Liver hemostasis with high-intensity ultrasound: repair and healing.
OBJECTIVE
Previous studies have shown that high-intensity focused ultrasound can effectively control bleeding from injuries of liver, spleen, and blood vessels. This study investigated long-term hemostasis and tissue repair after high-intensity focused ultrasound treatment in liver.


METHODS
A total of 21 rabbits were randomly assigned to 2 groups: high-intensity focused ultrasound treatment (n = 14) and sham treatment (n = 7). All animals had sterile laparotomy and liver exposure. The high-intensity focused ultrasound-treated animals received liver incisions, 20 to 25 mm long and 4 to 6 mm deep, followed immediately by high-intensity focused ultrasound application until complete hemostasis was achieved. After recovery, sonographic images, blood samples, and histologic samples were collected immediately and on days 1, 3, 7, 14, 28, and 60 after treatment.


RESULTS
All 14 liver injuries were hemostatic after an average +/- SD of 78 +/- 44 seconds of high-intensity focused ultrasound application, with no rebleeding at any time point after the treatment. Subsequent blood analysis showed no significant difference in serial hematologic or coagulation measures between the high-intensity focused ultrasound and sham groups. Alanine aminotransferase and aspartate aminotransferase levels increased immediately after surgery by as much as 285% up to day 3 and returned to normal values by day 7. Hematocrit and white blood cell counts showed no statistically significant difference from normal values at all time points. Histologic examination up to 60 days after treatment revealed scarring and liver tissue regeneration at the treatment site.


CONCLUSIONS
High-intensity focused ultrasound appears to provide long-lasting hemostasis of acute liver injury. Healing and repair mechanisms after high-intensity focused ultrasound application appear to be intact.
Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA 98105, USA. vaezy@apl.washington.edu
Shahram
S
Vaezy
Misty L
ML
Noble
Amid
A
Keshavarzi
Maria
M
Paun
Adrian F
AF
Prokop
Carol
C
Cornejo
Sam
S
Sharar
Emil Y
EY
Chi
Lawrence A
LA
Crum
Roy W
RW
Martin
D000818:Animals; D004195:Disease Models, Animal; D006489:Hemostatic Techniques; D008107:Liver Diseases / Q000000981:diagnostic imaging / Q000628:therapy*; D011817:Rabbits; D014464:Ultrasonic Therapy / Q000379:methods*; D014463:Ultrasonography; D014945:Wound Healing / Q000502:physiology