title: Effects of repeated use and resterilization on structural and functional integrity of microwave ablation antennas.
abstract: OBJECTIVE To determine effects of repeated use and resterilization on structural and functional integrity of microwave ablation (MWA) antennas. SAMPLE 17 cooled-shaft MWA antennas (3 groups of 5 antennas/group and 2 control antennas). PROCEDURES 1, 2, and 3 ablations in the livers of bovine cadavers were performed at the maximum recommended settings. Antennas were cleaned and sterilized in hydrogen peroxide plasma, and the process was repeated (reprocessing cycle; n = 6). Control antennas were only sterilized (6 times). Aerobic and anaerobic bacterial cultures were performed, and antennas were microscopically assessed for damage. RESULTS 6 cycles were completed. Thirteen of 15 MWA antennas remained functional for up to 4 cycles, 10 were functional after 5 cycles, and only 7 were functional after 6 cycles. Progressive tearing of the silicone coating of the antennas was observed, with a negative effect of the number of cycles for silicone tearing. Size of the ablation zone decreased mildly over time after cycles 5 and 6; however, this was not considered clinically relevant. No significant changes in the shape of ablation zones were detected. All cultures yielded negative results, except for an isolated case, which was considered a contaminant. CONCLUSIONS AND CLINICAL RELEVANCE Structural and functional integrity of the microwave antennas remained acceptable during repeated use and reprocessing for up to 4 cycles. However, there was a decrease in functional integrity at cycles 5 and 6. We suggest that these microwave antennas be subjected to > 3 reprocessing cycles. Antennas should be carefully examined before reuse.
authors.forename: Cyrielle A
authors.initials: CA
authors.lastname: Finck
authors.forename: Alex R
authors.initials: AR
authors.lastname: Zur Linden
authors.forename: Ameet
authors.initials: A
authors.lastname: Singh
authors.forename: Robert A
authors.initials: RA
authors.lastname: Foster
authors.forename: Stephanie G
authors.initials: SG
authors.lastname: Nykamp
authors.forename: William C
authors.initials: WC
authors.lastname: Sears
mesh_terms: D055011:Ablation Techniques / Q000191:economics / Q000295:instrumentation*; D000818:Animals; D002102:Cadaver; D002417:Cattle; D017743:Equipment Reuse; D006861:Hydrogen Peroxide; D008099:Liver; D008872:Microwaves; D013242:Sterilization
chemical_list: D006861:Hydrogen Peroxide