Role of pial collateral flow in acute ischemic stroke outcomes.

Objective: In the patients with acute ischemic stroke (AIS) due to middle cerebral artery (MCA) occlusion who underwent endovascular treatment (ET), we explored the relationship between digital subtraction angiography (DSA) pial collateral status and clinical outcomes. Background: Collateral flow can influence the pace and extent of evolution to irreversible tissue damage and thus have a significant impact on the clinical outcome of patients with AIS. Design/Methods: We reviewed the data of all patients with acute MCA occlusion treated with ET within the past 5 years. Baseline DSA collaterals were classified as - no (0), poor (1), intermediate (2) and good (3). Clinical outcomes were assessed using the National Institute of Health Stroke Scale (NIHSS) at 24-48 hours and at the time of discharge. Multivariable regression analysis was done to evaluate association of DSA collateral score with the outcome. The regression model was adjusted for age, baseline NIHSS, infusion of intravenous (IV) thrombolytic (tPA) and symptom-onset to angiographic recanalization time. Results: 50 patients with the MCA occlusion were treated with ET and 25 (50%) patients received IV tPA prior to ET. Median baseline NIHSS score was 19.5. Median time from the onset to IV tPA was 122 minutes and from onset to angiographic recanalization was 277 minutes. Every 1-point increase in the DSA collateral score was associated with 4.5-point reduction in NIHSS at 24-48 hours and 4.9 point reduction in NIHSS at the time of discharge (standard error 1.4, p\u3c0.01 for both). Conclusions: In the patients with acute ischemic stroke due to MCA occlusion, better collaterals on the DSA are independently associated with improved neurological outcome at 24-48 hour after ET and at the time of discharge. This concept needs to be explored further in a larger dataset that will also include additional imaging parameters