Demystifying the use of internal mammary vessels as recipient vessels in free flap breast reconstruction

BACKGROUND: The internal mammary vessels are commonly used as primary recipient vessels for free flap breast reconstruction. However, there is debate about the reliability of the left internal mammary vein. The authors explored the anatomy of the internal mammary vessels as revealed during free flap breast reconstruction to determine whether microvascular complications differed between the left and right sides. METHODS: All free flap breast reconstructions performed using internal mammary recipient vessels at the authors' institution between January of 2000 and December of 2010 were reviewed. The authors compared left and right breast reconstructions for internal mammary vessel diameters and microvascular complications, pedicle thrombosis, and total flap losses. RESULTS: Overall, 1773 free flap breast reconstructions were performed in 1336 patients using the internal mammary vessels: 899 unilateral and 437 bilateral. The left side was used in 904 cases and the right side in 869 cases. Although the mean sizes of the left and right internal mammary arteries (2.44 and 2.47 mm, respectively) did not differ significantly, the left vein was significantly smaller than the right vein (2.47 mm versus 2.93 mm; p = 0.038). The overall rate of venous thrombosis was significantly higher on the left than on the right (3.0 percent versus 2.3 percent; p = 0.028). The rates of flap loss in left and right breast reconstructions did not differ significantly (1.9 percent versus 2.2 percent). CONCLUSION: Although the left internal mammary vein is smaller than the right and is at higher risk for venous complications, it remains an acceptable recipient vessel for free flap breast reconstruction.