INTRODUCTION

Although breast cancer surgery can be traced back to AD 200, it was not until the early 18th century that French surgeon Jean Louis Petit first noted the significance of enlarged axillary nodes and that they should be removed along with the diseased breast tissue.¹ Axillary metastasis has since been shown to be the most important prognostic indicator of both patient survival² and breast cancer recurrence.³ Therefore, axillary surgery is a crucial step in the proper management of patients with carcinoma of the breast.

William Halsted’s ⁴ revolutionary radical mastectomy excised all three levels of axillary nodes as well as the breast and pectoralis major. This effectively eliminated all regional diseased tissue, but at the cost of great deformity to the patient. Subsequent management of both the breast and the axilla has trended toward conservation of as much nondiseased tissue as possible. Today, an axillary dissection removes most of the level I and II nodes. The extent of this dissection has been shown to be sufficient enough to reduce local recurrence, stage the patient’s level of disease, and determine the most effective treatment.⁵ Level III nodes are removed only if palpable or otherwise suspected of containing malignancy.

Seventy percent of patients with a clinically negative axilla will also prove to be microscopically free of axillary metastases.⁶ Axillary dissection carries significant long-term morbidity for these patients. The advent of the sentinel lymph node biopsy (SLNB), first successfully applied by Morton and colleagues⁷ for use in melanoma surgery, has allowed node-negative patients to be spared complete axillary dissection. When compared with axillary dissection, SLNB results in less postoperative morbidity (arm numbness and swelling) and allows for faster recovery.⁸ The sentinel lymph node is defined as the first lymph node to which a primary tumor will drain. In breast cancer, this is typically a level I node.

SLNB can reliably predict the status of a regional lymph node basin. Giuliano and coworkers ⁹ and Krag and associates¹⁰ applied this technique to breast cancer. Giuliano and coworkers used isosulfan blue dye to localize the sentinel node in 65.5% of patients. The rate improved to 78% with accumulated experience, accurately predicting axillary status in 95.6% of patients. Krag and associates used unfiltered technetium sulfur colloid to identify the sentinel node in 82% of patients, accurately predicting each case. Albertini and colleagues¹¹ utilized both isosulfan blue dye and technetium sulfur colloid, identifying a sentinel node in 92% of patients.

Axillary Dissection

OPERATIVE PROCEDURE

Axillary Dissection and Identification of Pertinent Nerves and Blood Vessels (Fig. 45-1)

Nerve Damage

• Consequence

Multiple nerves course through the axilla (Fig. 45-2), damage to which causes the following patient morbidities:

• Damage to the long thoracic nerve, which innervates the serratus anterior, causes winging of the scapula, shoulder pain, and inability to raise the arm above shoulder level.

• Damage to the thoracodorsal nerve, which innervates the latissimus dorsi, causes weakened arm pullups and adduction.

• Damage to the intercostobrachial nerves causes numbness and pain of the upper inner arm. These are the most commonly damaged nerves of an axillary dissection because they course through the axillary space and must sometimes be sacrificed with the specimen.

• Damage to the lateral pectoral nerve, which innervates the pectoralis major, causes muscle atrophy and limitation of shoulder motion.

Grade 1–3 complication

Figure 45-1 Axillary anatomy.

Figure 45-2 Nerves of the axilla.

• Repair

Typically, there is no repair for injury to these nerves. Some improvement does occur with time, especially with regard to sensory dysfunction. Although 76.5% of axillary dissection patients studied by Roses and coworkers ¹² initially complained of medial arm/axillary numbness or paresthesias, 82% of these had resolution of symptoms on follow-up assessment.

Recovery is less likely with damage to the motor nerves. On long-term follow-up of patients with injury to the long thoracic nerve, 81% cannot lift or pull heavy objects, 58% cannot play sports (such as tennis or golf), and 54% are unable to work with their hands above shoulder level.¹³ Attempts have been made to surgically restore normal scapulohumeral dynamics in cases of serratus anterior paralysis by transferring the pectoralis major tendon¹⁴ or fixing the inferior angle of the scapula.¹⁵ These therapies are still experimental and, if they prove successful, may be applied more readily in the future.

The overall incidence of motor nerve damage secondary to axillary dissection is not well reported. It appears to be so low that the most common presentation in the literature is in case report format.

• Prevention

All major nerves should be identified and preserved. As the dissection proceeds inferiorly from the axillary vein (Fig. 45-3), the long thoracic nerve of Bell should be identified coursing longitudinally along the investing fascia of the chest wall anterior to the subscapularis muscle and inserting into the serratus anterior. It passes approximately 2 cm deep to where the intercostobrachial nerve exits the chest wall. It should be separated from the specimen and allowed to remain against the chest wall. The thoracodorsal nerve should be identified deep in the axilla, alongside the subscapular vessels, traversing laterally and inferiorly toward the latissimus dorsi. The intercostobrachial nerves course transversely through the axilla, and although not always possible, an attempt should be made to spare these nerves. An attempt should also be made to preserve the pectoral neurovascular bundle as it passes laterally around the pectoralis major, inferior to the axillary vein. Use of cautery should be limited in the axilla, because it can transmit and cause damage to these nerves. Use clips and ties as necessary.

Figure 45-3 Operative anatomy of the axilla.

Lymphedema