title: Augmentation of low-frequency ultrasound-induced clot disruption by hydroxyethyl starch is dependent on the duration and intensity of ultrasound exposure; an in vitro study.
abstract: We investigated the synergistic effect between low-frequency ultrasound (US) and hydroxyethyl starch (HAES) on blood clot disruption, using different HAES concentrations, US duration and intensity. Human blood clots, 200 to 400 mg in weight, were placed in tubes containing 10 mL of normal saline alone or with HAES 0.1%, 1% or 2%. Clots were randomized to four intensities of US exposure: none, low, medium and high (maximal amplitude of motion at the tip of the horn: 0, 96, 144 and 192 micro m, respectively), and for three durations of US exposure (10, 20 and 40 s). After treatment, the clots were reweighed, and the percent differences in weights were calculated. US intensity, US duration and HAES concentration had a significant effect on the blood clot dissolution (p < 0.001 for all three variables). HAES augmented clot dissolution only when US intensity was medium or high. With low intensity, HAES did not augment clot lysis.
  
  
  CONCLUSIONS
  microparticle-containing solutions, such as HAES, have a potential for augmenting clot disruption by US. This effect is highly dependent on US intensity.
authors.affiliation: The Laboratory of Cardiovascular Biology, Felsenstein Research Institute and the Department of Cardiology, Rabin Medical Center, Petah-Tiqva, Israel.
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Adler
authors.forename: Adi
authors.initials: A
authors.lastname: Dagan
authors.forename: Gregory
authors.initials: G
authors.lastname: Golovchiner
authors.forename: Zaza
authors.initials: Z
authors.lastname: Iakobishvili
authors.forename: Israel
authors.initials: I
authors.lastname: Matz
authors.forename: Eli
authors.initials: E
authors.lastname: Lev
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Siegel
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
mesh_terms: D000704:Analysis of Variance; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000627:therapeutic use*; D008863:Microspheres; D015912:Thrombolytic Therapy / Q000379:methods*; D013927:Thrombosis / Q000628:therapy*; D013997:Time Factors; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D006895:Hydroxyethyl Starch Derivatives