Occipito-Vertebral Anastomosis; Its Clinical Significance

Abstract

SummaryA patient with an occipito-vertebral anastomosis associated with interesting clinical symptoms is presented. This 38-year-old male had a history of recurrent and reversible ischemic episodes of the vertebro-basilar system for more than 10 years . Surgical obliteration of this abnormal anastomotic channel resulted in gradual improvement of most of his clinical symptoms. The steal phenomenon of blood supply from the vertebro-basilar system to the external carotid artery via the anastomotic channel was thought to be responsible for clinical symptoms.

External Carotid Artery Steal Syndrome via Occipital-Vertebral Anastomosis

“…Some cases of ECA steal have been described with management ranging from conservative to surgical [3][4][5][6][7][8]. To our knowledge only one other case is found in the literature managed by endovascular therapy [3,8,9]. This case differs from ours in management and etiology of the steal.…”

“…After 12 years of recurrent symptoms of right sided hemiparesis and paresthesias, an angiogram revealed a large single anastomotic channel between the left occipital and left vertebral artery at the level of C1. There were no atherosclerotic changes or obliterative lesions in this patient, however, after surgical obliteration of this channel via clipping there was rapid postoperative improvement of his clinical symptoms [9]. Twenty years later, Harada et al published a case of ECA steal syndrome due to occipital-vertebral anastomosis in a patient who presented with syncope and recurrent episodes of dizziness.…”

“…Conversely, spontaneous anatomoses have been reported without concomitant obliterative lesions. The first reported case of symptomatic O-V anastomosis was published by Kondo et al in 1980, where they described a patient who presented with recurrent vertebra-basilar insufficiency [9]. After 12 years of recurrent symptoms of right sided hemiparesis and paresthesias, an angiogram revealed a large single anastomotic channel between the left occipital and left vertebral artery at the level of C1.…”

“…With regards to external carotid artery stenosis/occlusion, the mainstay of treatment involved ECA endarterectomy or angioplasty/ stenting. Indications for ECA endarterectomy include ipsilateral transient ischemic attacks (hemispheric or ocular) in patients with occlusion of the ipsilateral internal carotid artery and severe external carotid artery stenosis; occlusion of the ipsilateral internal carotid artery and moderate stenosis of the external carotid artery with ulceration; or ipsilateral transient ischemic attacks with a nonstenotic ipsilateral external carotid artery and thrombus within the cul-de-sac of the occluded ipsilateral internal carotid artery [9]. The most clearcut indication for external carotid artery endarterectomy is monocular amaurosis fugax in patients with ipsilateral internal carotid artery occlusion and a microembolic source in the origin of the external carotid artery or the occluded carotid sinus.…”

“…Due to its relatively recent development in the treatment of cerebrovascular disease, the durability of external carotid artery angioplasty has yet to be determined. Moreover, with current interest and emphasis on endovascular treatment of cerebrovascular disease and with improvements in endovascular procedures, a clearer demonstration of these collateral channels is now more frequently recognized and treated [9]. Endovascular obliteration for the treatment of ECA steal syndrome can range from coil-assisted occlusion as mentioned above or simply treatment of the occlusive disease as in this case illustration.…”