Control of splenic bleeding by using high intensity ultrasound.
BACKGROUND
High-intensity focused ultrasound (HIFU) has been shown to control bleeding from liver incisions, and blood vessel punctures and incisions. The objective of the current study was to investigate the capability of HIFU to stop bleeding from splenic injuries in a pig model.


METHODS
Surgical incisions, 25 to 50 mm in length and 2 to 8 mm in depth, were made in the spleens of five anesthetized pigs. HIFU with a frequency of 5 MHz was applied within 5 seconds of making the incision. A total of 39 incisions and HIFU treatments were performed.


RESULTS
Bleeding from all incisions was stopped completely after HIFU treatment. The average times to control and completely arrest the hemorrhage were 28 and 55 seconds, respectively. The mechanisms of hemostasis appeared to be thermally induced coagulation necrosis of splenic tissue and occlusion of blood vessels by a mechanically induced homogenized splenic tissue.


CONCLUSIONS
HIFU may provide a useful method of hemostasis for actively bleeding spleen. Because of its ability to induce hemostasis at adjustable depth, HIFU may prove to be a useful cauterization method both in the operating room and for patients who are managed nonoperatively.
Vaezy
S
S
Department of Bioengineering, University of Washington, Seattle 98195, USA. adasi@u.washington.edu
Martin
R
R
Keilman
G
G
Kaczkowski
P
P
Chi
E
E
Yazaji
E
E
Caps
M
M
Poliachik
S
S
Carter
S
S
Sharar
S
S
Cornejo
C
C
Crum
L
L
D000818:Animals; D016063:Blood Loss, Surgical / Q000517:prevention & control; D004195:Disease Models, Animal; D006470:Hemorrhage / Q000473:pathology / Q000628:therapy*; D006489:Hemostatic Techniques; D009336:Necrosis; D012039:Regional Blood Flow; D013154:Spleen / Q000293:injuries; D013158:Splenic Diseases / Q000473:pathology / Q000628:therapy*; D013552:Swine; D013997:Time Factors; D014159:Transducers; D014464:Ultrasonic Therapy / Q000295:instrumentation / Q000379:methods*