Doppler Features of Occlusion of the Internal Thoracic Artery due to Preoperative Branch Embolization

Abstract

he left internal thoracic artery (LITA) procedure is now generally accepted for grafts, having longterm patency in coronary artery bypass grafting (CABG). In particular, it is considered the most suitable graft for the left anterior descending coronary artery (LAD). 1 However, postoperative coronary steal due to unligated side branches of the LITA graft has been reported. [2][3][4][5] We performed selective transcatheter embolization of a large branch of the LITA preoperatively, and detected postembolization LITA occlusion based on changes of the Doppler wave form. In this paper, we discuss the validity of LITA branch embolization, as well as reviewing the relevant literature. Case ReportA 61-year-old male was referred to the surgical ward because of a diagnosis that surgery for angina pectoris was indicated. He had an old myocardial infarction and suffered from hypertension, hyperlipidemia, and diabetes mellitus as coronary risk factors. Preoperative coronary angiography (CAG) revealed significant stenosis of the LAD and segment 2 of the right coronary artery (RCA). On the left ventriculogram, global wall motion was severely hypokinetic and the ejection fraction (EF) was 26%. On preoperative angiography of the LITA, a large first intercostal branch was found at the proximal portion, which had a diameter bigger than that of the LITA itself. We considered that the Japanese Circulation Journal Vol.63, October 1999 patient's hemodynamics would deteriorate if the coronary steal phenomenon occurred postoperatively, because his cardiac function was already quite poor. Therefore, selective arterial embolization of the branch of the LITA with a micro coil and cyanoacrylate was carried out preoperatively (Fig 1). At 2 days after embolization, transthoracic pulsed Doppler echocardiography was performed using an Acuson Sequoia C256 machine equipped with a 6 MHz transducer. The Doppler wave form at the 2nd intercostal space of the grafted LITA, obtained by the transthoracic approach, showed a biphasic pattern with a higher systolic and a lower diastolic component. The diameter of the LITA was larger than before the procedure (Fig 2) and the Doppler peak flow velocity was increased above that before embolization.Jpn Circ J 1999; 63: 819 -821 (Received May 17, 1999; revised manuscript received June 28, 1999; accepted July 19, 1999) The Second Department of Surgery, Nihon University, School of Medicine, Tokyo, Japan Mailing address: Mitsumasa Hata, MD, 30-1 Ooyaguchi Kamimashi, Itabashi-ku, Tokyo 173-8610, Japan. T Doppler Features of Occlusion of the Internal Thoracic Artery due to Preoperative Branch EmbolizationMitsumasa Hata, MD; Motomi Shiono, MD; Yukihiko Orime, MD; Tomonori Yamamoto, MD; Shinya Yagi, MD; Shunichi Kimura, MD; Haruhiko Okumura, MD; Satoshi Kashiwazaki, MD; Shinsuke Choh, MD; Tetsuya Niino, MD; Hideo Kohno, MD; Nanao Negishi, MD; Yukiyasu Sezai, MD A 61-year-old male was referred to the surgical ward by cardiologists because of a diagnosis of unstable angina with 3-vessel disease. On preoperative lef...