Point-of-use treatment

1. What is the optimal timing and location for point-of-use treatment?

Recommendation:

1. 1. Apply point-of-use treatment promptly to initiate the cleaning process and/or to prevent soils from drying on the reusable medical device.

2. 2. Perform point-of-use treatment in accordance with the MIFUs for the cleaning product and the medical device.

2. What are the most effective means of treating a reusable medical device prior to transport to the location where sterilization or high-level disinfection (HLD) will be performed?

Recommendation:

1. 1. Treat reusable medical devices at the point-of-use with a process designed to begin cleaning and/or to keep devices moist until processing begins.

2. 2. Select the product and/or process for point-of-use treatment following the device’s MIFU for compatibility and consideration for effectiveness and for limiting adverse interactions with common contaminants (eg, blood, silicone). Do not use products known to be fixatives (eg, alcohol) for point-of-use treatment.

3. 3. In settings where there is a prolonged interval between the use of the medical device and initiation of processing, and in scenarios where reusable medical devices otherwise would dry out, use moisture retention products that are compatible with the devices, following the device’s MIFU and seeking technical data if needed.

3. What is the recommended response to delays in the start of point-of-use treatment?

Recommendation:

1. 1. If a delay occurs, follow the MIFU for remediation due to potential for biofilm formation and drying of soils. In the absence of guidance in the MIFU, follow the steps described in Section 2: Manufacturers’ instructions for use.

2. 2. Keep reusable medical devices moist between use and the start of treatment to prevent soils from drying, unless prohibited by the MIFU.

Rationale 1-3: Prompt point-of-use treatment of reusable medical devices following their use is important to reduce excess contamination before proceeding with the steps of sterilization or HLD. Although the ideal agent for biofilm disruption has not been established, enzymatic detergents, which are commonly recommended as part of a point-of-use treatment, have been shown to be effective at eliminating organic materials and for preparing reusable medical devices for processing. ^{Reference Fang, Shen and Li14–Reference Ren, Sheng, Huang, Zhi and Cai18}

Outbreaks have been linked to delays in processing of high-level disinfected reusable medical devices. ^{Reference Casini, Tuvo and Marciano19–Reference Smith, Araoye and Gilbert22} In a study of stainless steel surgical instruments, the bacterial load began to increase after 6 hours. ^{Reference Percin, Sav, Hormet-Oz and Karauz23} Biofilms have been demonstrated in vitro to lead to reduced susceptibility to commonly used high-level disinfectants. ^{Reference Brunke, Konrat and Schaudinn24} A study found that a 96-hour P. aeruginosa biofilm survived a 5-minute treatment with 2,000 ppm of peracetic acid and was resistant to >4,000 ppm of peracetic acid. ^{Reference Akinbobola, Amaeze, Mackay, Ramage and Williams25,Reference Akinbobola, Sherry, McKay, Ramage and Williams26} Experiments have demonstrated that delays in point-of-use treatment and manual cleaning can lead to retained biodebris and contamination, but repeated cleaning effectively can reduce the microbial load on reusable medical devices. ^{Reference Smith, Araoye and Gilbert22,Reference Evangelista Sde, dos Santos, de Resende Stoianoff and de Oliveira27}

Current studies have not compared the efficacy of moisture retention bags, non-drying sprays, gels, or containers.

4. What modifications in point-of-use treatment are required for lumened devices?

Recommendation:

1. 1. Adhere to the MIFU for each specific lumened device, including instructions for use of the flushing solutions and the appropriate types and sizes of cleaning brushes.

2. 2. Do not modify or adapt cleaning instructions intended for non-lumened devices for use on lumened devices.

Rationale: Most lumened devices are complex in nature with geometries and surface features that limit or prohibit practices that are common to many cleaning methods (ie, they cannot be directly visualized during cleaning) and present enhanced cleaning challenges (eg, biofilm accumulation) compared with non-lumened medical devices. A device’s MIFU provides the validated cleaning method and instructions for proper application to ensure adequate cleaning of each device.

5. What are the requirements for transporting contaminated critical or semi-critical devices within the facility to the location of processing?

Recommendation:

1. 1. Package or contain the reusable medical devices in accordance with OSHA requirements. ²⁸

2. 2. Transport contaminated critical or semi-critical devices to the location of processing in a manner that keeps reusable medical devices’ surfaces moist, unless prohibited by the MIFU, and prevents damage to the devices, exposure of individuals to body fluids, and contamination of the environment.

3. 3. Use a closed, rigid container or closable, fluid-resistant bag to transport contaminated devices.

Rationale: Critical and semi-critical devices that are contaminated with patients’ secretions and body fluids pose a risk to HCP ^{Reference Beilenhoff, Biering and Blum29} and should be handled according to OSHA standards. ²⁸ Point-of-use treatment does not disinfect equipment adequately to eliminate exposure risk. ^{Reference Grein and Murthy30} OSHA standards and organizational guidelines recommend dedicated carrying containers that are clearly labeled as contaminated, are leak and puncture-resistant, and are cleanable. ^{Reference Beilenhoff, Biering and Blum29}

Damage to endoscopic equipment most often occurs during transport. ^{Reference Amann, Beilenhoff and Carter31,Reference Higgins, Dugan, Bell, Bylund, Harris and Bhalodi32} Damaged equipment can increase the risk of biofilm formation and processing failure, thereby increasing the risk of transmission of infection. ^{Reference Ofstead, Quick and Wetzler33–Reference Sooriakumaran, Kaba, Andrews and Buchholz35} During transport, facilities should continue to follow recommendations for preventing exogenous contamination of processed equipment. Container material and ambient temperature, pressure, and humidity all affect the likelihood of contamination, ^{Reference Dunkelberg and Rohmann36–Reference Secker, Pinchin, Herve and Keevil38} although at least one study demonstrated that humidity alone does not affect the likelihood of contamination. ^{Reference Rubak, Lorenzen and Ripadal39}

6. What packaging-specific issues are relevant for transport outside of the facility to the location of processing?

Recommendation:

1. 1. Apply the same principles to transport outside of the facility as transport inside the facility. Transport items in a manner that keeps the reusable medical device’s surface moist, unless prohibited by the MIFU, and prevents damage to the medical device or packaging, exposure of individuals to body fluids, and contamination of the environment.

2. 2. Consider the effects of exposure to temperature extremes and the potential for damage to the reusable medical devices due to shock and vibration during transport outside of the facility.

3. 3. Follow applicable state and federal regulatory requirements related to transport.

