital univentricular heart defect. However, over time, it is associated with severe lymphatic complications such as plastic bronchitis, protein-losing enteropathy (PLE) and peripheral edema. It has been proposed that these complications arise due to a elevated central venous pressure of the changed circulation. The hypothesis of the study is that patients with a univentricular circulation have a changed morphology which may be associated with both the degree of lymphatic complications and their physical capacity. The morphology will be described using T2-weighted non-contrast MRI. The main lymphatic vessel, the thoracic duct, will be rendered and measured using 3D software, and the lymphatic changes characterized by Dr. Yoav Dori (CHOP, Pennsylvania, USA), using a newly published grading system. The above will be correlated with the amount of complications experienced by the patients, and their physical capacity measured by both IPAQ questionaire and CPX test. The study population consists of patients with a Fontan circulation operated at InCor Heart Institute, São Paulo, Brasil and Hospital das Clínicas, Ribeirão Preto, Brasil. Exclusion criteria were mental illness, genetic syndromes and age \<18 years. The patient group will be compared with age, gender and weight matched healthy controls.