Microbubble-Facilitated Ultrasound Catheter Ablation Causes Microvascular Damage and Fibrosis

• Published in: Ultrasound in medicine & biology Vol. 47; no. 1; pp. 131 - 138
• Main Authors: Nazer, Babak, Giraud, David, Zhao, Yan, Qi, Yue, Mason, O'Neil, Jones, Peter D., Diederich, Chris J., Gerstenfeld, Edward P., Lindner, Jonathan R.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.01.2021
• Subjects: Animals; Arrhythmias; Catheter Ablation - adverse effects; Catheter Ablation - methods; Electrophysiology; Fibrosis - etiology; Histotripsy; Mice; Microbubbles; Microbubbles - adverse effects; Microvessels - injuries; Phantoms, Imaging; Pulsed ultrasound ablation; Ultrasonic Therapy - adverse effects; Ultrasonic Therapy - methods; Microbubbles; Electrophysiology; Pulsed ultrasound ablation; Histotripsy; Arrhythmias
• ISSN: 0301-5629; 1879-291X
• DOI: 10.1016/j.ultrasmedbio.2020.09.007

High-intensity ultrasound (US) ablation produces deeper myocardial lesions than radiofrequency ablation. The presence of intravascular microbubble (MB) contrast agents enhances pulsed-wave US ablation via cavitation-related histotripsy, potentially facilitating ablation in persistently perfused/conducting myocardium. US ablation catheters were developed and tested in the presence of MBs using ex vivo and in vivo models. High-frame-rate videomicroscopy and US imaging of gel phantom models confirmed MB destruction by inertial cavitation. MB-facilitated US ablation in an ex vivo perfused myocardium model generated shallow (2 mm) lesions and, in an in vivo murine hindlimb model, reduced perfusion by 42% with perivascular hemorrhage and inflammation, but no myonecrosis.