Histotripsy and Catheter-Directed Lytic: Efficacy in Highly Retracted Porcine Clots In Vitro

Area of Science:

• Biomedical Engineering
• Interventional Radiology
• Cardiovascular Research

Background:

• Standard deep vein thrombosis (DVT) treatments face challenges with chronic, resistant thrombi.
• Histotripsy, utilizing mechanical cavitation, shows promise in augmenting thrombolytic therapies.

Purpose of the Study:

• To evaluate the efficacy of histotripsy in enhancing recombinant tissue plasminogen activator (rt-PA) mediated thrombolysis.
• To assess histotripsy's effectiveness on highly retracted porcine clots in an in vitro DVT flow model.

Main Methods:

• Porcine clots were treated with saline, rt-PA, histotripsy, or combinations with DEFINITY.
• Histotripsy employed 1.5 MHz pulses at 33.2 MPa peak negative pressure and 40 Hz pulse repetition frequency.
• B-Mode and passive cavitation imaging monitored bubble activity during treatment.

Main Results:

• Histotripsy with or without rt-PA demonstrated superior thrombolytic efficacy compared to controls.
• Histotripsy combined with rt-PA achieved 86.1% flow recovery, significantly outperforming histotripsy with saline (61.7%).
• The addition of DEFINITY did not improve thrombolytic efficacy or cavitation dose.

Conclusions:

• Histotripsy effectively enhances thrombolytic efficacy for DVT, even with chronic clots.
• The combination of histotripsy and rt-PA shows significant potential for DVT treatment in a physiological flow environment.