The lateral edge of the pectoralis minor is cleared of fascia to near its insertion on the corticoid process and several veins are ligated as they come off the axillary vein (Figure 7). A careful search is made for the medial nerve to the pectoralis major, which is preserved. Ligation rather than electrocoagulation is preferred for all vessels about the axilla and for those adjacent to the sternum.
The pectoralis major and minor are retracted upward and medially, exposing the uppermost tissues to be divided over the axillary vein. Some prefer to divide the pectoralis minor muscle from its insertion on the coracoid process as to gain better exposure of the medial area of the axillary vein and its lymph nodes.
The fascia over the serratus anterior muscle is dissected free, and the axillary fat and lymph nodes are mobilized off the chest wall and the axillary vein (Figure 8). The arm, wrapped in sterile drapes, is lifted up or manipulated to enhance the exposure as the dissection progresses in the axilla. The long thoracic nerve should be identified deep to the axillary vein. As it lies within the loose fascia over the serratus anterior muscle, it is possible to lift this nerve away from the muscle; hence, it must be carefully sought and dissected out from the axillary contents to be contained within the resected specimen. This nerve should be retained intact, because a “winged” scapula will result if it is divided. A sensory nerve that is often sacrificed is the more transverse intercostobrachial that appears beneath the second rib and provides sensory innervation to the upper inner aspect of the arm.
As the breast is retracted laterally (Figure 9), the long thoracic nerve as well as the thoracodorsal nerve should be free of redundant tissue. The thoracodorsal nerve is characteristically located adjacent to the deep subscapular vein and artery. Division of the thoracodorsal nerve is avoided unless there is tumor involvement, since its sacrifice has only a partial effect upon the latissimus dorsi muscle.
The specimen is freed from the latissimus dorsi muscle (Figure 10) and finally from the suspensory ligaments in the axilla, where large veins and lymphatics should be carefully ligated. The operative area is repeatedly inspected for any bleeding points, which are ligated. The two major nerves are checked to be certain ...