[Surgical approach to the 3rd segment of the vertebral artery by a paramedian posterior route].

Following an anatomical study of the lateral suboccipital region, the authors have devised an approach to the third segment of the vertebral artery, from C2 to the foramen magnum, which enabled them to treat an arteriovenous fistula in C1 while preserving the vertebral artery. The different operative stages and anatomical features are described. The simplicity and safety of this approach should encourage surgeons to use it.