Anatomy of the internal mammary veins and their use in free TRAM flap breast reconstruction

The anatomy of 61 internal mammary veins (IMV) in the 3rd, 4th and 5th intercostal spaces was studied in 34 fresh human cadavers by injection and corrosion methods and surgical dissection. The IMV was present in all 34 cadavers. Four different patterns of venous anatomy were identified: Types 1 (69%) and 2 (26%) were common, Types 3 (3 %) and 4 (2 %) were rare. The most common arrangement (Type 1) consists of the internal mammary vein running medial and parallel to the artery to the 4th intercostal space where it divides into the medial and the lateral IMV, the lateral crossing the internal mammary artery (IMA) anterior to it in direction from medial to lateral. Both veins are connected by interconnecting branches. The mean diameter of internal mammary veins is 2.7 mm (range 1.1-4.8 mm) for the medial and 1.8 mm (range 0.5-3.5 mm) for the lateral one. The mean distance from the lateral border of the sternum of the medial vein is 9 mm (range 2-18 mm) and 14 mm (range 9-24 mm) for the lateral veih. We present a review of 7 patients in whom internal mammary vessels were used as recipient vessels for breast reconstruction with free TRAM flaps with no complications, as well as the advantages and disadvantages of such a procedure. © 1995 The British Association of Plastic Surgeons.