Anomalies of the tricuspid valve, including pouches, resembling aneurysms of the membranous ventricular septum

Abstract The pathologic features of anomalies of the tricuspid valve superficially resembling congenital aneurysms of the membranous septum are described in 5 cases. In each of 3 cases a ventricular septal defect was associated with a pouch in a leaflet of the tricuspid valve. In the fourth and fifth cases, anomalous attachment of the septal leaflet of the tricuspid valve to the edge of a ventricular septal defect yielded a pouch-like structure. Left ventricular-right atrial communication was a common finding, a feature that may also be seen in cases of true aneurysms of the membranous septum. In 1 case a pouch of the anterior tricuspid leaflet had caused obstruction of the right ventricular infundibulum.