Rationale: Similar packaging considerations apply to transport within a facility as transport outside a facility, with some exceptions. ^{Reference Amann, Beilenhoff and Carter31} Point-of-use treatment is an even more important practice when transporting a device outside the facility for processing, as the total time is increased. ^{Reference Beilenhoff, Biering and Blum29,Reference Wang, Wu and Liu40} Increased time can lead to drying of the device, which will make effective processing of it more difficult. ^{Reference Secker, Pinchin, Herve and Keevil38,Reference Alfa41} Additionally, because point-of-use treatment does not disinfect equipment, ^{Reference Grein and Murthy30} care must be taken to prevent exposure to those who handle a device during transport. ²⁸ Temperature extremes and damage to devices can occur during transport, and facilities may need to account for extra time to examine equipment for damage after transport. ^{Reference Amann, Beilenhoff and Carter31}

Preparation at the location of processing

7. Which method(s) should facilities use to clean reusable medical devices at the location of processing?

Recommendation:

1. 1. At the location of processing by sterilization or HLD, follow the reusable medical device’s MIFU, including specified steps such as placing it in the open position, disassembling the device and its accessories, actuating it, and cleaning it to remove soils from surfaces.

2. 2. After manual cleaning, if recommended and in accordance with the MIFU, clean reusable medical devices with:

   1. a. A mechanical washer OR

   2. b. A mechanical washer with an ultrasonic cleaning phase.

Rationale: Reusable medical devices should be thoroughly cleaned prior to sterilization or HLD. Cleaning reduces the microbial load and removes organic residue that interfere with the sterilization process by acting as a barrier to the sterilization agent or HLD. ^{Reference Rutala, Gergen and Weber42}

HCP should be trained and deemed competent to perform proper cleaning (see Approaches to implementation). Poor cleaning may result in residual protein, blood staining, or particles (eg, bone) on the reusable medical device. ^{Reference Rutala, Gergen and Weber43} Successful cleaning occurs when all surfaces are exposed to the cleaning solutions and methods. Design features such as crevices, hinges, and covered surfaces (eg, screw threads covered by thumb screw) of surgical reusable medical devices can shield debris from the forced flow of liquids. ^{Reference Rutala, Gergen and Weber43} One study supported double manual cleaning with specific attention to an internal hinge more effective than double manual cleaning alone. ^{Reference de Melo Costa, Castillo, Vickery, Ferreira Veiga Tipple, de Oliveira Lopes and Hu44} Failure to fully disassemble endoscope accessories prior to sterilization or HLD has been associated with infection transmission events dating back to the 1980s. ^{Reference Ren-Pei, Hui-Jun, Ke, Dong, Xing and Zhao-Shen45}

Mechanical washers for cleaning are more systematic and reproducible than manual cleaning and can offer additional microbial reduction. ^{Reference Alfa, Olson and Al-Fadhaly46} Mechanical washers use cleaning solutions and rinsing under pressure to physically remove microorganisms. Mechanical washers are validated and are legally marketed per the FDA by demonstrating effectiveness in thoroughly cleaning medical devices. ^{Reference Rutala, Gergen and Weber43}

Ultrasonic cleaning and thermal inactivation at 150°F to 240°F are sufficient to reduce or eliminate microorganisms, but spores can be more resistant to thermal inactivation. ^{Reference Diab-Elschahawi, Furnkranz, Blacky, Bachhofner and Koller47,Reference Kremer, McDonnell and Mitzel48} Ultrasonic cleaning removes soil and microorganisms by cavitation and implosion, with waves of acoustic energy in aqueous solutions used to disrupt the bonds that hold particulate matter to surfaces. ^{Reference Rutala, Gergen and Weber43} Ultrasonic cleaning should meet the reusable medical device’s time and temperature parameters, as specified in the MIFU.

8. Are there any reusable medical devices that should be segregated from others for processing?

Recommendation: Facilities do not need to segregate reusable medical devices for infection prevention reasons, with the exception of potentially prion-contaminated reusable medical devices. Prions are out of scope for this document.

Rationale: From an infection prevention and control (IPC) perspective, facilities do not need to segregate reusable medical devices, except those with known or suspected prion contamination. Prions are out of scope for this document. Readers may review published guidelines specific to prions. ^{Reference Rutala and Weber3,49–Reference Cutler Peck, Brubaker, Clouser, Danford, Edelhauser and Mamalis51}

Facilities may need to segregate certain categories of reusable medical devices from others for non-infection prevention reasons. These reasons include preventing potential damage to delicate reusable medical devices (eg, ocular instruments), patient sensitivity to cleaning solutions and detergents, detergent residues that may contribute to ocular toxic anterior segment syndrome (TASS), ^{Reference Bodnar, Clouser and Mamalis50,Reference Cutler Peck, Brubaker, Clouser, Danford, Edelhauser and Mamalis51} and for occupational safety (eg, sharps safety).

9. What type of water should be used for rinsing medical devices in a mechanical washer?

Recommendation:

1. 1. Verify that all water supplied to the facility meets the requirements described in the mechanical washer’s MIFU.

2. 2. Ensure that the water used in processing is part of the facility’s water management plan.

Rationale: Water quality is a principal factor in cleaning and disinfection. Although limited data exist on water quality for rinsing of semi-critical reusable medical devices, ^{Reference Ji, Ning, Fei, Liu, Liu and Song52,Reference Marek, Smith and Peat53} to avoid damage to the devices being washed and disinfected and to the mechanical washer itself, the water used must have the temperature, pH, and chemical balances, as specified in the MIFU. ^{Reference Nakano, Akamatsu and Mori54–57} Water must be compatible with the disinfection process ^{Reference Muqbil, Burke, Miller and Palenik58,Reference Krolasik, Zakowska, Krepska and Klimek59} and must not increase microbial load or leave residual endotoxin above recommended levels specified in the MIFU. ⁵⁷ These goals can be achieved using treated water (eg, deionized, reverse osmosis, sterile, filtered; see Supplementary Material Table 2 for terminology and definitions), but no single treatment system will account for all issues and will need to be monitored and modified as needed. Water systems themselves can fail and must undergo regular maintenance and monitoring. ^{Reference Uetera, Kishii and Yasuhara60}

10. What methods should facilities use to verify that mechanical washers are working effectively?

Recommendation:

1. 1. To confirm that mechanical washers adequately perform all stages of the cleaning cycle, perform cleaning verification testing per the equipment’s MIFU.

2. 2. Record the results when the equipment is installed, after major repairs, and each day that it is used.

3. 3. Incorporate verification tests for mechanical washers that:

   1. a. Monitor at the point-of-use

   2. b. Generate immediate results

   3. c. Indicate that all stages in the mechanical washer’s cleaning cycle meet the mechanical cleaning parameters.

