title: Ultrasound accelerates thrombolysis of acutely induced platelet-rich thrombi similar to those in acute myocardial infarction.
abstract: BACKGROUND
  Although sonothrombolysis has been studied for development of recanalization that is safer and more efficacious than the methods currently used, there have been no studies of the efficacy of sonothrombolysis for the platelet-rich thrombi that typically cause acute myocardial infarction (AMI). The effects of adding ultrasound (US) to pharmacological lysis of platelet-rich thrombi was examined in a rabbit model of femoral artery occlusion.
  
  
  RESULTS
  In 35 rabbits, the right femoral artery was balloon-injured repeatedly at 4-week intervals to induce platelet-rich thrombi. Two hours after the induction of occlusive thrombi, 27,500 IU/kg tissue plasminogen activator (tPA) were injected via an ear vein, with or without transcutaneous US (continuous wave, 1 MHz, 0.75 W/cm2), or 13,750 IU/kg tPA was administered with US (n=10). Significantly higher rates of successful thrombolysis (Thrombolysis In Myocardial Infarction grade 3) were observed with US (90.0%) than without it (10.0%), irrespective of the dose of tPA used (p<0.01). The peak flow velocity in affected femoral arteries was significantly higher with US (p<0.01), and histological examination confirmed complete dissolution of thrombi. However, the thrombi were not affected by US alone (n=5).
  
  
  CONCLUSIONS
  US facilitates thrombolysis of platelet-rich thrombi and could be a useful component of thrombolytic therapy following AMI.
authors: First Department of Internal Medicine, Nara Medical University, 840 Shijo-cho, Kashihara 634-8522, Japan. hkawata@naramed-u.ac.jp
authors: Hiroyuki
authors: H
authors: Kawata
authors: Noriyuki
authors: N
authors: Naya
authors: Yasuhiro
authors: Y
authors: Takemoto
authors: Shiro
authors: S
authors: Uemura
authors: Tamio
authors: T
authors: Nakajima
authors: Manabu
authors: M
authors: Horii
authors: Yukiji
authors: Y
authors: Takeda
authors: Shinichi
authors: S
authors: Fujimoto
authors: Atsushi
authors: A
authors: Yamashita
authors: Yujiro
authors: Y
authors: Asada
authors: Yoshihiko
authors: Y
authors: Saito
mesh_terms: D000792:Angiography; D000818:Animals; D001792:Blood Platelets / Q000473:pathology; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005263:Femoral Artery / Q000000981:diagnostic imaging* / Q000473:pathology; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006331:Heart Diseases / Q000150:complications / Q000473:pathology / Q000628:therapy*; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology*; D011817:Rabbits; D015912:Thrombolytic Therapy / Q000379:methods*; D013927:Thrombosis / Q000150:complications / Q000473:pathology / Q000628:therapy*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014464:Ultrasonic Therapy / Q000379:methods*; D014463:Ultrasonography
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator