Breast Implant Rupture - How to know? - Are Routine MRI Scans Really Necessary?
Silicone gel filled implants were approved by the Food and Drug Administration (FDA) in November 2006. This approval was specified for use in women 22 years of age and older. (Saline implants are approved for ages 18 and older). The FDA made the following recommendation: routine MRI (Magnetic Resonance Imaging) should be performed to check for implant rupture. A little background information first. The shell, or "bag", of both saline (salt water) and silicone gel filled implants are both made of silicone and are essentially identical. Whenever a foreign body is placed into our tissues, whether this be a pacemaker, artificial joint, or breast implant, be it saline or silicone, thin layer of scar tissue called a "capsule" forms around the device within about three weeks. Normally, this scar tissue has no role, and is of no detriment. This is just the way our bodies react to having something that is not our own living tissue placed inside us. Silicone gel filled implants are pre-filled by the factory. Saline implants are inserted into the breast deflated and rolled up like a cigar. There is a small valve on the surface of the implant. A thin "fill tube" is attached to this valve just prior to insertion into the breast. It is through this tube that saline is placed into the implant. The tube is removed after filling and the valve is sealed, all while the implant is in place in the breast. Saline implants are prone to device failure by either leakage of saline through the valve or by failure (a tear) of the implant shell. A silicone gel implant doesn't have a valve, but failure can occur by a tear in the implant shell. The difference is that if a saline implant leaks, the device will deflate in about a couple of days and there will be a very noticeable difference in breast shape and a decrease in breast size as the saline is absorbed. Saline is nothing more than salt water, a normal component of our bodily fluids. In the case of silicone implants, the situation is a little different. If the implant shell develops a small opening, by its cohesive nature, the silicone gel will most likely remain inside the implant. If a tear develops in the implant shell, the silicone gel may leave the silicone shell, but will usually be contained within the natural scar tissue capsule that formed a few weeks after the implant was placed. If this happens, you may or may not notice a difference in your breast. There may or may not be some discomfort in the breast, or possibly a difference in the way the breast looks or the way it feels. Since the silicone gel is biologically inert (won't react with your tissues and vice-versa), a ruptured implant will not pose any risk to your health. Since you may not be aware of a problem with your implant, the FDA has taken the opinion that there should be some type of way to routinely check for a ruptured implant. MRI’s are an excellent way to check for a problem with your breast implant. MRI scans are very accurate and do not involve the use of ionizing radiation (X Rays) as is the case of mammograms and CT (computerized axial tomography) scans.
The FDA recommendation is as follows: an initial MRI examination is performed of the breasts three years after breast augmentation surgery and again every 2 years thereafter. Is this reasonable? What is the scientific basis for this recommendation? It is a fact that like all mechanical devices, breast implants do not last forever, and the longer you have a breast implant, the greater the chance of experiencing a device failure. How long implants will last is the question, and with time, certainly more information will be available regarding this. In the premarket approval studies that Allergan and Mentor, the manufacturers of breast implants (in 2006) submitted to the FDA, the risk of implant rupture in the first 7 years was exceedingly small. As of this writing (September 2014 2012), considering only the newer generation of silicone implants which were approved and became available for use in November 2006, as well as the Allergan style 410 highly cohesive "Gummy Bear" implants which became available in February 2013, I have not seen a single silicone implant device failure in either my own patients nor have I seen any such patients operated upon by another surgeon. However, as I stated before, with the passage of time, there will be a certain amount of women who will experience device failure of a silicone gel implant. Now, let's look at logistics. If all women with silicone implants receive an MRI scan each year, then we can assume that just about all of the implant failures would be identified. On the other hand, if no women are screened, then of course none of the women with implant failures will be identified. So then, how often should MRI screening be performed? Just like routine screening for any disease process, first one needs to have an understanding how often the disease actually occurs, how severe is the disease (is it life threatening? Is it a risk to quality of life? Is there a risk to the health of the community? Are the risks low?) and lastly one needs to consider the economic cost of the screening program. Most likely, any screening program will not evaluate everyone each year, which leads to the fact that some patients may develop a problem such as an implant rupture that goes unrecognized. The other question is: What are the consequences or risks of not identifying the problem? Will this situation impact one’s life, health, livelihood or their family? Fortunately, when considering breast implants, if a rupture is not detected, there is most likely NOT going to be a significant or consequent risk to the patient’s health. Silicone is biologically inert and fifteen years of studying breast implants (breast implants are the most studied medical devices in history!) have demonstrated that they are not a causative factor in the development of any systemic diseases, including autoimmune disorders and breast cancer.
The first question to ask is whether or not an MRI, which is not an inexpensive test, is an appropriate initial screening tool for a breast implant rupture. Although MRI is a great tool to examine a breast for cancer, mammograms remains the gold standard as the initial tool for breast cancer screening in the vast majority of patients (MRI is used in high risk patients like those who have received therapeutic radiation to the chest). If there are any abnormalities seen on mammogram, then ultrasound, not MRI, is the next test ordered to investigate further. This is not because MRI is inferior to ultrasound, but rather that ultrasound is a very good second screening test and is much more cost effective than proceeding directly to an MRI. Should there still be some question after ultrasound, an MRI is the third test used to help decide if there is a problem within the breast. This is the process I follow with my cosmetic breast surgery patients (augmentation, lift, reduction) who require routine screening prior to commencing surgery (this is determined by the patients age and risk factors for breast cancer). The following question now remains: why is MRI recommended as the initial screening tool for a silicone breast implant rupture? Why is it recommended to be performed every two years after surgery. Does this make sense rather than utilizing less expensive tests?
