An investigation of the dorsal scapular artery

Abstract

The dorsal scapular artery (DSA) arises in the root of the neck and courses along the medial scapular border. It may arise either from the subclavian (SCA) ‐ a direct DSA, or indirectly from SCA via the transverse cervical artery (TCA) ‐ an indirect DSA. This cadaveric study (N=56) assessed the frequency of each variant, including any side and sex differences. We found a direct DSA in 74% of cases and an indirect DSA in 26% of cases; slightly more direct DSAs were observed on the left than on the right (80% vs. 68%; P<0.05). Regardless of side, the direct DSA almost always originated from the 2nd or 3rd part of the SCA. Within an individual, the origins of the DSAs were symmetrical in 70% of cases (P=0.005). The pathway of the direct DSA was also stereotyped: 67% of direct DSAs passed between the superior and middle trunks of the brachial plexus; 29% passed between the middle and inferior trunks; 4% passed inferior to the plexus. The indirect DSA arose from the TCA, which coursed posteriorly across the superior trunk; the indirect DSA never went through or inferior to the plexus. Improved understanding of the DSA will aid in clinical practice (e.g., in trapezius flap procedures, brachial plexus blocks). The proposed nomenclature will not only improve communication among practitioners, but also offers a simple resolution to the nomenclature discrepancies in current anatomical and surgical literature.Grant Funding Source: None