by: Dinesh Puppala
3D printing was originally used to quickly make prototypes in the manufacturing industry, including the medical device industry. 3D printing has gained momentum as a manufacturing procedure by itself. Almost every day, over the last several months, there have been inspiring stories about how 3D printers are being used to create realistic implants. This is becoming more and more common among doctors and medical researchers. 3D printing has become the tool to enable researchers to create custom vertebrae and functional prosthetic hands. Researchers are even trying to print fully functional organs (kidney, liver). Now is the era of 3D printing, where we can print our own parts, or as “New Yorker” put it: It is now possible to “print thyself.”
In medicine, it has had most success with prosthetics, dental work, and hearing aids, which can all be made from plastic or other materials and often needs to be tailored to a specific patient. Customization is key for 3D printings success. Knee replacement is a very common procedure, but even the largest manufacturer of artificial knee implants has six or so different types and sizes of knees. With 3D printing, doctors aren’t limited to those six knees. They can design one specific to each patient. Projects like OpenHand Project, have aimed solely to establish a series of open-source hand designs, which can be easily customized and printed locally which would result in lower costs of printed prosthetic hands. So far, advancement in printed human tissue has not been to the level compared to other areas. 3D printed functional tissues in Petri dishes have seen application to be viable for testing drugs, and larger realistic surgical models have been useful for surgeons to practice technique before the actual operation.
Is 3D printing really the future of medical device manufacturing, or is it all hype? I don’t believe it is yet, as hospitals and major institutions buy medical devices in bulk, since the general specifications provided by manufacturers fit most of their needs. 3D printing their own devices, which don’t often need customization, doesn’t offer much of an advantage and is not cost effective for both the provider and the patient. 3D Printing may be best for when doctors need to create a new device on demand for rare, unpredictable conditions. Despite the many potential advantages 3D printing offers especially in the biomedical sector, this technology needs to overcome many obstacles before making it mainstream. A few of the concerns, as mentioned by Lee Ventola, are patent and copyright concerns (to make it a viable business model) and regulatory concerns.
Access to 3D printed devices by many surgeons is through a pathway used in emergency cases called humanitarian device (HDE), or custom device (CDE) exemption which comes into play when no other approved alternative treatment/device is applicable to the patient and is solely the discretion of the surgeon to use this device. To be approved for the general public, the Center for Devices and Radiological Health (CDRH), a division of the FDA, which reviews and approves devices to be marketed, has two pathways to market: a 510(k) route and Pre-market Application (PMA). While the prior is applicable for devices with similar intended use and technological characteristics of approved devices as of already marketed devices, PMA is for novel devices, under which most 3D printed devices fall. Approval of the PMA generally requires clinical data demonstrating reasonable assurance that the device is safe and effective in the target population.
While it is certain that 3D printing technology will transform health care especially medical devices, it is important to appreciate that this technology needs to make many more positive strides to make an impact the medical device industry.
- PRINT THYSELF How 3-D printing is revolutionizing medicine. New Yorker, November 24, 2014.
- Ventola CL. Medical Applications for 3D Printing: Current and Projected Uses. Pharmacy and Therapeutics2014;39(10):704-711.