Rationale: Verification methods for mechanical washers confirm that sufficient temperature, wash time, and detergent level was used. ^{Reference Rutala, Gergen and Weber43,Reference Alfa, Olson and Al-Fadhaly46,Reference Alfa, Olson and Murray61,Reference Heathcote and Stadelmann62} Facilities that use commercial cleaning verification tests for mechanical washers should ensure that they are validated by the manufacturer, as the FDA does not independently validate or clear mechanical washer verification tests.

11. Should healthcare facilities test the quality of water used for medical device processing at the point of use?

Recommendation: Beyond the testing required to support a facility’s water management program, no recommendation can be made for point-of-use water quality testing for reducing the risk of transmission of infectious pathogens, except:

1. 1. When indicated by the MIFU.

2. 2. When recommended by the local or state public health department.

3. 3. In the setting of outbreak investigation when a water source is suspected.

4. 4. When investigating staining, damage, or residue on processed medical devices.

Rationale: While water quality can be variable, ^{Reference Willis63} existing evidence does not support routine point-of-use testing of water quality to reduce the risk of transmission of infectious pathogens; however, there are exceptions to this, such as to help identify the potential source of contamination when a water source is suspected during an outbreak. ^{Reference Khalsa, Smith and Morrison64} Types of water that may be required by the MIFU have been defined. ⁶⁵

Several reports have documented instances of contamination of bronchoscopes ^{Reference Guimaraes, Chimara and do Prado66,Reference Scorzolini, Mengoni and Mastroianni67} and endoscopes ^{Reference Khalsa, Smith and Morrison64} from rinse water that ultimately were determined to represent pseudo-outbreaks. P. aeruginosa, M. abscessus, ^{Reference Guimaraes, Chimara and do Prado66} Mycobacterium gordonae, ^{Reference Scorzolini, Mengoni and Mastroianni67} and Aspergillus fumigatus ^{Reference Khalsa, Smith and Morrison64} were cultured, but none were clinically significant.

12. What additional methods, if any, are recommended to assess the cleanliness of reusable medical devices prior to sterilization and HLD?

Recommendation:

1. 1. Beyond external visual inspection (see 42), no recommendation can be made for additional methods for cleaning verification to prevent transmission events.

2. 2. No recommendation can be made for the use of surrogate tests to detect residual organic material (eg, ATP, protein, heme) to assess adequacy of cleaning. Currently, these tests are not correlated with reduction of risk for microbial contamination or transmission.

3. 3. For training purposes, facilities may consider including surrogate tests for medical devices that have a higher incidence of cleaning failure, such as lumened endoscopes.

Rationale: As standard practice, HCP should visually inspect reusable medical devices at various stages: prior to sterilization or HLD, after sterilization or HLD, and before use.

Surrogate tests (eg, ATP, protein, heme) to detect microbial growth cannot be used to assess for effectiveness of either cleaning or HLD for several reasons: ^{Reference Olafsdottir, Whelan and Snyder68–Reference Cattoir, Vanzieleghem and Florin70}

• ATP is a gross measure of organic material, and it may detect an organism’s residue rather than viable bacteria.

• Despite several studies that have correlated ATP and protein results with culture values, ^{Reference McCafferty, Abi-Hanna and Aghajani71–Reference Kwakman, Rauwers, Buijs, de Groot, Vos and Bruno79} specific measures and levels of cleaning effectiveness have not been validated as indicators of infection risk.

• The relationship between ATP and bacterial cultures is non-linear and may result in missing low levels of viable bacterial contamination.

Facilities may use surrogate tests to evaluate training, ^{Reference Heathcote and Stadelmann62,Reference Alfa, Fatima and Olson72,Reference Parohl, Stiefenhofer and Heiligtag80–Reference Sethi, Huang, Barakat, Banaei, Friedland and Banerjee84} investigate inadequate cleaning, and assess the impact of education and interventions, ^{Reference McCafferty, Abi-Hanna and Aghajani71,Reference Fitts, Yegge, Goris, Vinson and Dubberke81,Reference Ofstead, Wetzler, Heymann, Johnson, Eiland and Shaw85–Reference Masia, Dettori and Deriu91} but the frequency for using surrogate tests requires more study. If used, the results of surrogate tests should be interpreted according to manufacturer-recommended thresholds.

Immediate use steam sterilization

17. Is there a risk to immediate use steam sterilization (IUSS) when properly performed?

Recommendation:

1. 1. Although immediate use steam sterilization (IUSS) is an effective method of sterilization when properly performed, facilities should not routinely use IUSS.

2. 2. Design and implement processes that ensure that when IUSS is used:

   1. a. IUSS is performed by trained, competent HCP (see 43) in accordance with the reusable medical device or implant’s MIFU

   2. b. The sterilizer and the device or implant’s MIFUs include instructions for IUSS

   3. c. The device or implant is placed in a container validated for IUSS and legally marketed per FDA for this purpose

   4. d. The sterilization process is verified to be successful according to the appropriate indicator for the device or implant (see 14 and Supplementary Material Table 6 )

   5. e. Measures are taken to prevent contamination of the device or implant during removal from the sterilizer and transfer to the sterile field

   6. f. Before patient care, the device or implant that was subjected to IUSS is cooled to body temperature without compromising sterility.

Rationale: IUSS is effective when devices or implants are properly cleaned prior to IUSS, appropriate temperature, pressure, and exposure times are met, and adequate drying and cooling occurs. In practice, a higher usage of IUSS can be a result of ineffective planning for scheduled or frequently occurring but unscheduled procedures. Although IUSS can produce a sterile medical device, lack of equipment and supplies, and time constraints to process a device that is needed immediately for intraoperative use, can result in pressure on operating room HCP to eliminate or modify one or more steps prior to sterilization, increasing the risk for errors.

HCP who are not trained in the complex nature of processing with IUSS are not equipped to effectively perform the necessary processing steps. Facilities should restrict processing actions to HCP who have demonstrated competency in all the steps involved. Following an MIFU’s IUSS instructions is the only way to assure that the processing being used was validated to be effective. This includes the use of containers specified by the MIFU.

Monitoring and audits of HCP can verify that processing steps were performed in accordance with the MIFU, including the monitoring of the IUSS cycle (physical parameters, chemical indicators, biological indicators), and of patient outcomes (eg, intraoperative complications, prolonged procedure time, occurrence of surgical site infections [SSI]).

Limited research exists on the association between the use of IUSS and the incidence of SSI. In one large, retrospective review of more than 70,000 patients undergoing total knee arthroplasty, total hip arthroplasty, laminectomy, or spinal fusion, the increase in risk of SSI reported for patients whose procedures used instrumentation sterilized by IUSS versus non-IUSS was not statistically significant. ^{Reference Tantillo, Stapleton and Frane107}

HCP should use precautions to prevent burns (eg, transport tray using heat-protective gloves). Patient burns should be prevented by either air-cooling the instruments or immersion in sterile water. ^{Reference Rutala, Weber and Chappell108} A report of 2 patients who received burns during surgery from items that had undergone IUSS reinforces the need to develop policies and educate HCP to prevent the use of medical items hot enough to cause clinical burns.

