Distance to Thrombus in Acute Middle Cerebral Artery Occlusion

Abstract

Background and Purpose— In patients with acute middle cerebral artery (MCA) stroke, therapeutic decisions are influenced by the location of the occlusion. This study aimed to analyze clinical outcomes in patients with acute ischemic MCA stroke treated with systemic intravenous thrombolysis (IVT) using recombinant tissue plasminogen activator, according to the location of the occlusion. Methods— Of 621 patients screened, 136 with acute stroke and MCA occlusion confirmed by CT angiography were retrospectively included in this study. The distance from the carotid T to the thrombus (DT) on coronal maximum intensity projection images and the thrombus length were measured. The correlation between DT and the modified Rankin Scale score at 90 days was analyzed. Results— DT was an independent predictor of clinical outcome in stroke patients treated with IVT. A long DT was significantly correlated with a good clinical outcome (modified Rankin Scale score at 90 days ≤2). A poor clinical outcome was exponentially more likely than a good outcome when the DT was <16 mm ( P <0.001). The thrombus length was not correlated with the modified Rankin Scale score at 90 days. A long thrombus (>8 mm) occurred significantly more often in the proximal MCA than the distal MCA ( P <0.001). Conclusion— DT is an independent predictor of clinical outcome in patients with acute MCA occlusion treated with IVT. In acute stroke with MCA occlusion confirmed by CT angiography and DT <16 mm, the likelihood of a good clinical outcome after treatment with IVT was exponentially <50%. This might warrant the evaluation of other therapy forms than IVT in patients with proximal MCA occlusion.

Distance to thrombus on MR angiography predicts outcome of middle cerebral artery occlusion treated with IV thrombolysis

“…This corroborates the results of a recent work of our group, in which the assessment of DT with CTA revealed a significant correlation of DT with outcome (90d mRS) in a study population of 136 patients [12]. Moreover, DT seems to outperform DWI lesion volume at admission in predicting individual patient outcome.…”

“…As already stated before, only few recent studies investigated the influence of thrombus location on patient outcomes [12]. Saarinen et al found the mid-M1 segment to be a cutoff point to predict the outcome in patients undergoing IVT [34]; others reported on the importance of the clot location in relation to the perforating arteries in patients with occlusions of the M1 segment undergoing MT [35].…”

“…The distance to thrombus (DT) was measured in a curved line on CE-MRA images in paracoronally reformatted maximum intensity projections (MIP) with a slice thickness of 15 mm, similar to the technique used on CTA by Friedrich et al [12]. The DT was measured from the center of the carotid terminus, i.e., from the branching point of the internal carotid artery (ICA) into the anterior cerebral artery (ACA) and the MCA and the occlusion site ( Fig.…”

“…In a recent consensus paper, it was proposed that for clinical and study purposes, a precise localization of the occlusion site is mandatory [11]. Consequently, a new analysis of the precise thrombus localization in acute MCA occlusions, the distance to thrombus (DT), was established by our group [12]. It is an easy-to-apply measurement of the length from the carotid T to the occlusion site in MCA stroke on CT angiography (CTA).…”

Internal Carotid Artery and the Proximal M1 Segment Are Optimal Targets for Mechanical Thrombectomy

“…It is still unclear if MT outperforms IVT in the M2 segment because of the small number and heterogeneousness of patients with M2 occlusions in the randomized trials and other previous research [6,7,8]. Further, according to a recent recommendation and previous reports, the proximal and distal halves of the M1 segments should be examined separately because these vessel subsegments have differing properties that seem to influence the potential for good clinical outcome and the efficacy of revascularization therapies [8,9,10,11,12]. …”