Anatomical study of the pectoral branch of thoracoacromial artery.

Reconstructive surgery uses various musculocutaneous flaps following resection of head and neck malignant tumor. Numerous anatomical studies have reported that the thoracoacromial artery arises from the axillary artery, but those findings have not been completely confirmed. The aim of this study was to investigate the path from the origin of the thoracoacromial artery until its pectoral branches enter the pectoralis major muscle. The following results were obtained. 1. There were no cases in which the thoracoacromial artery arose from the third part of the axillary artery. 2. There were differences between the left and right sides in the vertical and horizontal origins of the thoracoacromial artery in relation to the clavicle and median line. 3. Pectoral branches showed a single origin from the thoracoacromial artery most frequently. 4. Pectoral branches descend in parallel to the median line most frequently on the right side and descended medially to the median line most frequently on the left side. 5. The largest number of branches approached the venter vertically at the height of the third rib. There findings suggest that, during operations involving a musculocutaneous flap, the surgeon must pay attention to the differences in vascular morphology of the right and left sides.