Transverse process anatomy as a guide to vertebral artery exposure during anterior cervical spine approach: A Cadaveric Study.

Safe exposure of the vertebral artery (VA) is needed during resection of tumors close to the artery and during repair of lacerations. We defined the anatomy of the anterior root of each transverse process (TP) from C3 to C6 for identification and exposure of the VA during the anterior approach. We examined the anatomy of the TP and assessed two approaches for safe identification of the VA, lateral to medial and medial to lateral dissection of the TP, in 20 cadavers. The safe zone at each level of the cervical spine was defined as an area in which the surgeon can start to dissect at the midline of that level on the TP and safely cross the VA laterally. For the lateral to medial approach the surgical safe zone lies between the mid axis of the TPs and a line 2 mm parallel to and above it. The average TP angle was 11 ± 10.2 degrees. The mean distance of the lateral border of the VA from the TP tip was 3.78-5.28 mm. For the medial to lateral approach, staying at the level of the upper vertebral end plate will lead the surgeon to the tip of the TP. From that point, dissection can be carried out as described above. This study examined the anatomy of the TP and defined the approach to expose the VA safely during anterior cervical spine exposure. Clin. Anat. 30:492-497, 2017.