Mechanical thrombectomy with Solitaire stent for acute internal carotid artery occlusion without atherosclerotic stenosis: dissection or cardiogenic thromboembolism.

BACKGROUND: In acute ischemic stroke patients, internal carotid artery occlusion with middle cerebral artery (ICA/MCA) occlusion in succession predicts a poor outcome after systemic thrombolysis. It is not known whether this occlusion subtype of the anterior circulation is due to dissections or cardiogenic thromboembolism. We aimed to find useful evidence to judge the condition with accuracy and establish reasonable treatment protocols.

PATIENTS AND METHODS: This retrospective study included 7 consecutive patients with acute ICA/MCA occlusion in succession who had undergone mechanical thrombectomy with a Solitaire stent retrieval between January 2012 and June 2013. Then we also reviewed the current literature.

RESULTS: The patients had a mean age of 56 years and a mean baseline National Institutes of Health Stroke Scale (NIHSS) score of 20. The procedure resulted in thrombolysis in cerebral ischemia (TICI) scores of 2a or better in all patients, but complete recanalization of the ICA occlusion segment was achieved in only 2 patients. Stenting was not performed in all patients. At 90 days, 1 patient was dead and 4 of the 7 patients had favorable functional outcomes (modified Rankin score (mRS) ≥ 2). We identified 9 studies with 85 patients with nonatherosclerotic acute ICA occlusion who underwent mechanical thrombectomy with Solitaire stent. The mean age was 65 years with a mean baseline National Institute Health Stroke Scale (NIHSS) score of 16 and mean time to treatment of 242 minutes. The mean time of the procedures ranged from 40-160 minutes in 9 studies. Successful recanalization was achieved in 69.4% of the patients and mortality was 16.5%. Favorable outcome (mRS ≤ 2) occurred in 42.4% of patients. Few studies stated whether complete recanalization was achieved in patients with ICA occlusion.

CONCLUSIONS: Our results and the literature review suggest that mechanical thrombectomy in acute stroke due to ICA/MCA occlusion is feasible and safe, with high rates of recanalization and favorable functional outcomes. More patients with ICA/MCA occlusion in succession could obtain favorable functional outcomes with accurate judgment of the lesion location and appropriate treatment protocols. However, there is no consensus on how to judge the correct location of the ICA dissected portion and whether stenting is appropriate.