Reperfusion rates following intra-arterial thrombolysis for acute ischemic stroke: The influence of the method for alteplase delivery

BACKGROUND AND PURPOSE: Because alteplase does not penetrate thrombus effectively, this study examined whether a method thought to maximize surface distribution of alteplase on the offending thrombus during IATT would result in greater reperfusion rates in acute ischemic stroke. MATERIALS AND METHODS: Clinical information, arteriograms, and CT scans following treatment from 85 consecutive patients who underwent IATT by using alteplase within 6 hours of stroke symptom onset were reviewed. Alteplase was delivered through a microcatheter embedded within the thrombus at 1 mg per minute in all cases, and the delivery never exceeded 100 mg of alteplase. Patients who underwent microcatheter contrast injections confirming that alteplase surrounded the thrombus were compared with patients who did not. RESULTS: Greater than 50% vascular territory reperfusion occurred in 82.2% of patients who underwent IATT with the intention of optimizing alteplase delivery versus 30.0% in patients without this intention (P < .0001, Pearson correlation) with an odds ratio of 15.8 based on nominal regression analysis. Hemorrhagic complication rates between methods were similar. The mRS at 1-3 months, infarct volume, change in NIHSS score by 24 hours, and hospital discharge were positively affected by optimizing alteplase delivery. CONCLUSIONS: A method that intends to evenly distribute alteplase around a thrombus resulted in better reperfusion rates and clinical outcomes compared with methods without this intention. Other predictors positively influencing reperfusion included the presence of slow antegrade flow distal to the clot, earlier time to treatment, lower presenting NIHSS score, and proximal occlusion site.