Experimental analyses of the cavitation generated by ultrasonically activated surgical devices

Recently, the incidence of postoperative pancreatic leakage has been reported to have significantly increased after laparoscopic gastrectomy for gastric cancers in comparison to open surgery. Although their lateral thermal spread has been shown to be smaller than that of other electrosurgical devices, ultrasonically activated surgical devices (USADs) have been suggested as one of the causes. We therefore hypothesized that cavitation generated by USADs could cause injuries to pancreatic tissue. Our retrospective study showed that the amylase activity in the drainage fluid of patients in whom surgery was performed using a USAD with a curved blade was significantly higher than that in patients in whom surgery was performed using a USAD with a straight blade. We therefore focused on the effects of straight and curved USAD blades.

The distribution of microbubbles generated in degassed water, which produce mechanical and biological tissue destructive forces, was measured and compared between the two types of USAD.

More microbubbles were found to be generated from the side aspect of the curved blade, and the mechanical and biological destructive forces were found to be significantly higher than those generated by the side aspect of the straight blade.

These findings strongly suggest that cavitation generated by USADs could injure pancreatic tissues in the clinical cases. Surgeons should be aware of these properties of devices to achieve safe and secure surgeries.