LIVER HEMOSTASIS USING HIGH-INTENSITY FOCUSED ULTRASOUND

Liver hemorrhage, the major cause of death in hepatic trauma, is notor iously difficult to control. We report on the use of high-intensity fo cused ultrasound (HIFU) to arrest the bleeding from incisions made in rabbit livers. A HIFU transducer, with a spherically curved aperture o f 6.34 cm(2) area, a focal length of 4 cm and a frequency of 3.3 MHz w as used. In approximately 94% of the incisions, the hemorrhage was red uced to a slow oozing of blood in less than 2 min. The maximum tempera ture of liver tissue around the incision area, during HIFU application , was measured to be 86 degrees C. The mechanism of hemostasis, confir med by histological examination, appears to be coagulative necrosis of a volume of liver tissue around the incision. We believe that acousti c hemostasis, with the unique characteristic of ''volume cauterization ,'' offers a novel method for the management of liver hemorrhage and, thus, has major clinical implications. (C) 1997 World Federation for U ltrasound in Medicine & Biology.