Ultrasound and thrombolysis

Area of Science:

• Biomedical Engineering
• Cardiovascular Medicine
• Medical Imaging

Background:

• Current treatments for arterial and venous thrombotic disease, such as thrombolytic therapy and mechanical interventions, have limitations including reperfusion failure and complications like bleeding and vessel damage.
• Ultrasound technology is emerging as a promising therapeutic tool for thrombotic conditions.

Purpose of the Study:

• To review the therapeutic potential of ultrasound in treating thrombotic disease.
• To explore two distinct ultrasound approaches: high-intensity for mechanical clot disruption and low-intensity for augmenting enzymatic fibrinolysis.

Main Methods:

• High-intensity ultrasound delivered via catheter or transcutaneously to mechanically fragment clots.
• Low-intensity ultrasound applied to enhance enzymatic thrombolysis, focusing on non-thermal mechanisms and frequency-dependent effects.
• Evaluation in in vitro studies, animal models, and initial clinical investigations.

Main Results:

• High-intensity ultrasound demonstrated clot fragmentation in vitro and in animal models, with initial clinical studies showing promise for peripheral/coronary arterial thrombosis and bypass grafts.
• Low-intensity ultrasound accelerated enzymatic thrombolysis via improved drug transport, particularly at lower frequencies offering better penetration and less heating.
• Animal models confirmed accelerated thrombolysis, increased reperfusion, and minimal toxicity with low-intensity ultrasound.

Conclusions:

• Ultrasound presents a novel therapeutic strategy for occlusive thrombotic disease.
• Both mechanical disruption of thrombi using high-intensity ultrasound and enhanced enzymatic thrombolysis with low-intensity ultrasound show significant potential.
• Ultrasound offers a promising alternative or adjunct to existing treatments for thrombotic conditions, with potential for improved outcomes and reduced complications.