Catheter-based high-intensity ultrasound for epicardial ablation of the left ventricle: Device design and in vivo feasiblity

Vasant A. Salgaonkar, Babak Nazer, Peter D. Jones, Yasuaki Tanaka, Alastair Martin, Bennett Ng, Srikant Duggirala, Chris J. Diederich, Edward P. Gerstenfeld

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

The development and in vivo testing of a high-intensity ultrasound thermal ablation catheter for epicardial ablation of the left ventricle (LV) is presented. Scar tissue can occur in the mid-myocardial and epicardial space in patients with nonischemic cardiomyopathy and lead to ventricular tachycardia. Current ablation technology uses radiofrequency energy, which is limited epicardially by the presence of coronary vessels, phrenic nerves, and fat. Ultrasound energy can be precisely directed to deliver targeted deep epicardial ablation while sparing intervening epicardial nerve and vessels. The proof-of-concept ultrasound applicators were designed for sub-xyphoid access to the pericardial space through a steerable 14-Fr sheath. The catheter consists of two rectangular planar transducers, for therapy (6.4 MHz) and imaging (5 MHz), mounted at the tip of a 3.5-mm flexible nylon catheter coupled and encapsulated within a custom-shaped balloon for cooling. Thermal lesions were created in the LV in a swine (n = 10) model in vivo. The ultrasound applicator was positioned fluoroscopically. Its orientation and contact with the LV were verified using A-mode imaging and a radio-opaque marker. Ablations employed 60-s exposures at 15 - 30 W (electrical power). Histology indicated thermal coagulation and ablative lesions penetrating 8 - 12 mm into the left ventricle on lateral and anterior walls and along the left anterior descending artery. The transducer design enabled successful sparing from the epicardial surface to 2 - 4 mm of intervening ventricle tissue and epicardial fat. The feasibility of targeted epicardial ablation with catheter-based ultrasound was demonstrated.

Original languageEnglish (US)
Title of host publicationEnergy-Based Treatment of Tissue and Assessment VIII
EditorsThomas P. Ryan
PublisherSPIE
ISBN (Electronic)9781628414165
DOIs
StatePublished - Jan 1 2015
Event2015 SPIE Conference: Energy-Based Treatment of Tissue and Assessment - San Francisco, United States
Duration: Feb 8 2015Feb 9 2015

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume9326
ISSN (Print)1605-7422

Other

Other2015 SPIE Conference: Energy-Based Treatment of Tissue and Assessment
CountryUnited States
CitySan Francisco
Period2/8/152/9/15

Keywords

  • HIFU
  • cardiac ablation
  • image guidance
  • therapeutic ultrasound
  • ventricular tachycardia

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

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    Salgaonkar, V. A., Nazer, B., Jones, P. D., Tanaka, Y., Martin, A., Ng, B., Duggirala, S., Diederich, C. J., & Gerstenfeld, E. P. (2015). Catheter-based high-intensity ultrasound for epicardial ablation of the left ventricle: Device design and in vivo feasiblity. In T. P. Ryan (Ed.), Energy-Based Treatment of Tissue and Assessment VIII [93260H] (Progress in Biomedical Optics and Imaging - Proceedings of SPIE; Vol. 9326). SPIE. https://doi.org/10.1117/12.2079629