[Disabling segmental occlusion of the vertebral artery. Surgical treatment using a venous by pass from the external carotid to the C1-C2 portion if the vertebral artery (2 cases) (author's transl)]. / Les occlusions vertébrales segmentaires mal tolérées. Traitement par pontage veineux entre la carotide externe et le segment C1-C2 de l'artère vertébrale (2 observations).

ABSTRACT

The authors report the cases of two patients who were severely disabled due to signs and symptoms of vertebrobasilar insufficiency caused by unilateral segmental occlusion of one vertebral artery. The patency of the occluded vertebral artery beyond C3 was demonstrated by a faint angiographic injection through anastomic ascending cervical arteries which provided insufficient blood supply. The opposite vertebral artery was abnormal in both cases a proximal kinking with intracranial atheromatous stenosis in the first and an atheromatous ostial stenosis in the second one. A venous by pass from the external carotid artery (end to end anastomosis) to the C1-C2 portion of the vertebral artery (en to side anastomosis) was performed through an incision from the tip of the mastoid process along the S.C.M. the division of which was unnecessary. Post operatively the signs and symptoms disappeared immediately. The stability of this result is attested by a follow up period of 13 months in the first case and 9 months in the second one. A control angiogram demonstrated a good supply to the vertebro-basilar system through the bypass, the excellent permeability of which was further confirmed by repeated Doppler ultrasound examinations. The indication of this technique is discussed.