Although the Food and Drug Administration (FDA) has reported progress on reducing overall infection rates with enhanced safety measures and better disinfection methods, the risks associated with reusable medical devices are an ongoing challenge, with drug-resistant microbes and other organisms continuing to survive the cleaning process at an unacceptable rate.1

A technician inserts surgical instruments into an autoclave for sterilization. (Credit: iStock)

The reality is that medical device cleaning is a complex undertaking under the best of circumstances, and the risk of human error cannot be entirely eliminated — putting patients at risk. Even when processes are followed precisely, problems can occur. In its ongoing efforts to mitigate infection transmission associated with duodenoscopes, the FDA notes that the problem was found even when manufacturer specifications for cleaning, disinfection, and sterilization had been followed.2

While cleaning instructions, training, and testing with microbiological culturing and identification remain key strategies for reducing infection risk, a growing area of focus is centered on device design.

Cleanability Optimization Starts with Design

The practice of incorporating “cleanability” into medical device design can yield significant benefits. Design features that inhibit or resist the growth of organisms, and designs that make devices easier to clean are key to reducing patient infections — an outcome made all the more urgent by the emergence of antibiotic resistant bacteria like methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococus (VRSA) and others.3

Medical device cleaning problems are a persistent theme among the equipment research organization ECRI Institute’s annual list of Top 10 Health Technology Hazards.4 As Scott Lucas, the organization’s associate director of accident and forensic investigation explained following release of the 2017 list, the problem is greater than issues with any single device or shortcoming in cleaning processes.5 “This is really a systemic challenge,” Lucas said, adding that the FDA was likely to begin pushing device makers to take cleaning into consideration during the design process.

Design Imperfections Identified Prior to Production

A source of opportunity for improving cleanability design of medical devices has emerged from a lesser known metal finishing process called electropolishing.6

Rivets in an orthopedic medical tray expose a risk that pathogens and other hazardous substances would not be removed in the cleaning process, creating a risk of infection transmission. (Credit: iStock)

In an era of increasing collaboration on infection control between medical device manufacturers and healthcare researchers and providers, electropolishing occupies a unique position as a bridge between design and infection control. This is because electropolishing, a process for improving the surface finish of metal parts, is one of the last steps before medical devices and surgical instruments made of the following materials become available on the market:

  • Implantable alloys.

  • 316L stainless steel.

  • Cobalt chrome.

  • Ti 4L6V (Grade 4 titanium).

  • Nitinol, tantalum (refractory metals).

  • Other alloys used in medical device manufacturing.

  • 17-4 PH, 17-7 PH.

  • 300 series stainless.

  • 400 series stainless.

  • Aluminum, copper, steel, and virtually any alloy.

While electropolishing is used to create an ultraclean and corrosion-resistant finish, a key benefit for medical device manufacturers is the visibility it provides into designs that impair the cleanability of their products, including elements that trap bacteria, water and other liquids, and make devices more susceptible to pathogen growth. This is often discovered when medical device components cannot be pre-cleaned and rinsed in a controlled and repeatable manner.

Finish First methodology results in design changes that optimize device cleanability and make the electropolishing process more effective. (Credit: Able Electropolishing)

Medical device engineers looking for ways to improve cleanability are increasingly adopting a collaborative approach in the R&D and prototyping phase of design, turning to metal finishing and electropolishing experts like Chicago-based Able Electropolishing to leverage the electropolisher’s expertise with metal finishing. This approach, which Able has dubbed its “Finish First” methodology, has resulted in design changes that optimize device cleanability and make the electropolishing process more effective.

It’s an approach with enormous potential for improving patient safety, reducing product recalls, improving time to market and preventing late-stage design changes. Of all the medical devices sent to us for electropolishing — both reusable and non-reusable — approximately half exhibit major cleanability issues because they were not designed with cleanability in mind.