Viability of Airborne Tumor Cells during Excision by Ultrasonic Device

Background. Laparoscopic surgery has become more widely used, but peritoneal dissemination and port-site metastasis have been reported to occur in these surgeries. One reason for these problems is the ultrasonically activated scalpel (UAS) used for laparoscopic surgery. This study aimed to investigate the viability of airborne cells released during cancer dissection using a UAS. Methods. Flank tumors measuring about 2 cm were induced in male NOD-Cg-Rag1^tm1MomIL2rg^tm1wjl/SzJ mice by subcutaneous injection of 1 × 10⁶ HepG2 cells. Dissection was performed with UAS (in high or low power modes) and PowerStar bipolar scissors. The mist of released tissue was collected in cell culture medium. The viability of the cellular material was assessed with trypan blue exclusion cell counting, counting after immunofluorescence staining, and flow cytometric analysis. Results. Large quantities of cellular debris were trapped in the tissue dispersed by both devices. In all experiments, there were significantly more viable cells produced by the UAS in high power mode. By using suction at the excision site, the number of viable cancer cells was reduced. Conclusions. This study demonstrates that viable cancer cells can be released into the nearby environment during tumor ablation with a UAS.