title: Can a commercial diagnostic ultrasound device accelerate thrombolysis? An in vitro skull model.
abstract: OBJECTIVE
  Recently, 3 clinical trials revealed encouraging results in recanalization and clinical outcome in acute stroke patients when 2-MHz transcranial Doppler monitoring was applied. This study investigated whether a 1.8-MHz commercial diagnostic ultrasound device has the potential to facilitate thrombolysis using an in vitro stroke model.
  
  
  METHODS
  Duplex-Doppler, continuous wave-Doppler, and pulsed wave (PW)-Doppler were compared on their impact on recombinant tissue plasminogen activator (rtPA)-mediated thrombolysis. Blood clots were transtemporally sonicated in a human stroke model. Furthermore, ultrasound attenuation of 5 temporal bones of different thickness was determined.
  
  
  RESULTS
  In comparison, only PW-Doppler accelerated rtPA-mediated thrombolysis significantly. Without temporal bone, PW-Doppler plus rtPA showed a significant enhancement in relative clot weight loss of 23.7% when compared with clots treated with rtPA only (33.9+/-5.5% versus 27.4+/-5.2%; P<0.0005). Ultrasound attenuation measurements revealed decreases of the output intensity of 86.8% (8.8 dB) up to 99.2% (21.2 dB), depending on temporal bone thickness (1.91 to 5.01 mm).
  
  
  CONCLUSIONS
  Without temporal bone, PW-Doppler significantly enhanced thrombolysis. However, because of a high attenuation of ultrasound by temporal bone, no thrombolytic effect was observed in our in vitro model, although Doppler imaging through the same temporal bone was still possible.
authors.affiliation: Department of Internal Medicine II, University of Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Pfaffenberger
authors.forename: Branka
authors.initials: B
authors.lastname: Devcic-Kuhar
authors.forename: Christian
authors.initials: C
authors.lastname: Kollmann
authors.forename: Stefan P
authors.initials: SP
authors.lastname: Kastl
authors.forename: Christoph
authors.initials: C
authors.lastname: Kaun
authors.forename: Walter S
authors.initials: WS
authors.lastname: Speidl
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Weiss
authors.forename: Svitlana
authors.initials: S
authors.lastname: Demyanets
authors.forename: Robert
authors.initials: R
authors.lastname: Ullrich
authors.forename: Heinz
authors.initials: H
authors.lastname: Sochor
authors.forename: Christian
authors.initials: C
authors.lastname: Wöber
authors.forename: Josef
authors.initials: J
authors.lastname: Zeitlhofer
authors.forename: Kurt
authors.initials: K
authors.lastname: Huber
authors.forename: Martin
authors.initials: M
authors.lastname: Gröschl
authors.forename: Ewald
authors.initials: E
authors.lastname: Benes
authors.forename: Gerald
authors.initials: G
authors.lastname: Maurer
authors.forename: Johann
authors.initials: J
authors.lastname: Wojta
authors.forename: Michael
authors.initials: M
authors.lastname: Gottsauner-Wolf
mesh_terms: D001777:Blood Coagulation; D005343:Fibrinolytic Agents / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D012886:Skull / Q000000981:diagnostic imaging*; D020521:Stroke / Q000097:blood / Q000000981:diagnostic imaging / Q000188:drug therapy*; D013701:Temporal Bone / Q000000981:diagnostic imaging; D015912:Thrombolytic Therapy / Q000295:instrumentation*; D010959:Tissue Plasminogen Activator / Q000494:pharmacology / Q000627:therapeutic use; D018616:Ultrasonography, Doppler, Duplex; D018617:Ultrasonography, Doppler, Pulsed; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator