Sonothrombolysis of intra-catheter aged venous thrombi using microbubble enhancement and guided three-dimensional ultrasound pulses.

BACKGROUND

Central venous and arterial catheters are a major source of thromboembolic disease in children. The investigators hypothesized that guided high-mechanical index (MI) impulses from diagnostic three-dimensional (3D) ultrasound during an intravenous microbubble infusion could dissolve these thrombi.

METHODS

An in vitro system simulating intracatheter thrombi was created and then treated with guided high-MI impulses from 3D ultrasound, using low-MI microbubble sensitive imaging pulse sequence schemes to detect the microbubbles. Ten aged thrombi >24 hours old were tested using 3D ultrasound coupled with a continuous diluted microbubble infusion (group A) and 10 with 3D ultrasound alone (group B).

RESULTS

The mean thrombus age was 28.6 hours (range, 26.6-30.3 hours). Group A exhibited a 55 +/- 19% reduction in venous thrombus size compared with 31 +/- 10% in group B (P = .008). Feasibility testing was performed in four pigs, establishing an in vivo model to investigate further the efficacy of this approach.

CONCLUSIONS

Sonothrombolysis of aged intracatheter venous thrombi can be achieved with commercially available microbubbles and guided high-MI ultrasound from a diagnostic 3D transducer.