Internal Mammary Perforators

perforantes arteriae mammariae internae

The internal mammary artery gives off intercostal perforators through the second and third intercostal spaces into the breast tissue and overlying skin. These perforators are the basis of the internal mammary artery perforator (IMAP) flap and are used as recipient vessels for anastomosis in free flap breast reconstruction when the thoracodorsal vessels have been sacrificed by previous axillary surgery.

Region: Chest

Clinical Relevance

Clinical Notes

The internal mammary vessels (artery and vein) at the third or fourth intercostal space are the most commonly used recipient vessels for free flap breast reconstruction with DIEP and SIEA flaps, requiring removal of a cartilaginous rib segment to access the vessels. The IMA perforators at the second intercostal space can be used as recipients in a perforator-to-perforator anastomosis technique that avoids rib removal. Pre-operative CT angiography identifies the IMA and its perforators for surgical planning.

Pathology

Common Injuries & Conditions

Internal Mammary Vessels as Recipients for Free Flap Breast Reconstruction

The internal mammary artery and vein at the third or fourth intercostal space provide the standard recipient vessels for DIEP free flap anastomosis in breast reconstruction; the intercostal space is accessed by removing a 2-3 cm segment of the third costal cartilage under direct vision, and the vessels are dissected proximally on the chest wall for adequate length and diameter.