Explants: analysis of failures can lead to improvements all round

by Jason Wilson of Medical Explants Ltd

[IN RECENT YEARS surgery has benefited from some technological breakthroughs, with the introduction of successive medical devices and procedures. Over time some of these innovative theoretical breakthroughs saw questionable durability in humans; and unfortunately some have led to catastrophic failure – such as with the case of metalon-metal hips and certain breast implants.

Explanted medical devices – or used medical devices (UMDs) – are generally disposed of in the theatre bin, returned to the manufacturer or – in far fewer numbers – analysed by independent centres, usually at the behest of concerned surgeons or as a direct result of becoming part of a litigation case. The concern of course is that some devices may be disposed of prior to any subsequent litigation; then the device evidence is lost and the surgery itself receives a greater level of focus, which can waste time and effort.

The routine analysis of UMDs should be seen in a positive context, since there are huge benefits in improving products, surgical techniques and patient outcomes, and it serves as a useful adjunct to post-market clinical studies, clinical research and national joint registries – as well as providing transparency in litigation cases. “9.8 POST-MARKET SURVEILLANCE

The main challenge in both pre- and post-market phases of regulatory review is the lack of adequate study endpoints and diagnostic and/or prognostic tools…Currently, it is extremely difficult to determine whether symptoms are related to the implanted device or other causes. Predictive assessment of the pro-inflammatory potential and subsequent tissue remodelling remains a major challenge affecting real-world performance of implantable devices and biomaterials.”

A global issue

Around the world, advanced healthcare systems recognise the need for independent assessment of medical devices. The Australian Department of Health states: “It is recommended that all explanted medical devices (not only those associated with fault or adverse events) are sent for assessment to provide an overview of device performance.”

In the USA the FDA requests that all adverse incidents are reported; and moreover has started to focus on more indepth reviews in some areas.

The FDA is also concerned about the biological response to metal implants. Its document Biological responses to metal implants states:

In Europe there has been a focus on and support for explant analysis. In particular, a recent paper, What Do We Learn From Explant Analysis Programs? explains that UMD analysis is likely to be the key to improvements in surgery. Failures are largely under-reported; however, reporting of failures is mandatory, so analysis helps distinguish between sporadic events and general failure.

“…explants should be sent to centralised centres dedicated to these issues. Ideally, such centres should be independent from the industry… Transparency should be based on establishing a strong link between the centres and major scientific societies that could report to health authorities.”

In the UK the recommendations for the NHS are set out very clearly on its website and include the following:

“An adverse incident is an event that causes, or has the potential to cause, unexpected or unwanted effects involving the safety of device users (including patients).

“For example: • A patient’s treatment is interrupted or compromised by a medical • device failure • A misdiagnosis due to a medical device failure leads to • inappropriate treatment • A patient’s health deteriorates due to medical device failure. Causes • may include: design…”

Furthermore, the MHRA – the body responsible for regulating medical devices – states: “All items should be quarantined if possible. Do not throw them away, repair them or return them to the manufacturer.”

The NHS has also recognised the need for independent analysis and that is currently being implemented in centres across the UK. Surgeons across the world have recognised the need to fully evaluate failed devices.

In summary, as the number of medical devices, procedures and manufacturers increases, the likelihood of more adverse events affecting patient safety is likely to climb. Independent analysis in specialist centres allows the explant to be considered in line with patient safety concerns. It also allows reporting on how the device has performed; and in the case of any subsequent litigation, allows full transparency. q