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Enhancement of enzymatic fibrinolysis with 2‐MHz ultrasound and microbubbles
Author(s) -
Cintas P.,
Nguyen F.,
Boneu B.,
Larrue V.
Publication year - 2004
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/j.1538-7836.2004.00746.x
Subject(s) - microbubbles , fibrinolysis , thrombolysis , ultrasound , medicine , biomedical engineering , tissue plasminogen activator , nuclear medicine , chemistry , radiology , myocardial infarction
Summary. Background : Microbubbles used for echo‐contrast agents accelerate enzymatic fibrinolysis of clots exposed to low‐frequency ultrasound (US). It is not known whether microbubbles are also effective in enhancing high‐frequency US‐driven enzymatic fibrinolysis. Methods and results : Calibrated whole blood clots were exposed to US, or US and galactose‐based microbubbles (Levovist ® ), with or without recombinant tissue plasminogen activator (rt‐PA) in an in‐vitro flow system. We used low‐intensity, 2‐MHz, pulsed wave US. Relative weight reduction of clot ± SD was 30.7 ± 9.5% after exposure to microbubbles, rt‐PA and US, 13.1 ± 2.6% after exposure to rt‐PA and US, 10.9 ± 3.6% after exposure to microbubbles and US, and 6.1 ± 1.9% after exposure to US alone. anova demonstrated a significant effect of rt‐PA ( P = 0.001), microbubbles ( P = 0.012), and interaction of both ( P = 0.022). Conclusions : The application of galactose‐based microbubbles (Levovist ® ) strongly accelerates lysis of clots exposed to 2 MHz, low‐intensity US in vitro both with and without rt‐PA. The findings suggest a synergy between microbubbles and rt‐PA. These methods routinely used for transcranial diagnostic applications have the potential to improve the efficacy of intravenous rt‐PA in acute ischemic stroke.