Beyond Large Vessel Occlusion Strokes: Distal Occlusion Thrombectomy

Background and Purpose Endovascular therapy is the standard of care for the treatment of proximal large vessel occlusion strokes. Its safety and efficacy in the treatment of distal intracranial occlusions has not been well studied. Methods The data that support the findings of this study are available from the corresponding author on reasonable request. Retrospective review of a prospectively collected endovascular database (2010-2015, n=949) for all patients with distal intracranial occlusions treated endovascularly. Distal occlusions were defined as any segment of the anterior cerebral artery (ACA), posterior cerebral artery, or occlusion at or distal to the middle cerebral artery (MCA)-M3 opercular segment. Results Distal occlusions were treated in 69 patients. The mean age was 66.715.8 and 57% were male. Patients (29 [42%]) received intravenous tPA (tissue-type plasminogen activator). The median preprocedure National Institutes of Health Stroke Scale score was 18 (interquartile range, 13-23). The distal occlusion was the primary treatment location in 45 patients, in 23 patients the distal occlusion was treated as a rescue strategy after successful treatment of a proximal large vessel occlusion strokes, and 1 patient had both primary and rescue treatment. The locations of the primary cases were MCA-M3 (n=21), ACA alone (n=8), ACA with a concomitant MCA-M1 or MCA-M2 (n=10), ACA with a concomitant MCA-M3 (n=3), and posterior cerebral artery (n=3). The locations of the rescue cases were MCA-M3 (n=11), ACA (n=7), posterior cerebral artery (n=4), and both MCA-M3 and ACA (n=1). There was a single patient with primary ACA and MCA-M2 occlusions treated, who then had a rescue MCA-M3 thrombectomy addressed after initial reperfusion. The most common treatment modalities used were stent-retrievers (n=37, 54%), intra-arterial tPA (n=36, 52%), and thromboaspiration (n=31, 45%). Near complete or complete reperfusion of the distal territory (modified Treatment In Cerebral Ischemia [mTICI] 2b-3) was achieved in 57 cases (83%). Three parenchymal hematomas (4%) occurred in the territory of the treated distal occlusion with 2 of these patients also receiving intravenous tPA. At 90 days, 21 patients (30%) had a modified Rankin Scale score of 0 to 2 and 14 (20%) had died. Conclusions Distal intracranial occlusions can be treated safely and successfully with endovascular therapy. These results need to be corroborated by larger prospective controlled studies.