What is the primary blood supply to the pectoralis major flap?

The primary blood supply to the pectoralis major flap is indeed the thoracoacromial artery. This artery branches from the second part of the axillary artery and provides crucial vascular support to the pectoralis major muscle, making it a reliable choice for reconstructive and surgical flaps.

The thoracoacromial artery gives off several branches, including the pectoral branches that specifically nourish the pectoralis major muscle. This vascularization is essential for the viability of the flap during and after surgical procedures.

While the subclavian artery and the internal mammary artery do have significant roles in the vascularization of the thoracic region, they are not the primary vessels supplying the pectoralis major flap. The radial artery, while important in various contexts, does not provide blood flow to the pectoralis major. Thus, the correct understanding of the vascular anatomy in this context highlights the thoracoacromial artery as the main source of blood supply to the pectoralis major flap.