Spontaneous recanalization of internal carotid artery occlusion evaluated with color flow imaging and contrast arteriography.

AIM: In strokes of embolic origin a partial recanalization of the intracranial occluded vessel occurs with a high incidence (as high as 80%). In the literature, we find few cases of revascularization, detected with color flow imaging (CFI) or with arteriography (AGF), at carotid siphon or at the origin of an occluded internal carotid artery (ICA). Up to now there have been no reliable data on the incidence and clinical consequences of SR of an extracranial ICA occlusion. In this case-report we document 8 cases of SR of occluded ICA observed in the last 10 years in our Care Unit. METHODS: We observed 8 complete ICA occlusion at the origin, detected with CFI (8 of 8) and with AGF (7 of 8). All symptomatic patients and 2 of 5 asymptomatic patients underwent CT scan in the acute phase of stroke. All patients underwent CFI follow-up (every 6-12 monhts) to evaluate contralateral CCA and ICA and the presence of new focal neurological symptoms. All patients assumed BMT (antiplatelet or anticoagulant therapy). RESULTS: SR occurred in 6 patients between 24 and 96 months, in 1 patient within 8 months and 1 patient within 6 months from the diagnosis of ICA occlusion. Diagnosis of SR was based in all patients with CFI and in 4 patients confirmed with AGF. Five patients underwent CT scan that excluded haemorrhagic transformation of previous ischemic areas or new ischemic events (2 patients did CT scan only after SR). All patients underwent CFI follow-up in a 3-88 months period. There were no new focal neurological symptoms in 7 of 8 patients, 1 patient presented aspecific neurological symptoms. CONCLUSION: Diagnosing SR of occluded extracranical ICA seems to be more frequent than expected. SR is an event that has to be researched in follow-up of these patients; besides, it seems to have a relatively benign outcome with respect to the onset of new neurological symptoms.