Coarctation of the aorta complicated by patency of the ductus arteriosus; physiologic considerations in the classification of coarctation of the aorta.

The study of the anatomic and hemodynamic relationships in a case of coaretation of the aorta complicated by patency of the ductus arteriosus and pulmonary hypertension indicated the necessity for a physiologic approach to the classification of coarctation of the aorta. The origin of existing classifications has been briefly traced and basic anatomic and physiologic considerations in this malformation have been reviewed. A classification is presented which takes into account the state of the ductus arteriosus, its relationship to the coareted segment and the influence of the collateral circulation. The microscopic appearance of the pulmonary vessels is included.