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Substantially Equivalent – How medical devices can deviate
I saw Dr. Towfigh’s announcement about the Patient Advocacy Forum and started thinking about questions. In researching how new products are approved by the FDA I found some links that are very informative. You can see, on one page, the trail of new products, all, apparently, derived from a few past products. Some of the changes described seem very significant, but are glossed over, under the description of “Substantially Equivalent”. For example, Bard Soft Mesh has fibers that are much smaller than Bard Mesh. Therefore, for the same weight of mesh, per unit area, the Soft Mesh will have dramatically more surface area. Surface area is what the body sees and responds to, with inflammation. None of this is addressed in the FDA approval documents. It seems that there is a cursory examination of a document written by the device makers, then a decision to approve is made, because it “looks” substantially equivalent, on paper.
It’s incredible that the FDA approval summary also talks about the “soft feel” of the new Soft Mesh, as a feature. Like it’s important in the long run, after tissue ingrowth and shrinkage ties it all up into a boardy structure.
You can click on the summary links in the later documents. Early documents don’t have it. But they all seem to derive from previous devices, maybe going all the way back to silver filligree. The FDA does not seem to do any actual work in approving new devices.
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1 Reply
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Here is an example of how far back they go for the original material that everything following is equivalent to. The trail of equivalence starts in 1976.
Of course, there are other requirements to meet before selling the product. But the bar seems very low from the start.
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