Efficacy and safety of medical implants

Medical implants can be life-saving. For example, a pacemaker or cardiac defibrillator can prevent life threatening malfunctioning of the heart in at-risk patients.21 Implants can also restore mobility and improve quality of life.22 They can help to cut the costs of ill-health by reducing the need for regular treatment or enabling people to return to work.23 Remote monitoring using active implants can mean fewer visits to hospital are needed, potentially freeing up patient and staff time.24

However, implants can pose physical risks arising from surgery, including the possibility that the body might reject or react to the implant. There might also be psychological effects.25 Some implants, such as deep brain stimulation devices, are associated with effects on mood and behaviour, with possible wider effects on family and social networks.26 Implantable cardioverter defibrillators issue electric shocks which can be distressing to the patient and have been associated with depression, anxiety disorders, and post-traumatic stress.27 The UK Government recently launched a review into the safety of medicines and medical devices (see Box 2).

Evidence gathering and clinical trials

Some features of medical implants create challenges for assessing their efficacy and safety while ensuring timely access for patients. In clinical trials of medicines, the medicine can be given in small doses initially and the trial can be stopped at any time. In contrast, medical implants cannot be gradually introduced and once implanted they can be difficult or risky to remove. How well an implant works might also depend on other factors, such as the selection of patients, and the skill and experience of the surgeon. Because implants are often designed to stay in the body for many years, the timeframe for fully testing their lifetime safety and efficacy would be much longer than for medicines.28

Technology assessment and guidance

The National Institute for Health and Care Excellence (NICE) can assess the safety and cost-effectiveness of medical implants where they are relevant to NHS guidance on the management of particular conditions.29 NICE sometimes issues separate guidance on single technologies or interventional procedures, which could involve medical implants, if they offer plausible additional benefits to patients and the healthcare system.30 The UK Government has committed funding to increase the number of technology assessments carried out by NICE by 2020.31

Post-market surveillance

Once an implant has been certified, it is the manufacturer’s responsibility to collect data relating to safety and report adverse incidents to the competent authorities.32 Under the new EU Regulation, manufacturers must upload information relating to some aspects of their post-market surveillance for each device to the EUDAMED database. However, these data will not be available to the public or to clinicians.33

Registries can play an important role in monitoring the safety of implants.34 For example, the National Joint Registry (NJR) provides early warning for patient safety issues associated with joint replacements and a means of re-contacting patients if issues arise.35 NICE has recommended that a national registry of surgery for urinary incontinence and pelvic organ prolapse should be established, which would monitor all uses of vaginal mesh.36 The Royal College of Surgeons has recommended the establishment of a UK-wide registry to track all new interventional procedures and implants, with independent oversight and review.37 During Parliamentary debate in February 2019, it was stated that the Government is considering establishing a national medical devices registry.38

However, registries are expensive to run and their cost-effectiveness can be difficult to demonstrate.39 Joining up data from different sources is another approach to monitoring the safety and efficacy of medical implants.40 Current plans to join up digital systems across the NHS could offer new ways to capture information about the performance and safety of implants.41

Box 2. The independent medicines and medical devices safety review

In February 2018, the UK Secretary of State for Health and Social Care announced an independent review into the safety of medicines and medical devices, triggered by concerns about the effects of three medical interventions including vaginal mesh.42 Mesh was used to treat urinary incontinence in women, but increasing numbers of women reported complications including pain, infection, and mobility problems. The review may make recommendations about how the healthcare system can improve its response to concerns raised about medical devices in the future.43 The review is expected to conclude in 2019.


24 Mengt E and Sheybani R (2014) Insight: implantable medical devices Lab chip 14: 3233-40.
25 Harmon SHE, Haddow G and Gilman L (2015) New risks inadequately managed: the case of smart implants and medical device regulation Law Innov Technol 7: 231-52.
26 Gardner J and Warren N (2018) Learning from deep brain stimulation: the fallacy of techno-solutionism and the need for ‘regimes of care’ Med Health Care Philos. Published online first.
27 Shiga T, Suzuki T and Nishimura K (2013) Psychological distress in patients with an implantable cardioverter defibrillator Journal of Arrythmia 29: 310-3.
28 HoC Science and Technology committee (2012) Regulation of medical devices in the UK and EU.
29 For example, the use of vaginal mesh is considered in NICE (2019) Urinary incontinence and pelvic organ prolapse in women: management.
30 Groves PH et al. (2018) Review of the role of NICE in promoting the adoption of innovative cardiac technologies Heart 104: 1817-22; NICE (2018) Submission to the independent medicines and medical devices safety review.
31 Gov.uk (2018) Life sciences sector deal 2, 2018.
32 MHRA (2015) Medical devices: guidance for manufacturers on vigilance.
33 Fraser AG et al. (2018) The need for transparency of clinical evidence for medical devices in Europe Lancet 392: 521-30.
34 Lübbeke A et al. (2017) The role of national registries in improving patient safety for hip and knee replacements BMC Musculoskelet Disord 18.
35 For example, the recall of the DePuy hip implants was in part prompted by data from the NJR showing a higher than expected number of patients requiring revision surgery. National Joint Registry (2017) About the NJR; National Joint Registry (no date) Statement regarding metal-on-metal implants.
36 NICE (2019) Urinary incontinence and pelvic organ prolapse in women: management.
37 Royal College of Surgeons (2018) Future of surgery.
38 HC Deb (12 February 2019) c857.
39 Taylor J (2014) Methodological challenges in evaluating the value of registers Intl J Technol Assess Health Care 30: 28-33.
40 Campbell B et al. (2018) Long-term evidence for new high-risk medical devices Lancet 391: 2194-5.
41 Gov.uk (2017) Policy paper: The future of healthcare: our vision for digital, data and technology in health and care.
42 See: http://www.immdsreview.org.uk/.
43 NHS Improvement and NHS England letter (9 July 2018) Vaginal mesh: high vigilance restriction period.

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