Percutaneous transluminal angioplasty in coronary-internal thoracic-subclavian steal syndrome.

Internal thoracic artery implants are widely used as conduits in coronary artery bypass surgery because of their resistance to the development of atherosclerosis. Two cases are reported of subclavian artery stenosis proximal to the internal mammary artery in patients who had undergone coronary bypass surgery. In both cases, an atypical pattern of postsurgical angina developed, with retrosternal chest pain occurring specifically with upper extremities exercise. Coronary and graft angiography revealed retrograde flow in the left internal thoracic artery during injection of the grafted coronary. Severe stenosis was identified in the subclavian artery. Treatment consisted of dilation of the subclavian artery stenosis with stent placement in one patient. Both patients had marked symptomatic improvement after the procedure.