An unusual course and relations of the human axillary artery.

The axillary artery was studied by dissection of 50 human cadavers over a two-year period. Except in one instance, the course and relations of the axillary artery of all the other cadavers conformed to the normal description found in standard textbooks of Anatomy. In the exceptional cadaver, the axillary artery of the right side showed two unique features: (1) it pursued a tortuous course and made two sharp bends, and (2) it was situated superficial, rather than deep to, the pectoralis minor muscle. Its branches and relationship to the brachial plexus were also altered. On the left side, the artery was not tortuous but was also situated in front of the pectoralis minor. The present observation has several implications: (1) such a configuration of the artery would render it more prone to kinking and hence compression; (2) surgically, it might make axillary block of the brachial plexus and block dissection of the axillary lymph nodes during radical mastectomy more difficult; (3) it is at risk during infraclavicular percutaneous cannulation of the subclavian vein for a central line insertion or for insertion of a subclavian cannula for haemodialysis.