title: High-intensity focused US: a potential new treatment for GI bleeding.
abstract: BACKGROUND
  High-intensity focused US has been shown to achieve hemostasis in lacerated large veins and arteries. High-intensity focused US was studied as a potential endoscopic treatment for GI bleeding.
  
  
  METHODS
  A segment of the auricular vein of the rabbit was lacerated longitudinally and then treated with a high-intensity focused US transducer driven at 3.9 MHz (focal intensity of 750 W/cm(2)) in 15 animals until hemostasis was achieved. Sham treatment was delivered to 3 vessels. Rabbits were euthanized on days 0, 2, 7, 14, and 28 to allow for histologic evaluation of the response to treatment.
  
  
  RESULTS
  Hemostasis was achieved in all treated vessels and in none of the sham treatments. Mean treatment time was 13 seconds. Histology initially demonstrated acute thermal injury with subsequent thrombus formation and chronic inflammation leading to replacement of the vessel by fibrous scar tissue.
  
  
  CONCLUSIONS
  High-intensity focused US causes hemostasis in acutely bleeding veins and results in occlusion of treated vessel with subsequent granulation tissue formation.
authors.affiliation: Department of Medicine, Division of Gastroenterology, Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle 98195-6424, USA.
authors.forename: Joo Ha
authors.initials: JH
authors.lastname: Hwang
authors.forename: Shahram
authors.initials: S
authors.lastname: Vaezy
authors.forename: Roy W
authors.initials: RW
authors.lastname: Martin
authors.forename: Mee-Yon
authors.initials: MY
authors.lastname: Cho
authors.forename: Misty L
authors.initials: ML
authors.lastname: Noble
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Crum
authors.forename: Michael B
authors.initials: MB
authors.lastname: Kimmey
mesh_terms: D000818:Animals; D001707:Biopsy, Needle; D004195:Disease Models, Animal; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000473:pathology* / Q000628:therapy*; D006489:Hemostatic Techniques; D007150:Immunohistochemistry; D008297:Male; D011817:Rabbits; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014464:Ultrasonic Therapy / Q000295:instrumentation / Q000379:methods*