Three-dimensional computed tomographic angiography as preoperative evaluation of a patent internal thoracic artery graft

Abstract

damage to the patent LITA during sternotomy and dissection of cardiac adhesions. In the present case, 3-dimensional (3D) computed tomographic (CT) angiography was useful for recognizing the position of the patent LITA and avoiding vessel injury. Clinical summary. A 75-year-old man had recurrent angina pectoris 8 years after primary CABG. Current coronary angiography revealed 90% stenosis of the left main coronary artery, the left circumflex artery, and the right coronary artery; an obstruction of the saphenous vein graft; and a patency of the LITA graft. Because the recurrent angina was refractory to medication and catheter interventions, reoperative CABG was proposed for the right coronary artery and the left circumflex artery by using a saphenous vein graft and a right internal thoracic artery graft. The location of the patent LITA was preoperatively assessed to avoid injuring it during the operative procedure. Multislice helical CT scanning (Aquillion; Toshiba, Tokyo, Japan) was performed with a scanning time of 0.5 s/r and a slice thickness/pitch of 1 mm/6. The 3D reconstruction method used was multiplanar reconstruction with a reconstruction pitch of 0.5 mm. The 3D image demonstrates the distance between the LITA and the sternum, the midline, the aorta, and the pulmonary artery (Fig 1). On the basis of the 3D image, the sternum was dissected in the midline with an oscillator saw, the LITA was dissected from the sternum, and comRecent reports predict a further increase in the number of patients requiring reoperative coronary artery bypass grafting (CABG).1 Although reoperative CABG for patients with a patent left internal thoracic artery (LITA) graft is less common, injury of the patent LITA during sternotomy causes sudden and severe myocardial ischemia, sometimes leading to lethal myocardial infarction. Kaul and associates2 reported that 4 (7.6%) of 52 patent LITAs were injured and required intravascular shunts to restore distal coronary circulation. Verkkala and colleagues3 also reported that 6 (17.6%) of 34 patent LITAs were injured, and they concluded that a wellfunctioning LITA might be a relative contraindication for reoperative CABG. Thus, most surgeons try to avoid any THREE-DIMENSIONAL COMPUTED TOMOGRAPHIC ANGIOGRAPHY AS PREOPERATIVE EVALUATION OF A PATENT INTERNAL THORACIC ARTERY GRAFT