Endovascular Thrombectomy for Acute Ischemic Stroke due to Calcified Cerebral Emboli

<b>Background:</b> Calcified cerebral emboli (CCEs) represent a rare cause of acute ischemic stroke and can pose technical challenges for neurointerventionalists. The few studies on endovascular thrombectomy (EVT) of CCE to date show poor recanalization rates and unfavorable outcomes. <b>Objective:</b> This study is aimed at investigating the technical and clinical results concerning EVT of CCE compared with noncalcified cerebral emboli (NCCEs). <b>Methods:</b> All cases of EVT for acute stroke from January 2014 to December 2021 from a single center were analyzed retrospectively. Emboli with a maximum density of ≥ 130 Hounsfield units on preinterventional CT scans were considered calcified. Propensity score matching was performed to compare technical and clinical results between patients with CCE and NCCE. <b>Results:</b> CCEs were present in 26 of 1004 cases (2.6%). Successful recanalization (mTICI ≥ 2b) was achieved less frequently in CCE (CCE: 62%, NCCE: 92%, <i>p</i> = 0.009). Also, first-pass reperfusion was less common in CCE (CCE: 12%, NCCE: 46%, <i>p</i> = 0.006). In CCE, infarct growth was more frequent (CCE: 81%, NCCE: 42%, <i>p</i> = 0.004) and more severe (<i>p</i> = 0.005). National Institutes of Health Stroke Scale improvement after EVT was lower in CCE patients (CCE: median 2, range -23 to 20, interquartile range (IQR) 2.75; NCCE: median 5, range -8 to 17, IQR 11, <i>p</i> = 0.008). <b>Conclusion:</b> First-pass reperfusion is less common in EVT of CCE. Also, there is a more frequent and severe infarct growth in CCE patients after EVT, which helps to understand the poorer clinical results. Thrombectomy devices optimized for CCE are desirable to improve outcomes in this subgroup of stroke patients.