Today's entry is kind of an "inside baseball" thought that occured to me reading an article on medicine.
There was a breathless article on the news wire "Participants Left Uninformed in Some Halted Medical Trials" (syndicated from a New York Times story) earlier this week about the fate of patients who were enrolled in clinical trials for devices or drugs that had been discontinued. In many instances these patients (and occasionally their doctor) were apparently unaware of this fact. They used two medical devices as examples - vascular stents used to treat aortic aneurysms and a type of breast implant used in cancer reconstruction.
The stents are a potential big problem in that if they don't perform as designed, the patient will die. The breast implant patients (two women in south Florida) seem to be having much less an urgent issue. From the thumbnail description it sounds like the women were having some degree of capsule pain, which is not terribly uncommon especially in breast reconstruction patients who've been radiated. Capsular contracture is also the way some silicone implant ruptures present.
Implied in the NYT article is the implication that these women are "sitting on a time bomb" with their implants which is really silly and makes the juxtaposition from the stents scenario kind of ridiculous. In this instance, I'm not sure you'd do anything at all different for these women other then checking for rupture. No one would recomend "prophylactic" removal of those implants in the abscence of documented rupture, particularly if the implants were less then 10 years old. We have plenty of information about the treatment of silicone breast implant ruptures, and it's well established that the problems you get are local issues to the chest wall. A capsular contracture or ruptured implant is it's own issue, but to hold it up next to potential life-threatening device failures misses the real serious problems with medical devices and their surveillance.
They don't really go into much detail other then identifying the implant manufacturer, Allergan, and that the particular implant had been discontinued recently (~2005). If I had to guess, it's probably the Inamed "Style 153" implant these women had, which was an anatomically shaped silicone gel device that preceded the more advanced Style 410 "gummy bear" implants. Those implants, which were voluntarily pulled from the market by the manufacturer during their approval process negotiations with FDA for their conventional type of silicone gel breast implants.
The style 153 implant had an innovative "double lumen" core that had an apparent higher failure rate when you studied them on MRI scans (the best test for rupture). Confusing the issue is the resemblance of the double shell for some of the described signs of intracapsular implant rupture which is well described in this full text American Journal of Radiology article. There are a great many surgeons who strongly believe MRI's (or at least the radiologists reading them) have a tendency to over-estimate ruptures, particularly with this specific implant. At the end of the day Inamed made the decision in 2005 to "cut bait" on such a minor product to better their chances of FDA approval for their other products. The style 153 was a good implant for it's time, but it really was just a transitional model to the form-stable devices like the 410.
* Below is an MRI showing the characteristic "double lumen" sign confused for rupture occasionally with style 153 device