Ultrasound-guided tissue fractionation by high intensity focused ultrasound in an in vivo porcine liver model.
The clinical use of high intensity focused ultrasound (HIFU) therapy for noninvasive tissue ablation has been recently gaining momentum. In HIFU, ultrasound energy from an extracorporeal source is focused within the body to ablate tissue at the focus while leaving the surrounding organs and tissues unaffected. Most HIFU therapies are designed to use heating effects resulting from the absorption of ultrasound by tissue to create a thermally coagulated treatment volume. Although this approach is often successful, it has its limitations, such as the heat sink effect caused by the presence of a large blood vessel near the treatment area or heating of the ribs in the transcostal applications. HIFU-induced bubbles provide an alternative means to destroy the target tissue by mechanical disruption or, at its extreme, local fractionation of tissue within the focal region. Here, we demonstrate the feasibility of a recently developed approach to HIFU-induced ultrasound-guided tissue fractionation in an in vivo pig model. In this approach, termed boiling histotripsy, a millimeter-sized boiling bubble is generated by ultrasound and further interacts with the ultrasound field to fractionate porcine liver tissue into subcellular debris without inducing further thermal effects. Tissue selectivity, demonstrated by boiling histotripsy, allows for the treatment of tissue immediately adjacent to major blood vessels and other connective tissue structures. Furthermore, boiling histotripsy would benefit the clinical applications, in which it is important to accelerate resorption or passage of the ablated tissue volume, diminish pressure on the surrounding organs that causes discomfort, or insert openings between tissues.
Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, WA 98195;Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and tdk7@uw.edu.
Tatiana D
TD
Khokhlova
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Yak-Nam
YN
Wang
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Julianna C
JC
Simon
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Bryan W
BW
Cunitz
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Frank
F
Starr
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Marla
M
Paun
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Lawrence A
LA
Crum
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; and.
Michael R
MR
Bailey
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105; andDepartment of Acoustics, Physics Faculty, Moscow State University, Leninskie Gory, Moscow 119991, Russia.
Vera A
VA
Khokhlova
D000818:Animals; D004912:Erythrocytes / Q000166:cytology; D057086:High-Intensity Focused Ultrasound Ablation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D008099:Liver / Q000098:blood supply / Q000166:cytology / Q000601:surgery*; D008102:Liver Circulation; D008168:Lung / Q000166:cytology / Q000601:surgery; D023421:Models, Animal; D013347:Subcellular Fractions / Q000000981:diagnostic imaging*; D034421:Sus scrofa; D014159:Transducers; D014464:Ultrasonic Therapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D014463:Ultrasonography