After a full median sternotomy, the retractor is placed and the posterior rectus sheath is dissected from the sternum and costal cartilages, to improve the exposure of the internal thoracic artery. When the course of the internal thoracic artery is identified, the endothoracic fascia is incised approximately 7 to 10 mm medial to the internal thoracic artery and low-energy electrocautery is used to dissect the veno-arterial pedicle from the chest wall, carefully clipping both venous and arterial collateral branches, from the rectus sheath to the level of the subclavian vein which crosses the artery. There, the first intercostal branch is clipped to avoid a steal phenomenon.
Left internal mammary artery harvesting