18. When may IUSS be used?

Recommendation:

1. 1. As a last resort when the standard sterilization process cannot be performed (eg, intraoperative contamination of a unique device with no replacement available) and the risk of a delayed procedure exceeds risk of using IUSS, provided that all processing steps prior to IUSS are done according to the MIFU.

2. 2. Only when the devices or implants are heat-stable, the MIFU provides instructions for IUSS, and the facility has a process in place that involves IPC, patient safety, risk management/legal, and appropriate clinicians to evaluate whether benefits exceed the risks of using the implant or device.

Rationale: IUSS may be performed in the event of unexpected unavailability of an implant or reusable medical device for a procedure. ^{Reference Rutala and Weber109} This unavailability might be an issue of intraprocedural contamination, an urgent or emergently performed procedure with inadequate time to identify and locate all the needed medical items in advance, or another unforeseen event. IUSS should not be used routinely as an alternative to planned and scheduled procedures.

High-level disinfection of lumened devices

23. What are the requirements for adequate germicide flow?

Recommendation:

1. 1. Ensure that germicide flows through lumened reusable medical devices’ channels unimpeded with appropriate flow dynamics. The physical force of fluid through the channels aids in removal of microorganisms and may aid in the removal of biofilms.

2. 2. Passive flow is insufficient for removal of microorganisms. Positive pressure is required; however, no recommendation can be made for the minimum pressure required.

Rationale: AERs are designed to immerse and flush the lumened reusable medical device and its internal channels with liquid cleaning and disinfecting/sterilizing agents. Most AERs also perform one or more of the following: final water flush, alcohol rinse, and air purge.

When using an AER, facilities should follow the MIFU and confirm proper use of connectors to ensure that germicide and rinse water flow through the device’s channels. ^{Reference Weber and Rutala118} AERs should be monitored according to their MIFUs to verify ongoing adequacy of cycles. ^{Reference Alfa119} Individual AERs have specific flow and temperature ranges for operation and flow sensors to detect channel obstruction. ^{Reference Alfa41} If an AER cycle is interrupted, sterilization or HLD cannot be ensured and the entire cycle should be repeated. If using manual disinfection, facilities should follow the lumened reusable medical device’s MIFU.

24. Is there a preferred drying method following HLD of a lumened device?

Recommendation:

1. 1. Dry exterior surfaces of the lumened reusable medical device according to the specifications in the MIFU (eg, cloth that is clean or sterile, low-linting, or lint-free).

2. 2. Use pressure-regulated instrument air or HEPA-filtered air to dry the device’s lumens following HLD for the time specified by the device’s MIFU.

3. 3. Always dry a device following HLD, even if it is planned for immediate use.

Rationale: Any moisture remaining on the exterior and interior surfaces of the device can facilitate microbial growth and biofilm formation during storage. Moisture retained in processed flexible endoscopes has been associated with patient infections, ^{Reference Bajolet, Ciocan and Vallet6,Reference Aumeran, Poincloux and Souweine120} biofilm growth, ^{Reference Kovaleva, Degener and van der Mei121} microbial contamination, ^{Reference Ofstead, Doyle and Eiland90,Reference Ofstead, Heymann, Quick, Eiland and Wetzler117,Reference Liu, Peng, Wang, Huang and Chang122} and increased ATP values. ^{Reference Ofstead, Heymann, Quick, Eiland and Wetzler117,Reference Barakat, Girotra, Huang and Banerjee123} Drying should always occur, as residual moisture poses a risk to patients by supporting microbial growth.

Purging lumens with instrument air or HEPA-filtered air facilitates drying and prevents the introduction of contaminants that may be present in lower-quality air. The MIFU may provide guidance on the maximum air pressure that can be used. Air pressure that is too high may damage the internal channels of the endoscope. Some AERs have a cycle to purge rinse water from the endoscope at the end of the processing cycle, but this cycle may not be sufficient to dry the endoscope channels.

Studies have assessed drying times up to 10 minutes for manual and automated drying. ^{Reference Alfa, Degagne and Olson78,Reference Ofstead, Heymann, Quick, Eiland and Wetzler117,Reference Barakat, Girotra, Huang and Banerjee123–Reference Barakat, Huang and Banerjee127} In one study, manual drying was associated with significantly more fluid droplets on borescope inspection and higher ATP values at 48 hours and 72 hours after processing, compared with automated drying.

Flushing channels with alcohol, either manually or as part of an AER cycle, may facilitate drying of the endoscope channels and may prevent contamination; however, studies are mixed on whether use of alcohol leads to an increase in drying time or is effective at preventing contamination. ^{Reference Singh, Duerksen and Schultz82,Reference Ofstead, Wetzler, Heymann, Johnson, Eiland and Shaw85,Reference Ofstead, Doyle and Eiland90,Reference Ofstead, Heymann, Quick, Eiland and Wetzler117,Reference Liu, Peng, Wang, Huang and Chang122,Reference Barakat, Girotra, Huang and Banerjee123,Reference Nerandzic, Antloga, Litto and Robinson125} Concern also has been raised that alcohol may serve as a fixative, making biofilm more difficult to remove. ^{Reference Nerandzic, Antloga, Litto and Robinson125}

25. How should lumened reusable medical devices be stored following HLD?

Recommendation:

1. 1. After HLD, store lumened reusable medical devices and their accessories in accordance with their MIFUs. This includes but may not be limited to:

   1. a. Completely drying lumened reusable medical devices and accessories (see 24).

   2. b. Storing lumened devices and accessories in a manner that protects them from contamination and damage, in accordance with their MIFUs.

   3. c. Placing lumened devices in the position indicated by their MIFUs (ie, vertical or horizontal position) and the validated design of the storage cabinet. If placed in a vertical position, the device should not be coiled and should not touch the bottom of the cabinet.

2. 2. Place storage cabinets in a secure location that protects their contents from contamination and damage.

3. 3. Ensure storage cabinets are kept clean and dry.

4. 4. Adequately maintain storage cabinets per their MIFUs.

5. 5. No recommendation can be made for the use of drying cabinets to prevent the transmission of infections.

Rationale: Lumened devices are more difficult to dry than non-lumened devices. According to their MIFUs, lumened devices should be dried and stored in secure, dedicated cabinets to prevent contamination and damage.

