In vitro ablation of cardiac valves using high-intensity focused ultrasound.
The purpose of this study was to evaluate the possibility of using high-intensity focused ultrasound (US), or HIFU, to create lesions in cardiac valves in vitro. Calf mitral valves and aortic valves were examined. Focused US energy was applied with an operating frequency of 4.67 MHz at a nominal acoustic power of 58 W for 0.2, 0.3 and 0.4 s at 4-s intervals. Mitral valve perforation was achieved with 20.8 +/- 3.7 exposures of 0.2 s, 15.4 +/- 2.1 exposures of 0.3 s or 11.2 +/- 2.3 exposures of 0.4 s. Aortic valve perforation was achieved with 13.3 +/- 2.4 exposures of 0.2 s, 10.3 +/- 2.2 exposures of 0.3 s or 8.4 +/- 1.8 exposures of 0.4 s. The mean diameter of the perforated area was 1.09 +/- 0.11 mm. The lesions were slightly discolored and coagulation of tissue around the perforation was observed. HIFU was successful in perforating cardiac valves. With further refinement, HIFU may prove useful for valvulotomy or valvuloplasty.
Otsuka
Ryo
R
Department of Medicine, Columbia Presbyterian Medical Center, New York, NY 10032, USA. otsukaryo@aol.com
Fujikura
Kana
K
Hirata
Kumiko
K
Pulerwitz
Todd
T
Oe
Yukiko
Y
Suzuki
Takeki
T
Sciacca
Robert
R
Marboe
Charles
C
Wang
Jie
J
Burkhoff
Daniel
D
Muratore
Robert
R
Lizzi
Frederic L
FL
Homma
Shunichi
S
D000818:Animals; D001021:Aortic Valve / Q000473:pathology; D001024:Aortic Valve Stenosis / Q000628:therapy; D002417:Cattle; D066298:In Vitro Techniques; D008943:Mitral Valve / Q000473:pathology; D008946:Mitral Valve Stenosis / Q000628:therapy; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation / Q000379:methods*