Abstract
This anatomical study aimed to demonstrate the co-dominance of the transverse cervical artery (TCA) and dorsal scapula artery (DSA) in their blood supply to the trapezius muscle. Dissection was performed on ten fresh cadavers (20 hemi-trunks), with the use of pigmented latex injections to trace the vascular course and methylene blue injections to delineate cutaneous territories. In 63% of specimens, the transverse cervical artery (TCA) and the dorsal scapular artery (DSA) originated separately, while 37% displayed a common origin from the thyrocervical trunk. The average calibre of the TCA was 2.70 mm and the DSA 2.66 mm. The DSA was found to be equal to or larger in calibre than the TCA in 56% of specimens. The cutaneous territory for the TCA measured 15 × 10 cm and was located above the spine of the scapula. The cutaneous territory of the DSA measured 20 × 15 cm and was seen below the spine of the scapula and extending 10 cm beyond the lateral border of the trapezius. There was significant overlap between these two cutaneous territories. Two clinical cases illustrate the application of simultaneous dual flaps harvested from the trapezius based on the TCA and DSA, highlighting the importance of recognising the DSA as a major vascular contributor. This study challenges the conventional notion of unilateral vascular dominance of the TCA, proposing that the trapezius muscle should be classified as a type III flap supplied by co-dominant vessels.