Thrombus Attenuation Gradient Can Predict Successful First-Pass Recanalization Following Stentriever Thrombectomy.

Objective: Computed tomography angiography (CTA) derived thrombus enhancement characteristics can predict first-pass recanalization. We studied whether dynamic contrast kinetics within the clot in multiphase CTA can predict first-pass recanalization following stentriever thrombectomy.

Methods: Patients with acute large vessel occlusive stroke evaluated with multiphasic CTA who underwent stentriever thrombectomy were selected. Thrombus perviousness on various phases including arterial, venous, and delayed phases was calculated. Thrombus attenuation gradient (TAG), defined as average attenuation difference between adjacent phases, was also evaluated and correlated with successful first-pass outcome (modified Treatment in Cerebral Ischemia score ≥2b).

Results: Of 69 patients, 32 (47%) had successful first-pass recanalization (group 1), and 37 (53%) required >1 attempt (group 2). TAG showed significant differences in arterial-plain and venous-arterial phases. The early increase in TAG was seen in group 1 in the arterial-plain phase, as opposed to group 2 (12.6 vs. 9, P = 0.01), which plateaued in the venous-arterial phase for group 1 and showed a further increase in group 2 (2.1 vs. 5.1, P = 0.02). A cutoff value of 9.2 HU for arterial-plain phase (P = 0.001) and 4.2 HU (P = 0.001) for venous-arterial phase was predictive of first-pass effect. Combining 2 metrics had an odds ratio of 2.8 for first-pass recanalization (P = 0.035). Accuracy evaluated in a validation cohort yielded 74%. Other features including histology were not significant.

Conclusions: TAG evaluated from multiphase CTA can predict first-pass effect in stentriever thrombectomy.