Evaluation of cleaning and sterilization of liposuction cannulas after intentional contamination with human fat, Mycobacterium abscessus subspecies bolletii, and Geobacillusstearothermophilus.

BACKGROUND: The complex design of cannulas is a major challenge for reprocessing due to the retention and accumulation of fat residues. AIM: To evaluate the cleaning of liposuction cannulas and the protective effects of the remaining fat residues on Mycobacterium abscessus subspecies bolletii (MASB) and Geobacillus stearothermophilus inactivation during steam sterilization. METHODS: In phase 1, six standard operating procedures were evaluated for cleaning of liposuction cannulas. In phase 2, the sectioned lumens of the liposuction cannulas were contaminated with the largest and smallest volume of human fat found in phase 1, with the addition of MASB. In phase 3, the same volumes of human fat from phase 2 were used to contaminate paper strips containing G. stearothermophilus. FINDINGS: In phase 1 the residual amount of fat ranged from 6 to 52 mg. In phases 2 and 3, the minimum and maximum amounts of fat (6 and 50 mg) protected micro-organisms during steam sterilization at 134 °C for 1.5 and 3 min. CONCLUSION: Effective cleaning and sterilization of liposuction cannulas intentionally contaminated with human fat, MASB and G. stearothermophilus could not be performed.

Performance evaluation of chemical, biological and physical indicators in the process of sterilization under the effect of non-condensable gases.

BACKGROUND: The risk concerning the presence of non-condensable gases (NCGs) has already been demonstrated, but routine monitoring still requires further research to be implemented in each sterilization cycle. AIM: Performance evaluation of the physical, chemical and biological indicators used in monitoring in comparison with a sterilizer integrated detector for NCG in the Sterilization Process. METHODS: Chemical indicators (type 2 Bowie-Dick test, type 5 and type 6 models), self-contained biological indicators and physical indicators (temperature, pressure, thermal qualification and a patented integrated air detector) were used to monitor the steam sterilization process in two situations of controlled failure: chamber leakage and door seal failure. This controlled failure was obtained by the presence of a known amount of air: 0-30 L/min for chamber leakage and 0-30% for the door seal failure. Evaluation tests were carried out with and without the use of process challenge devices (PCDs). FINDINGS: In both studies, the Bowie-Dick Test showed different results, according to the manufacturer. The biological, physical or chemical indicators without a PCD were unable to detect small volumes of NCGs in both simulations. CONCLUSION: The integrated air detector can be considered an option for the detection of NCGs in each cycle.