Background and Purpose Despite advancement in technique, around 30% of mechanical thrombectomies (MT) for acute large vessel occlusion (LVO) are unsuccessful. Current prediction models fail to address the association between patient’s specific factors and post-procedural reperfusion. In the present study, we aim to evaluate pre-thrombectomy clinical and radiological features and their association with failed MT.

Methods We retrospectively analyzed consecutive, adult, MT patients with anterior circulation LVO (2012–2017) treated at two large comprehensive stroke centers. We collected clinical and procedural data and reviewed imaging features from non-contrast enhanced head computed tomography (CT), CT angiography (CTA) and digital subtraction angiography (DSA). We performed a quantitative assessment of hyperdense vessel on CT, measuring Hounsfield unit (HU) in the occluded side and its counterpart. The primary outcome was unsuccessful recanalization measured by the Thrombolysis in Cerebral Infarction (TICI) score (0-2A). We utilized univariate and multivariate logistic regression to examine these associations.

Results Out of 348 anterior LVO patients, 87 had failed MT. In univariate analysis, smoking, difficult arch, vessel tortuosity, vessel calcification specifically matching the LVO location, diminutive vessels, truncal M1 occlusion and quantitative measures for hyperdense MCA (delta HU and HU ratio) were significantly associated with failed MT. When we fitted 2 separate multivariate models delta HU or HU ratio; both delta HU<6 (OR: 2.07, 95% CI: 1.09–3.92, p=0.0253) and HU ratio≤ 1.1 (OR: 2.003, 95% CI: 1.05–3.81, p=0.0034) were independently associated with failed MT after adjusting by smoking, diminutive vessels, vessel tortuosity, and difficult arch. (Table 1) Our final model ROC plots presented an AUC of 0.717.

Conclusions Quantitative assessment of HU utilizing delta HU and HU ratio may help identify patients refractory to standard thrombectomy strategies.

Disclosures S. Ortega Gutierrez: 2; C; MEDTRONIC, STRYKER. C. Zevallos: None. F. Siddiqui: None. S. Dandapat: None. A. Dajles: None. K. Ume: None. M. Weber: None. D. Quispe: None. M. Farooqui: None. S. Ansari: None.