2020 Scientific Sessions

Title:

Stuck Between a Rock and a Hard Place: Bifurcation Intervention to the Subclavian and Internal Mammary Arteries

Introduction:

Subclavian artery stenosis proximal to the LIMA graft can lead to myocardial ischemia and is seen in patients with peripheral vascular disease. We present a case of a patient with LIMA to LAD bypass who presented with chest pain and subclavian artery stenosis at the ostium of the LIMA take-off causing anterior wall ischemia and underwent bifurcation subclavian-LIMA intervention.

Clinical Case:

A 69-year-old man with a history of coronary artery disease and prior coronary artery bypass graft surgery presented with chest pressure and shortness of breath, as well as left arm claudication. Myocardial perfusion imaging showed a large area of anterior and apical ischemia and reduced left ventricular ejection fraction of 31%. Coronary angiography showed a totally occluded LAD after the first septal perforator, and no antegrade filling of the native LCx or RCA. A LIMA to LAD graft and vein graft to the diagonal branch were patent, with occluded vein grafts to the OM and RCA. There was severe stenosis of the left subclavian artery with a 60mmHg gradient between the aorta and the subclavian. A CTA of the chest showed severe stenosis of the left subclavian artery with heavy calcification and mixed plaque involving the ostium of the LIMA. A duplex ultrasound showed left-sided subclavian-vertebral steal. We attempted antegrade intervention to the occluded native LAD but the true lumen could not be recanalized, and retrograde intervention via the LIMA graft was precluded by severe angulation of the anastomosis. Due to the patient’s high risk anatomy we proceeded with left subclavian stenting. Dual access was obtained via the left common femoral artery and left ulnar artery. A 6Fr guide catheter was used to engage the proximal left subclavian artery, and an 0.014 Runthrough wire was placed in the LIMA. A 6Fr guiding sheath was advanced from the ulnar artery to the distal subclavian artery. The subclavian artery was predilated with a 5.0 x 40mm semi-compliant balloon. A 7 x 37mm bare metal stent was positioned in the subclavian artery and a 3 x 30mm drug eluting coronary stent was placed adjacent to the subclavian stent as a “chimney” into the LIMA. The stents were deployed simultaneously. Intravascular ultrasound was used to optimize expansion of the LIMA chimney DES. Repeat angiography showed significant improvement in the subclavian stenosis and excellent flow in the LIMA. The pressure gradient in the subclavian artery was reduced to 10mmHg. The patient has remained symptom and event free for more than twelve months.

Discussion

Left subclavian artery stenting with provisional LIMA intervention carried the risk of jailing the LIMA, which was the only patent bypass graft. Simultaneous kissing stent placement proved to be a successful strategy for treatment of left subclavian artery stenosis that involves the ostial LIMA.