Now that the 3D printing of medical devices has become a promising reality, the U. S. "Food and Drug Administration (FDA) is preparing for a wave of new technologies that are nearly certain to transform medical practice,” said FDA Commissioner Scott Gottlieb, MD in a statement announcing the final guidance for 3D printed medical devices.
On December 4, 2017, the FDA issued first-of-its-kind guidance to manufacturers of 3D printed medical devices in response to the technology’s growing adoption by the healthcare industry. The FDA’s guidance offers manufacturers of 3D printed medical devices a path to regulatory compliance. The guidance finalizes the draft version from May 2016 and largely keeps intact the recommendations and considerations laid out in the draft. “We’re working to provide a more comprehensive regulatory pathway that keeps pace with those advances, and helps facilitate efficient access to safe and effective innovations that are based on these technologies,” says Gottlieb.
With so many disruptive medical technologies coming on the market, manufacturers need this guidance to help them navigate faster and more easily the time consuming process of FDA approval. The guidance seeks to help manufacturers better understand the Agency’s requirements for device design, function, durability and quality-system requirements as well as technical considerations associated with the 3D printing processes as these applications move forward. So what is new? Here is some of the highlights of the guidance.
The FDA's overall criteria for evaluation and testing of 3D printed medical devices are fundamentally similar to those associated with traditionally manufactured devices. However, while 510(k) and de novo premarket submissions do not typically include any manufacturing information, the final guidance makes it clear that FDA will expect to review certain ‘manufacturing’ information, such as the orientation of a printed object and the printing location. FDA even suggests that manufacturers submit a production flow diagram and a high-level summary of each critical manufacturing process step. The rationale given for this is, “The effects of the different steps in the [additive manufacturing] processes can be seen in final device testing; however, determining the root cause of failures from manufacturing defects can be very difficult without a clear understanding of each step.”
The FDA also recommends that manufacturers compare and document the desired design of the device to the “manufacturing tolerances of the individual machine” to ensure that the 3D printed device can be reliably built. FDA notes that quality may vary when an identical medical device or component is built using different additive manufacturing machines, even when using the same machine model, parameters, process steps and raw materials. “Therefore, knowledge of how the variability of each input parameter and processing step affects the final finished device or component is critical to ensuring part quality.”
The manufacture of 3D printed devices often requires use of multiple software programs at various stages of the process; thus, files must be compatible across software applications. The final guidance expands upon the recommendations for file format conversions in the draft guidance, noting that file critical attributes and performance criteria should be verified as part of the software workflow validation to ensure expected performance, particularly for Patient-Matched Devices (PMDs).
One of the most notable changes in the final guidance is the inclusion of additional issues in the section regarding PMD Designs. FDA recommends that manufacturers clearly identify clinically relevant design parameters, the range (minimum/maximum) for these parameters, and which of these parameters can be modified for patient-matching. A concern expressed by the FDA is the passage of time, as explained: “When the device is intended to match a patient’s anatomy, and that anatomy can change over time (e.g., with disease progression), the time that can elapse between when the patient is imaged and when the final device is used may need to be reflected in the expiration date of the device.”
Another concern expressed in the guidance is that PMDs that follow the patient’s anatomy are vulnerable to errors in file conversion because they involve complex anatomic curves that can create difficulties when calculating conversions. The guidance recommends that manufacturers of PMDs follow considerations on maintaining data integrity throughout file conversions.
The final guidance also provides a description of the type of information FDA recommends in a premarket submission of a device made using additive manufacturing, including what FDA expects from a device description, mechanical testing, dimensional measurements, material characterisation, removing manufacturing material residues, sterilization and biocompatibility.
While the FDA final guidance document is more of a “general blanket statement” on the topic, it is an initial step to recognizing that there is a role for this technology in medicine. All this information contained in the guidance will prove useful for manufacturers planning product submissions for FDA approval, as it outlines clearly what to include in the premarket submission for a device that uses additive manufacturing. As the technology continues to grow, it can be anticipated that the FDA will become more and more involved in the process. The fact that this guidance is non-binding from the Food and Drug Administration (FDA) on the 3D printing of medical devices is likely a sign that U.S. regulators are gearing up to release more suggestions in 2018 and beyond.
