Decontamination of surgical instruments with MIDAS
These new methods for cleaning surgical instruments completely remove protein contamination, including prions – the infectious agents that cause Creutzfeldt-Jakob Disease (CJD) in humans.
- Sterilisation of metal instruments used in surgery, dentistry or food preparation
The MIDAS methods, that were developed at the University of Edinburgh, use radiofrequency (RF) gas-plasma technology and are highly effective in removing contamination, including protein, from a variety of surfaces. Biological assays using infective implants have verified that the technique eliminates TSE infectivity.
Prion diseases are resistant to inactivation by conventional chemical and physical decontamination. This creates a risk of cross-contamination from instruments used during surgical procedures on patients.
Conventional sterilisation does not deactivate the infective agent of prion diseases. Many instruments must, therefore, be removed entirely from service. MIDAS technologies involve a series of pre-treatments, followed by exposure of the surgical instruments to RF plasma. The plasma treatment scours the surfaces, breaking down any biological tissue and converting it to non-toxic gases. Test samples pre-contaminated with TSE infective brain tissue and then treated using the MIDAS method show that contamination has been eliminated.
The technique can remove contaminating biomolecules from stainless steel surfaces (to levels a thousand times lower than those achieved by existing methods) and leaves no visible trace of any residual contaminated material. Verification techniques include SEM, spectrofluorimetric detection and biological TSE infectivity testing conducted by an independent laboratory.
- Metal instruments are not damaged by the plasma techniques
- Surgical instruments can be reused
- Stock-piled instruments can be brought back into service
- Removal of all protein contamination, including prions
- Surgical Instrument Decontamination: efficacy of introducing an argon:oxygen RF gas-plasma cleaning step as part of the cleaning cycle for stainless steel instruments. Baxter et al IEEE Trans. Plasma Sci., 2006, 34, 1337- 1344.