Echocardiographic
contrast agents enhance
blood clot disruption by ultrasound. It has been suggested that the
microbubbles add nuclei for the enhancement of cavitation by ultrasound. However,
microbubbles are rapidly destroyed by the ultrasound energy. We assessed whether non-gas filled colloidal solutions (hyperoncotic medium molecular hydroxyethyl
starch and degraded
gelatin polypeptides) will facilitate clot disruption by ultrasound. In two separate experiments human
blood clots, 200-400 mg in weight, were weighed and then immersed for 15 seconds in 10 ml
normal saline solution containing 0%, 0.1%, 1%, 2%, and 5% of hyperoncotic medium molecular hydroxyethyl
starch or 0%, 0.035%, 0.175%, 0.35%, and 0.7% degraded
gelatin polypeptides. Clots were randomized to 10 seconds 20 kHz ultrasound or immersion without ultrasound.
After treatment, the clots were reweighed, and the percent difference in weight was calculated. Non-gas filled microparticle-containing solutions such as hyperoncotic medium molecular hydroxyethyl
starch and degraded
gelatin polypeptides significantly augmented
blood clot disruption by ultrasound. The effect is dependent on the colloidal
solution concentration with maximal effect achieved with 1% hyperoncotic medium molecular hydroxyethyl
starch and 0.35% degraded
gelatin polypeptides.