Drying storage cabinets have a system that circulates and forces dry, usually HEPA-filtered air, through the endoscope channels. ^{Reference Kovaleva128} Several small studies suggested that drying cabinets may reduce the risk of growth of organisms like Pseudomonas aeruginosa. ^{Reference Perumpail, Marya, McGinty and Muthusamy129,Reference Saliou, Cholet, Jezequel, Robaszkiewicz, Le Bars and Baron130} One study inoculated Pseudomonas aeruginosa into colonoscope, enteroscope, and duodenoscope channels and compared bacterial growth rates over time between endoscopes that were stored in automated drying and storage cabinets with forced compressed air circulated through channels versus endoscopes that were stored outside the cabinet. This study reported a decline in bacterial growth over time for endoscopes stored in automated drying cabinets compared with increases over time in endoscopes stored in a non-controlled environment. ^{Reference Pineau, Villard, Duc and Marchetti131}

Some data have suggested that optimizing drying before storage (eg, by using automated drying devices that apply continuous air through all channels for a set period of time) results in minimal potential incremental benefit to using a ventilated storage cabinet. ^{Reference Barakat, Huang and Banerjee124} Although drying and ventilating storage cabinets may address challenges related to assessing dryness, there is an absence of clear acceptable levels for dryness. Also, the use of drying cabinets has not been demonstrated to reduce infection risk. Thus, a facility may conduct a risk assessment that considers factors that affect the ability to adequately dry endoscopes prior to storage, the potential benefits of augmented drying options, and resources required to acquire, install, and maintain cabinets to make decisions about the type of storage cabinet(s) for their specific setting.

Special considerations for high-level disinfection

26. When and how should lubricating and defoaming agents be used for medical devices?

Recommendation:

1. 1. Use lubricating or defoaming agents for medical devices when clinically needed and as permitted and specified by the MIFU.

2. 2. Preferentially choose water-soluble agents over non-water-soluble agents, if permitted by the MIFU.

3. 3. Prior to processing, clean the device after use to remove lubricating or defoaming agents in accordance with the MIFU.

4. 4. For lumened, semi-critical reusable medical devices:

   1. a. Minimize the use of non-water-soluble defoaming agents consistent with the amount clinically needed for a successful completion of the procedure.

   2. b. When the device is used with simethicone:

      1. i. Apply the minimum amount of simethicone required for a successful procedure.

      2. ii. Follow the MIFU for how to add the simethicone to the device.

      3. iii. If the MIFU does not specify the process for adding simethicone to the device, ideally deliver simethicone directly into the working channel, rather than into the irrigation water bottle.

      4. iv. After use, clean the device as specified by the MIFU.

Rationale: Lubricating agents prevent friction that can result in tissue abrasion and prevent corrosion of the medical device, and defoaming agents may be technically necessary for specific procedures (eg, for adequate visualization).

Lubricants and defoaming agents that are not water-soluble are difficult to remove from flexible endoscopes and may not be permitted by the endoscope’s MIFU. A multisite study found oily, sticky residue on endoscopes and a mass inside a patient-ready ultrasound endoscope. ^{Reference Ofstead, Hopkins, Eiland and Wetzler132} The researchers reported finding use of cooking oil, silicone sprays, and tissue adhesives during endoscopies, despite the endoscope’s MIFU stating to avoid using simethicone, oil, petroleum, or silicone-containing products because they are not water soluble. If oil- or grease-based agents are used, they should be specified as permitted by the MIFU, and facilities should use cleaning agents that are specifically effective in removing them. ^{Reference Croke133}

Water-soluble alternatives for lubricants (eg, lidocaine jelly) are preferred if they are allowed by the device’s MIFU because cleaning does not consistently remove oil- or grease-based agents entirely from reusable medical devices. ^{Reference Mallard, Roswell and Sylvester134}

Multiple studies have found that simethicone is commonly identified during borescope inspection in patient-ready endoscope channels, appearing as white liquid residue and crystallized white fragments. ^{Reference Ofstead, Wetzler, Heymann, Johnson, Eiland and Shaw85,Reference Ofstead, Heymann, Quick, Eiland and Wetzler117,Reference Ofstead, Hopkins, Eiland and Wetzler132,Reference Ofstead, Wetzler, Johnson, Heymann, Maust and Shaw135,Reference Ofstead and Hopkins136} Simethicone use has been associated with retained moisture in processed endoscopes, which can impair drying and may be related to increased ATP values. ^{Reference Ofstead, Wetzler, Heymann, Johnson, Eiland and Shaw85,Reference Barakat, Huang and Banerjee127,Reference Ofstead, Hopkins, Eiland and Wetzler132,Reference Ofstead, Wetzler, Johnson, Heymann, Maust and Shaw135} A study compared different concentrations of simethicone (0.5%, 1%, 3%) to water and performed borescope inspection and ATP testing, finding that medium-to-high concentrations of simethicone were associated with significant increases in ATP values and the number of retained fluid droplets. Simethicone was detected at low concentrations after 2 AER processing cycles in endoscope channels. ^{Reference Barakat, Huang and Banerjee127} In contrast, another study that conducted borescope inspections did not find simethicone despite its use at the facility. ^{Reference Thaker, Kim, Sedarat, Watson and Muthusamy137}

One study assessed the effects of varying levels of simethicone concentrations and delivery using an irrigation water bottle versus injection through the working channel. Simethicone concentrations were higher when the solution was added to the irrigation water bottle. When simethicone was added to the working channel rather than the irrigation water bottle, the total volume of simethicone solution needed for procedures was reduced (940 mL vs 180 mL; P < 0.001). The investigators found that simethicone was detectable after processing in the working channels, even when used at low concentration. ^{Reference Barakat, Huang and Banerjee127}

27. Does HLD inactivate human papilloma virus, multidrug-resistant bacteria, mycobacteria, and multidrug-resistant fungi (eg, C. auris)?

Recommendation: HLD, when properly performed, is shown to be effective against human papilloma virus (HPV), multidrug-resistant microbes including multidrug resistant bacteria and fungi (eg, carbapenem-resistant Enterobacterales, C. auris). Mycobacteria, however, are relatively resistant to some high-level disinfectants.

