Epicardial tumor-like angiofibromatous proliferative lesion. An unusual complication of coronary bypass surgery.

The first report of an unusual complication of coronary bypass surgery for myocardial revascularization is presented. In a dog used for experimental studies of internal mammary artery (IMA)-coronary bypass and killed three months later, the postmortem examination of the heart showed a tumor-like epicardial angiofibromatous nodule at the site of the IMA-left anterior descending (LAD) coronary artery anastomosis. The lesion, consisting of plexiform vascular channels in a fibrocollagenous stroma, measured 2 by 1.5 by I cm. This was the only lesion found in the animal. It was speculated that the lesion might have arisen from a hematoma developing at the site of arterial anastomosis.