Selective arterialization of coronary veins for diffuse coronary occlusion. An experimental evaluation

The selective arterialization of coronary veins as a surgical therapy for diffuse coronary arteriosclerosis was studied in canine and sheep experiments. The arterialized blood can be delivered promptly to the selected region of the myocardium and an adequate runoff exists for this mode of revascularization, so that myocardial edema and hemorrhage do not occur. The retrograde blood flow through an anastomosis between the internal mammary artery (IMA) and great cardiac vein (GCV) is excellent, with a predominantly diastolic flow pattern. Follow-up studies indicate significant but partial protection of the myocardium against diffuse LAD occlusion. The size of infarcts is decreased. However, the focal or small transmural infarcts observed are usually located near the apex of the heart. The studies with radioactive microspheres (15 plus or minus 5 mu diameter) revealed that the degree of capillary trapping of microspheres is very much less when the microspheres are injected retrograde into the vein than when injected into the artery. This may indicate that significant "shunt" blood flow exists when the coronary vein is arterialized. Thus this study demonstrates both the potential and the limitation of the selective arterialization of coronary veins in revascularizing patients suffering from diffuse coronary arteriosclerosis.