Presence of the hyperintense acute reperfusion marker on MRI after mechanical thrombectomy for large vessel occlusion is associated with worse early neurological recovery.

BACKGROUND: Mechanical thrombectomy has become the accepted treatment for large vessel occlusion in acute ischemic stroke. Unfortunately, a large cohort of patients do not achieve functional independence with treatment, even though the results are more robust than with medical management. The hyperintense acute reperfusion marker (HARM) on MRI is an indication of the breakdown of the blood-brain barrier and reperfusion injury. OBJECTIVE: To examine the hypothesis that the presence of HARM on MRI correlates with worse neurological recovery after reperfusion therapy. METHODS: We retrospectively reviewed 35 consecutive patients who between February 24, 2016 and April 23, 2016 underwent MRI to determine the presence of HARM after thrombectomy for anterior circulation large vessel occlusion. Demographic, radiographic imaging, and outcome data were collected. Univariate and binary logistic regression models were performed to assess predictors for improvement of the National Institutes of Health Stroke Scale (NIHSS) score by ≥8 points at 24 hours. RESULTS: The 35 patients studied had an average age of 64±14 years of age with a median NIHSS score of 15 (IQR 9-20). Eighteen patients (51%) were found to have a HARM-positive MRI. In univariate analysis, patients with HARM were older, had lower reperfusion rates and more postprocedural hemorrhages. In binary logistic regression modeling, the absence of HARM was independently associated with a ≥8-point NIHSS score improvement at 24 hours (OR=7.14, 95% CI 1.22 to 41.67). CONCLUSIONS: This preliminary analysis shows that the presence of HARM may be linked to worse neurological recovery 24 hours after thrombectomy. Reperfusion injury may affect the number of patients achieving functional independence after treatment.

Longer procedural times are independently associated with symptomatic intracranial hemorrhage in patients with large vessel occlusion stroke undergoing thrombectomy.

BACKGROUND: Time to reperfusion is an essential factor in determination of outcomes in acute ischemic stroke (AIS). OBJECTIVE: To establish the effect of the procedural time on the clinical outcomes of patients with AIS. METHODS: Data from all consecutive patients who underwent mechanical thrombectomy between September 2010 and July 2012 were analysed retrospectively. The variable of interest was procedural time (defined as time from groin puncture to final recanalization time). Outcome measures included the rates of symptomatic intracranial hemorrhage (sICH, defined as any parenchymal hematoma-eg, PH-1/PH-2), final infarct volume, 90-day mortality, and independent functional outcomes (modified Rankin Scale 0-2) at 90 days. RESULTS: The cohort included 242 patients with a mean age of 65.5±14.2 and median baseline National Institutes of Health Stroke Scale score 20. 51% of the patients were female. The mean procedure time was significantly shorter in patients with a good outcome (86.7 vs 73.1 min, respectively, p=0.0228). Patients with SICH had significantly higher mean procedure time than patients without SICH (79.67 vs 104.5 min, respectively; p=0.0319), which remained significant when controlling for the previous factors (OR=0.974, 95% CI 0.957 to 0.991). No correlation was found between the volume of infarction and the procedure time (r=0.10996, p=0.0984). No association was seen between procedure time and 90-day mortality (77.8 vs 88.2 min in survivals vs deaths, respectively; p=0.0958). CONCLUSIONS: Our data support an association between the risk of SICH and a longer procedure time, but no association between procedural times and the final infarction volume or long-term functional outcomes was found.

Clinical, angiographic and radiographic outcome differences among mechanical thrombectomy devices: initial experience of a large-volume center.

BACKGROUND AND PURPOSE: Higher reperfusion rates have been established with endovascular treatment of acute ischemic stroke (AIS). There are limited data on the comparative performance of mechanical thrombectomy devices. METHODS: A retrospective single-center analysis was undertaken of all consecutive patients who underwent thrombectomy using Merci, Penumbra or stent retrievers (SR) from September 2010 to November 2012. Baseline characteristics, rates of successful recanalization (modified Thrombolysis in Cerebral Infarction (mTICI) score 2b-3), symptomatic intracerebral hemorrhage (sICH), final infarct volume, 90-day mortality and independent functional outcomes at 90 days were compared across the three devices. RESULTS: Our cohort included 287 patients. There were mild imbalances in baseline characteristics with trends towards higher National Institutes of Health Stroke Scale (NIHSS) score in patients in the Merci group (SR=18 vs Merci=21 vs Penumbra=19, p=0.06) and lower Alberta Stroke Program Early CT Score (ASPECTS) in patients in the SR group (>7: SR=51% vs Merci=61% vs Penumbra=62%, p=0.12). On univariate analysis there were no differences in the rate of sICH (SR=7% vs Merci=7% vs Penumbra=6%, p=0.921) and infarct volume (SR=61.5 mL vs Merci=69.5 mL vs Penumbra=59.2 mL, p=0.621). Trends towards better functional outcomes were found with Penumbra and SR vs Merci (41% vs 36% vs 25%, respectively, p=0.079). Complete or near complete reperfusion (mTICI 2b-3) was higher in the SR and Penumbra groups than in the Merci group (86% vs 78% vs 70%, respectively, p=0.027). Binary logistic regression showed that SR was an independent predictor of good functional outcome (OR 2.27, 95% CI 1.018 to 5.048; p=0.045). CONCLUSIONS: Although our initial data confirm the superiority of SR technology over the Merci device, there was no significant difference in near complete/complete reperfusion, final infarct volumes or clinical outcomes between SR and Penumbra thromboaspiration.