Effects of repeated use and resterilization on structural and functional integrity of microwave ablation antennas

• Autores: Cyrielle A. Finck, Alex R. zur Linden, Ameet Singh
• Localización: American Journal of Veterinary Research, ISSN-e 1943-5681, ISSN 0002-9645, Vol. 78, Nº. 4, 2017, págs. 508-516
• Idioma: inglés
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• Resumen

  • 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.