Blog - Why we obsolete GMDN Terms

7 February 2024


Why we obsolete GMDN Terms – by Dr Vasileios Zampetoulas, PhD, Nomenclature Developer at the GMDN Agency

As a member of the Term Development Team at the Global Medical Device Nomenclature (GMDN) Agency I have written this blog as I wanted to explain to our stakeholders why we sometimes must obsolete GMDN Terms. By doing so it means that we can maintain the quality of the GMDN in the dynamic and innovative industry of medical devices.

The examples I have listed below highlight the top five most common reasons for obsoletion:

1. Systems that don’t exist at the point of sale

One example that illustrates this reason for obsoletion was the GMDN Term Video capsule endoscopy system, which was made obsolete as it was found that these systems do not exist under a single Unique Device Identifier (UDI) or stock keeping unit (SKU) at the point of sale (the system is compiled at the point of use). A GMDN Term represents a device at the point of sale. So, for this obsolete Term we therefore provide these alternative GMDN Terms:

·       Video capsule endoscopy system capsule magnetic manipulation unit

·       Video capsule endoscopy system capsule magnetic activator

·       Video capsule endoscopy system capsule

·       Video capsule endoscopy system application software


2. Excess granularity

Sometimes GMDN Terms are too granular. For example, the below stent Terms were made obsolete and replaced by a single GMDN Term of broader scope that better represents the intended use of devices on the market, therefore removing overly cumbersome granularity: 

·       Bare-metal renal artery stent (obsolete)

·       Iliac artery stent, bare-metal (obsolete)

·       Biliary/peripheral artery stent (obsolete)

Alternative GMDN Term: 

·       Peripheral artery stent, bare-metal


3. Unclear definition

On occasion a GMDN Term definition is not clear or overlaps with other concepts. As the Term Development Team at the GMDN Agency, we put a lot of effort into this being avoided and I’m please to say that instances of this are not common.

One example of this was the GMDN Term Orthopaedic bone wire. We made this Term obsolete as the scope of the Term had become too broad and overlapped with related Terms.


4. Innovation 

As technologies evolve the attributes which distinguish devices within a particular area may need to be re-considered. The scope of a GMDN Term cannot be narrowed so if more specific attributes are required to be introduced, we must then make previous GMDN Terms obsolete and create new, more granular Terms.

A good example of when we had to do this followed extensive consultation with the medical device industry and it was decided that the GMDN Term Multi-axis foot prosthesis was needed to be made obsolete and the following alternative GMDN Terms were created in its place:

·       Motorized external ankle-foot prosthesis

·       Mechatronic external ankle-foot prosthesis

·       Mechanical-resistance external ankle-foot prosthesis

·       Hydraulic/pneumatic external ankle-foot prosthesis


5. Regulatory Feedback

Finally, the GMDN Agency has strong relationships and works closely with medical device Regulators across the world. The GMDN is used by Regulators in over 70 countries worldwide and has become a critical component of the global regulatory infrastructure for medical devices.

As the GMDN is a dynamic UDI database data field sometimes there is a need for the GMDN to specify new attribute distinctions to meet the needs of the Regulators.

A crucial example of this followed the discovery of a clinical significance of textured surface breast implants with respect to Breast Implant Associated Lymphoma (BIA-ALCL). Regulators asked the GMDN Agency to specify the “textured” attribute within its Terms. In response to this request the following GMDN Terms were made obsolete:

·       Saline-filled breast implant, unstructured (obsolete)

·       Silicone gel-filled breast implant (obsolete)

And these alternative GMDN Terms were published:

·       Autologous adipose tissue reconstruction breast implant

·       Saline-filled breast implant, internally-structured

·       Saline-filled breast implant, unstructured, smooth-surface

·       Saline-filled breast implant, unstructured, textured-surface

·       Silicone gel/saline-filled breast implant

·       Silicone gel-filled breast implant, polyurethane-foam-surface

·       Silicone gel-filled breast implant, smooth-surface

·       Silicone gel-filled breast implant, textured-surface

Whilst I recognise that these changes may cause short-Term disruption, I would like to highlight that replacement GMDN Terms are easily found on the GMDN website and if any of our members are struggling to find then they should contact the Agency and we are always happy to provide advice and support.

Please contact us for more information.