Anthony Visioni and Julian A. Kim

Introduction

British surgeon Sir Berkeley Moynihan stated, “Surgery of cancer is not the surgery of the organs; it is the surgery of the lymphatic system.” This statement is especially true of breast cancer and melanoma, in which specific operations are carried out to remove regional lymph node metastases. Lymph node dissection (LND) was the standard of care for staging as well as treating these patients. However, sentinel lymph node biopsy (SLNB) changed the way surgeons stage and treat both breast cancer and melanoma (see Chapter 48).

Currently, LND is rarely used as a staging procedure. Furthermore, emerging evidence indicates LND may not impact survival rate in select patients with breast cancer. However, it continues to have a role in regional treatment of cancer for melanoma and breast cancer. Typically, most patients seen for LND have had their primary tumor excised and SLNB performed, which has shown metastatic disease in lymph nodes. These patients then undergo a workup to determine whether they are free of distant metastatic disease. Patients with distant metastatic disease are usually not candidates for LND and would benefit more from systemic therapies.

Axillary Lymph Node Dissection

A thorough understanding of the anatomy of the axilla is extremely important when performing an axillary lymph node dissection (ALND). The procedure involves an extensive dissection around important neurovascular structures.

The boundaries of the axilla are the axillary vein superiorly, serratus anterior muscle and chest wall medially, subscapularis and teres minor posteriorly, latissimus dorsi laterally, and pectoralis minor and major muscles anteriorly (Fig. 49-1, A). These structures create a pyramid, with the apex positioned superiorly.

The lymph nodes of the axilla are divided into levels I, II, and III, on the basis of their anatomic location in relation to the pectoralis minor (Fig. 49-1, B). Level I nodes are lateral to the lateral edge of the pectoralis minor muscle, level II nodes are posterior to the pectoralis minor, and level III nodes are medial to the medial edge. Lymph nodes are also located between the pectoralis minor and major muscles (Rotter’s interpectoral nodes).

The patient should be positioned with the arm abducted 90 degrees. If the patient is undergoing a modified radical mastectomy, access to the axilla is gained through the mastectomy incision (see Chapter 46). Otherwise, a curvilinear incision at the inferior margin of the axillary hairline is typically used (Fig. 49-2, A). If present, a scar from previous SLNB should be used for the incision instead.