New tests reveal more failures

A major study by researchers at the University of Sheffield has revealed new evidence of material failures at the heart of the vaginal mesh scandal.

The study, published in Journal of the mechanical behavior of biomedical materialssuggests that polypropylene mesh, which was widely used to treat urinary incontinence and pelvic organ prolapse often experienced by women after childbirth, may begin to degrade within 60 days of implantation.

An international team of scientists, led by Sheffield, studied the material in sheep and found that the PP mesh fibers began to degrade before 60 days, becoming stiffer and showing signs of oxidation. This degradation was further increased in materials implanted up to 180 days. Sheep models were studied because of their very similar pelvic anatomy to humans.

Of particular concern to the researchers was the discovery of polypropylene particles within the tissue surrounding the implant site. The concentration of these particles was significantly higher, more than 10 times higher, after 180 days than at 60 days.

The researchers say this raises critical questions about the stability of the PP mesh and its suitability for long-term implantation in women.

The use of PP mesh has been stopped in the UK and earlier this year (August 2024) more than 100 women received compensation for traumatic complications after having vaginal mesh implants. The academics hope the new findings can be used to find safe alternatives, with up to 50% of women suffering from pelvic organ prolapse and between 4% and 35% suffering from stress urinary incontinence over the course of the his life

Dr Nicholas Farr, a researcher at the University of Sheffield who led the study, said: “Our results provide strong evidence for 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 certainly a welcome development, there is still an urgent clinical need for safer materials to address pelvic organ prolapse. I hope that the insights from this study will be recognized by manufacturers of current and future meshes and will contribute to the continued 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, emphasized the importance of the study.

She said: “This research provides objective physical evidence that this material does not adapt well to implantation in the pelvis. This is crucial because it is imperative to develop new and better materials for the many thousands of patients who suffer from stress urinary incontinence and pelvises.We now know how to critically evaluate any problems with new materials before they are implanted in women.It is vital to have tests to detect possible material failures, rather than testing unproven materials.