Superficial subscapular artery: Incidence in the Black South African Population

Abstract

The subscapular artery, the largest branch of the axillary artery, usually arises from the third part of the axillary artery at the inferior border of subscapularis muscle. Approximately 4cm from its origin it divides into the circumflex scapular and thoracodorsal arteries. Separate origins of its terminal branches have been referred to as an absent subscapular artery. Yamada (1967) distinguished two types of subscapular artery: the first one arose from the axillary artery proximal to the point where the axillary artery passed between the lateral and medial roots of median nerve and the second type arose distal to this point. Yamada (1967) referred to the former as the superficial subscapular artery(SSA) and the later as the deep subscapular artery (DSA). This study aims to determine the incidence of SSA in the South African black population. The study comprised of bilateral dissections of 50 adult black South African cadavers (n = 100 axillary arteries). The site of origin of each vessel was recorded. Additional branches and variations were also noted. SSA was found in 47% cases. In 31.9% cases, it was bilateral. DSA was found in 42%. In 15%, subscapular artery gave rise to the posterior circumflex humeral artery; lateral thoracic artery in 30%, and to upper subscapular artery in 36% cases. It was absent in 11%. The literature review records this incidence to range between 0–16% in the following population groups: Japanese, Indians, Whites and Negroes which differ significantly to this study. The results of this study may have clinical significance as a superficial course of arteries make them vulnerable to injury during surgical procedures.