title: Stent-thrombus interaction and the influence of aspiration on mechanical thrombectomy: evaluation of different stent retrievers in a circulation model.
abstract: BACKGROUND
  Different devices and techniques are available for endovascular treatment of ischemic stroke. In this in vitro study, we examined the stent-thrombus interaction and the influence of additional aspiration on the efficiency of mechanical thrombectomy with established stent retrievers.
  
  
  METHODS
  Human blood thrombi were made in a Chandler loop. The thrombi were placed into the middle cerebral artery of a vascular silicon phantom. A programmable piston pump was used to acquire physiological flow in the model. Resistances were interposed to gain physiological pressure. The stent retrievers Trevo, Solitaire FR, Separator 3D, and Aperio were used to perform thrombectomy under direct visual control. For the additional aspiration, we used intermediate catheters.
  
  
  RESULTS
  Ten attempts per device were made with and without aspiration under standardized conditions, a total of n = 80. For all thrombectomy maneuvers, it was demonstrated that the thrombus was pushed by the stent struts against the vessel wall and was retracted along it. The stent-thrombus interaction was only superficial for all devices. Using additional distal aspiration, the amount of distal embolism and rate of embolism in new territories was significantly lower than without. Moreover, additional aspiration reduced the number of recanalization maneuvers and the recanalization time.
  
  
  CONCLUSIONS
  Distal aspiration with intermediate catheters increases the efficacy of mechanical thrombectomy with stent retrievers significantly. In contrary to earlier suggestions, the interaction between the thrombus and the stent retriever is only superficial, rather than an integration of the thrombus into the retriever. No significant differences between the proven devices could be shown in our model.
authors.affiliation: Department of Radiology and Neuroradiology, Hospital Schleswig-Holstein (UKSH), Arnold-Heller-Str. 3, House 41, 24105, Kiel, Schleswig-Holstein, Germany, jawid.madjidyar@uksh.de.
authors.forename: Jawid
authors.initials: J
authors.lastname: Madjidyar
authors.forename: Julian
authors.initials: J
authors.lastname: Hermes
authors.forename: Sandra
authors.initials: S
authors.lastname: Freitag-Wolf
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
mesh_terms: D001783:Blood Flow Velocity; D001807:Blood Vessel Prosthesis; D020878:Device Removal / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D061185:Mechanical Thrombolysis / Q000295:instrumentation*; D015607:Stents; D013396:Suction / Q000295:instrumentation; D013526:Surgical Mesh; D013927:Thrombosis / Q000503:physiopathology* / Q000628:therapy*; D016896:Treatment Outcome