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Free & Goss Attorneys

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Over the next few weeks, we will be discussing various topics surrounding the new transvaginal mesh (TVM) FDA warnings.  Rather than posting a single, overwhelming discussion on this topic, we’ll instead narrow our focus to different, distinctive aspects of the device, what is known and unknown, and what exactly it is the FDA is now so concerned about.  Our hope is to relay to the reader why this is quickly becoming  a contentious issue for consumers, attorneys, government officials at the FDA, and device manufacturers.  To start, we’ll be discussing a general overview of the device, as well as its approval history, since this is where the controversy starts.  For reference, there is an excellent publication in Female Patient by Dr. Littman which can be accessed here.  In it, you will notice that he’s developed a very informative ‘family tree’ of TVM devices in figure 1.  Furthermore, table 3 nicely illustrates what will be discussed below, namely the rationales used by TVM device manufacturers to have their products approved.

While the FDA deserves praise for issuing a recent warning concerning the safety and effectiveness of transvaginal mesh devices, there are two major criticisms.  First, the warning is coming far too late.  Hundreds of thousands of these devices have been installed in women to treat pelvic organ prolapse (POP) and stress urinary incontinence (SUI).  Furthermore, some wonder whether these devices should have been approved in the first place, pointing to the void in understanding the long-term outcomes in terms of the safety and effectiveness of the device.  Second, many believe defects associated with the device, both known and unknown, are serious enough that the FDA should consider an immediate recall, or at least strengthen and continue to disseminate the warnings given the magnitude of the problems.

TVM devices have a strange but not necessarily uncommon approval history.  The FDA approves new devices through one of two routes, either based on pre-market approval (PMA), or a finding of substantial similarity to previously approved devices (called the 510(k) process).  The PMA process is intensive, involves extensive testing by the manufacturer, and requires the FDA to spend on average around 1,200 hours reviewing each application.  Conversely, the 510(k) process is far less rigorous, requiring little to no manufacturer testing, and only requiring on average 20 hours of review time by the FDA.  It should be noted, however, that this is a somewhat simplified overview of the process, and there are exceptions as is the case with devices posing a high potential risk (e.g. pacemakers, coronary stents).  While there are benefits to PMA approval, namely pre-emption (in a sense, a bar) to medical device lawsuits, the 510(k) process is simply put quick and easy.  For example, TVM was approved based on the manufacturer’s argument that the device was substantially similar to mesh used in abdominal hernia surgery.  Each subsequent TVM manufacturer could then point to the previously approved TVM device, claim substantial similarity, and walk away with the right to market a ‘new’ device.

A major problem with this simplified approval process, and is evident with TVM devices, is that it often comes with uncertainty regarding long-term consequences, and in a manner of speaking is no better than crossing ones fingers and hoping for the best.  In the TVM scenario, these assumptions have proved devastating in areas such as mechanics, bioactivity, placement, and surgical skill.  These defects, and the untoward adverse effects arising from them, will be discussed in detail in the next installment.  What is of primary importance to this discussion however, is the fact that TVM devices were approved using a loose connection to hernia mesh products.  Thus, the argument over whether hernia and vaginal meshes can actually be considered substantially similar, is an area of major disagreement, and is in part responsible for the FDA’s current review of the 510(k) process.  To illustrate this point, some argue that on its face, abdominal surgery and vaginal surgery are vastly different.  Fundamentally, the abdomen is mechanically and structurally distinct from the vagina.  For instance, the thick muscular structure of the abdomen makes it far more amenable to mesh insertion and acceptance.  The vaginal area and pelvis however, lack many of these supporting aspects, and instead rely in many cases on placement using hooking mechanisms inserted into the surrounding anatomy to anchor and support a TVM device.

On top of differences in anatomy, TVM and abdominal mesh also differ in terms of the structure of the material, the shape and size of the devices, the method of placement, and the manner of surgery (i.e. placement through the abdomen vs intravaginally).  These differences readily apparent just by looking at images of one type of mesh compared to another.

The TVM saga also highlights the dangers of approving subsequent lines of me-too devices.  What often happens, and is the case here, is the success of an initial manufacturer’s device leads to development of equivalent devices by secondary manufacturers.  The same ‘me-too’ phenomenon is seen with pharmaceuticals as well.  Unlike pharmaceuticals however, follow-on manufacturers can simply point to the initial device and claim substantial similarity, thereby reducing the time it takes to market the device, as well as maximizing the window of profitability before the device is rendered obsolete by future technology.  In one sense, this is why the 510(k) process was developed.  However, when the initial device is defective, poorly understood, or never intended for the use the follow-on product claims, problems arise.  Some of the transvaginal mesh devices were approved following this chain of action, and bring us to where we are today, only with a greater concern over the viability of the 510(k) process.