Can a Commercial Diagnostic Ultrasound Device Accelerate Thrombolysis?: An In Vitro Skull Model

S. Pfaffenberger, B. Devcic-Kuhar, C. Kollmann, S. P. Kastl, C. Kaun, W. S. Speidl, T. W. Weiss, S. Demyanets, R. Ullrich, H. Sochor, C. Wober, J. Zeitlhofer (+6 others)
2004 Stroke  
and Purpose-Recently, 3 clinical trials revealed encouraging results in recanalization and clinical outcome in acute stroke patients when 2-MHz transcranial Doppler monitoring was applied. This study investigated whether a 1.8-MHz commercial diagnostic ultrasound device has the potential to facilitate thrombolysis using an in vitro stroke model. Methods-Duplex-Doppler, continuous wave-Doppler, and pulsed wave (PW)-Doppler were compared on their impact on recombinant tissue plasminogen activator
more » ... (rtPA)-mediated thrombolysis. Blood clots were transtemporally sonicated in a human stroke model. Furthermore, ultrasound attenuation of 5 temporal bones of different thickness was determined. Results-In comparison, only PW-Doppler accelerated rtPA-mediated thrombolysis significantly. Without temporal bone, PW-Doppler plus rtPA showed a significant enhancement in relative clot weight loss of 23.7% when compared with clots treated with rtPA only (33.9Ϯ5.5% versus 27.4Ϯ5.2%; PϽ0.0005). Ultrasound attenuation measurements revealed decreases of the output intensity of 86.8% (8.8 dB) up to 99.2% (21.2 dB), depending on temporal bone thickness (1.91 to 5.01 mm). Conclusion-Without temporal bone, PW-Doppler significantly enhanced thrombolysis. However, because of a high attenuation of ultrasound by temporal bone, no thrombolytic effect was observed in our in vitro model, although Doppler imaging through the same temporal bone was still possible. (Stroke. 2005;36:124-128.)
doi:10.1161/01.str.0000150503.10480.a7 pmid:15591211 fatcat:lo7xv2jvfbcwxpmgfsh5govene