The Allergan Natrelle 410 highly cohesive silicone gel ("Gummy bear") implant
What is the Allergan 410 implant?
Saline is by nature non-cohesive. In other words, its molecules do not cling together. Drop water on the floor and it goes everywhere. Silicone is by nature cohesive as are all “gels”. The molecules stick together. Cohesiveness varies from one gel to another, and even varies amongst different types of silicone gels used in various breast implants. The cohesiveness even varies between the three manufacturers (Allergan, Mentor and Sientra) of form-stable implants. Form-stable means to “retain its shape”. This requires these implants to be filled with a more cohesive, firmer silicone. If the gel isn’t firm, the implant will not hold its shape. Simple as that. I’m glad that this part is out of the way because if you do not understand this, the rest won’t make much sense.
The Allergan 410 implant is an anatomical (or teardrop, breast shaped) implant that contains a highly cohesive silicone gel that is form-stable. This implant holds its shape, unlike a round implant which is not form-stable. It is not the shell of the implant that gives it its unique shape, but rather the distribution of the highly cohesive gel within the implant that gives it shape. To achieve its unique shape, the gel does need to be firmer than a standard silicone gel implant. There is a trade off here: the more the implant holds its shape and resists shell folding, the firmer the gel needs to be. As stated above, it is important to realize that different manufacturers of cohesive gel implants use silicone gels of differing firmness. This implant was developed by Dr. John Tebbetts in the 1990’s. It has been in use around the world for about twenty years as well as in clinical trials in the United States for approximately 12 years, and several hundred thousand women around the world have these implants. In February, 2013, the Food and Drug Administration (FDA) gave approval to the Allergan 410 implant for use in this country. Prior to having access to this implant, surgeons must be trained and certified to use it by Allergan. These implants are the most extensively studied breast implant ever. Many research studies on this device support this implant as having the best safety profile of all breast implants.
I started doing breast augmentation surgery in 1994. Back then, there were more limited choices for implants. Only saline was available and the choice was either round or anatomical (teardrop). It made no sense to me to put a round implant in the breast when I had the option to use a teardrop implant, so I gravitated to the teardrop saline implant immediately. I did have patients who wanted the look of a round implant, so occasionally I used round implants as well. For a brief while, I was offering transaxillary placement of implants to avoid a scar on the breast, and in these cases, I used a round implant as I felt it was too difficult to accurately position a teardrop implant through an armpit incision. So I found myself placing mostly teardrop saline implants and occasionally, round implants. When I questioned my colleagues, the vast majority were placing only round implants. Certainly, it is much easier to place a round implant than a shaped device (another term for a teardrop implant). My colleagues told me that after a year, breasts with round and teardrop implants look the same and that teardrop implants turn inside the breast. I couldn’t differ more. When I compared my own results (you can see them here- Saline teardrop / round implants, I thought that the teardrop implants were superior in shape. And throughout my experience with them, I have only had one patient who experienced turning of the implant in one breast, as she did not even want it re-operated! So in my mind, at least with saline, teardrop implants are superior to round implants. So from a shape standpoint, I am a big believer in a teardrop implant over a round implant!
In November, 2006, the FDA approved round silicone gel filled implants for use. This was a game changer. Silicone is a cohesive filler, and saline is a non-cohesive filler. The shell, or bag of both types of implants is still made of a thin, silicone material, but unlike a saline implant, a silicone gel implant is filled with silicone gel rather than saline. A cohesive substance sticks together – a gel is cohesive in nature. A non-cohesive substance doesn’t stick together. Saline is essentially salt water. Drop water on the flow and it runs everywhere. Drop silicone gel on the floor and it sticks together in one gelatinous mound. So what is the difference? A bag filled with a non-cohesive filler like saline will be much more firm to the touch than a bag filled with a cohesive substance like silicone. The result – a breast that feels much softer to the touch, more like human breast tissue than a bag of water! Furthermore, because silicone implants are by nature so much softer than saline implants, the breast shape with a round silicone gel implant was not bad at all! It was like the breast tended to give a silicone implant its shape where as a saline implant tended to force its shape upon the breast. So, over a thousand implants later, my patients and I are very happy with the softer feel and look of a breast with a round silicone gel implant. There are times, however, when you want the feel of a silicone gel implant, yet also influence the shape of the breast and that is just what the Allergan 410 silicone implant will do. It is firmer than a conventional silicone gel implant, softer than a saline implant, and better retains its natural shape. In breast augmentation, just like there is no perfect breast with perfect tissues, there is also no perfect implant. It’s all about understanding the advantages and disadvantages of each device, assessing the patient’s tissues and making a decision based upon understanding how each device will behave within a given type of breast tissue. There are always some tradeoffs, and this is why it is so important to really take the time to understand these issues for yourself, and consult with an experienced breast augmentation surgeon, one who has extensive experience with saline, silicone round as well as silicone shaped devices like the Allergan 410.
