Clinical implications of CT hyperdense artery sign in patients with acute middle cerebral artery occlusion in the era of modern mechanical thrombectomy.

The clinical implications of the CT hyperdense artery sign have yet to be established in the new era of modern mechanical thrombectomy. This study aimed to investigate prognostic implications of the CT hyperdense middle cerebral artery sign (HMCAS) on treatment outcomes after mechanical thrombectomy for acute MCA occlusions. A retrospective analysis of CT and clinical data from 212 patients with acute MCA occlusions who underwent mechanical thrombectomy was conducted. HMCAS was determined with visual assessment by consensus of two readers. Interobserver agreement was measured. HMCAS was classified into two groups: M1 and M2 HMCAS. Associations between HMCAS and vascular risk factors, stroke etiology, and treatment outcomes were analyzed. Of 212 patients, HMCAS was identified in 118 patients (55.7%). Overall, successful reperfusion was achieved in 82.5% (175/212) and a good outcome in 45.8% (97/212). There was no significant association between HMCAS and treatment outcomes after mechanical thrombectomy, regardless of HMCAS location. Cardioembolism was more frequent in patients with a positive HMCAS (67.8 vs 48.9%, P = 0.005). Large-artery atherosclerosis was more frequent in patients with a negative HMCAS (31.9 vs 12.7%, P = 0.001). Underlying severe MCA stenosis was more frequently observed in patients with a negative HMCAS (25.5 vs 3.4%, P < 0.001). Our study suggests that the prognostic implication of a HMCAS in predicting outcomes after endovascular therapy in patients with acute MCA occlusion may be low in the era of modern mechanical thrombectomy. Negative HMCAS is predictive of in situ thrombotic occlusion due to underlying severe atherosclerotic stenosis in such patients.