INNOVATION IN THE AUTOMATED REPROCESSING OF DA VINCI INSTRUMENTS XI 8MM

Participants:

Enrique Hernández1; Elena Lorenzo2; Dr. Nelson Carreras3; Marino Alonso4.
1Global Product Manager Washing Systems, 2IPC&MIEC Global Manager, 3Global Product Manager Consumables, 4Director of marketing.

 

INTRODUCTION

During 2022/23, MATACHANA and INTUITIVE jointly conducted a feasibility study to demonstrate the possibility of optimizing the automated reprocessing of Robotic EndoWrist[1] Xi 8mm Instruments through an innovative automated process.

 

CHALLENGE

Work Labor in SPDs is very valuable as it is getting increasingly challenging to find reprocessing specialized staff. As technologies innovate and more complex instruments need to be reprocessed, it is crucial to focus on optimizing workflows. Due to the complex design of da Vinci Xi 8mm instruments, some precleaning manual steps are required for successful reprocessing. Reprocessing of da Vinci Xi 8mm instruments requires additional time compared to other surgical instruments. Below is an example of the Intuitive IFU, which shows all required manual pre-cleaning steps described in detail.

For reprocessing da Vinci Xi 8mm instruments, a custom wash cycle is required, validated and provided by the washer disinfector manufacturers. Such a cycle is currently longer in duration than an MIS cycle; however, there are developments in optimizing such cycles as well.

Common Washer disinfector current profile:

1. Pre-wash
2. 1st Phase of washing
3. 2nd Phase of washing
4. 1st Rinse
5. 2nd Rinse
6. Thermal disinfection
7. Drying

 

SCOPE OF INNOVATION

Thanks to MATACHANA ‘s experience as a leading manufacturer in the medical device reprocessing sector and faced with the imperative need to validate every stage of reprocessing on our medical devices, we were confident that it was possible to completely automate the reprocessing of the EndoWrist Xi 8mm Instruments. Therefore, we took on the challenge of optimizing the process, considering the following premises:

• Due to its morphology and internal architecture, it is a complex that requires specific manual precleaning treatment.
• They are reusable instruments with limited uses that require careful and gentle treatment to avoid any damage or reduction in their intended lifespan.
• The process was to improve ergonomics and reduce staff time.
• Its design reduced total reprocessing time, increasing material turnover and availability.
• The consumption of energy, water, and detergents needed in the overall process was to be reduced. 
• The material was to be unloaded in the Inspection and Preparation area, after the corresponding cleaning, thermal disinfection, and drying stage, avoiding any possibility of recontamination caused by additional handling in the dirty area before its transfer to the clean area.
• The cleaning process had to be validated.

 

TYPE TESTS

To validate the effectiveness of instrument cleaning, different procedures, processes, and tests were defined, considering the most demanding conditions:

INSTRUMENTS CONSIDERED THE WORST CASE

Specifically, the cauterization instruments “Maryland Bipolar Forceps, ref. 470172” and “Monopolar Curved Scissors, ref. 470179” were identified as the most challenging instruments for cleaning and thus representative for the Xi 8mm Instruments family. During the cauterization process, residues of burned tissue typically remain at the instrument’s distal tip.

 

SOILING

• Coagulated sheep blood was used as soil according to the recommendations of ISO 15883-5 and AAMI TIR 30:2011 (later replaced by ANSI/AAMI ST98:2022) Standards. A volume of 70 µl was defined for soiling the interior channel, injected and distributed throughout the lumen, and soiling the distal tip by immersion in the same solution.
• It was left to dry for 60-65 minutes at room temperature to ensure the worst-case scenario and represent the greatest challenge to the cleaning process.
• As the inner instrument channel is not visually accessible, a first test was conducted using the Radionuclide Method (RNM). By measuring the radiation, it was verified that the distribution of dirt on the instrument was optimal by the soiling method used.

Although this test is not according any standard, it shows clearly the real distribution of the soil.

 

REQUIREMENTS FOR AUTOMATED PRE-CLEANING

• The process reduces user manipulation to placing and removing instruments from the pre-washing unit.
• Subsequently, the EndoWrist instruments are subjected to an ultrasonic irrigation process with distal tip movement for 10 minutes. This process is performed on the MATACHANA MAT UIRI unit which includes a Trison 4000 system manufactured by Bandelin.
• Following this procedure, the instruments are visually inspected using a magnification glass per Intuitive’s RIFU, and the distal tip is brushed if necessary.

