Factors influencing variation in the diameter of anterior and posterior intercostal arteries

Abstract

The anterior and posterior intercostal arteries are the principal blood supply to the intercostal spaces and ribs. Each intercostal space is supplied by an anastomosing anterior and posterior intercostal artery, as well as their collateral branches. These anastomoses can provide important alternate routes of blood flow for individuals with clinical conditions such as a coarctation of the aorta, or when an internal thoracic artery is harvested for a coronary bypass graft. The clinical significance of these vessels raises several questions regarding their relationships, such as: Is there a correlation between the relative diameters of the ipsilateral paired intercostal arteries under normal conditions?; Is there a pattern to the changes in vessel diameter in different intercostal spaces, particularly comparing superior with inferior spaces?; Do the left posterior intercostal arteries increase in diameter when the left internal thoracic artery has been harvested for a bypass graft? In this study, cadaveric paired samples of the 2nd through 6th anterior and posterior intercostal arteries were collected and their diameters measured. Initial data analysis suggests that both anterior and posterior intercostal arteries increase in diameter as one progresses from the 2nd to the 6th intercostal spaces. Analysis of these vessels will be correlated with specific clinical conditions noted in each cadaver.