Clinical and tissue response to intravenous thrombolysis in tandem internal carotid artery/middle cerebral artery occlusion: an MRI study.

BACKGROUND AND PURPOSE The benefit of intravenous thrombolysis in tandem internal carotid artery (ICA)/middle cerebral artery (MCA) occlusion remains unclear. We studied clinical and imaging outcome of intravenous thrombolysis in MRI-selected patients with tandem ICA/MCA occlusion as compared to isolated MCA occlusion. METHODS We analyzed data of MRI-selected acute ischemic stroke patients treated with intravenous tissue plasminogen activator within 6 hours. Initial perfusion and diffusion lesion volumes were calculated. Final infarct volume was assessed on follow-up imaging after 5 to 8 days. Recanalization/reperfusion was assessed after 24 hours using MRA. Favorable outcome was defined as a modified Rankin scale score of 0 to 1 after 90 days. RESULTS Of 38 patients with proximal MCA occlusion, 14 (37%) had a tandem ICA/MCA occlusion. Median NIHSS on admission (15 vs 15), initial perfusion (246 vs 246 mL), and diffusion lesion volume (22 vs 21 mL), final infarct volume (30 vs 39 mL), and the proportion of patients with a favorable outcome after 3 months (50% vs 46%) were similar in tandem ICA/MCA occlusion versus isolated MCA occlusion. CONCLUSIONS The presence of tissue at risk appears to play a key role for the likelihood of clinical recovery after intravenous tissue plasminogen activator treatment in acute stroke patients with tandem ICA/MCA occlusion. There appears to be no evidence to exclude patients with tandem ICA/MCA occlusion from intravenous thrombolysis.