JUM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nedelmann, M.
Right arrow Articles by Hopf, H. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nedelmann, M.
Right arrow Articles by Hopf, H. C.
© 2002 by the American Institute of Ultrasound in Medicine
J Ultrasound Med 21:649-656 • 0278-4297

Low-Frequency Ultrasound Induces Nonenzymatic Thrombolysis In Vitro

Max Nedelmann, MD, B. Martin Eicke, MD, Ernst G. Lierke, PhD, Axel Heimann, DVM, Oliver Kempski, MD and Hanns C. Hopf, MD

Department of Neurology (M.N., B.M.E., E.G.L., H.C.H.) and Institute for Neurosurgical Pathophysiology (A.H., O.K.), Johannes Gutenberg University, Mainz, Germany.

Address correspondence and reprint requests to Max Nedelmann, MD, Department of Neurology, Johannes Gutenberg University, Langenbeckstrasse 1, 55101 Mainz, Germany.

Objective. To evaluate whether ultrasound, applied over a distance of several centimeters and in the absence of thrombolytic agents, may have a thrombolytic effect on blood clots. Methods. Lowfrequency (20 kHz) continuous wave ultrasound at different intensity levels (0.15–1.2 W/cm2) and exposure times (5, 10, and 20 minutes) was assessed for its potential to induce thrombolysis of fresh human blood clots. The ultrasound effect was also studied in combination with recombinant tissue-type plasminogen activator–mediated thrombolysis. Experiments were carried out in a flow model in degassed sodium phosphate buffer at 37°C at a distance of 3 cm from the ultrasonic probe to the blood clots. Regardless of ultrasound exposure times, blood clots in all experimental groups and the control group were left in the flow system for 20 minutes. Results. The use of ultrasound alone showed a significant thrombolytic effect compared with the control group, with a statistically significant effect at 0.15 W/cm2 and exposure of 10 minutes (P = .02). There was a clear correlation between the extent of weight loss and the chosen intensity level and exposure time. Complete disruption in 8 of 10 blood clots occurred at 1.2 W/cm2 within 10 min. Addition of ultrasound to recombinant tissue-type plasminogen activator–mediated thrombolysis significantly enhanced thrombolysis compared with application of recombinant tissue-type plasminogen activator or ultrasound alone (P = .0001), with the results pointing toward a purely additive, nonsynergistic effect of the 2 treatment modalities. Lysis was more effective in fresh thrombi. Conclusions. The use of low-frequency ultrasound alone, without addition of a thrombolytic drug, has the potential to induce thrombolysis over a distance. Combination of ultrasound with recombinant tissue-type plasminogen activator is superior to either treatment alone. Ultrasound is a promising tool for developing an alternative or additional treatment modality for acute cerebral vessel occlusion.

Abbreviations: rt-PA, recombinant tissue-type plasminogen activator

Key Words: ultrasound • thrombolysis • fibrinolysis • tissue-type plasminogen activator • stroke




This article has been cited by other articles:


Home page
 StrokeHome page
T. Saguchi, H. Onoue, M. Urashima, T. Ishibashi, T. Abe, and H. Furuhata
Effective and Safe Conditions of Low-Frequency Transcranial Ultrasonic Thrombolysis for Acute Ischemic Stroke: Neurologic and Histologic Evaluation in a Rat Middle Cerebral Artery Stroke Model
Stroke, March 1, 2008; 39(3): 1007 - 1011.
[Abstract] [Full Text] [PDF]

Home page
 StrokeHome page
T. Wilhelm-Schwenkmezger, P. Pittermann, K. Zajonz, O. Kempski, M. Dieterich, and M. Nedelmann
Therapeutic Application of 20-kHz Transcranial Ultrasound in an Embolic Middle Cerebral Artery Occlusion Model in Rats: Safety Concerns
Stroke, March 1, 2007; 38(3): 1031 - 1035.
[Abstract] [Full Text] [PDF]

Home page
 StrokeHome page
F. Schneider, T. Gerriets, M. Walberer, C. Mueller, R. Rolke, B. M. Eicke, J. Bohl, O. Kempski, M. Kaps, G. Bachmann, et al.
Brain Edema and Intracerebral Necrosis Caused by Transcranial Low-Frequency 20-kHz Ultrasound: A Safety Study in Rats
Stroke, May 1, 2006; 37(5): 1301 - 1306.
[Abstract] [Full Text] [PDF]

Home page
 J Ultrasound MedHome page
B. M. Hardig, H. W. Persson, G. Gido, and S. B. Olsson
Does Low-Energy Ultrasound, Known to Enhance Thrombolysis, Affect the Size of Ischemic Brain Damage?
J. Ultrasound Med., December 1, 2003; 22(12): 1301 - 1308.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2002 by the American Institute of Ultrasound in Medicine.