Introduction: The prediction of non-recanalization after IV thrombolysis (IVT) may be helpful to avoid unnecessary treatment and determine the strategy of recanalization treatment. Thrombus volume and density can be measured using software, which may provide accurate and reliable information on thrombus characteristics.
Hypothesis: We hypothesized that the thrombus volume and/or density could predict non-recanalization after IVT.
Methods: This was a post-hoc analysis of prospective cohort who underwent thin-section noncontrast CT (1 or 1.25 mm) and recanalization therapy. Among them, this study considered patients who received IVT due to anterior circulation stroke from Nov. 2006 to Dec. 2015. The volume and density of thrombus were measured semi-automatically using 3-dimensional software. Recanalization was assessed on CT angiography at the end of IVT or conventional angiography in cases further treated with intra-arterial treatment. Successful recanalization was defined as arterial occlusive lesion grade 2 or 3.
Results: Among 345 patients considered, 218 with visible thrombus in the intracranial arteries were included for this study. Successful recanalization was achieved in 79 patients (36.2%). Thrombus volume was significantly larger in patients with non-recanalization than those with successful recanalization (median [interquartile range]: 117.8mm3 [60.0 - 216.8 mm3] vs. 56.9 mm3 [31.1 - 105.0 mm3]. p<0.001). In the multivariate analysis, thrombus volume was independently associated with non-recanalization (p<0.001). Recanalization failed in all cases with thrombus > 300 mm3, and in 41 of 44 cases (93.2%) with thrombus > 200 mm3. Thrombus density did not differ between the groups (non-recanalization vs. successful recanalization: 54.0 ± 9.1 vs. 52.6 ± 8.5, p=0.263).
Conclusions: Thrombus volume was predictive of non-recanalization after IVT. Measurements of thrombus volume may be helpful to determine the strategy of recanalization treatment.