BACKGROUND Subacute and chronic symptomatic internal carotid artery occlusion (SCSICAO) are associated with 6‐20% annual risk of recurrent cerebrovascular events. We report our experience of endovascular recanalization using intravascular ultrasound guidance and identifying features of occluded segments that can predict technical and clinical success. Methods We included patients who had SCSICAO with cerebral ischemic symptoms within average 5 days (range 1‐30) days. We report technical success, characteristics of occlusion as determined by intravascular ultrasound and selective angiography, and clinical and radiographic follow‐up. The occlusion was characterized based on three features as follows: Grade 1, proximal cervical occlusion (with patent vascular distal to initial occlusion); Grade 2, proximal cervical occlusion and thrombosis of mid and distal cervical segments (with patent intracranial vascular); and Grade 3, proximal cervical occlusion with intracranial occlusion with or without thrombosis of mid and distal cervical segments. The success and complication of recanalization are reported based on the classification. Results Thirty‐five patients with SCSICAO were evaluated during a 4‐year period; 10 were excluded because of non‐atherosclerosis etiology (n=6 patients) or the procedure was not attempted (n=4 patients). Out of 25 patients, the occlusion was classified as Grade 1 in 9, Grade 2 in 6, and Grade 3 in 10. The endovascular technique included cervical angioplasty and stent placement (n=21), cervical thrombectomy (n=6), intracranial thrombectomy (n=3), and intracranial angioplasty and/or stent placement (n=3). The completion recanalization was as follows: 9 in Grade 1, 4 in Grade 2, and 2 in Grade 3 occlusions. One month stroke and/or death rates were as follows: 0 in Grade 1, 0 in Grade 2, and 2 in Grade 3 occlusions. Conclusion Our study highlights the heterogeneity in occlusion seen in patients with SCSICAO. Our proposed grading scheme incorporating the main features of heterogeneity may assist in predicting the technical success and risk of one month stroke and/or death associated with the procedure. REFERENCES: 1.Flaherty ML, Flemming KD, McClelland R, et al. Population‐based study of symptomatic internal carotid artery occlusion: incidence and long‐term follow‐up. Retrieved from https://pubmed.ncbi.nlm.nih.gov/15232124/2 . Sundaram S, Kannoth S, Thomas B, Sarma PS, et al. Collateral assessment by CT Angiography as a predictor of outcome in symptomatic cervical internal carotid artery occlusion. Retrieved from https://pubmed.ncbi.nlm.nih.gov/27765736/ 3.Zhou C, Cao Y‐Z, Liu S, et al. Endovascular recanalization of symptomatic chronic internal carotid artery occlusion: proposal of a modified angiographic classification and clinical outcomes. Retrieved from https://pubmed.ncbi.nlm.nih.gov/36822826/ 4.Mo L, Ma G, Dai C, et al. Endovascular recanalization of symptomatic subacute and chronically occluded internal carotid artery: feasibility, safety, a modified angiographic classification system and clinical outcomes. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32494963/ 5.Hasan D, Zanaty M, Starke R, et al. Feasibility, safety and changes in systolic blood pressure associated with endovascular revascularization of symptomatic and chronically occluded cervical internal carotid artery using a newly suggested radiographic classification of chronically occluded cervical internal carotid artery: pilot study. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29775153/
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