Internal thoracic artery blood flow is not affected by major side branch.

We report a case of a 73-year-old man in which coronary angiography demonstrated a large side branch of the internal thoracic artery (ITA). The side branch was identified intraoperatively. As assessed intraoperatively by transit time Doppler flow measurement, temporary occlusion of the side branch showed no effect on ITA flow, which remained unchanged at 49 mL/min after anastomosis to left anterior descending coronary artery.