Thorough Sanitation of Robotic Surgical Instruments Unattainable

Removing all traces of contamination from robotic surgical instruments is virtually impossible, even after multiple cleanings, according to a new study.

Researchers at the University of Tokyo Hospital (Japan) conducted a study to determine the level of residual contamination of instruments for robotic surgery, and to develop a method to evaluate cleaning efficacy for complex surgical devices. In all, they examined 132 robotic and ordinary instruments over a 21-month period, with instruments undergoing in-house cleaning using manual procedures and ultrasonication, as per the manufacturers' instructions. Residual protein concentrations were collected from tools following three subsequent cleanings.


The results revealed that the cleanings were 97.6% effective for robotic instruments and 99.1% effective for ordinary instruments. The amount of protein left on the robotic instruments after in-house cleaning was 650, 550, and 530 µg per instrument after each of three serial measurements, respectively. The researchers suggested that due to the complex structures of robotic instruments, they had a greater protein residue and lower cleaning efficacy, and suggested that it might be necessary to establish new cleaning standards. The study was published on October 31, 2016, in Infection Control & Hospital Epidemiology.

“Complete removal of surface contaminants from these tools may be unattainable, even after following manufacturers' cleansing instructions, leaving patients at risk for surgical site infections,” said lead author Yuhei Saito, RN, PHN, MSc. “Our results show that surgical instruments could be placing patients at risk due to current cleaning procedures. One way to address this issue is to establish new standards for cleaning surgical instruments, including multipart robotic tools.”

Extremely complex robotic instruments are composed of a myriad of thin electrical and mechanical elements, electrical motors and articulations, wire cables running over small reels, narrow lumens, and optical fibers and lenses that require delicate cleaning protocols, with a limited possibility of visual inspection. In addition, the complexity of the instruments requires that the drying phase should be kept as short as possible.

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