ENDARTERECTOMY OF THE INTRADURAL VERTEBRAL ARTERY VIA THE FAR LATERALAPPROACH

TRANSIENT ISCHEMIC ATTACKS (TIAs) of the posterior circulation are ass ociated with a significant risk of subsequent infarction, particularly when caused by stenotic lesions in the intracranial portion of the ve rtebral artery (VA). Eight patients who had persistent posterior circu lation TIAs despite receiving maximal medical therapy (including antic oagulation) and who had angiographic evidence of severe stenosis of th e proximal intracranial VA with poor collateral flow were treated by e ndarterectomy of the intradural VA. Their ages ranged from 52 to 65 ye ars. Five of these operations were performed via the far lateral appro ach. In all patients, the contralateral VA was hypoplastic or occluded , or ended in the posterior inferior cerebellar artery. Postoperative angiograms showed that the arteries of five of the patients were widel y patent, one was improved but still stenotic, and two were occluded. The latter two patients subsequently underwent thrombectomy, after whi ch the artery was patent in one patient and remained occluded in the o ther. After surgery, the TIAs of seven patients were relieved complete ly, and the patients were neurologically intact. The patient with pers istent occlusion ultimately had moderate disability. Complications inc luded the two cases of thrombotic occlusion that required a second ope ration, three cases of communicating hydrocephalus that required lumbo peritoneal shunts, and two cases of transient dysfunction of the 9th a nd 10th cranial nerves. Suitable patients with persistent posterior ci rculation TIAs refractory to medical therapy who have appropriate angi ographic evidence of proximal VA stenosis and poor collateral flow may benefit from endarterectomy of the intradural VA. Surgical exposure u sing the far lateral approach provides much better access to the intra dural portion of the VA for endarterectomy than the standard suboccipi tal approach.