Enhanced intravascular lithotripsy (IVL) with ultrasound-shockwave catheter

Intravascular shockwave lithotripsy (IVL) is an effective treatment for vascular calcification. Previous studies suggest that ultrasound can enhance the efficiency of extracorporeal shockwave lithotripsy (ESWL) by mitigating the bubble shielding effect. We developed a novel ultrasound-shockwave catheter that combines flowing liquid and ultrasound to suppress bubble shielding and enhance lithotripsy efficiency. Experimental results confirm the bubble shielding effect in IVL, which can be mitigated by flowing liquid or ultrasound. Fracture experiments using Ultracal-30 as phantoms demonstrate the ultrasound emitted after 10 ms of shockwave generation and combines with bubbles can enhance lithotripsy efficiency. Specifically, the addition of ultrasound and bubbles reduced the mass percentage of fragments larger than 4.5 mm by 38.56 % compared to the control. Spectrum analysis of ultrasound reveals cavitation's role in improving lithotripsy efficiency. In summary, while bubbles initially attenuate shockwave intensity and reduce lithotripsy efficiency, their combination with ultrasound-induced cavitation enhances treatment outcomes.