Rationale: Although some studies have suggested resistance of HPV to certain high-level disinfectants, ^{Reference Meyers, Ryndock, Conway, Meyers and Robison138} ample evidence has shown the effectiveness of a wide range of HLD agents against HPV. ^{Reference Ozbun, Bondu and Patterson139,Reference Egawa, Shiraz and Crawford140} Methods that are legally marketed per FDA using hypochlorite, peracetic acid, or ortho-phthalaldehyde (OPA) may be used as specified per the device’s MIFU for processing. ^{Reference Moody, Rutala and Gergen141} HLD disinfectants have efficacy against vegetative multidrug-resistant bacteria. ^{Reference Kanamori, Rutala, Gergen, Sickbert-Bennett and Weber142} Similarly, HLD methods that are legally marketed per FDA have been shown to be effective against C. auris. ^{Reference Rutala, Kanamori, Gergen, Sickbert-Bennett and Weber143} Mycobacteria are relatively resistant to glutaraldehyde and OPA; ^{Reference Fisher, Fiorello, Shaffer, Jackson and McDonnell144,Reference Burgess, Margolis, Gibbs, Duarte and Jackson145} however, peracetic acid and hydrogen peroxide effectively kill aldehyde-resistant strains of mycobacteria. An outbreak of M. abscessus in a Brazil hospital unit was attributed to cross-contamination and resistance to glutaraldehyde. ^{Reference Guimaraes, Chimara and do Prado66}

28. Is automated processing superior to manual HLD?

Recommendation:

1. 1. Automated processing is preferred over manual HLD because it has been shown to result in more reliable processing and to achieve higher microbe elimination than manual HLD, and the use of automated processing systems may reduce exposure of HCP to chemicals.

2. 2. Maintain automated processing systems according to their MIFUs.

Rationale: Automated processing has been shown to be either equally effective or superior to optimal manual HLD for a variety of reusable medical devices, including lumened endoscopes, solid surgical reusable medical devices, and ultrasound probes. ^{Reference Rodriguez and Hooper83,Reference de Camargo, Almeida, Bruna, Ciofi-Silva, Pinto and Graziano89,Reference Barakat, Huang and Banerjee124,Reference Ofstead, Wetzler, Snyder and Horton146–Reference Forte and Shum152} Automated processing provides greater reliability, reduced potential for operator errors or inadequate manual cleaning, ^{Reference Ofstead, Wetzler, Snyder and Horton146} and reduced exposure of HCP to potentially harmful chemical agents, such as OPA, ^{Reference Miyajima, Yoshida and Kumagai153} glutaraldehyde, ^{Reference Cohen and Patton154} and others. ^{Reference Warburton155}

Use of automated systems does not completely remove the need for vigilance and human involvement. The systems need to be maintained, as they can have failures that can result in transmission. ^{Reference Yetkin, Ersoy and Kuzucu156–Reference Volkman and Author161} Factors unrelated to automation, such as germicidal agent activity and equipment damage, can influence the quality of HLD by automated processing. ^{Reference McCafferty, Aghajani, Abi-Hanna, Gosbell and Jensen34,Reference Sooriakumaran, Kaba, Andrews and Buchholz35,Reference Ren-Pei, Hui-Jun, Ke, Dong, Xing and Zhao-Shen45,Reference Desilets, Kaul and Tierney162,Reference Zhang, Zhou, Jiang, Wang, Li and Huang163} Finally, no fully automated HLD system currently exists, meaning at least one or more steps involve manual intervention, including visual inspection. ^{Reference Ofstead, Quick and Wetzler33,Reference Rodriguez and Hooper83,Reference Ofstead, Wetzler, Heymann, Johnson, Eiland and Shaw85,Reference Desilets, Kaul and Tierney162} Automation with proper monitoring and quality assurance of both the automated and manual steps is likely the safest, most effective approach. ^{Reference Alfa119}

It should be noted that automated and manual HLDs are performed in addition to the initial manual cleaning of devices, and automated cleaning features in AERs are used in addition to manual cleaning, per the device MIFU (see 7).

29. What should facilities monitor to ensure that HLD conditions are achieved?

Recommendation: Monitor compliance with the MIFU, including the concentration of the active ingredient(s) in a liquid chemical sterilant or high-level disinfectant (ie, the minimum effective concentration (MEC) and minimum recommended concentration [MRC]), temperature, and time.

Rationale: Inadequate concentrations or duration of exposure can lead to residual contamination. ^{Reference Ofstead, Hopkins, Buro, Eiland and Wetzler164}

30. Should facilities routinely use microbial cultures to assess the effectiveness of HLD for lumened and non-lumened devices?

Recommendation: No recommendation can be made for routinely using microbial cultures to assess the effectiveness of the HLD process.

Rationale: Although facilities can reliably measure the effectiveness of HLD by culturing reusable medical devices for residual bacterial contamination, routine culturing is resource intensive and there is no evidence to support that routine microbial surveillance reduces risk of transmission events. Facilities that are considering routine culturing will need to balance the cadence of surveillance (eg, after each HLD event, monthly, or after a defined number of uses) with the cost of additional devices to make up for those that are embargoed while awaiting culture results, as well as costs for culturing and HCP. ^{Reference De Wolfe, Safdar and Meller165,Reference Ma, Pegues and Kochman166} Specialized reference laboratories also may be required, as most clinical laboratories are not equipped to process environmental samples. Additionally, variability in culturing techniques affects the tests’ sensitivity (eg, sampling solutions, culture media, incubation period, antegrade versus retrograde collection). ^{Reference De Wolfe, Safdar and Meller165,Reference Aumeran, Thibert, Chapelle, Hennequin, Lesens and Traore167–Reference Buss, Been and Borgers169} Resources exist to help facilities culture scopes, including culturing protocols for duodenoscopes from FDA, CDC, and the American Society for Microbiology (ASM) ¹⁷⁰ and preassembled toolkits to facilitate aseptic collection for culturing by a reference laboratory. ^{Reference Ofstead, Doyle and Eiland90}

Facilities that have implemented routine surveillance culturing of lumened endoscopes after HLD have reported a broad range of positive culture rates from 3% to 35.7%. Skin contaminants were more frequently cultured than enteric organisms. ^{Reference Gillespie, Arnold and Noble-Wang171–Reference Cottarelli, De Giusti and Solimini174} In post-market surveillance, researchers cultured high-concern organisms in 6.6% of samples from fixed end-cap design duodenoscopes and in 1.1% of duodenoscopes with single use components. ¹⁷⁵

Facilities may consider culture-based or non-culture-based methods as part of a quality assurance program to detect errors in processing, contamination of AERs, and unsuspected endoscope damage ^{Reference Casini, Tuvo and Marciano19,Reference Vincenti, Colamesta and Nurchis176} (see 12) or as part of an outbreak investigation where a medical device may be implicated in transmission (see 16). ^{Reference Veater, Jones-Manning, Mellon, Collins and Jenkins177} Although no recommendation is available for routine culturing of endoscopes, if a facility does perform cultures (as part of research, outbreak investigations, or quality assessment) and identifies growth of organisms, actions and mitigation strategies should occur in accordance with the FDA/CDC/ASM guideline, ¹⁷⁰ which references the types of pathogens recovered (eg, high concern organisms, low/moderate concern organisms) and the level of growth and provides recommended actions (see 39-41 for tracking of reusable medical devices). Positive endoscope cultures of high-concern organisms per the FDA/CDC/ASM guideline ¹⁷⁰ have been associated with transmission and outbreaks. There is no minimum acceptable threshold for the number of high-concern organisms cultured. Positive endoscope cultures after HLD with low- or moderate-concern organisms do not necessarily represent a failure of processing but may be related to recontamination during the storage or culturing process. ¹⁷⁰ Microbial limits for low-concern organisms identified through culturing endoscope channels have not been correlated to patient outcomes. Microbial limits depend on culturing methods and techniques that have not been standardized.

