Surgical anatomy of the axillary artery: clinical implications for open shoulder surgery

Abstract

Background: Axillary artery injury is a devastating complication related to anterior shoulder surgery and can result in significant morbidity and/or mortality. The purpose of our study was to evaluate the course of the axillary artery in relation to bony landmarks of the shoulder and identify variations in artery position with humeral external rotation.

Materials and methods: Dissection of 18 shoulders (9 fresh whole-body cadavers) with simulated vessel perfusion using radiopaque dye was performed. The axillary artery position was measured from multiple points including 2 points on the coracoid base (C1 and C2), 3 points on the coracoid tip (C3-C5), 4 points on the glenoid: superior, middle, and inferior glenoid (D1-D4), and 2 points on the lesser tuberosity (L1 and L2). Fluoroscopic measurements were taken and compared at 0° and 90° of external rotation (F1 vs. F1' and F2 vs. F2'). Manual and fluoroscopic measurements were compared with one another using Kendall's τ_b correlation.

Results: There were 6 male and 3 female cadavers with an average age of 67.2 ± 9.3 years (range: 49-77 years). The mean distance from the axillary artery to the coracoid base (C1 and C2) measured 21.1 ± 7.3 and 22.3 ± 7.4 mm, respectively, whereas the mean distance to the coracoid tip (C3, C4, and C5) measured 30.7 ± 9.3, 52.1 ± 20.2, and 46.5 ± 14.3 mm, respectively. Measurements relative to the glenoid face (D1, D2, and D3) showed a progressive decrease in mean distance from superior to inferior, measuring 31.6 ± 10.3, 16.5 ± 7.5, and 10.3 ± 7.3 mm, respectively, whereas D4 (inferior glenoid to axillary artery) measured 17.8 ± 10.7 mm. The minimum distance from the axillary artery to any point on the glenoid was as close as 4.1 mm (D3). There was a statistically significant difference in F1 (0° external rotation) vs. F1' (90° external rotation) (18.5 vs. 13.4 mm, P = .03). Kendall's τ_b correlation showed a strong, positive correlation between manual and fluoroscopic measurements (D4: 16.0 ± 12.5 mm vs. F1: 18.5 ± 10.7 mm) (τ_b = 0.556, P = .037).

Conclusion: The axillary artery travels an average of 1-1.8 cm from the inferior glenoid margin, which puts the artery at significant risk. In addition, the artery is significantly closer to the inferior glenoid with humeral external rotation. Surgeons performing anterior shoulder surgery should have a thorough understanding of the axillary artery course and understand changes in the position of the artery with external rotation of the humerus.

Keywords: Axillary artery; cadaveric study; coracoid; fluoroscopy; glenoid; shoulder anatomy; shoulder surgery; vascular anatomy.