AN IN-VITRO MODEL FAILS TO DEMONSTRATE AEROSOLIZATION OF TUMOR-CELLS

Background: We investigated the ability of pressurized CO2, gas to aer osolize B16 melanoma (B16) tumor cells in an in vitro model. Methods: The experimental apparatus consisted of an 18.9-L plastic cylindrical vessel and a compliant latex pouch was attached to the top. Two 5-mm p orts penetrated the vessel; insufflation and desufflation were carried out through them. A culture dish containing 20 million B16 cells in l iquid culture media was placed at the base within the container. Tn th e first experiment, the vessel was insufflated with CO2 gas to a stati c pressure of 15 or 30 mm Hg with the outflow port closed. After 10 mi n, the outflow port was opened and the gas was desufflated through a c ollecting device containing sterile culture medium. In a second experi ment, a continuous flow of CO2, through the vessel was maintained afte r a pressure of 15 or 30 mm Hg was established. A total of 10 L CO2, w as cycled through the vessel. In both experiments, 24 determinations w ere carried out at each pressure. Each experimental culture dish was m icroscopically scanned for 2 weeks for the presence of tumor cells. Th e third and fourth experiments tested for the presence of aerosolized nonviable tumor cells in the expelled gas. Using the model described a bove, after 10 mins of 30 mm Hg static pressure, the CO2, gas was expe lled directly onto a glass slide and cytofixed. Alternately, after 10 mins at 30 mm Hg static pressure, the gas was expelled through a salin e-filled Soluset (Abbott Laboratories), centrifuged, and the residue c ytofixed onto a glass slide. Each of the five slides per experiment we re examined microscopically for the presence of cells. Results: In the first and second experiments, no cells or growth were observed in any of the 96 experimental dishes. In experiments three and four, no cell s were detected on any of the slides. Conclusions: It was not possible with this model to aerosolize tumor cells in a pressurized CO2, envir onment. Our results suggest that aerosolization of tumor cells is not the mechanism of port site recurrences after laparoscopic surgery for malignant disease.