Handling reusable medical devices after high-level disinfection

31. After processing, how should reusable medical devices that have undergone HLD be handled for storage?

Recommendation:

1. 1. Follow the MIFU for how to handle reusable medical devices that have undergone HLD and are ready for storage.

2. 2. Perform hand hygiene before handling devices that have undergone HLD.

3. 3. No recommendation can be made for the use of gloves in addition to hand hygiene to reduce the risk of transmission of infectious agents to patients. Gloves are not a substitute for hand hygiene.

Rationale: An experimental study using ATP testing found that when HCP performed hand hygiene or donned gloves, the reusable medical devices that were tested had less contamination. ^{Reference Costa, Lopes and Tipple178} There is no evidence to support requiring HCP to don gloves after they have properly performed hand hygiene to reduce the risk of contamination or transmission.

32. Is there a maximum time that properly processed non-lumened and lumened devices can be stored, after which facilities should repeat HLD to reduce the risk of transmission of infection?

Recommendation:

1. 1. No recommendation can be made for a maximum time after which facilities should repeat HLD for devices, including lumened devices, if a maximum time is not specified by the MIFU, and the devices have been properly cleaned, processed, and stored without evidence of breaches or events leading to potential contamination (eg, flood, non-contained construction).

2. 2. If a maximum time is not specified by the device MIFU, a facility may use a risk assessment to determine whether to use a time- or event-based method for defining how long to store non-lumened and lumened devices.

3. 3. If there is evidence of contamination, repeat HLD, processing the device in accordance with the MIFU.

Rationale: Previous recommended time-based durations of storing lumened reusable medical devices (ie, their “hang time”) were varied and was based on limited evidence. ^{179,Reference Heroux, Sheppard and Wright180} The existing literature is limited by variability in the storage conditions tested (eg, cabinet, no cabinet), the type of processing (sterilization or HLD), the types of lumened devices studied (eg, duodenoscopes, echoendoscopes, bronchoscopes, gastroscopes, colonoscopes), the duration tested, and where culture samples were gathered (channels or endoscope surfaces), although studies that assessed for contamination at various time points from 2 days to 12 weeks found that lumened reusable medical devices can be safely stored for these durations. ^{Reference Lacey, Good, Toliver, Jenkins and DeGuzman181}

Due to inconclusive evidence to provide a maximum storage interval, several guidelines have recommended that institutions perform a risk assessment to establish their own policies, ^{94,Reference Petersen, Chennat and Cohen182,Reference Day, Kwok, Visrodia and Petersen183} using a time- or event-based approach (eg, a breach in storage conditions) for determining when to repeat processing. No evidence has directly addressed the maximum time for storage of non-lumened devices. Facilities should consider the utility of a policy that is based on these factors. For example, a “hang time” policy would be useful for devices that a facility uses infrequently, but such a policy may not be useful for devices that a facility uses often.

Considerations for developing a facility-specific policy should include storage conditions, types of processing, the types of devices used, their frequency of use, wear and tear, available HCP, and cost.

Augments and alternatives to high-level disinfection

33. Is there evidence to support the use of additional cycles of HLD (ie, double HLD or “dHLD”) to reduce the risk of residual contamination?

Recommendation: No recommendation can be made for the use of more than one cycle of HLD for the purpose of reducing microbial contamination.

Rationale: In response to the reported outbreaks of carbapenem-resistant Enterobacterales-associated with endoscopic retrograde cholangiopancreatography procedures between 2013 and 2015, FDA issued recommendations for enhanced processing methods for duodenoscopes to reduce the risk of transmission. ¹⁸⁴ Optional supplemental measures after single HLD of the duodenoscopes included double HLD, liquid chemical sterilant processing system, ethylene oxide sterilization, and low-temperature sterilization measures that are legally marketed per FDA. A meta-analysis that included reviewed reports from January 1, 2010 until March 10, 2020 concluded that the contamination rates were dependent on the processing method used. ^{Reference Larsen, Russell and Ockert185} A single HLD resulted in an contamination rate of 16.14% ± 0.019% (95% Cl: 12.43%-19.85%). After the use of double HLD or ethylene oxide, the contamination rate decreased to 9.20% ± 0.025% (95% Cl: 4.30%-14.10%). However, randomized studies showed comparable contamination rates in the 3 methods (single HLD, double HLD, and HLD/ethylene oxide), ^{Reference Snyder, Wright and Smithey186} and no difference between single HLD and double HLD. ^{Reference Bartles, Leggett and Hove187,Reference Yassin, Hariri, Hamad, Ferrelli, McKibben and Doi188}

34. Instead of HLD, should certain semi-critical devices preferentially be sterilized?

Recommendation:

1. 1. When sterilization technologies are shown to be effective in clinical settings and cycle specifications are validated and included in the MIFU, facilities should begin developing an institutional process for converting from HLD to sterilization for semi-critical reusable medical devices that are associated with a high risk of transmission of infection to patients.

2. 2. Facilities may choose to evaluate sterilization along with other alternatives to HLD, eg, use of sterile, single use devices (see 36) or alternative therapeutic or diagnostic modalities as appropriate, while considering infection outcomes, clinical functionality of the devices, feasibility, and patients’ access to care.

Rationale: The risk of contamination and pathogen transmission related to specific semi-critical devices, particularly duodenoscopes, is well documented. ^{Reference Ofstead, Wetzler, Snyder and Horton146} Alternative strategies to reduce the risk of infection transmission associated with processing of endoscopes (eg, double HLD) generally have not been successful (see 33). ^{Reference Larsen, Russell and Ockert185–Reference Bartles, Leggett and Hove187,Reference Ayres, Wozniak and O’Neil189–Reference Heuvelmans, Wunderink, van der Mei and Monkelbaan191} An FDA panel on duodenoscopes in May 2015 discussed the rationale for transitioning from HLD to sterilization for high-risk scopes. ¹⁸⁴

Currently, sterilization processes for endoscopes, which use ethylene oxide gas and hydrogen peroxide gas plasma are legally marketed per FDA; however, they may not be implementable by all facilities or for certain devices. The use of ethylene oxide sterilization on duodenoscopes during infectious outbreaks has been associated with terminating these outbreaks, ^{Reference Naryzhny, Silas and Chi192} although ethylene oxide sterilization of clinically used endoscopes has not demonstrated complete microbial eradication. ^{Reference Snyder, Wright and Smithey186} Endoscope contamination with multidrug-resistant organisms has been reported after ethylene oxide sterilization. ^{Reference Naryzhny, Silas and Chi192} The length or diameter of lumens and the presence of inorganic salts or organic materials can affect the effectiveness of sterilization with ethylene oxide. ¹⁹³ Although a sterilizer that uses hydrogen peroxide exists and is legally marketed per FDA, this sterilizer has not been evaluated with clinically used endoscopes.

