Abstract 193: Preliminary Clot Length Analysis of Anterior Circulation Large Vessel Occlusions:
Purpose: Thin-section (≤ 2.5 mm) non-enhanced CT images may be used to reliably measure clot lengths in acute MCA occlusions, with clots ≥ 8mm long having a low probability of recanalization with IV rtPA alone. However, it is unclear what proportion of large vessel anterior circulation strokes have clot lengths ≥ 8mm and may potentially benefit from a bridging interventional approach.
Methods: A multicenter imaging case review (target enrollment= 200 patients at 5 U.S. centers) was initiated to determine the proportion of patients meeting the below study criteria who have clot lengths ≥ 8mm. Study criteria include presentation within 8 hours of onset; imaging evidence of ICA-T, MCA M1, or M2 occlusion; and thin slice (≤ 2.5 mm) admission non-contrast CT images. Results are reported from an interim analysis of the data.
Results: At 2 comprehensive stroke centers, all consecutive stroke admissions between August 2011 and July 2012 were reviewed for eligibility. Of these patients, 64 met study criteria (mean age= 72.3 years; 60% female; mean baseline NIHSS= 18). Mean times from symptom onset to presentation and to CT scan were 3.6 and 4.4 hours, respectively. Primary occlusions were located in the ICA-T (26.6%), M1 (64.1%), and M2 MCA (9.4%). Thrombus was visible in 92% (59/64) of cases, with lengths ranging from 3.0 to 64.8mm (mean = 18.6mm). Of these, 83% were ≥ 8mm in length. Clot length was statistically significantly longer in ICA-T occlusions and for those who did not receive IV rtPA prior to CT scan.
Conclusion: This interim analysis suggests that the vast majority of anterior circulation large vessel occlusions have extensive (≥ 8mm length) clot burden, and may benefit from an IV-IA bridging approach. This idea will be tested in the ongoing THERAPY randomized controlled trial.
- © 2012 by American Heart Association, Inc.