Tricuspid atresia (2% of heart defects) is the absence of the valve at the opening of the right ventricle. As such it can be classified with 'single ventricle' defects, since repair of both ventricles is not possible, all the more so that the right ventricle is usually hypoplastic. Depending on the size of interventricular communication and the position of the vessels (correctly positioned or transposed), pulmonary stenosis can be observed (80% of cases), as well as pulmonary atresia (10% of cases) or pulmonary arterial hypertension, which is often combined with subaortic stenosis. Cyanosis is systematic, and the electrocardiogram is characteristic (QRS axis - 30° with no straight vector in the precordial position). The echography confirms the diagnosis and establishes hemodynamics upon which treatment is based. In forms with pulmonary atresia or very tight stenosis, systemic-pulmonary anastomosis is indicated in the neonatal period, followed by partial cavopulmonary derivation if desired (after the age of 6 months), possibly completed with total cavopulmonary derivation (after the age of 2 years). In forms with pulmonary arterial hypertension, a ring is placed first, the rest of the surgical management being similar. Long-term outcome is uncertain and often poor, as in other forms of single ventricle malformations.
Last update: November 2004