Early and Mid-Term Angiographic Assessment of Internal Thoracic Artery Grafts Anastomosed to Non-Stenotic Left Anterior Descending Coronary Arteries

Abstract

Background: Mild to moderately stenotic coronary arteries present a major problem as the progression of atherosclerosis is unpredictable. In addition, residual flow from the native coronary artery has been proposed as a mechanism that reduces blood flow in bypass grafts resulting in failure of the graft. Patients and Methods: The internal thoracic artery was anastomosed to the left anterior descending coronary artery for different reasons in three patients who underwent coronary arterial surgery, with stenosis of this coronary artery changing from none to 30 %. Patients were monitored by coronary arteriography at different intervals postoperatively (from 6 days to 25 months) to assess the patency of the internal thoracic artery graft. Results: Internal thoracic artery grafts were found to be patent in all coronary arteriographies during the follow-up period. Twenty-five months after surgery, one patient showed total occlusion of the native coronary artery which was previously normal. Conclusions: Competitive flow from the native coronary artery does not seem to influence internal thoracic artery patency when grafted to a normal or mildly stenotic left anterior descending coronary artery. This information could be of help in some patients undergoing coronary artery bypass surgery with non-critical stenosis of this coronary artery. If the non-critical lesion is located proximally and if the patient has additional risk factors for coronary artery disease progression, prophylactic grafting of the left anterior descending coronary artery to the internal thoracic artery should be considered to prevent any future cardiac event, keeping in mind that this procedure may accelerate the progression of the native coronary artery disease.

Key words

Internal thoracic artery - left anterior descending coronary artery - flow competition - mild stenosis

References

• 1 Waters D, Craven T E, Lesperance J. Prognostic significance of progression of atherosclerosis.  Circulation. 1993;  87 1067-1075
• 2 Lust R M, Zeri R S, Spence P A, Hopson S B, Sun Y S, Otaki M, Jolly S R, Mehta P M, Chitwood R. Effect of chronic native flow competition on internal thoracic artery grafts.  Ann Thorac Surg. 1994;  57 45-50
• 3 Cosgrove D M, Loop F D, Saunders C L, Lytle B W, Kramer J R. Should coronary arteries with less than fifty percent stenosis be bypassed?.  J Thorac Cardiovasc Surg. 1981;  82 520-530
• 4 Spence P A, Lust R M, Zeri R S, Jolly S R, Mehta P M, Otaki M, Sun Y S, Chitwood W R. Competitive flow from a fully patent coronary artery does not limit acute mammary graft flow.  Ann Thorac Surg. 1992;  54 21-26
• 5 Kawasuji M, Sakakibara N, Takemura H, Tedoriya T, Ushijima T, Watanabe Y. Is internal thoracic artery grafting suitable for a moderately stenotic coronary artery?.  J Thorac Cardiovasc Surg. 1996;  112 253-259
• 6 Bruschke A VG, Kramer J R, Bal E T, Ul Haque, Detrano R C, Goormastic M. The dynamics of progression of coronary atherosclerosis studied in 168 medically treated patients who underwent coronary arteriography three times.  Am Heart J. 1989;  117 296-305
• 7 Hackett D, Davies G, Maseri A. Pre-existing coronary stenoses in patients with first myocardial infarction are necessarily severe.  Eur Heart J. 1988;  9 1317-1323
• 8 Little W C, Constantinescu M, Applegate R J, Kutcher M A, Burrows M T, Kahl F R, Santamore W P. Can coronary angiography predict the site of a subsequent myocardial infarction in patients with mild-to-moderate coronary artery disease?.  Circulation. 1988;  78 1157-1166
• 9 Loop F D, Cosgrove D M, Kramer J R, Lytle B W, Taylor P C, Golding L R, Groves L K. Late clinical and arteriographic results in 500 coronary arterial reoperations.  J Thorac Cardiovasc Surg. 1981;  81 675-685
• 10 Dincer B, Barner H B. The “occluded” internal mammary artery graft: restoration of patency after apparent occlusion associated with progression of coronary artery disease.  J Thorac Cardiovasc Surg. 1983;  85 318-320
• 11 Seki T, Kitamura S, Kawachi K, Morita R, Kawata T, Mizuguchi K, Hasegawa J, Kameda Y, Yoshida Y. A quantitative study of postoperative luminal narrowing of the internal thoracic artery graft in coronary artery bypass surgery.  J Thorac Cardiovasc Surg. 1992;  104 1532-1538
• 12 Kitamura S, Kawachi K, Seki T, Sawabata N, Morita R, Kawata T. Angiographic demonstration of no-flow anatomical patency of internal thoracic-coronary artery bypass grafts.  Ann Thorac Surg. 1992;  53 156-159
• 13 Shimizu T, Hirayama T, Suesada H, Ikeda K, Ito S, Ishimaru S. Effect of flow competition on internal thoracic artery graft: postoperative velocimetric and angiographic study.  J Thorac Cardiovasc Surg. 2000;  120 459-465
• 14 Urschel H C, Razzuk M A, Miller E, Chung S Y. Operative transluminal balloon angioplasty. Adjunct to coronary bypass for extended myocardial revascularization of more than 3000 lesions in 1000 patients.  J Thorac Cardiovasc Surg. 1990;  99 581-589
• 15 Barron D J, Livesey S A. Patency of an internal thoracic artery graft despite maximal competitive flow.  Ann Thorac Surg. 1995;  59 1556-1557