Pathology of the radial and internal thoracic arteries used as coronary artery bypass grafts

Background. This investigation compared the incidence and the degree of atherosclerosis present in radial artery (RA) and internal thoracic artery segments remaining after coronary artery bypass grafting. Methods. One hundred seventy specimens from 102 patients were histologically analyzed, including 106 RA specimens. Results. The mean degree of pathology for the RA was 0.89 on a 0 (none) to 4 (lumen completely obliterated) scale; the mean grade of pathology for the internal thoracic artery was 0.30 (p < 0.001). Presence of diabetes, aortofemoral disease, femoral-popliteal disease, age, and male gender correlated with an increase in RA pathology. Flow in the in situ RA did not correlate with the degree of pathology. Conclusions. Study of the excess RA and internal thoracic artery segments remaining after coronary artery bypass grafting demonstrated that the RA had a higher degree of atherosclerosis than the internal thoracic artery at the time of harvest. Overall severity of disease in the RA was low. The long-term performance of RA grafts will determine whether this level of atherosclerotic disease has any clinical significance. (C) 1997 by The Society of Thoracic Surgeons.