In 1998, Chung performed a scientific study at the University of Michigan looking at the accuracy of ultrasound as a diagnostic tool for implant rupture. He reported that if ultrasound was the initial screening tool for a breast implant rupture and the ultrasound test was read as normal, then the chance of a false negative result (the chance that the normal interpretation of the ultrasound was incorrect and that there really was a rupture which was undetected) was only 2.2%. On the other hand, if an ultrasound did suggest a rupture, and an MRI obtained afterwards also supported a diagnosis of implant rupture, then the chance that the implant was in fact truly ruptured was 86%. This is a high enough chance of rupture to support the plan of surgical exploration and implant replacement.
In a separate study in 2001, Cher found that in women with breast implants who have a specific complaint referable to the breast such as pain, capsular contracture or a change in the appearance of the breast, an MRI is better than 80% accurate in predicting an implant rupture. This does NOT imply that there is an 80% chance of a rupture if a woman has symptoms. It only means that if a woman has symptoms and in fact does have a ruptured breast implant, there is an 80% chance that MRI will detect the rupture. However, when women with implants did not report any symptoms, the predictive value of MRI was much less. The conclusion was clear: if a women with silicone gel breast implants has no symptoms, then MRI is not justified as the initial screening tool for implant rupture. The Royal College of Radiologists in the United Kingdom found that ultrasound is 91% accurate if it demonstrates an intact implant, and this is similar to the findings of the University of Michigan study previously discussed. Furthermore, the Royal College of Radiologists concluded that the initial screening tool for breast implant rupture should be an ultrasound. If the ultrasound suggests an implant rupture, then an MRI study using a dedicated breast coil and a magnet strength greater than 1.5 Tesla is indicated.
So in summary, these studies clearly indicate that ultrasound, an inexpensive test, is both accurate and cost effective when screening women for implant rupture, and the chance of finding a ruptured implant is greater when the woman is symptomatic. If the ultrasound suggests that there is a rupture, then an MRI is indicated prior to proceeding with surgical exploration.
How often does rupture really occur? I follow the belief that the device failure rate is approximately 0.5 to 1% per implant, per year. Mentor’s core study of 420 patients demonstrated a 0.5% rupture rate at three years out from surgery, but there have been other studies that don’t show ruptures for even up to seven years (Sharpe and Collis - United Kingdom). If you believe that it makes sense to do an MRI in all women, asymptomatic or not, then assuming a 0.5% rupture rate, you are subjecting 199 women to undergo MRI examinations just to find one other patient with a ruptured implant!
So, is it reasonable to follow the current FDA recommendation and obtain an initial MRI examination of the breasts three years after breast augmentation surgery and again every two years thereafter?
- Consider that as third party payers (your health insurer) have strict clinical guidelines for the authorization of a breast MRI, it is quite possible that these routine MRI’s in an asymptomatic patient may not be paid for by health insurance.
- Consider the fact that a missed implant rupture is highly unlikely to represent a health risk to the individual.
- Consider that a normal ultrasound demonstrating an intact implant is better than 90% accurate
- Consider that the rupture rate is approximately 0.5% - 1% after three years.
My personal opinion, based on the information presented above, is that the FDA guidelines are excessive in terms of the use of diagnostic resources and expense. In other words, these recommendations are not cost effective, and probably counterproductive. By stating the FDA’s recommendations are not cost effective is that a less expensive alternative, namely ultrasound, is highly effective as a screening tool for implant rupture. Given the fact that breast implant rupture occurs with such a low frequency and is not a health hazard brings into question the relatively frequent intervals that the FDA is recommending for MRI examinations to conduct breast surveillance for implant rupture. Now, by counterproductive I am stating that if MRI’s are not covered by health insurance (unless there is a clinical problem, and even then possibly only after a mammogram and ultrasound have first been performed) then based upon the financial cost alone I would expect that most women with breast implants would not voluntarily follow the FDA guidelines. So the reality of it all will be that less, rather than more women will undergo such routine surveillance, which is the exact opposite of the FDA’s intended goals. I do not know, and no one I know is aware of just what body of scientific evidence was used by the FDA to create these recommendations. Based upon my understanding of the available current scientific data, the FDA recommendations are not supported my any medical data. The FDA’s recommendations are only just that, “recommendations”, not law, and it is up to the individual patient to decide how to use this information. I feel that it is my obligation to present not only the FDA’s position, but my own position as well.
In summation, there is good news for women desiring to undergo breast augmentation with silicone gel implants. Breast implants, saline or silicone, are safe and will not cause disease or harm your body. Breast implants, like all mechanical and bioprosthetic devices will not last forever. Fortunately, their integrity can be easily and inexpensively monitored with breast ultrasound. Currently, breast ultrasound is also not “rationed” by third party payers as are breast MRI examinations.