We developed a new ultrasonically activated device (USAD) for endoscopic surgery. The current investigation was conducted to evaluate the security of the arteries occluded and divided by this USAD. The intraperitoneal arteries of anesthetized living pigs were individually occluded by the USAD at power levels of 70% or 100%. The burst pressures of the harvested arteries were measured in vitro. For comparison, arteries occluded by laparoscopic clips or silk ligatures were evaluated in the same manner. The pressures to burst the occluded artery ranged from 353 to 2,148 mmHg with an average of 1,204 mmHg in the USAD group at 70% power level; from 324 to 2,207 mmHg with an average of 1,193 mmHg in the USAD group at 100% power level; from 794 to 1,868 mmHg with an average of 1,421 mmHg in the clip group; and from 618 to 3,207 mmHg with an average of 1,586 mmHg in the silk ligature group. The data suggest the improbability that small- to medium-size arteries appropriately occluded and divided by the USAD can burst when exposed to intravascular pressures commonly found in living animals.