Extracardiac coronary arterial anastomoses.

The collateral arterial circulation of the heart has been extensively studied. However, less attention has been paid to extracardiac anastomoses, which may also be of significant clinical importance. In this review, we will describe the most common types of these anastomoses, which include bronchial to coronary arteries and internal thoracic to coronary arteries. In a much lesser degree, anastomoses between coronary arteries and pericardiacophrenic branches of the internal thoracic arteries, anterior mediastinal arteries, intercostal arteries, and esophageal arterial branches have also been described. Knowledge of the likely morphology and function of the anastomoses, therefore, could prove helpful in the clinical evaluation of patients with myocardial ischemia, particularly when selecting candidates for myocardial revascularization.