Failed depiction of patent bypass graft due to presence of large lateral costal artery.

We report a rare case of failed depiction of a patent right internal thoracic artery (RITA) to left anterior descending artery (LAD) bypass on 64-slice multidetector row computed tomographic (MDCT) angiography due to the presence of a large lateral costal artery. A 66-year-old male with acute coronary syndrome due to triple vessel disease underwent urgent coronary artery bypass grafting, in which bilateral ITA and saphenous vein grafts were used. Postoperative MDCT angiography showed an occluded RITA-LAD bypass, which was eventually shown to be patent by angiography. Angiography also revealed a large lateral costal artery that was considered to affect the flow to the LAD. Thus, coil embolization of the branch was attempted. However, it was abandoned because the patient suffered from severe back and intercostal pain during balloon occlusion of the lateral costal artery. Postoperative MDCT angiography is not always accurate for the assessment of graft patency in patients with large ITA side branches. In addition, embolization is not always possible because occlusion of this large branch may cause severe pain when its size becomes quite large.