The lateral thoracic artery revisited

Although the variations in the origin of the branches of the axillary and subclavian arteries have been well documented, little information regarding the highly variable lateral thoracic artery (LTA) is available. Descriptions of the LTA variations may prove useful during procedures of the lateral aspects of the thorax such as reconstructive plastic surgery and modified radical mastectomy.

The aim of this study was to examine the anatomy of the LTA and offer an accurate account of its variability.

The entire course and distribution of the LTA was examined in 420 formalin-fixed adult human cadavers.

The LTA was found in 96.7 % of the specimens, showing great morphological variability and classified into six types according to its origin. The most common type was where the LTA arose from the thoracoacromial artery (Type I 67.62 %). In decreasing order of incidence were origins from: the axillary artery (Type II 17.02 %), the thoracodorsal artery (Type III 5 %), and the subscapular artery (Type IV 3.93 %). Additionally, multiple LTAs were present (Type V 3.09 %) and complete absence of LTA (Type VI 3.33 %) was observed.

Despite variations in origin of the vessels, our dissections demonstrated that the ultimate tissue distribution of the LTA remained typical in the vast majority of the specimens and descended on the lateral border of the pectoralis minor. Our results illustrate the need for re-evaluation of the branches of the thoracoacromial artery with possible consideration that the LTA arises from it, instead of directly from the axillary artery. We hope that the information supplied by this study will provide useful information to anatomists and surgeons alike.