Internal mammary artery (IMA) to coronary vein anastomosis in patients with diffuse coronary artery disease: study of perfusion with Tc-99m MAA injection into IMA

All of the patients had repeat coronary angiography to investigate the graft patency three weeks following the surgery. To study hemodynamic and perfusion characteristics of the new anastomotic system in two patients, one mCi of Tc-99m labeled MAA is injected into the orifice of IMA following the coronary angiography. Anterior images of the chest were obtained with a gamma camera interfaced to a digital computer. These images have shown the partition of the particles between the myocardium and the lungs, indicating the presence of arteriovenous shunting. The magnitude of the shunting to the lungs can be calculated by the counts obtained from both lungs and the myocardium. Coronary angiograms and radionuclide techniques were repeated one year after the surgery in these two patients. The repeat studies revealed patency of the the grafts on the basis of the angiograms, however, the radionuclide images showed visualization of only the myocardium but not the lungs