title: Mechanical thrombectomy for acute ischemic stroke: thrombus-device interaction, efficiency, and complications in vivo.
abstract: OBJECTIVE
  Mechanical thrombectomy is a promising new modality of interventional stroke treatment. The various devices differ with regard to where they apply force on the thrombus, taking a proximal approach such as aspiration devices or a distal approach such as basket-like devices. The study compares the in vivo effectiveness and thrombus-device interaction of these 2 approaches.
  
  
  METHODS
  Angiography and embolization with a radioopaque whole blood thrombus was performed in 10 swine. Mechanical thrombectomy was performed in 20 cranial vessels using a proximal aspiration device (Vasco35) and a distal basket-like device (Catch) with and without proximal balloon occlusion. Fifty-six retrieval attempts were made.
  
  
  RESULTS
  The proximal device allowed fast repeated application with a low risk of thromboembolic events (3%) and vasospasm, but it had a significantly lower success rate (39.4%) in retrieving thrombotic material than the distal device (DD) (82.6%; odds ratio, 7.3; 95% CI, 2.0 to 26.4). The compaction of the thrombus during retrieval with DD increased the risk of vessel wall irritation significantly (P<0.01) and complicated retrieval into the guiding catheter. The number of embolic events was significantly higher with DD (26%; odds ratio, 11.3; 95% CI, 1.35 to 101.6) unless proximal balloon occlusion was used.
  
  
  CONCLUSIONS
  The proximal and the distal approaches to mechanical thrombectomy proved to be effective at achieving recanalization of cranial vessels. The proximal device is faster in application and allowed repeated attempts with a low complication rate. The DD is more successful at removing thrombotic material, but its method of application and attendant thrombus compaction increase the risk of thromboembolic events and vasospasms.
authors.affiliation: Department of Interventional and Diagnostic Neuroradiology, University of Bern, Bern, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Gralla
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schroth
authors.forename: Luca
authors.initials: L
authors.lastname: Remonda
authors.forename: Krassen
authors.initials: K
authors.lastname: Nedeltchev
authors.forename: Johannes
authors.initials: J
authors.lastname: Slotboom
authors.forename: Caspar
authors.initials: C
authors.lastname: Brekenfeld
mesh_terms: D000208:Acute Disease; D000818:Animals; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000601:surgery*; D011859:Radiography; D020521:Stroke / Q000000981:diagnostic imaging / Q000601:surgery*; D013552:Swine; D017131:Thrombectomy / Q000379:methods*; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000601:surgery*