Title : Electrochemical prevention of needle - tract seeding

Needle-tract seeding refers to the implantation of tumor cells by contamination when instruments, such as biopsy needles, are employed to examine, excise or ablate a tumor. The incidence of this iatrogenic phenomenon is low but it entails serious consequences. Here, as a new method for preventing neoplasm seeding, it is proposed to cause electrochemical reactions at the instrument surface so that a toxic microenvironment is formed. In particular, the instrument shaft would act as the cathode and the tissues would act as the electrolyte in an electrolysis cell. By employing numerical models and experimental observations reported by researchers on Electrochemical Treatment of tumors, it is numerically showed that a sufficiently toxic environment of supraphysiological pH can be created in a few seconds without excessive heating. Then, by employing an ex vivo model consisting of meat pieces, validity of the conclusions provided by the numerical model concerning pH evolution is confirmed. Furthermore, a simplified in vitro model based on bacteria, instead of tumor cells, is implemented for showing the plausibility of the method. Depending on the geometry of the instrument, suitable current densities will probably range from about 5 mA/cm to 200 mA/cm and the duration of DC current delivery will range from a few seconds to a few minutes. Key terms: neoplasm seeding, needle-tract seeding, tumor cell dissemination, electrochemical treatment