Ultrasound enhanced systemic thrombolysis (UEST), also known as sonothrombolysis, is a method that uses ultrasound waves to mechanically break the thrombi, or clots, using the vibration carried via soundwaves.^[1] A large portion of initial research was conducted by Christy Holland, a Professor at the University Cincinnati and the Director of the University of Cincinnati Heart, Lung, and Vascular Institute, who also holds the patent for use of trans cranial ultrasound in stroke patients.^[2] One of the main studies characterizing the use of UEST in the setting of acute stroke was the CLOTBUST Trial, which was published in 2004 in the Journal of Neuroimaging.^[3] Since then, research with UEST has explored its use in other thrombotic scenarios such as pulmonary embolism and deep vein thrombosis. One major advantage of using ultrasound versus systemic thrombolysis is a reduced risk of bleeding, and improved heart function in the case of pulmonary embolism.^[4]

UEST works by using ultrasound waves at different frequencies as an additional treatment that works with the conventional thrombolytics such as tissue plasminogen activator (tPA). Typically, frequencies are in the megahertz (MHz) range,^[5] however, some studies suggest that there is no statistically significant difference in frequency use 2 MHz or <2 MHz in the setting of ischemic stroke.^[6]

While there is a lot of promise in the use of sonothrombolysis, there are limitations at this time. For example, in the setting of ischemic stroke, patients with MCA territory stroke benefit the most. Moreover, the thickness of the temporal bone may also reduce efficacy of sonothrombolysis.^[12] With regard to use in cardiac disease, the coronary arteries are much more difficult to visualize with ultrasound for several reasons including obstructions and movement of the arteries while the heart contracts and relaxes.^[13]

As ultrasound technology advances, the applications continue to expand. For instance, the use of a mobile ultrasound that can pair to mobile devices could be used instead of a bulky machine, which could allow for increased access to the technology.^[14] Additionally, as the technology advances, there could be potential for sonothrombolysis to replace conventional thrombolytics given its safer side-effect profile and good efficacy.

• Reperfusion therapy
• Stroke
• Thrombolysis
• Ultrasound
• Pulmonary Embolism
• Deep Vein Thrombosis
• Myocardial Infarction
• Anticoagulation