[Morphofunctional characteristics of wound inflicted by an ultrasonic destroyer]

A surgical model of EstoRex ultrasound destroyer operating at a frequency of 60 KHz, power of 6 W, and vibration amplitude at the tip of the tool of 15 microns was used to make incisions on rat liver. 5 to 7 s or 24 hr after surgery the specimens of the wound wall were fixed and further processed for electron microscopy and histochemical visualization of glucose-6-phosphatase at the ultrastructural level. In a separate series 2 mm-thick strips of the tissue were excised from the liver, processed by the destroyer for 45 s, and then exposed to a digestion treatment with mixture of trypsin and chymotrypsin for 24 hr at 37 degrees C or in solution of cathepsin L for 60 hr at 25 degrees C. The results showed that ultrasound caused not only thermal but also nonthermal ultrastructural and histochemical alterations, due probably to cavitation and viscous stresses. The ultrasound wound did not contain any proteolytically resistant material. Since ultrasound-processed tissue turned out to be highly susceptible to proteolytic digestion we suggest that the ultrasound destroyer, unlike Nd:YAG laser surgical instrument, would be a promising surgical tool with respect to wound cleaning and healing.