Anatomical Organisation of the Circumflex Scapular Artery: A Comprehensive Topographic Analysis with Surgical Implications

The circumflex scapular artery (CSA) is an important vascular pedicle of the posterior shoulder region and is of major relevance in reconstructive and trauma surgery. However, its detailed topography, branching variability, and relationship to the medial axillary space (MAS) remain limited. This study aimed to investigate the branching pattern, morphometry, and topographic relationships of the CSA.

Forty scapular regions from twenty formalin-fixed body donors underwent standardised, systematic bilateral anatomical dissection and morphometric analysis. The CSA's origin, course, branching pattern, vessel calibre, and distances to predefined bony landmarks were assessed.

The CSA originated from the subscapular artery in 36/40 specimens (90%) and directly from the axillary artery in 4/40 (10%). A cutaneous branch traversing the MAS and an anastomotic connection between the CSA and suprascapular artery were identified in all specimens. Three intrafossal branching patterns were observed: Type 1 in 22/40 specimens (55.0%), Type 2 in 15/40 (37.5%), and Type 3 in 3/40 (7.5%). No significant systematic side-related differences were observed in the morphometric parameters or branching-pattern distribution. Sex-related differences were observed for parameters a, b, c, A, and Tmi, with greater values in male donors after Holm correction.

The CSA demonstrates recurring intrafossal branching patterns with clinically relevant variability in branching architecture. These findings provide a practical framework for flap planning, intraoperative orientation, and reducing the risk of vascular injury in reconstructive and posterior shoulder surgery.