Development of an articulating ultrasonically activated device for laparoscopic surgery

Background: Ultrasonically activated devices (USADs) offer excellent coagulating dissection performance and are broadly used, particularly in endoscopic operations. Traditional USADs, however, have fixed linear shape and are thus limited in the directions from which organs can be approached. We have developed a small USAD transducer attached to the tip of an articulating device, offering a new kind of USAD in which the tip can bend as desired. We describe herein an evaluation of the coagulating dissection performance of this new articulating USAD and an in vivo confirmation of clinical usefulness. Methods: To evaluate coagulating dissection performance, we compared coagulating shearing on porcinesplenic arteries between the articulating USAD and a Harmonic Scalpel II (HSII), representing a traditional USAD. Changing the amplitude of vibration between 60 μm and 80 μm and grip force among 1, 2, and 3 N, we measured the time required for division and bursting pressure of coagulating dissection. An in vivo experiment in a pig was also used to confirm the usefulness of the articulating USAD in laparoscopic operations. Results: Division time did not differ significantly between the articulating USAD and HSII with an 80-lm amplitude of vibration and a grip force of 2 or 3 N. Bursting pressure of blood vessels showed no significant difference between articulating USAD and HSII under all experimental conditions. In the in vivo experiment, the new bendable tip of the articulating USAD displayed coagulating dissection performance equivalent to that of the traditional USAD. Conclusions: We have developed a new articulating USAD that can broaden the range of methods and approaches available for USADs and improve usefulness and safety.