Intravenous thrombolysis of basilar artery occlusion: thrombus length versus recanalization success.
OBJECTIVE
In middle cerebral artery occlusion, probability of recanalization after intravenous tissue-type plasminogen activator thrombolysis (IVT) was reported to drop <1% for thrombi exceeding 8 mm. We aimed to evaluate the effect of thrombus length and location on success of recanalization after IVT in basilar artery occlusion.


METHODS
We evaluated 164 consecutive patients with angiography-proven basilar artery occlusion and available thrombus length. We excluded 24 patients who underwent endovascular treatment. All included patients (n=140) received IVT. Thrombolysis in myocardial infarction 2 to 3 was considered as successful recanalization.


RESULTS
Of the 140 included patients, 37 (26.4%) lacked post-treatment angiography, mostly because of early death. Of the remaining 103 patients, those with recanalization had shorter thrombi (median, 5.5 mm and mean, 9.7 mm) when compared with those with nonrecanalized (median, 15.0 mm and mean, 16.6 mm; P<0.001). Thrombi shorter than 10 mm had 70% to 80% probability of recanalization, whereas 10 to 20 mm, 20 to 30 mm, and >30 mm long thrombi had probabilities of 50% to 70%, 30% to 50%, and 20% to 30%, respectively. Patients with thrombi <10 mm (n=52) and recanalization had more frequently top-of-the basilar (92.5%) and less frequently caudal or midbasilar (7.5%) clot location (P=0.01). In multivariable analysis, thrombus length was independently associated with recanalization (P=0.001). Their relationship remained linear across all lengths.


CONCLUSIONS
Although recanalization of basilar artery occlusion with IVT depends on thrombus length, its probability even in patients with thrombi >30 mm (20%-30%) was substantially higher than minimal recanalization of middle cerebral artery thrombi exceeding 8 mm. There was no threshold length, beyond which basilar artery occlusion recanalization with IVT could ad hoc be deemed hopeless.
From the Department of Neurology (D.S., T.S., P.J.L.) and Helsinki Medical Imaging Center (H.S., O.S.), Helsinki University Central Hospital, Helsinki, Finland; and Molecular Neurology, Research Program Unit, Biomedicum Helsinki, and Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland (P.J.L.). daniel.strbian@hus.fi.
Daniel
D
Strbian
From the Department of Neurology (D.S., T.S., P.J.L.) and Helsinki Medical Imaging Center (H.S., O.S.), Helsinki University Central Hospital, Helsinki, Finland; and Molecular Neurology, Research Program Unit, Biomedicum Helsinki, and Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland (P.J.L.).
Tiina
T
Sairanen
From the Department of Neurology (D.S., T.S., P.J.L.) and Helsinki Medical Imaging Center (H.S., O.S.), Helsinki University Central Hospital, Helsinki, Finland; and Molecular Neurology, Research Program Unit, Biomedicum Helsinki, and Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland (P.J.L.).
Heli
H
Silvennoinen
From the Department of Neurology (D.S., T.S., P.J.L.) and Helsinki Medical Imaging Center (H.S., O.S.), Helsinki University Central Hospital, Helsinki, Finland; and Molecular Neurology, Research Program Unit, Biomedicum Helsinki, and Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland (P.J.L.).
Oili
O
Salonen
From the Department of Neurology (D.S., T.S., P.J.L.) and Helsinki Medical Imaging Center (H.S., O.S.), Helsinki University Central Hospital, Helsinki, Finland; and Molecular Neurology, Research Program Unit, Biomedicum Helsinki, and Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland (P.J.L.).
Perttu J
PJ
Lindsberg
D000368:Aged; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D015912:Thrombolytic Therapy; D013997:Time Factors; D014715:Vertebrobasilar Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy
thrombolytic therapy; thrombosis