Resection of abdominal solid organs using high-intensity focused ultrasound.

Our objective was to evaluate high-intensity focused ultrasound (HIFU) for minimizing blood loss during surgery by hemodynamically isolating large portions of solid organs before their resection. A high-power HIFU device (in situ intensity of 9000 W/cm(2), frequency of 3.3 MHz) was used to produce a wall of cautery for sealing of blood vessels along the resection line in surgically exposed solid organs (liver lobes, spleen and kidneys) of eight adult pigs. Following HIFU application, the distal portion of the organ was excised using a scalpel. If any blood vessels were still bleeding, additional HIFU application was used to stop the bleeding. The resection was achieved in 6.0 +/- 1.5 min (liver), 3.6 +/- 1.1 min (spleen) and 2.8 +/- 0.6 min (kidneys) of HIFU treatment time, with no occurrence of bleeding for up to 4 h (until sacrifice). The coagulated region at the resection line had average width of 3 cm and extended through the whole thickness of the organ (up to 4 cm). Blood vessels of up to 1 cm in size were occluded. This method holds promise for future clinical applications in resection of solid tumors and hemorrhage control from high-grade organ injuries.