Microparticle-containing oncotic solutions augment in-vitro clot disruption by ultrasound

Echocardiographic contrast agents enhance blood clot disruption by ultrasou nd. It has been suggested that the microbubbles add nuclei for the enhancem ent of cavitation by ultrasound. However, microbubbles are rapidly destroye d by the ultrasound energy, We assessed whether non-gas filled colloidal so lutions (hyperoncotic medium molecular hydroxyethyl starch and degraded gel atin polypeptides) will facilitate clot disruption by ultrasound. In two se parate experiments human blood clots, 200-400 mg in weight, were weighed an d then immersed for 15 seconds in 10 ml normal saline solution containing 0 %, 0.1%, 1%, 2%, and 5% of hyperoncotic medium molecular hydroxyethyl starc h or 0%, 0.035%, 0.175%, 0.35%, and 0.7% degraded gelatin polypeptides. Clo ts were randomized to 10 seconds 20 kHz ultrasound or immersion without ult rasound. After treatment, the clots were reweighed, and the percent differe nce in weight was calculated, Non-gas filled microparticle-containing solut ions such as hyperoncotic medium molecular hydroxyethyl starch and degraded gelatin polypeptides significantly augmented blood clot disruption by ultr asound. The effect is dependent on the colloidal solution concentration wit h maximal effect achieved with 1% hyperoncotic medium molecular hydroxyethy l starch and 0.35% degraded gelatin polypeptides. (C) 2000 Elsevier Science Ltd. All rights reserved.