Incidence of lateral costal artery, a branch of left internal mammary artery in coronary artery bypass grafting

In CABG, during lima harvesting, usuall branches of lima are ligated, but almost always the left thoracic cavity for an aberrant lima side- branch, which is usualy named Lateral costal artery, is not explored. In case, this unusual branch exists and is not excluded, it could cause the Coronary Steal Phenomenon. The aim of this study was evaluating the incidence of LCA in Iranian patients. In the cross sectional study, 909 coronary patients operated in cardiac surgery department of Ghaem hospital in Mashhad from 2004 to 2009. All lima patients were harvested and the left pleura was opened widely. the presence of LCA was cotrolled and also its traversed length was recorded, based on the number of intercostal space, then it was ligated and excluded We analyzed the length of that branch between males and females by X2 test at the significant level (P ≤ 0.05). Fiftyfive out of 909 patients had Lateral Costal Artery (6%). It extended to the second intercostal in 18 patients (1.6%) (12 males-6 females); fourth space in 26 patients (2.8%) (18 males-8 females); sixth space in 11 patients (1.2%) (8 males-3 females). This variation in 37 patients (4%) (4th, 6th costal space) was long and large enough and there was no meaningful difference in length between men and women by χ2 test (P = 0.7). During CABG, after the pleura is widely opened, the exploration of left thoracic cavity is prudent to exclude the presence of this variation. This will avoid the coronary steal phenomenon, which is a controvertial issue in future. The incidence of LCA was 6% in Iranian patients.