 

REQUIREMENTS FOR CLEANING, DISINFECTION AND AUTOMATED DRYING

• The washing, thermal disinfection, and drying process is carried out in a washer disinfector according to EN ISO 15883 part 1,2. For this purpose, a MATACHANA MAT LD1000 washer disinfector with standard configuration, da Vinci Xi 8mm instrument rack, and conventional MIS[2] cycle with the following profile[3] was used:
  • Pre-wash
  • 1 Washing phase
  • 2 Rising phase
• The same enzymatic detergent suitable for the automated washing of medical devices was selected. This precluded any possibility of incompatibility between different chemicals and the need for intensive manual rinsing of the instruments between the ultrasonic irrigation and the washer disinfector.
• As in any Validation procedure, several reprocessing cycles were repeated with both instruments defined as the worst-case. In this way, we could confirm the consistency and repeatability of the results.

 

EXTRACTION, RECOVERY, AND QUANTIFICATION OF SOIL

The extraction, recovery, and quantification methods of residues were carried out following the procedures of an accredited and independent external laboratory. This laboratory ensured the capture, evaluation, analysis and documentation of all possible residues after the process.

 

ACCEPTANCE REQUIREMENTS

Acceptance requirements were assessed according to the highest standards:

CRITERION	Acceptance Value	Reference Standard
Amount of visible dirt in the sample at the end of the washing process	No visible dirt	EN ISO 15883-5:2021-11 RKI guideline: 2012 ANSI/AAMI ST98: 2022 Guideline DGKH, DGSV, AKI: 2017
Total amount of protein per sample	<100 μg	RKI guideline: 2012
Total amount of protein per sample	< 200 μg	EN ISO 15883-1:2014
Amount of protein/cm2	< 3.0 μg/cm2	Guideline DGKH, DGSV, AKI: 2017 EN ISO 15883-5:2021-11
Amount of protein/cm2	< 6.4 μg/cm2	ANSI/AAMI ST98: 2022

RESULTS

The tests and analyses were conducted at the SMP GmbH laboratory in Tübingen, Germany, which is accredited for this type of testing.

The results of all the tests were consistent with those from the previous trials conducted in the internal laboratories of INTUITIVE and MATACHANA. In all cases, the trace levels of soiling after washing were significantly lower than the established thresholds. Most samples showed protein presence values below 50% of the strictest limits.

The results’ analysis confirmed that the new reprocessing proposal improves washing efficiency, possibly reducing manual pre-cleaning time while maintaining cleaning efficacy compared to manual pre-cleaning steps as described by the manufacturer Intuitive.

 

FINAL CONCLUSIONS

MATACHANA and INTUITIVE have collaborated on the development of an innovative alternative for reprocessing EndoWrist XI 8mm Instruments.

The new process brings numerous advantages for both the Hospital and its users:

 

1. High performance:

• Simultaneous reprocessing of up to 14 instruments[4], resulting in a significant increase in productivity.
• The increased rotation of instruments allows for more uses during the same workday.

 

 2. Reduction in the total reprocessing time:

• It reduces the time required for automatic reprocessing of instruments by more than 50% and about 75% compared to manual reprocessing.
• Allows reprocessing of the four instruments used in a conventional intervention in only 60 minutes vs. >120 minutes currently.

 

Could potentially reduce the current nine steps of automatic reprocessing:

To four steps, whereas this is currently not reflected in Intuitive reprocessing instructions. In countries where reprocessing needs to be validated, this shortened process might be an option to consider.

The responsibility of such an approach is always at the preprocessor based on national guidelines.

 

3. Economic advantages:

• The optimization of cycle times increases the availability of the units for other tasks, increasing the overall productivity of the facilities.
• It minimizes manual tasks and reduces the time workers spend on them, allowing them to focus on other departmental activities.

 

 4. Sustainability:

•  We reduce water, energy and chemical consumption. The most important difference is achieved thanks to the change in the cycle profile that can be configured in the washer-disinfector, especially when it is previously used in an automatic pre-cleaning system. This change allows for a reduction in:
  
  •  -30% Cycle time.
  •  -50% Chemicals consumption.
  • –35% Water and energy consumption.
  • 
•  The reduction in water, chemicals and energy consumption also represents significant cost savings for healthcare institutions.

 

5. Other advantages:

• Improved ergonomics for users
• Ensuring all critical process parameters.
• Facilitates process validation.
• Less reliance on manual tasks
• Automatic recording of processes and any incidents

 

 Collaboration between expert companies and the pooling of knowledge and resources is the key to innovation in the reprocessing of new medical devices.

 The preliminary result of this study was made public during the WFHSS 2022 in Barcelona.

 

 

DEFINITIONS AND EXPLANATIONS

1 EndoWrist: Articulated instruments, reusable, used in robotic surgery and manufactured by Intuitive.

2 MIS: Cycle configuration for Minimally Invasive Surgery material. 

3 The profile does not include thermal disinfection and drying phases when assessing the washing efficiency. 

4 In the case of the MAT LD1000 model, using the da Vinci Xi rack with a capacity for 14 instruments