Pulmonary Atresia and Ventricular Septal Defect: Definitions, Nomenclature, and Classification

This manuscript will provide information about pulmonary atresia + ventricular septal defect, including definitions, nomenclature, and classification, based on the 2021 <i>International Paediatric and Congenital Cardiac Code</i> (IPCCC) and the <i>Eleventh Revision of the International Classification of Diseases</i> (<i>ICD-11</i>). The 2021 IPCCC and <i>ICD-11</i> provide the following definition for Tetralogy of Fallot with pulmonary atresia: Tetralogy of Fallot with pulmonary atresia is defined as "A congenital cardiovascular malformation that is a variant of tetralogy of Fallot in which there is no direct communication between the right ventricle and the pulmonary arterial tree." The 2021 IPCCC and <i>ICD-11</i> provide the following definition for Tetralogy of Fallot with pulmonary atresia and systemic-to-pulmonary collateral arteries: Tetralogy of Fallot with pulmonary atresia and systemic-to-pulmonary collateral arteries is defined as "A congenital cardiovascular malformation that is a variant of tetralogy of Fallot in which there is no direct communication between the right ventricle and the pulmonary arterial tree and there are collateral blood vessels between the systemic and pulmonary arteries." "Tetralogy of Fallot + pulmonary atresia" is a specific type of "pulmonary atresia + ventricular septal defect" where the intracardiac malformation is more accurately defined. The presence or absence of major aortopulmonary collateral arteries (MAPCA[s]) does not change these definitions. Therefore, "tetralogy of Fallot + pulmonary atresia + MAPCA(s)" is a specific type of "pulmonary atresia + ventricular septal defect + MAPCA(s)" where the intracardiac malformation is more accurately defined. In the universe of patients with pulmonary atresia + ventricular septal defect, the anatomy and morphology of the pulmonary circulation to a large extent determines the surgical approach and overall outcome, with the intracardiac anatomy playing a secondary role. Based on the characterization of the pulmonary circulation, patients with pulmonary atresia + ventricular septal defect can be classified into three groups: In type A, pulmonary blood flow is provided by native pulmonary arteries (NPAs). In type B, pulmonary blood flow is provided by both NPA and MAPCA(s). In type C, pulmonary blood flow is provided only by MAPCA(s).