title: Treatment of basilar artery embolism with a mechanical extraction device: necessity of flow reversal.
abstract: OBJECTIVE
  The success of local fibrinolysis in vertebrobasilar thromboembolism depends on the volume and composition of the clot. Since thrombolysis can also be time consuming and cause bleeding, we investigated the feasibility of a mechanical clot retraction device based on a nitinol basket advanced through a microcatheter.
  
  
  METHODS
  Five patients with acute embolism of the basilar artery who presented with progressive stroke and impaired consciousness were included in a multicenter study (Neuronet Evaluation in Embolic Stroke Disease [NEED]). In 3 patients flow reversal was induced with the use of silicone balloons or coaxial catheters. Three patients required additional fibrinolysis.
  
  
  RESULTS
  The device failed to retrieve the clots in our first 2 patients with distal basilar artery embolism. After successful recanalization by local fibrinolysis, both patients survived, 1 disabled and 1 with little residual impairment. In the next 3 patients the anterograde flow in the basilar artery was reversed during the short retraction period by temporarily blocking the vertebral or subclavian arteries. Two of these patients were completely recanalized by solely mechanical means; the third patient needed additional fibrinolysis before also being recanalized. All 3 patients survived: 1 remained disabled, 1 had almost a full recovery, and 1 became asymptomatic the day after the procedure.
  
  
  CONCLUSIONS
  Mechanical thrombus extraction seems to be a feasible method for preventing infarction by rapid, complete, and safe recanalization of the basilar artery. We recommend the use of flow control to support retrieval of the thrombus (which the proximal flow would otherwise keep in place like a cork) and to protect the distal vessels from embolization by fragments.
authors.affiliation: Department of Neuroradiology, Klinikum Grosshadern, Ludwig-Maximilians University, Munich, Germany. T.E.Mayer@ikra.med.uni-muenchen.de
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Mayer
authors.forename: Gerhard F
authors.initials: GF
authors.lastname: Hamann
authors.forename: Hartmut J
authors.initials: HJ
authors.lastname: Brueckmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000497:Alloys; D015901:Angiography, Digital Subtraction; D001488:Basilar Artery / Q000601:surgery*; D001921:Brain / Q000098:blood supply / Q000601:surgery; D002404:Catheterization / Q000295:instrumentation; D002533:Cerebral Angiography; D002544:Cerebral Infarction / Q000517:prevention & control; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology; D017128:Embolectomy / Q000295:instrumentation* / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D015600:Glasgow Coma Scale; D006801:Humans; D020766:Intracranial Embolism / Q000188:drug therapy / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000295:instrumentation* / Q000379:methods; D017131:Thrombectomy / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000497:Alloys; D005343:Fibrinolytic Agents; C013616:nitinol