35. Should facilities choose reusable or sterile, single use duodenoscope components (eg, distal endcaps, elevator mechanisms) and accessories (eg, biopsy port caps, valves, buttons)?

Recommendation:

1. 1. Choose duodenoscope designs that have sterile, single use components and accessories to lower the risk of transmission of infection.

2. 2. Use endoscope components and accessories that are compatible with the endoscope, recommended by the endoscope’s MIFU, and are legally marketed per FDA.

Rationale: With data from post-market surveillance studies (also known as 522 studies) revealing challenges in cleaning and disinfection of duodenoscopes, FDA has recommended movement toward device designs that make processing easier and more effective through single use components (eg, distal endcaps, elevator mechanisms) or designs that obviate the need for processing and reuse (eg, single use, flexible endoscopes). As of this publication, several duodenoscopes that facilitate processing with single use components and some duodenoscopes that are fully disposable are legally marketed per FDA.

Single use components

Single use components lower the risk of HLD failure but do not eliminate the risk of contamination. A randomized clinical trial found reduced contamination in single use elevator cap duodenoscopes following HLD, compared with standard scope designs (3.8% single use versus 11.2% standard) without affecting technical performance and safety of endoscopic retrograde cholangiopancreatography (ERCP). ^{Reference Forbes, Elmunzer and Allain194}

Single use accessories

Facilities may choose reusable or single use endoscope accessories (eg, biopsy port caps, valves, buttons). ^{Reference Pasquale, Maurano and Cengia195,Reference Ofstead, Wetzler and Doyle196} Some evidence has supported reduced risk of transmission with single use biopsy forceps, compared with reusable biopsy forceps ^{Reference Lim, Choi and Kim197} due to challenges in adequate cleaning reusable biopsy forceps. ^{Reference Yoon, Yoon and Lee198} When reusable accessories are used, reprocess them according to MIFU.

In addition to infection prevention considerations, facilities may evaluate how single use products may affect patients’ access to care, institutional finances, and the environment. Access to care, financial, and environmental considerations were not included in the scope of this document, and the authors cannot recommend frameworks or models for evaluating them.

36. When available and feasible, should facilities use sterile, single use endoscopes?

Recommendation: Facilities may choose sterile, single use endoscopes to eliminate the risk of transmission of pathogens from the device to patients, especially when the available resources (physical space, expertise, training, and staffing) do not support processing.

Rationale: The intricate design and configuration of reusable flexible endoscopes or certain components of the endoscope (eg, elevator mechanism) represent significant challenges to effective cleaning and processing. Facilities may not have available resources (eg, physical space, expertise, training, staffing) to support safe processing of reusable endoscopes.

For many procedures that are performed by experienced endoscopists, evidence supports the technical performance of single use duodenoscopes versus reusable duodenoscopes. ^{Reference Bang, Hawes and Varadarajulu199–Reference Muthusamy, Bruno and Kozarek201} A systematic review of 21 studies of single use flexible ureteroscopes and cystoscopes showed no difference in clinical outcomes. ^{Reference Anderson, Patterson, Skolarikos, Somani, Bolton and Davis202}

Investigational devices

37. How should facilities process critical or semi-critical investigational reusable medical devices?

Recommendation:

1. 1. Only use investigational devices following:

   1. a. Issuance by FDA of an investigational device exemption (IDE) or approval of an investigational new drug (IND) application, OR

   2. b. Approval by the facility’s Institutional Review Board (IRB) with determination that the device is “minimal risk” and with approval of cleaning and sterilization or HLD instructions by both IPC experts and the IRB.

2. 2. When using investigational devices in accordance with the above recommendations, involve IPC in processing protocols developed for investigational reusable medical devices.

Rationale: The FDA and the facility’s IRB needs to approve the use of all investigational devices that pose a “significant risk.” ⁹² For devices that are deemed to pose a “non-significant risk” (ie, “a study device does not meet the definition of a significant risk device”) the IRB may approve the study without the investigators obtaining an IDE from the FDA. For devices that pose a “non-significant risk,” the IRB and IPC should ensure that methods have been established and put in place for processing any investigational reusable medical devices. It should be noted that most healthcare facilities have neither the equipment nor adequately trained HCP to conduct the necessary cleaning and sterilization or HLD validations to be able to establish safe and effective processing.

38. How should 3-dimensional-printed (ie, 3D-printed or additively manufactured) critical or semi-critical reusable medical devices be processed?

Recommendation:

1. 1. Ensure that devices that are 3D-printed are legally marketed per FDA.

2. 2. Follow the validated processing instructions provided in the MIFU.

3. 3. When a 3D-printed device is considered investigational, follow the requirements for investigational devices (see 37).

Rationale: Devices that are produced using 3D printers may also be referred to as “additively manufactured.” These may include a subcategory of devices referred to as “patient-matched devices.” Often, these are unique in design. FDA recommends that the manufacturers of 3D-printed devices establish a “design envelope” that effectively brackets the device’s design. Once the cleaning and sterilization instructions have been validated on devices that represent the most challenging extremes, these brackets may serve as surrogates, and it can be assumed that these, as well as all intermediate, mid-sized versions of the device, have been adequately evaluated to be legally marketed per FDA.

Experimental, investigational 3D-printed devices that are manufactured onsite should not be used unless they present a “non-significant risk,” and the IRB and IPC ensure that methods have been established and put in place for processing these medical devices (see 37). 3D-printed devices that are manufactured at a healthcare facility are likely to present unique designs for which surrogates are not available as subjects for conducting cleaning and sterilization validations. For example, a study of orthopedic fracture models demonstrated that gas plasma failed to sterilize the inside of a hollow model and steam sterilization deformed the model. ^{Reference Aguado-Maestro, De Frutos-Serna, González-Nava, Merino-De Santos and García-Alonso203} Additionally, 3D-printed devices should be manufactured in a manner to ensure that residual manufacturing materials have been reduced to levels that are safe. Most healthcare facilities do not have the equipment and cleaning methods to sufficiently remove manufacturing materials or the adequately trained HCP to conduct cleaning and sterilization or HLD validations.