[Anastomosis between subclavian artery and V. A. at C1-C2 level. Case report and reappraisal of surgical possibilities on the third portion of the vertebral artery (author's transl)].

A reappraisal of surgical possibilities on the third portion of the Vertebral Artery (V.A.) above C2, have been done from an anatomical study on 20 autopsied specimen. A route passing between the Internal Jugular Vein and the Sternocleido-mastoidian muscle allows a rather simple approach of the transverse process of C1. After dividing two muscles taking insertion on this process, 1,5 cm of the V.A. can be exposed. For larger exposure of the artery, the Foramen Transversaris of C1 must be unroofed and the artery dissected in the guttering of the posterior arch of Atlas. This surgical route was used in a case of aneurismal dysplasia at C3 level. An anastomosis between Subclavian Artery and V.A. at C1-C2 level was realized with an autologous saphenous vein graft. The keypoints are the highest possible freeing of the XI nerve and the head position. Rotation and extension move the transverse process and the posterior arch of Atlas superficially and anteriorly.