The role of coronary artery abnormalities in the prognosis of truncus arteriosus.

A high incidence of coronary ostial and arterial abnormalities was found in a study of 30 pathologic specimens of classic truncus arteriosus at Children's Hospital of Pittsburgh. The following were of special note: (1) left coronary ostium in a posterior and high position; (2) close relation of the left coronary ostium to the pulmonary artery segment in three-leaflet truncal valves; (3) stenosis of the coronary ostium caused by small size, slitlike shape, or the location of the ostium above or in a commissure; (4) the acute angle takeoff of the coronary artery; (5) the position of the left anterior descending artery as it courses posteriorly and close to the truncal wall, and then to the left of the interventricular septum; (6) the size and course of the conal and diagonal arteries from the right coronary artery across the right ventricular outflow area; (7) other coronary abnormalities, including a single coronary artery or ostium with branches crossing the right ventricle below the truncus, the circumflex arising from the right coronary artery and coursing behind the truncus, and the right coronary artery originating from the left anterior descending artery and vice versa. Eight heart specimens with conduit repair were reviewed, and all had injury to coronary arteries, possibly responsible for or contributing to the deaths of six of the eight patients. Coronary abnormalities, often several occurring in combination, may contribute to high operative mortality rate and may be a cause of late sudden death in truncus arteriosus. Surgical procedures should be planned with a view to protecting coronary arteries in the region of the right ventricular outflow tract below the truncus. Coronary artery obstruction (ostial or luminal) can occur and may need to be addressed as a separate issue during surgical procedures.