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Abstract 3615: Degree of CTA Collaterals determines the Early and Final MRI DWI Lesion Volumes in Endovascular Treatment of Acute Ischemic Stroke


 Background:
 Large pre-treatment DWI lesion volumes have been correlated with poor response to intra-arterial (IA) stroke therapies. In patients with large intracranial vessel occlusion, the degree of collateral vessel seen on CT Angiography (CTA) has also been correlated with patient outcomes. However, the relationship between the degree of collaterals on CTA and DWI lesion volume early on and after intervention has not been described and may be useful in patient selection for acute therapies.
 
 
 Objectives:
 To assess the relationship of CTA collaterals and DWI lesion volumes in patients eligible for IA stroke therapy, and to assess pre-treatment CTA collaterals with final infarct volume in patients receiving IA therapy for acute stroke.
 
 
 Methods:
 Single tertiary center retrospective review of patients considered for IA stroke therapy from May 2010 to June 2011. CTA collaterals were assessed as 0 - no collaterals, 1 - minimal collaterals (<50% of affected territory), 2- partial collaterals (> 50% of affected territory), and 3 - full collaterals. DWI volumes on initial MRI scans and post-treatment MRI scans (done 24-96 hours) were calculated by region of interest analysis. Univariate and multivariate analyses were performed (STATA, College Station, TX)
 
 
 Results:
 71 patients were available for analysis. Acute CTA imaging revealed no collaterals in 6 patients, minimal collaterals in 5 patients, partial collaterals in 33 patients and full collaterals in 27 patients. Baseline NIHSS correlated inversely with the degree of collaterals: In patients with no collaterals the median NIHSS was 20.5 (IQR 11.5 - 25.5), with minimal collaterals 18 (IQR 14-23.5), and with partial or full collaterals 13 (IQR 10-17). Initial DWI lesion volume correlated well in an inverse fashion with CTA collaterals as follows: none or minimal collaterals 88.7cc (intraquartile range (IQR) 51.6cc - 177.43cc), partial 19.7cc (IQR 13.7cc - 36.9cc) and full collaterals 9.7cc (IQR 4.7cc - 29.6cc). Final DWI lesion volumes also inversely correlated as follows: none 152.0cc (IQR 76.0cc - 204.4cc), minimal 118.8cc (IQR 57.5cc - 141.1cc), partial 34.9cc (IQR 14.2cc - 107.4cc), and full 17.2cc (IQR 8.6cc - 47.9cc). On multivariate analysis, baseline NIHSS and CTA collaterals were significantly correlated with DWI lesion volume of > 80cc (P<0.05)
 
 
 Conclusion:
 The degree of CTA collaterals are significantly inversely correlated with DWI lesion volumes before and after IA therapy for acute stroke
