Roentgenography of patent ductus arteriosus

Abstract

Conventional roentgenography of the chest in many instances may confirm the diagnosis of patent ductus arteriosus. Right heart catheterization often establishes the diagnosis but cannot exclude with certainty an aorticopulmonary window, transposition of the great vessels and truncus arteriosus. Entry of the catheter into the patent ductus and aorta during right heart catheterization is revealing and particularly valuable if a permanent record, either with film or cineangiocardiography, is made. Intravenous or selective angiocardiography provides indirect evidence of a patent ductus arteriosus, i.e., blanching of the pulmonary artery at the time of right heart filling, followed by reopacification of the pulmonary arteries when the left heart structures are filled. If there is pulmonary hypertension and reversal of blood flow through the patent ductus, intravenous angiocardiography furnishes direct evidence of this by visualizing the ductus filling from the pulmonary artery and opacifying the descending aorta. Also, when there is a left-sided patent ductus, a right-sided aorta and atresia of the pulmonary artery, direct opacification of the ductus can be achieved by intravenous angiocardiography. Countercurrent aortography by injection of a small quantity of dilute contrast material into the left brachial artery of infants and small children usually via arteriotomy or needle puncture is often sufficient for diagnosis of patency of the ductus arteriosus. Such a study may also reveal coarctation of the aorta. An aorticopulmonary window, a coronary arterio-venous fistula and ruptured aortic sinuses may also be excluded if the ascending aorta and aortic sinuses are visualized. Failure to visualize the entire aorta may make necessary a right brachial arterial injection of dilute contrast media in order to study the structures at the aortic root. Percutaneous retrograde femoral or brachial catheterization with the selective visualization of a patent ductus followed by exploration of the rest of the aorta by the injection of a small quantity of dilute contrast material is the most reliable method for demonstrating patent ductus arteriosus and excluding other disease of the aortic root such as an aorticopulmonary window, ruptured aortic sinus, coronary arteriovenous fistula, aortic insufficiency and truncus arteriosus. Advances in roentgen technics [image amplification roentgenoscopy, multiple serial roentgen studies (in biplane) and cineangiocardiography], low reactive contrast agents, improved percutaneous retrograde catheter technics, and radiopaque (easily shaped) catheters allow selective exploration and visualization of the infundibulum and ascending portions of the aorta and have resulted in a very high degree of success in diagnosis and differential diagnosis of patent ductus arteriosus.