Intra-arterial thrombolytic therapy for acute intracranial large artery occlusive disease in patients selected by magnetic resonance image

Background and purpose: We reported an experience of intra-arterial thrombolysis (IAT) study triaged by emergent MRI.

Methods: Patients were recruited if vascular occlusions were identified by emergent MRA. Urokinase was infused hyperselectively within 6h after onset to a maximum dose of 900,000IU or recanalization achieved with mechanical thrombus disruption. Heparin infusion was discontinued after 2 hemorrhage in the first 7 patients. TIMI grade 2 and 3 recanalization was recognized as successful. Favorable outcomes were mRS 0-3 at 3months.

Results: Among 4225 ischemic stroke patients during the 29months study period, 52 patients met the inclusion criteria with 49 screened by MRA and 3 screened by CT, 30 patients were enrolled and 25 were treated. Three patients (10%) were unable for the MRI examination due to time or equipment limit. There were 5 ICA, 13 MCA, and 7 VBA occlusions. Among 27 patients screened from MRA, 25 patients had the same occluded vessels and 2 patients had compatible occluded vessels confirmed by cerebral angiography. The median NIHSS was 26 and median time from symptom onset to IAT was 283min. Successful recanalization was achieved in 68% (17/25). Intracerebral hemorrhage was recognized as symptomatic in 3 (12%) and asymptomatic in 8 (32%) at 3months. Mortality was 32%. 36% patients had a mRS of 0-3 at 3months. Patients with lower initial NIHSS score (20.9 vs. 28.4, P=0.02) and MCA occlusions (69.3%, 9/13, P<0.001) tend to have favorable outcomes.

Conclusions: Though the incidence was low, IAT triage with emergent MRI appeared to be feasible. MRI screening might be incorporated in the future IAT studies. Mechanical thrombus disruption and heparin infusion in IAT might need further investigation in this area.