Left Carotid-to-Subclavian Artery Bypass Grafting for Recurrent Angina Caused by Coronary-Subclavian Steal Syndrome
A 60-year-old man presented to the hospital with exertional chest pain. Eleven years earlier he had undergone off-pump coronary artery bypass grafting (CABG) using a bilateral internal thoracic artery (ITA) Y-composite graft based on the in situ left ITA. At that time there were no significant stenoses at both the right and left subclavian arteries. The left anterior descending artery and the first diagonal branch were sequentially anastomosed using the left ITA, and the posterolateral branch was revascularized using the right ITA.\nPhysical examination revealed a cold and pale left arm and a weaker left radial pulse than the right. The blood pressure in the right and left arms was 144/80 mmHg and 126/70 mmHg, respectively. Native coronary angiography showed retrograde visualization of the distal grafts through the patent distal anastomoses. Arch aortography demonstrated near-total occlusion of the left subclavian artery (LSCA) at the level of the ostium. Computed tomographic angiography also revealed near-total occlusion of the LSCA at the level of the ostium (). Myocardial single photon emission computed tomography (SPECT) demonstrated a reversible perfusion decrease in the apical to mid-anterior and mid-anterolateral walls, and persistent perfusion defects in the apex, whole inferior, mid-basal inferoseptal, and inferolateral walls.\nBypass surgery of the left common carotid artery (LCCA) to the LSCA was performed using a 6 mm knitted vascular conduit (Hemashield; Boston Scientific Co., Wayne, NJ, USA) via a left supraclavicular incision. The patient was given heparin (1 mg/kg) before clamping of the LCCA. After the proximal and middle sections of the LCCA were clamped, the proximal section of the beveled vascular conduit was anastomosed to the side of the LCCA using a 6-0 polypropylene continuous suture. Because cerebral oximetry has been reported to be accurate enough for detecting early changes in cerebral blood flow that might result in cerebral ischemia [], we used continuous cerebral oximetry during the operation. Cerebral oximetry demonstrated 57% perfusion in both sides of the brain after anesthetic induction, and it remained at 57% and 55% in the right and left sides of the brain, respectively, during the LCCA clamping of 22 minutes. The distal beveled conduit was anastomosed to the middle segment of the LSCA using a 6-0 polypropylene continuous suture.\nThe postoperative blood pressure in the right and left arms was 118/61 mmHg and 111/64 mmHg, respectively. Computed tomographic angiography performed on the third postoperative day revealed that the bypass conduit between the LCCA and LSCA was patent, and that the left ITA was well perfused (). The patient underwent antiplatelet therapy (Clopidogrel, 75 mg/day) until one day before surgery and resumed therapy on postoperative day 1. The patient was discharged on postoperative day 4 without any complications and was free of angina during the 2 months of follow-up. Myocardial SPECT was performed two months after surgery and demonstrated improved stress perfusion in the anterior and anterolateral walls compared with the preoperative findings ().