An In Vivo Study on the Feasibility of Catheter-Assisted Pulsed Focused Ultrasound Ablation of Atherosclerotic Plaques.

OBJECTIVE

Atherosclerosis is a condition where arteries become constricted due to plaque deposition, impairing blood supply and potentially leading to stroke and other cardiovascular diseases. This study aims to develop a minimally invasive technology that combines focused ultrasound (FUS) with a catheter to remove arterial plaques through the cavitation effect.

METHODS

In this investigation, via an ex vivo study in atherosclerotic plaque samples, we demonstrated that the onset of cavitation events can be enhanced by placing a catheter in the focal spot of the FUS field. Then, in a balloon injury-induced rabbit atherosclerosis model, FUS treatments with and without a catheter in the FUS field were performed on the femoral artery at 500 kHz with a 4 MPa peak negative pressure (PNP), 10% duty cycle and 100 Hz pulse repetition rate.

RESULTS

In our ex vivo study using a catheter with a 0.67 mm diameter in the focal zone of an FUS transducer of 500 kHz center frequency, cavitation was initiated at a PNP of 1.9 MPa, whereas FUS alone required a PNP above 4 MPa to induce cavitation. In our in vivo study, FUS-only group demonstrated negligible lumen re-canalization effect by applying 4 MPa PNP, whereas using catheter-assisted FUS therapy resulted in maximum lumen re-canalization using the same PNP. Results were statistically significant between groups (p < 0.001).

CONCLUSION

The results showed that catheter-assisted pulsed FUS therapy was effective in re-canalizing a blocked artery.