Some Thoughts on Mesh: Product Design & Development
~March 1, 2013
I helped Adam Slater as an expert with what became Gross v Ethicon from early in 2009. My job was to help Mr. Slater make sure Ethicon had produced all its relevant documents. I have the qualifications to do that because I am a veteran researcher and have run product development for other medical device companies, not Ethicon. I’m not going to write about those documents, or Ethicon. I can’t. You perhaps read some of their production through the Gross v Ethicon trial and have your own opinions.
I have two points to make about product design and development:
First, responsible inquiry is a zero-based effort. It is unfailingly shortsighted to base today’s product solely on the last one. For implant devices, at the least, consideration of the biocompatibility of ALL materials in ALL potential end uses gives the researcher clues as to where he/she can’t go in their work.
I remember in 1992 my group was considering a particular material as a surgical suture candidate. But one of my scientists found an obscure reference that plates made of this material inserted under the eye to repair bone had swollen over the years and needed to be removed. I stopped the project. Another major device company soon introduced a suture like the one I avoided. That product was removed from the market after many instances of long-term foreign body reactions were reported.
Let’s think about meshes.
What is the true surgeon’s nightmare? It’s leaving a gauze pad behind after surgery, wouldn’t you say?
Gauzes are open weave cotton meshes; they remind you of, well, polypropylene implants. A left behind sponge is often benign. But maybe 25% of the time it results in a persistent shrinkage and walling off into a troublesome massive foreign body. Sound familiar?
When I think of all the materials from which implant meshes have been made; polypropylene, polyester, Teflon®, polylactide, all seem to have triggered serious complications in patients. No one and I mean no one has shown that any of these synthetics would be expected to act any differently than that nightmare cotton gauze. Designers fail to do their job, in my opinion, if they give short shrift to the entire history of implants before bringing the next one forward.
Actually hernia meshes result in fewer adverse effects than the transvaginal mesh products that have generated more than 15,000 product liability plaintiffs. Why? Have designers really ignored the mechanics of a relatively unrestrained vaginal mesh as it flexes, distorts and undergoes the shrinkage forced of fibrous capsule formation resulting in mesh movement, nerve capture, erosion and pain?
I suspect that flexible implants are a separate class of biomaterial, behaving relatively independent of composition and require much more intense design efforts attended to by scientists of many disciplines.
My second point is we scientists fail to heed the powerful voices of the affected. Listen as Hope Pagano says, “We need a patch test so that we can detect an individual’s allergic response to mesh.” Nonie Wideman writes that we should test for an individual’s susceptibility to excessive response to polypropylene. Smack on, ladies.
This is individualized medicine, focused on preventing harm. It’s not obvious how one would carry out these studies but I know this: If one of these women was my boss at a device company and gave me this order I sure would figure out how to get it done!
Matthew E Hermes
March 1, 2013
Dr. Hermes has a PhD in Chemistry from the University of Maryland 1959. He worked as a research scientist at DuPont (20 years), Celanese (4 years) and US Surgical, now Covidien (13 years), where he developed and introduced synthetic implant devices such as sutures, clips and staples. Dr. Hermes was the inventor and holds 32 US Patents. For the past decade he has worked as a consultant and expert in devices particularly intellectual property and products liability on absorbable and non absorbable fibers, films, meshes and devices.
He has a Masters in Literature from Wesleyan U. (Middletown, CT), and authored “Enough for One Lifetime”, biography of DuPont’s inventor of nylon, Wallace Carothers whose suicide at 41 ended an extraordinary creative career of scientific genius. He lives near Greenville, SC, and is a Research Associate Professor, Bioengineering at Clemson University.