Three-dimensional anatomical vascular distribution in the pectoralis major myocutaneous flap.

BACKGROUND

In head and neck reconstruction, the pectoralis major myocutaneous flap, located adjacent to the area of reconstruction, is a very useful and easy-to-prepare flap. However, it is reported to have an unstable blood circulation that could result in partial necrosis of the skin island. The current study investigated the detailed three-dimensional vascular network in the flap to establish a method of preparation with a stable circulation.

METHODS

The pectoralis major muscle and the anterior chest skin on 12 sides of eight fresh cadavers were subjected to angiographic procedures in which contrast medium was injected selectively to the internal thoracic artery and the thoracoacromial artery. On another fresh cadaver, resin was injected in the same manner, and a clear specimen of the pectoralis major myocutaneous flap was prepared.

RESULTS

The pectoralis major muscle consists of two anatomical vascular territories that the choke vessels in the muscle at the level of the fourth costal cartilage divide into cranial and caudal sides. The chest skin area on the caudal side where the skin island of the flap is prepared receives its blood supply from a dense anastomotic network formed by the fourth, fifth, and sixth intercostal perforating branches.

CONCLUSIONS

The blood flow in the pectoral branch of the thoracoacromial artery runs through the choke vessels that dilate at the elevation of the pectoralis major myocutaneous flap, first into the fourth intercostal perforating branches; then to the anastomotic vascular network of the fourth, fifth, and sixth intercostal perforating branches; and finally to reach the periphery of the skin island.