Endovascular thrombectomy for occlusions due to intracranial atherosclerosis: correlation with intracranial carotid artery calcification and treatment implications

Abstract

Objective: To report and compare the degree of intracranial carotid artery calcification (ICAC), procedural and clinical outcomes of patients with intracranial atherosclerosis-related occlusions (ICAS-O) treated with thrombectomy. Methods: The clinical characteristics, imaging, and thrombectomy outcomes of ICAS-O and nonICAS-O patients were analysed from our prospective database. ICAC was determined on the noncontrast CT at presentation, using the Woodcock scale which assessed the thickness and severity of calcification. Patients were treated with an aspiration-first approach, and stent-retriever was used as rescue when required. Stenting and angioplasty of the stenotic vessel was performed if there was early re-occlusion after thrombectomy. Results: Between 2006 to May 2017, 64 consecutive patients treated with endovascular thrombectomy for acute large vessel occlusion stroke were included. The mean age was 63.4 years (range 20-92) and 98.4% were ethnic Chinese. 14.1% were ICAS-O. The mean Woodcock scale for ICAC was significantly higher in the ICAS-O group compared to non-ICAS-O (2.8 vs 1.6, p ¼ 0.044). There were no significant difference in the rate of successful reperfusion (defined as TICI2b/3), functional independence at 90 days, and mortality between groups. ICAS-O was associated with significantly higher need of rescue therapy with stent –retriever (55.6% vs 5.5%, p ¼ 0.001) and adjuvant stenting and angioplasty due to early reocclusion (33.3% vs 0%, p ¼ 0.002). Conclusion: The severity of ICAC may be correlated with ICAS-O in thrombectomy patients. Compared with other stroke etiologies, ICAS-O was associated with a higher need of stent-retriever rescue, adjuvant stenting and angioplasty, but clinical outcomes were similar.