2MHz ultrasound enhances t-PA-mediated thrombolysis: comparison of continuous versus pulsed ultrasound and standing versus travelling acoustic waves.
In addition to fibrinolytic enzymes, ultrasound has the potential to enhance thrombolysis. High frequency ultrasound has the advantage that a combination of diagnostic and therapeutic ultrasound with only one device is possible. Therefore, we investigated the optimal high frequency (2 MHz) ultrasound field characteristics and application mode in vitro. Continuous ultrasound significantly enhanced rt-PA mediated thrombolysis: in a travelling wave field thrombolysis was augmented by 49.0 +/- 14.7% and in a standing wave field by 34.8 +/- 7.3%. In an intermittent application mode (1Hz, 10Hz, 100Hz, 1kHz) most efficient results were obtained for both wave fields using 1 Hz (46.4 +/- 10.7% and 39.1 +/- 6.6%, respectively). Referring to a possible in vivo application our in vitro data suggests that an intermittent application of a 2 MHz high frequency ultrasound using a travelling wave field would be the most potent application for lysing blood clots.
Pfaffenberger
Stefan
S
Department of Internal Medicine II, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
Devcic-Kuhar
Branka
B
El-Rabadi
Karem
K
Gröschl
Martin
M
Speidl
Walter S
WS
Weiss
Thomas W
TW
Huber
Kurt
K
Benes
Ewald
E
Maurer
Gerald
G
Wojta
Johann
J
Gottsauner-Wolf
Michael
M
D000162:Acoustics; D003131:Combined Modality Therapy; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D015912:Thrombolytic Therapy / Q000379:methods*; D013927:Thrombosis / Q000188:drug therapy / Q000378:metabolism / Q000628:therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014464:Ultrasonic Therapy / Q000379:methods*
D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D010959:Tissue Plasminogen Activator