3D printing raises significant technical considerations for device manufacturers.

In response to the increasing use of 3D printing in the medical device arena, on May 10, the US Food and Drug Administration (FDA or Agency) issued a draft guidance titled “Technical Considerations for Additive Manufactured Devices.”[1] FDA describes the guidance document as a “leapfrog” guidance because it provides the Agency’s “initial thoughts” on this emerging technology. Given the newness of the technology, FDA states that its recommendations may change as more information becomes available.

3D Printing (also known as additive manufacturing) is one of the more exciting recent developments in the medical device area. A report prepared by UPS and the Consumer Technology Association states that the medical device industry is the third largest 3D printing market, and that 98% of hearing aids worldwide are manufactured using 3D printing.[2] Notably, the US hearing aid industry converted to 3D printing in less than 500 days.[3] Given the rapid adoption of this technology, device manufacturers should assess its potential applicability to their product manufacturing process and the impact of the draft FDA guidance on its use.

THE PROMISE AND CHALLENGES OF 3D PRINTING

3D printing promises to provide both economic and life-saving solutions. Using this technology, manufacturers are able to produce small batches of devices for certain target populations more economically. Moreover, the ability to customize a device to an individual patient’s anatomy presents the opportunity for life-changing healthcare advances, including 3D-printed kidneys, living skin grafts, and advanced prosthetics.

In 2013, for example, researchers at the University of Michigan saved a baby’s life by treating the baby’s collapsed bronchus with a customized 3D-printed tracheal splint. In the past few years, FDA has cleared or approved over 85 devices manufactured with 3D printing techniques, including a skull replacement, dental crowns and braces, hearing aids, hip cups, and surgical instruments.

Additive manufacturing is a process that produces a three-dimensional (3D) object by building successive layers of raw material, joining each to the layer below, until the object is complete. This process raises a number of technical issues, such as whether the layer-wise fabrication will affect a load-bearing medical device’s strength at its edges or whether an implant’s material will cool or harden consistently as the device is produced layer-by-layer from one direction to another (e.g., left to right).

FDA’s draft guidance does not set forth specific requirements, but describes in extensive detail the types of issues that should be considered and addressed during a product’s development and in a premarket submission to the FDA. Many of these considerations were discussed during an FDA public workshop held on October 8-9, 2014.

FDA’S PROPOSED TECHNICAL CONSIDERATIONS

The draft guidance addresses two major topics: (1) design and manufacturing process considerations; and (2) device testing considerations.

For the former, the Agency describes considerations that should be addressed as part of complying with FDA’s Quality System Regulation requirements. These include device design, software workflow, material controls, post-processing, process validation and acceptance activities, and quality data. Each of these categories can present issues not seen with traditional manufacturing methods. For example, device design using 3D printing can be affected by pixelation of features caused by a mismatch of machine resolution and model resolution. Devices that rely on imaging to control the size and shape of a 3D-printed device can be affected by inaccuracies in the imaging data.

Under the second topic on device testing considerations, the draft guidance describes the type of information that should be included in a premarket submission for a 3D-printed device. Included are device description, mechanical testing, dimensional measurements, material characterization, cleaning and sterilization, biocompatibility, and additional labeling considerations. The draft guidance states, however, that not all of the testing described will be required for every device, given the variety of devices that may be manufactured using 3D printing techniques. Additionally, FDA recommends that manufacturers that plan to submit premarket submissions for 3D-printed devices seek more detailed feedback through the Center for Devices and Radiological Health’s Pre-Submission Program.[4]

COMMENT PERIOD

FDA is accepting comments on the draft guidance and recommends that comments be submitted by August 8, 2016, to ensure that they will be considered in the preparation of the final guidance document.