Plastic cups have more protective additives to stop them degrading than surgical mesh, expert warns
PUBLISHED: 20:35 19 May 2018 | UPDATED: 20:45 19 May 2018
Campaigners are calling for the Government to revisit the science of mesh implants amid shocking evidence from a leading chemist who says an airline plastic water cup contains more protective additive than the controversial surgical mesh material.
There are growing concerns that the polypropylene plastic implants are unstable and can break down in the body, yet earlier this year health secretary Jeremy Hunt said he would not look at the research when he launched a review into three women’s health scandals - primodos, valproate and mesh.
Campaigners say this is a major failing of the Government review, led by Baroness Julia Cumberlege and a team at King’s College Hospital in London.
The Cambs Times, which this week won the prestigious Making A Difference award for Sling The Mesh, approached a leading plastics expert for his views on the polypropylene implants, used to treat incontinence in women and men, pelvic and rectal prolapses and hernia repairs.
Chris DeArmitt, a consultant to the Fortune 100, is a chartered chemist, a fellow of the Royal Society of Chemistry and author of the book Innovation Abyss. We asked for his expert opinion:
1. Question: What can happen to polypropylene (PP) mesh once implanted?
Answer: PP can cause an inflammatory reaction because it is not biocompatible. Truly biocompatible materials are known and they cause no such reaction. Improperly stabilised PP will degrade, lose its strength and eventually break apart. The PP mesh I have looked at so far was dramatically under-stabilised for its intended use. I checked with other world-class experts and they all share that view. For example, there is more antioxidant (stabiliser) in a Delta Airlines disposable water cup than there is in some mesh products on the market.
2. Question: Can you explain why PP is unsuitable for a medical implant?
Answer: Firstly, it is well-known that it can cause chronic inflammation leading to discomfort and pain. I have heard manufacturers claim that this is not the case, however, when you look at their own brochures you will see them advertising new coated PP mesh to overcome the problems with their older uncoated mesh. I have attached a clip from such a brochure. How can they claim there is no problem when their own brochure says otherwise?
The second main reason is that PP is one of the most unstable commercial plastics on the market. It is so sensitive to oxygen that stabiliser is added immediately as it is produced at the factory to prevent instant attack by oxygen. PP gives the illusion of stability as long as there is enough stabiliser left to protect it. Once the stabiliser is used up protecting the PP, or washed out by contact with water, the PP will start to degrade rapidly. These are very well established facts published in countless peer reviewed journal articles.
3. Question: Research shows PP mesh can shrink and degrade once implanted, but this research is ignored by our Government. How can we make them take it seriously?
Answer: I have reviewed over 400 articles on PP mesh and the body response to it. It is very hard to get the message across and there are many reasons for that. Firstly, either side can find articles that seem to support their view. It is only when you have read hundreds of articles that you have a true understanding of where the truth lies. Few people have the time, training and dedication to do that. So, for example, how would a politician or regulatory person decide in light of so much data? A second problem lies with the fact that this is a big industry and that can give rise to its own problems. For example, when American documentary makers, 60 Minutes, wanted to have the mesh analysed, US labs refused to touch it once they learned it was Boston Scientific mesh. How can one present the facts when it’s hard to collect basic data?
4. Question: I’ve been told that adding blue dye makes plastic more unstable is this correct?
Answer: I wrote about this in one of my expert reports. It is well known that pigments and dyes can make polymers more unstable. It has been shown that the phthalocyanine blue pigment makes PP stiffer and more brittle. I have seen no detailed studies comparing uncolored PP mesh fibre to the blue fibres.
5. Question: If the product is so unstable then how do these surgical mesh implant manufacturers get their product approved so easily?
Answer: I am not an expert in the approval procedures so I could only give a layperson’s perspective on this. From what I understand, the “Marlex” type PP was approved decades ago before thorough testing was required. It has since been grandfathered in and assumed to be safe. It is very interesting that the manufacturers of Marlex stated that it could be used for short-term implants but cannot be used for permanent implants. Why did they state that? To me the reason is clearly that they know there is nowhere near enough stabiliser in the product for long-term use inside the body.
• Chris DeArmitt says his opinion is backed by other PP stabilisation leaders worldwide. He added: “I am not on anyone’s “side” which means my views are based on the evidence. My daily job is not expert witnessing but being a plastics expert who creates new and better plastic materials.” His comments are made free of charge and he is not affiliated to any law firms as a medical expert.