News story

Interrogating research to protect public health

Part of the work of the medicines and medical device regulator involves looking at existing research to help reach conclusions about potential and emerging issues with devices.

Medicines and Healthcare products Regulatory Agency

Monitoring new and emerging safety issues with medicines and medical devices is a major part of the work the Medicines and Healthcare products Regulatory Agency (MHRA) undertakes to protect public health.

In addition to monitoring reports from our Yellow Card Scheme, teams of experts across the agency review published information to assist in understanding areas where concerns have been raised regarding medical devices. In this instance, concerns were raised about the safety of implanting polypropylene into patients. Our review resulted in the publication of a paper in an internationally respected, peer reviewed journal.

This work has never before been undertaken in such a thorough and systematic way and has served to gather all of the relevant data together in one place for the first time.

The International Urogynecology Journal has recently published a paper by Michelle Kelly, Katherine Macdougall, Oluwafisayo Olabisi and Neil McGuire of the MHRA device division titled In vivo response to polypropylene following implantation in animal models: a review of biocompatibility.

Polypropylene is a material commonly used to treat pelvic floor conditions such as pelvic organ prolapse (POP) and stress urinary incontinence (SUI). It is the material used in the majority of mesh medical devices.

All relevant abstracts from original articles investigating the host response of mesh ‘in vivo’ were reviewed. Papers were obtained and categorised into various mesh material types and the results from the studies were carefully interrogated and evaluated.

Ultimately, the review of the evidence shows that polypropylene evokes a less inflammatory response compared to other materials which are or can be used in mesh devices in humans. It was also indicated that a lightweight, large pore mesh provides the most satisfactory outcomes.

While some promising outcomes have been observed with the use of biologically derived and fully reabsorbable meshes, both these types of material currently lack the mechanical strength required for long-lasting repair.

What was seen, and continues to be seen through research evaluated as part of this paper, is that the greater proportion of the clinical community agree the use of these devices in the UK is a valuable treatment option for the distressing conditions of stress urinary incontinence and pelvic organ prolapse. However it is clear longer term studies need to be completed in patients. As with all implanted medical devices, to date, it is recognised they all produce some degree of inflammatory reaction so the search for even better alternatives must continue, even though this is in part, how they produce their strengthening action.

We are committed to helping to address the serious concerns that have been raised by some patients and continuously assess findings of studies undertaken by the clinical community over many years, as well as considering feedback from all sources. MHRA sympathises greatly with women who have suffered complications after surgery.

Published 20 June 2016