Image-guided acoustic hemostasis for hemorrhage in the posterior liver

We investigated the use of ultrasound image-guided high intensity focused ultrasound (HIFU) to stop bleeding from injuries in the posterior liver. A HIFU transducer with focal length of 3.5 cm and frequency of 3.2 MHz was integrated with an intraoperative high-resolution ultrasound-imaging probe. Wedge tissue extractions, 30-mm long, 5-mm wide and 8-mm deep, were made in the posterior liver surface of five pigs to induce bleeding. The device was positioned on the anterior surface of the liver and HIFU was applied using ultrasound image-guidance. Hemostasis was achieved in 66 +/- 18 s (mean +/- standard deviation) for 17 HIFU treatments. During 7 min of sham HIFU treatment, none of the control incisions (n = 7) became hemostatic. Ultrasound image-guided HIFU offers a promising method for hemostasis in surgical settings in which the hemorrhage site is hidden and/or not accessible.