Hemorrhage control using high intensity focused ultrasound.

Hemorrhage control is a high priority task in advanced trauma care, because hemorrhagic shock can result in less than a minute in cases of severe injuries. Hemorrhage was found to be solely responsible for 40-50% of traumatic civilian and battlefield deaths in recent years. The majority of these deaths were due to abdominal and pelvic injuries with hidden and inaccessible bleeding of solid organs such as liver, spleen, and kidneys, as well as major blood vessels. High intensity focused ultrasound (HIFU) offers a promising method for hemorrhage control. An important advantage of HIFU is that it can deliver energy to deep regions of tissue where hemorrhage is occurring, allowing cauterization at depth of parenchymal tissues, or in difficult-to-access anatomical regions, while causing no or minimal biological effects in the intervening and surrounding tissues. Moreover, HIFU can cause both thermal and mechanical effects that are shown to work synergistically for rapid hemorrhage control. The major challenges of this method are in development of bleeding detection techniques for accurate localization of the injury sites, delivery of large HIFU doses for profuse bleeding cases, and ensuring safety when critical structures are in the vicinity of the injury. Future developments of acoustic hemostasis technology are anticipated to be for applications in peripheral vascular injuries where an acoustic window is usually available, and for applications in the operating room on exposed organs.