High-intensity focused ultrasound ablation for the treatment of colorectal liver metastases during an open procedure: study on the pig.
OBJECTIVE
To demonstrate in a porcine model that high-intensity focused ultrasound (HIFU) with toroid-shaped emitters may have a role in treating unresectable colorectal liver metastases.


BACKGROUND
Surgical resection is the only curative option for colorectal hepatic metastases. Only 20% of patients are suitable for surgery. Many ablative techniques have been assessed but several limitations have been documented: traumatic puncture of the parenchyma, limited size of lesions, and inability to monitor the treatment in real time.


METHODS
A HIFU device with 256 toroid-shaped emitters and integrated ultrasound imaging probe was used. Single lesions, induced in 40 seconds, and juxtaposition of 6 single lesions were created under ultrasound guidance on 13 pigs. The lesions were studied on sonograms, macroscopically and microscopically up to 30 days after the treatment.


RESULTS
Ninety percent of the HIFU lesions were immediately hypoechoic on ultrasound imaging. The average coagulated volume obtained from a 40 seconds total exposure in the liver was 7.0 +/- 2.5 cm (1.5-20.0), average diameter: 19.5 +/- 3.8 mm (10.0-29.0). Using the real-time visualization of the treated region, single lesions were easily juxtaposed to produce larger lesions up to 6 cm in diameter without any major complication.


CONCLUSIONS
This toroid HIFU device allows short treatment times, noninvasiveness regarding the liver and real time ultrasound guidance. It seems to be simpler and more reliable to use than current ablative methods. Additionally, lesions through large vessels (up to 5 mm) being feasible, treatment of some juxta-vascular metastases should be possible.
Parmentier
Hubert
H
INSERM, U556, Lyon, France.
Hubert
Parmentier
P
Melodelima
David
D
David
Melodelima
M
N'Djin
Apoutou
A
Apoutou
N'Djin
N
Chesnais
Sabrina
S
Sabrina
Chesnais
C
Chapelon
Jean Yves
JY
Yves
Chapelon Jean
CJ
Rivoire
Michel
M
Michel
Rivoire
R
D000818:Animals; D015179:Colorectal Neoplasms / Q000473:pathology*; D004867:Equipment Design; D008099:Liver / Q000473:pathology / Q000601:surgery; D008113:Liver Neoplasms / Q000556:secondary* / Q000601:surgery / Q000628:therapy*; D013552:Swine; D014464:Ultrasonic Therapy / Q000295:instrumentation