Fig. 2

Intraoperative image. A linear skin incision was made from the inion to the C2 spinous process to expose the C1 posterior arch and C2 vertebral arch, and C1 laminectomy and C2 partial upper laminectomy were performed. The left persistent first intersegmental artery (PFIA) (white arrow) severely compressed the spinal cord at the C1 level. Left C2 dorsal root nerves (white arrow head) were observed around the left PFIA (a). The right PFIA (white arrow) course was also in contact with the spinal cord but with spinal cord compression. Right C2 dorsal root nerves (white arrow head) were observed around the right PFIA (b). The adhesion between the PFIA and surrounding vessels and nerves was dissected, and the PFIA was transposed using polytetrafluoroethylene bands (white arrow) and anchored to the dura mater. After transposition, sufficient space was established between the PFIA and spinal cord (c)