Concurrent thyroid ima artery, high-riding brachiocephalic trunk, and supreme intercostal artery in thoracic...

To report a cluster of five concurrent cervical vascular variants identified on computed tomography angiography (CTA), including a thyroid ima artery (TIA) from a high-riding brachiocephalic trunk (BCT), a supreme intercostal artery (SIA) in thoracic vertebral artery (TVA) configuration, and associated variants, and to discuss their embryological basis and combined surgical implications.

Retrospective review of an archived CTA study of a 74-year-old female patient, using the Horos DICOM workstation with multiplanar reformatting and three-dimensional volume-rendered reconstruction. All measurements were performed by a single observer, repeated on a separate session, and the mean reported.

Five concurrent vascular variants and one skeletal variant were identified. (1) A common origin of the brachiocephalic trunk and left common carotid artery (the so-called bovine aortic arch). (2) A high pretracheal BCT course (calibre 1.29 cm, length 2.9 cm) with its upper margin 1.74 cm above the manubrial notch, crossing the anterior trachea from left to right. (3) A TIA arising from the BCT immediately proximal to its bifurcation and supplying both thyroid lobes. (4) An inferior mediastinal loop of the right subclavian artery (1.72 cm) with an intrathoracic origin of the right vertebral artery at 0.99 cm below the neck of the first rib. (5) A right SIA (calibre 1.1 mm) arising from the right vertebral artery at the level of the C7 transverse process in the TVA configuration, passing through the C7 transverse foramen and descending posterior to the necks of ribs 1-3. In addition, bilateral poor sternoclavicular joint articulation converted the suprasternal notch into an interclavicular space simultaneously containing the BCT, TIA, and thyroid isthmus.

This combination of variants places multiple vessels in a shared pretracheal/interclavicular operative plane and appears to be undocumented as a combined pattern in the anatomical literature reviewed for this report. The embryological basis, clinical implications, and role of preoperative CTA in detection are discussed.