Screening for subclinical subclavian artery stenosis before coronary artery bypass grafting: Should we do it?

Atherosclerotic subclavian artery disease is detected in about 5% of patients referred for coronary artery bypass (CABG) surgery. The internal mammary artery, a branch of the subclavian artery, is the most frequently utilized graft to restore coronary circulation because of its longevity. Stenosis or occlusion of the subclavian artery can cause retrograde blood flow in the ipsilateral internal mammary artery, known as "steal," compromising coronary circulation supplied by the graft. Steal may be asymptomatic or may result in symptoms of myocardial ischemia. Symptomatic subclavian artery stenosis post bypass is referred to as coronary subclavian steal syndrome post-CABG. The incidence is not well defined, and the benefits of screening patients referred for CABG are not known. Despite the various modalities available to detect subclavian artery stenosis, current guidelines fail to provide guidance about screening high-risk patients for this entity. Detection of subclavian artery disease prior to CABG can reduce complications posed by post-mammary artery graft cardiac ischemia. This review discusses the utility of preoperative subclavian artery screening prior to CABG.