Evaluation of stainless steel surgical instruments subjected to multiple use/processing

Area of Science:

• Materials Science
• Biomedical Engineering
• Surgical Technology

Background:

• Surgical instruments undergo repeated use and processing cycles.
• Assessing the long-term quality and contamination of stainless steel instruments is crucial.

Purpose of the Study:

• To evaluate the impact of multiple use and processing cycles on the quality of stainless steel surgical instruments.
• To investigate protein contamination, bacterial presence, and structural integrity of discarded instruments.

Main Methods:

• Discarded surgical instruments were analyzed for protein contamination (bicinchoninic acid assay) and bacterial presence (microbial culture).
• Scanning electron microscopy (SEM) was used to detect biofilm and structural damage.
• Instruments were categorized by design complexity (hinged/serrated, screw, cannulated, flexible, irregular).

Main Results:

• Protein contamination varied significantly, from 24 μg in new screws to over 3.7 million μg in discarded forceps.
• More complex instrument designs showed higher levels of protein contamination.
• SEM confirmed biofilm on 50% of tested instruments and revealed soil, holes, or black stains on all instruments.

Conclusions:

• Multiply processed surgical instruments harbor substantial protein contamination, biofilm, and structural damage.
• New, multiply processed instruments also showed signs of contamination.
• Further research is needed to define the lifespan and establish retirement criteria for surgical instruments.