Transverse Process of the Atlas(C1)--an Important Surgical Landmark of the Upper Neck

Background: The internal carotid artery, the internal jugular vein, and the spinal accessory nerve are the main structures that are preserved in conservative neck dissections. In the upper neck, one surgical landmark used to find these structures is the transverse process of a cervical vertebral body. There is controversy about the origin of the transverse process in the upper neck.

Methods: We applied three-dimensional computerized tomography (3-D CT), an intraoperative navigational system and cadaver dissection of the neck to clarify the controversy.

Results: The origin of the transverse process was from the atlas (C1).

Conclusions: The transverse process of the atlas is an important surgical landmark in the upper neck. The neurovascular bundle is located anteriorly. The transverse process of the axis (C2) is less prominent and is situated antero-inferior to the spinal accessory nerve where the nerve emerges from the posterior border of the internal jugular vein.