Reversed left internal mammary artery graft for coronary bypass. Evaluation of function with digital subtraction angiography and radionuclide imaging.

Reversed left internal mammary artery grafting with retrograde flow to the left anterior descending coronary branch was used in five of 500 consecutive bypass operations. The indications were significant stenosis in the left subclavian artery (3 patients) or the proximal left internal mammary artery (1) and proximal damage to the left internal mammary artery during dissection from the thoracic wall (1). The postoperative clinical course was smooth in all five patients, with no evidence of myocardial ischemia. In follow-up averaging 14 months four patients were asymptomatic. The reversed internal mammary artery graft was visualized with digital subtraction angiography in four cases. Radionuclide imaging during exercise confirmed graft patency in all but the symptomatic patient, who was found to have an area of reversible ischemia anteriorly in the left ventricle.