- University of Sheffield researchers have led a major new study into the stability of polypropylene mesh (PP mesh) - the material at the centre of the vaginal mesh scandal that left thousands of women with life-changing complications
- Study in animal models found PP mesh fibres become stiffer and showed signs of degradation 60 days after implantation
- Researchers also discovered PP mesh particles in tissue surrounding the implantation site
- Findings provide new evidence of the material’s instability and could be used to help design safe alternatives
New evidence of the failings of the material at the centre of the vaginal mesh scandal has been revealed by a major study by researchers at the University of Sheffield.
The study, published in the Journal of the Mechanical Behavior of Biomedical Materials, suggests that polypropylene mesh - that was widely used to treat urinary incontinence and pelvic organ prolapse often experienced by women after childbirth - can begin to degrade within 60 days of being implanted.
An international team of scientists, led by Sheffield, studied the material in sheep and found that PP mesh fibres began to degrade before 60 days, becoming stiffer and showing signs of oxidation. This degradation increased further in materials implanted for up to 180 days. Sheep models were studied due to their pelvic anatomy closely resembling humans’.
Of particular concern to the researchers was the discovery of polypropylene particles within the tissue surrounding the implantation site. The concentration of these particles was significantly higher— over 10 times greater—after 180 days than at 60 days.
The researchers say this raises critical questions about the stability of PP mesh and its suitability for long term implantation in women.
The use of PP mesh has been paused in the UK, and earlier this year (August 2024) more than 100 women were awarded compensation for suffering traumatic complications after having vaginal mesh implants. The academics hope the new findings can be used to find safe alternatives with up to 50 per cent of women experiencing pelvic organ prolapse and between four and 35 per cent experiencing stress urinary incontinence in their lifetime.
Dr Nicholas Farr, Research Fellow at the University of Sheffield, who led the study said: "Our results provide strong evidence of the instability of PP and offer new insights into the mechanisms that contribute to its degradation within the body.
“While the recent monetary compensation for affected patients is undoubtedly a welcome development, there remains an urgent clinical need for safer materials to address pelvic organ prolapse. It is my hope that the insights from this study will be recognised by current, and future, mesh manufacturers and will contribute to the ongoing development of safer alternatives."
Sheila MacNeil, Emeritus Professor of Biomaterials and Tissue Engineering at the University of Sheffield, who has worked in this area for many years, emphasised the importance of the study. She said: “This research provides objective physical evidence that this material does not cope well with implantation in the pelvis. This is crucial because it is imperative that we develop new and better materials for the many thousands of patients suffering from stress urinary incontinence and pelvic organ prolapse. We now know how to critically assess any issues in new materials before they are implanted in women. It is vital to have tests to detect potential failures in materials, rather than trialling untested materials in patients.”
The study, Evidence of time dependent degradation of polypropylene surgical mesh explanted from the abdomen and vagina of sheep, is published in the Journal of the Mechanical Behavior of Biomedical Materials. Read the paper.
