Anterior cerebral artery emboli in combined intravenous and intra-arterial rtPA treatment of acute ischemic stroke in the IMS I and II trials

Abstract

Background and purpose: Anterior cerebral artery (ACA) emboli may occur before or during fibrinolytic revascularization of middle cerebral artery (MCA) and internal carotid artery (ICA) T occlusions. We sought to determine the incidence and effect of baseline and new embolic ACA occlusions in the Interventional Management of Stroke (IMS) studies.

Materials and methods: Case report forms, pretreatment and posttreatment arteriograms, and CTs from 142 subjects entered into IMS I & II were reviewed to identify subjects with baseline ACA occlusion, new ACA emboli occurring during fibrinolysis, subsequent CT-demonstrated infarction in the ACA distribution, and to evaluate global and lower extremity motor clinical outcome.

Results: During M1/M2 thrombolysis procedures, new ACA embolus occurred in 1 of 60 (1.7%) subjects. Baseline distal emboli were identified in 3 of 20 (15%) T occlusions before intra-arterial (IA) treatment, and new posttreatment distal ACA emboli were identified in 3 subjects. At 24 hours, 8 (32%) T occlusions demonstrated CT-ACA infarct, typically of small volume. Infarcts were less common following sonography microcatheter-assisted thrombolysis compared with standard microcatheter thrombolysis (P = .05). Lower extremity weakness was present in 9 of 10 subjects with ACA embolus/infarct at 24 hours. The modified Rankin 0 to 2 outcomes were achieved in 4 of 25 (16%) subjects with T occlusion overall, but in 0 of 10 subjects with distal ACA emboli or ACA CT infarcts (P = .07).

Conclusions: With IV/IA recombinant tissue plasminogen activator treatment for MCA emboli, new ACA emboli are uncommon events. Distal ACA emboli during T-occlusion thrombolysis are not uncommon, typically lead to small ACA-distribution infarcts, and may limit neurologic recovery.

Fig 1.

A, Pretreatment arteriogram with M1 occlusion and patent ACA. Baseline NIHSS 25. B, Control arteriogram after 45 minutes of IA treatment demonstrates A2 occlusion, with partial M1 recanalization. C, Final arteriogram after IA treatment demonstrates persistent occlusion of the distal left pericallosal artery superimposed on partial filling of the right ACA, complete recanalization of the M1 trunk with TICI 2 perfusion. D–F, A 24-hour CT demonstrates deep, insular, and inferior frontal infarct. MCA infarct extends superiorly (E) toward the distal posterior frontal lateral cortical borderzone and the distal ACA infarct (F).

Fig 2.

Single 24-hour CT images from each of 8 subjects demonstrates ICA T occlusion with infarcts in the ACA distribution. Infarcts were all of small volume, located in the ACA cortical areas (A, B), cortical with subjacent white matter and internal borderzone areas (C–E), or in continuity with larger MCA infarct demonstration (F–H).