3D printed medical devices: a tough trial for regulation?

In 2016, the growing number of approved 3D printed devices encouraged the FDA to issue preliminary guidance to manufacturers using 3D printing. The guidelines focus on design and manufacturing considerations, as well as device testing concerns.

The FDA has two major classes of 3D printed medical devices. The first group includes products that can be created using any manufacturing processes, including 3D printing. To get products in this class approved, manufacturers only have to prove that the final medical device product is substantially equivalent to a product that is already on the market.

According to Jacobson, the rationale behind this approach is "we know the product that it is already on the market is safe and effective and this product is substantially equivalent to that, so it must also be safe and effective".

Gilmour, who previously held a position at the FDA approving medical devices, explains: “If it’s a passive device that means it just has to comply with good manufacturing controls and processes.

“Manufacturers don't have to send the device into the FDA, they just have to show they have good manufacturing standards.”

The second FDA class covers devices that are deemed to be higher risk and must go through a pre-market approval process as there is nothing similar on the market.

The European Union (EU) has largely followed the FDA’s example. Relevant authorities have approved 3D printed medical devices and have published advice for companies and others using 3D printing manufacturing techniques to create medical devices. 

The EU’s governance is contained in Medical Devices Regulation 2017/745, where it establishes that quality management systems are central to production, like with other manufacturing techniques.

After approving the country’s first 3D printed medical device in 2015, the Chinese FDA (CFDA) released its own advisory document in March 2018. The focus of the guidance was on required data needed in the approval process, such as validation testing of materials, equipment and software, as well as of the final product. It also discussed the role of healthcare professionals in design input and output for 3D printed medical devices.

Guidelines written by national regulators have been accompanied by international organisations, such as the ISO and ASTM, starting to create consistent, global standards for 3D printing of medical devices.

Jacobson explains: “Their goal is that wherever you are manufacturing a medical device, you can use this one set of standards and be able to comply with all the country's regulations.”

He believes they are "making a lot of progress; they have made a lot over the past three, four, almost five years" but it is slowing because "they are trying to come up with the more unique standards that apply to 3D printing rather than copied over from traditional manufacturing".

All of the 3D printed medical devices currently on the market in the US are in the first class, meaning their creator has proved the 3D printed device is substantially similar to a product already on the market.

The most complicated devices to regulate within the first class are patient-specific devices, such as prostheses. Jacobson identifies this as the biggest challenge facing authorities in regulating 3D printed medical devices.

He explains: “Traditionally manufactured medical devices are a one size fits all, but with a product that is customisable there can be issues with testing every single device that is made.

“When you're manufacturing something for a specific person that is different than how regulations are currently set up where they are looking at the end device. Regulations will need to pay attention to those differences between people, whereas right now those regulations pay attention to similarities rather than differences.”

Regulators have tried to overcome this issue by requiring companies to set a minimum and maximum size for the customisable aspect of the device and testing the ‘worst case’ of the design boundaries, according to Gilmour.

Another challenge in regulating 3D printed medical devices is that too many overlapping, possibly contradictory regulations from national and international bodies can create a regulatory minefield for companies seeking to use the technology to manufacture medical devices.

This is because the onus is on the manufacturer to prove that the device is safe and effective. As such, companies have to demonstrate that they understand and abide by industry standards.

Jacobson believes that regulations will probably slow down innovation, because even if a company has a good idea for a 3D printed device, "understanding the governmental regulatory process and how to get a product legally on the market can make it very difficult for a person to actually execute the idea".

“Companies have a lot to lose if they don't comply with the industry standards,” he concludes.