Ultrasound Evaluation of Subclavian Artery and Internal Thoracic Artery Before Coronary Artery Bypass Grafting as Part of Preoperative Vascular Assessment

Abstract

Noninvasive diagnostic imaging of subclavian artery (SCA) and internal thoracic artery (ITA) is crucial to the patients planning to use ITA for coronary artery bypass grafting (CABG). The guidelines have not yet provided guidance on screening high-risk groups. The present study aimed to evaluate the contribution of ultrasonography in the assessment of SCA and ITA, especially for the patients referred for CABG who planned to use ITA graft. Patients diagnosed with multivessel coronary heart disease were enrolled and some of them planned CABG. Bilateral SCAs and ITAs were routinely evaluated by color Doppler ultrasound (CDUS) before operation. The luminal diameter and the peak systolic velocity of the proximal and distal parts of SCA and ITA were measured. Depending on the Doppler waveform, the lumen narrowing rate was calculated. The final analysis was carried out in 572 patients. Thirty-five patients had moderate (50%-69%), severe (70%-99%) stenosis or occlusion in the SCA (left-sided in 21 and right-sided in 14). One patient had severe proximal stenosis in left ITA and one patient had no flow in left ITA due to the occlusion in left SCA. One patient had anatomic variation of isolated right aortic arch with aberrant left SCA. All of those cases were confirmed with multidetector computed tomography angiography. CDUS could be used for the evaluation of SCA and ITA before CABG as part of presurgical vascular assessment and provide an import basis for the imaging diagnosis and surgical plan.