Evaluation of cleaning process efficacy of instruments for robotic surgery using the adenosine triphosphate test

Despite the advances in robotic surgery and its benefits for the patient and surgeon, there are difficulties and challenges in reprocessing surgical instruments, including with regard to patient safety, such as the risk of infection. The aim of this article is to evaluate the effectiveness of manual plus ultrasonic cleaning of EndoWrist devices used in robotic surgery using the adenosine triphosphate bioluminescence quantitative test.

A prospective cross-sectional study assessed the cleanliness of robotic instrumentals used in surgeries. Surgical instruments were collected immediately after the end of the surgery and sent for cleaning and disinfection following standard hospital procedures. The adenosine triphosphate test was done after visual evaluation. According to our hospital standard, instruments were classified as "approved" if the test found ≤50 relative light units.

We evaluated 279 EndoWrist instruments from 65 robotic surgeries. The most frequently used instruments were needle drivers (102; 39%), followed by bipolar instruments (65; 25%). Median relative light units were 49 (range = 4-13,095); 54% of instruments were classified as approved according to the hospital's threshold (relative light units ≤50) and 78% when the manufacturer's threshold (relative light units ≤150) was used. Monopolar instruments presented the best rate of approval (94% considering relative light units ≤50 and 100% with relative light units ≤150). The average relative light units did not vary with the number of reuses. There were no surgical site infections.

Manual plus automated cleaning processes reduced bioburden in all situations evaluated. It seems that instruments can be safely reprocessed ≤9 times and that monopolar instruments are the easiest to clean.