In vitro bactericidal effect of a modified thermal nitinol electrode

Purpose: A standard electrode surgical generator connected to a Nitinol coi l was used in vitro to evaluate whether the generated electromagnetic energ y had any bactericidal effect on Escherichia coil, Materials and Methods: The ATCC 259222 E, coli strain was used. We mixed 13 5 mL of a 1.5% non-nutritive agar with 15 mL of a 10(6) CFU/mL inoculum and transferred it to gas-sterilized plastic containers lined with aluminium f oil. A 22F cylindrical shape was cut from the center of the agar, and a Nit inol coil was placed in that space and connected to a standard electrode su rgical generator, Electrical energy was then applied from 5 to 25 V at 5-V increments. Temperatures were measured with two thermocouples placed in the middle and periphery of each agar, The treatment was stopped when the temp erature at the middle thermometer reached 50 degreesC. The control group wa s not treated and was embedded in a water bath at 45 degreesC. Three 3 x 7- mm pieces were sliced from the inner to the outer part of the agar and proc essed, and colony counts were performed. Results: We observed statistically significant deleterious effects on E, co li in all three zones when the treatment voltage was 15 and 20, When the po tential was raised to 25 V, we observed a significant result only in the co re zone. The treatment duration was 50 minutes for 5 and 10 V, 45 minutes f or 15 V, 15 minutes for 20 V, and 10 minutes for 25 V, Conclusion: The bactericidal effect was mainly in the central area, decreas ing linearly toward the periphery, and was related to the temperature reach ed during activation of the electrical generator, These results were disapp ointing with regard to the utility of Nitinol stents to treat bacterial pro statitis.