Clinical Relevance: The workhorse recipient vessels for free flap breast reconstruction include the internal mammary vessels and the thoracodorsal vessels. Several case reports and small series have been published which describe the ability to utilize the internal mammary perforators as alternate recipient vessels for free flap breast reconstruction. Palmer and Taylor (1986) performed excellent anatomic studies of the vascular territories of the anterior chest wall, but the diameter of the perforators was not noted.

Methods: Five fresh cadavers were dissected through an anterior midline presternal incision. Using a micrometer under loupe magnification, bilateral measurements were taken of the first five internal mammary perforators and the IMA/ IMV between the 2nd and 3rd ribs.

Results: The five dissected cadavers consisted of three females and two males with an average age of 80.4 years. The size of the arterial perforators ranged from 0.5 to 2.7 mm, with an average of 1.1 mm (sd 0.54). The venous perforators ranged from 0.25 to 3.0 mm, with an average of 1.2 mm (sd 0.61). When only the largest perforators from each side were evaluated, the artery averaged 1.84 mm (sd 0.57), with a range of 1.1 to 2.7 mm. The veins of the largest perforators also averaged 1.84 mm (sd 0.84), with a range of 0.75 to 3.0 mm. The largest perforator was located in the 1st rib space twice, 2nd rib space four times, and 3rd rib space four times.

Conclusion: Every cadaver had perforators that measured at least 1 mm diameter. The largest perforators appeared adequate for microsurgical anastomosis. These “principal perforators” were most commonly found in the 2nd or 3rd rib space. There are several advantages to the internal mammary perforators – decreased time to expose recipient vessels, no rib resection, IMA saved for future CAB conduit, and no need to perform microsurgery in a hole between ribs. Certainly, the reconstructive breast surgeon will need excellent cooperation with the general surgeon to preserve these perforators during mastectomy. This study has elucidated a protocol which we recommend for recipient vessel dissection – map perforators w/ Doppler, search for an adequate perforator in 2nd and 3rd rib space, and be prepared for partial rib resection to expose IMA/ IMV if needed.