THE BREAST AND AXILLA 35 



the scapula. The subscapular vein and the branches of the 

 anastomosis are associated with the posterior group of lymph 

 glands, and all these structures are removed, as a routine measure, 

 in excision of the breast. After the thoraco-dorsal (long 

 subscapular) nerve has been isolated, the subscapular vessels 

 are tied close to the axillary artery and then stripped downwards. 

 In the process the lower (middle) subscapular nerve is exposed, 

 as it runs laterally, in front of the subscapularis and behind the 

 vessels, to reach the teres major. 



The LYMPH GLANDS of the axilla are arranged in four groups : 



1. The Pectoral lymph glands lie in the medial part of 

 the interval between the suspensory ligament of the axilla 

 (p. 30) and the posterior surface of the pectoralis major. They 

 drain not only the breast, but also the superficial layers of the 

 anterior abdominal wall above the umbilicus. 



An abscess arising from these glands cannot extend upwards 

 into the neck as the two layers of fascia between which it lies 

 are both attached to the clavicle (Fig. 9). This abscess tends 

 to point either at the upper or lower border of the pectoralis 

 major. Incisions should be made parallel to these borders to 

 avoid injuring the deltoid branch of the thoraco-acromial artery 

 (p. 30) in the one case; and the lateral thoracic artery (p. 31) 

 in the other. 



2. The Central lymph glands (Leaf) accompany the 

 axillary vein and lie on the lateral wall of the axilla. They 

 receive the efferents from the upper limb and are involved early 

 in lymphangitis of the fingers and forearm. 



An abscess arising from these glands lies in the axilla behind 

 the clavi-pectoral fascia and produces a bulging of the axillary 

 fascia. The pus cannot pass far backwards owing to the 

 attachment of the serratus anterior to the scapula, but it may 

 burrow through the intercostal spaces and infect the pleura, or 

 it may pass upwards behind the axillary sheath (p. 32) and 

 appear in the root of the neck. Rarely, the pus burrows through 

 the subscapularis and infects the shoulder-joint. 



This abscess should be opened through the axillary fascia 

 by cutting in the direction of the medial wall and parallel to the 

 long thoracic nerve (of Bell). In this way the lateral thoracic 

 artery on the anterior wall, the subscapular vessels and thoraco- 

 dorsal nerve on the posterior wall, and the great vessels and 

 nerves on the lateral wall, are all avoided. 



3. The Subscapular group of lymph glands lies on the 



3 a 



