Anterior Circulation Acute Ischemic Stroke Associated with Atherosclerotic Lesions of the Cervical ICA: A Nosologic Entity Apart

Abstract

Background and purpose: Mechanical thrombectomy for patients with acute ischemic stroke with tandem occlusions has been shown to present varying reperfusion successes and clinical outcomes. However, the heterogeneity of tandem occlusion etiology has been strongly neglected in previous studies. We retrospectively investigated patients with acute ischemic stroke atherothrombotic tandem occlusion.

Materials and methods: All consecutive patients with acute ischemic stroke with atherothrombotic tandem occlusions treated with mechanical thrombectomy in our center between September 2009 and April 2015 were analyzed. They were compared with patients with acute ischemic stroke with dissection-related tandem occlusion and isolated intracranial occlusion treated during the same period. Comparative univariate and multivariate analyses were conducted, including demographic data, safety, and rates of successful recanalization and good clinical outcome.

Results: Despite comparable baseline severity of neurologic deficits and infarct core extension, patients with atherothrombotic tandem occlusions were older (P < .001), were more frequently smokers (P < .001), and had globally more cardiovascular risk factors (P < .001) than the other 2 groups of patients. The patients with atherothrombotic tandem occlusions had significantly longer procedural times (P < .001), lower recanalization rates (P = .004), and higher global burden of procedural complications (P < .001). In this group, procedural complications (OR = 0.15, P = .02) and the TICI 2b/3 reperfusion scores (OR = 17.76, P = .002) were independently predictive factors of favorable clinical outcome.

Conclusions: Our study suggests that atherothrombotic tandem occlusions represent a peculiar and different nosologic entity compared with dissection-related tandem occlusions. This challenging cause of acute ischemic stroke should be differentiated from other etiologies in patient management in future prospective studies.

Fig 1.

Algorithm of endovascular therapeutic strategies for tandem occlusions. The absence (n = 0) or presence (n = 1) condition the proximal treatment or not. The algorithm of the therapeutic decisions describes 2 strategies consisting of the treatment of, first, the proximal lesion (proximal occlusion strategy [POF]) or, first, the distal occlusion (distal occlusion first strategy [DOF]). The decision between the POF or DOF strategies is based on the following considerations raised during the endovascular procedure: 1) the ease of crossing the proximal occlusion site (easy crossing? difficult or impossible crossing?); 2) the patency and efficiency of the circle of Willis (efficient CoW or absence of CoW?); and 3) how threatening is the proximal atherosclerotic lesion? (unstable ulcerated plaque? moderate regular plaque?). In thrombus on ulcerated plaque, usually a single thromboaspiration allows easily crossing the proximal occlusion site and treating the distal (ie, intracranial) occlusion. In case of POF (a), the antiplatelet regimen consisted of the periprocedural intravenous administration of a unique loading dose of aspirin (250 mg) until the first imaging follow-up at 24 hours postoperatively. After ruling out any hemorrhagic transformation at 24 hours, a daily dual-antiplatelet therapy (160 mg of aspirin + 75 mg of clopidogrel) was instituted. In case of DOF (b), no anticoagulation or antiplatelet therapies were administered until the first imaging follow-up at 24 hours postoperatively. After we ruled out any hemorrhagic transformation at 24 hours, a daily monoantiplatelet therapy (160 mg of aspirin) was instituted. CoW indicates circle of Willis (efficient = 1; nonefficient or absent = 0); Prox. THREAT indicates any threatening of the proximal lesion (either atherosclerotic or dissecting).

Fig 2.

Baseline MR imaging. A 69-year-old patient was admitted for a left middle cerebral artery ischemic stroke, with an NIHSS score of 18 at 3 hours after symptom onset. The DWI and ADC maps (A and B, red asterisk) showed a limited infarct core of the lenticular nucleus, negative findings on FLAIR, and a clot in the M1 segment of the artery with susceptibility artifacts on the T2 echo gradient (D, yellow arrow) acquisition. Some evidence of slow flow was also visible on FLAIR as sulcal hypersignals (C, red arrows).

Fig 3.

DSA of intracranial reperfusion. The same patient as in Fig 2 underwent mechanical thrombectomy following a distal occlusion first recanalization strategy. The figure shows the angiogram of the intracranial vasculature of left internal carotid artery before and after MT with a stent retriever. Before MT (A and B), the angiogram shows the occlusion of left middle cerebral artery (segment M1) with a TICI score of 0 and a poor pial collaterality from the anterior cerebral artery. MT allowed complete reperfusion of the MCA territory with a TICI score of 3 (C and D) without any distal emboli.

Fig 4.

DSA of proximal carotid treatment. After full reperfusion of the intracranial occluded vessel, the patient underwent a stent placement and angioplasty of the extracranial carotid artery. The DSA shows an ulcerated atherosclerotic plaque of the carotid bulb before the treatment (A). After the angioplasty (B), a full recanalization of the vessel was achieved (C).