Endovascular Thrombectomy of Calcified Emboli in Acute Ischemic Stroke: A Multicenter Study

Abstract

BACKGROUND AND PURPOSE: Large intracranial vessel occlusion due to calcified emboli is a rare cause of major stroke. We assessed the prevalence, imaging appearance, the effectiveness of mechanical thrombectomy, and clinical outcome of patients with large-vessel occlusion due to calcified emboli. MATERIALS AND METHODS:We performed a retrospective analysis of clinical and procedural data of consecutive patients who underwent mechanical thrombectomy due to calcified emboli in 7 European stroke centers. RESULTS:We screened 2969 patients, and 40 patients matched the inclusion criteria, accounting for a prevalence of 1.3%. The mean maximal density of the thrombus was 327 HU (range, 150-1200 HU), and the mean thrombus length was 9.2 mm (range, 4-20 mm). Four patients had multiple calcified emboli, and 2 patients had an embolic event during an endovascular intervention. A modified TICI score of $2b was achieved in 57.5% (23/40), with minimal-to-no reperfusion (modified TICI 0-1) in 32.5% (13/40) and incomplete reperfusion (modified TICI 2a) in 10% (4/40). Excellent outcome (mRS 0-1) was achieved in only 20.6%, functional independence (mRS 0-2) in 26.5% and 90-day mortality was 55.9%. CONCLUSIONS:Acute ischemic stroke with large-vessel occlusion due to calcified emboli is a rare entity in patients undergoing thrombectomy, with considerably worse angiographic outcome and a higher mortality compared with patients with noncalcified thrombi. Good functional recovery at 3 months can still be achieved in about a quarter of patients. ABBREVIATIONS: CLASS ¼ calcium load assessment; MT ¼ mechanical thrombectomy; mTICI ¼ modified TICI C alcified emboli are a rare, underreported cause of ischemic stroke. 1 Their prevalence has been estimated as between 2.7% and 5.9% of all patients presenting with acute ischemic stroke. 1,2 Intravenous rtPA seems to be an ineffective treatment, probably due to the thrombus composition. 3 Endovascular

Reasons for Failed Mechanical Thrombectomy in Posterior Circulation Ischemic Stroke Patients

“…No specific target vessel occlusion side, which involved the basilar artery in all cases in this cohort, was associated with a higher risk of MT failure. Corresponding to studies of the anterior circulation, further investigation is needed to identify probable associations of thrombus length or texture and MT failure [21,22]. Overall, a sufficient recanalization result for stroke patients and MT of the posterior circulation was achieved in 86.2%, which is comparable to the 90.3% and 84.5% success rate of MT in basilar artery occlusions published by Meinel et al and Sun et al, respectively, and underlines the notion that success rates for MT in the posterior circulation are comparable to the anterior circulation [16,23].…”

Acute Calcific Cerebral Embolism Large Vessel Occlusion: A Unique Stroke Mechanism With Hard Challenges

“…ET has been suggested as an alternative therapy, although no definite treatment guidelines have been established. One retrospective multicenter study of 40 patients with CCE who underwent ET reported modified thrombolysis in cerebral infarction score of >2b in 57.5% of patients and excellent outcome (mRS 0-1) in 20.6% of patients [ 2 ]. Co-administration of tPA did not lead to better outcomes or more complications [ 2 ].…”

“…One retrospective multicenter study of 40 patients with CCE who underwent ET reported modified thrombolysis in cerebral infarction score of >2b in 57.5% of patients and excellent outcome (mRS 0-1) in 20.6% of patients [ 2 ]. Co-administration of tPA did not lead to better outcomes or more complications [ 2 ]. However, patients who underwent ET may have worse angiographic outcomes and a higher mortality rate when compared with noncalcified thrombi.…”

“…Calcified cerebral emboli (CCE) are a rare cause of acute ischemic stroke, with an estimated incidence of 2.7%-5.9% [ 1 , 2 ]. Intravenous (IV) tissue plasminogen activator (tPA) and/or endovascular thrombectomy (ET) for the treatment of calcified cerebral emboli large vessel occlusions (CCE LVO) has been reportedly associated with unique challenges with poor outcomes.…”

Characterising acute ischaemic stroke thrombi: insights from histology, imaging and emerging impedance-based technologies

“…12 16 Calcified emboli are quite rare in AIS patients with large vessel occlusions, but when present, calcification is associated with poor recanalisation and higher mortality. 52 The presence of atheromatous gruel also showed a negative correlation with successful EVT recanalisation. 10 Funatsu et al found a trend suggesting the presence of vascular wall components was associated with lesser recanalisation success.…”