[Surgical treatment of extrinsic and neoplastic vertebral artery compression]

Extrinsic lesions whatever their origin, tumoral or not, inducing a compression of the vertebral artery, are rarely identified as they are uncommon and often not investigated. The surgical exposure of the vertebral artery in its second and third portion, i-e in the transverse canal from C6 to the foramen magnum is considered very difficult if possible. We report on our experience of 142 cases including 120 tumors, 5 osteophytic spurs, 6 fibrous bands, 4 traumatic lesions, 3 craniocervical junction anomalies and 2 nervous elements. Compression was most commonly observed in the third portion (above C2); intermittent compression was rare and always of non tumoral origin. Ischemic events were quite uncommon in the whole series (N = 15). Surgical treatment was decided either to suppress a tumor or to release the arterial compression if it had clearly been demonstrated its relation with vertebrobasilar symptoms. Whatever the reason for surgical indication, the vertebral artery was first controlled, thus allowing to remove the compressive factor safely and as completely as possible. This requires a precise technique which is described. Our experience demonstrates the interest of investigating every lesion developed in the proximity of the transverse canal; it also shows that it is possible and often useful to control the vertebral artery to achieve complete removal of tumors and to preserve the vertebro-basilar flow.