Now enter the Allergan 410 form-stable teardrop shaped “Gummy-bear” implant. everyone seems to think that the purpose of this implant is to prevent leaking. If the implant shell is compromised (tears), the gel will not come out. This is partly true, but this is not the purpose of the implant. When compared to a typical silicone gel implant, if the shell breaks, the gel will still come out of the shell, perhaps at a much slower rate. In either case, the gel is still contained within the scar capsule that forms around every breast implant starting just a few weeks after surgery. Silicone gel is inert anyway, that is to say that it doesn’t react with the body and vice-versa, therefore it is non-toxic. The real benefit, the real beauty of this implant is that it gives the breast the best possible shape and maintains that shape years longer than a standard silicone gel implant. Isn’t that what a woman would want anyway?
Although the implant is new to the US market, I have been extremely impressed with the results I have been obtaining with this implant. The shape reminds me of the shape I achieved with the older teardrop saline implants, perhaps a little better still, but with the more natural feel of a silicone gel implant. And my patients who have chosen this implant are similarly impressed as well!
Since 2004, I have been a staunch advocate of soft tissue based planning, as taught to me by Dr. Tebbetts, who created the concept. For more information, see “Choosing the Right Size Implant“. In a nutshell, the concept is this: No bag can contain an infinite volume, all bags have an ideal volume that when filled to this volume will result in a full, but not overfilled, look. This is true whether we are talking about a plastic zip-loc bag, a bag of oranges, a balloon or a breast. On a computer screen I can stretch a breast infinitely, but in real life, the tissue has limited ability to stretch to a certain volume. Overstretching is not good for a breast either. If you overstretch, you destroy the tissue and can create uncorrectable (that is bad!) deformities. Some breasts are tight and require less volume to achieve adequate fullness. Some breasts are lax and require more volume to fill them. Certainly, putting an implant or a bag of rice inside your bra on top of your breast is ludicrous. Yes, ludicrous. It tells you nothing about the underlying breast and what is a safe volume for that breast. What it will do is lead to placing implants way too large, creating problems and more future surgeries, but that is an entirely different discussion. In my opinion, if your surgeon advocates such methods for implant selection, I would suggest obtaining a consultation from another surgeon. Whether I am placing a round saline, a teardrop saline, a round gel or a teardrop gel (the 410), I insist upon soft tissue based planning to determine proper implant size. Soft tissue based planning, simplified, looks at the base width of the breast as a starting point to determine the ideal volume for that breast. Next, tissue elasticity and thickness are assessed, and the implant volume determination is modified, upwards or downwards, so that an ideal volume for that breast is then determined. If you follow this thought process, then you are rewarded with a beautiful looking breast, with the quickest recovery and shortest downtime, as well as the least complications coupled with the lowest published re-operation rates in the plastic surgical literature! Now, who wouldn’t want that?
When using soft tissue based planning for a round smooth implant, I have found that sometimes there is a little wiggle room on the volume. Not much, maybe an ounce or a little more, but that is about it. However, with the Allergan 410, the sweet spot is even more narrow, meaning it is absolutely crucial to identify the correct volume for a given patient and that patient needs to understand this. If you try to go too large, closing the surgical wound may become problematic. This is because the implant is shaped, and this shape cannot be temporarily altered during surgery so as to facilitate closure of the surgical wound.
In summary, while with conventional implants I recommend soft tissue based planning with a little (not much) wiggle room in the size, with the 410 implant, selecting the proper size is even more critical.
Since 2009, I have utilized the Vectra 3D computerized imaging system (Canfield Scientific) in my breast augmentation practice. I am also on the advisory board (unpaid position) for this device which gives me input into the ongoing software and hardware development for this wonderful technology. Now, that said, I DO NOT use the imaging system to show a patient their breasts in 3D and say “let’s try different implants and see which size you like best.” That would be a ticket to future problems and totally would defeat the purpose of soft tissue based planning. Instead, what I do is determine optimum implant size using the same tissue based planning system I described above. I take a 3D image of the patient’s breasts and then enter the implant size I chose for the patient using tissue based planning. The computer system contains a database of all the silicone gel implants including their dimensions from Allergan including the 410 implants. This way, the software can then create a simulation of the patient with the selected breast implant inserted into the breast, demonstrating to the patient how they might look with the selected implant. It can even show how they look with a bra/bikini top! Most all my patients to whom I have demonstrated this system absolutely love it!
- Better shape and long term maintenance of that shape – the gel is highly cohesive and stable. This is what gives the implant its unique shape and allows it to impart its shape to the breast. It has a greater ability to shape the breast over round implants.
- Lower capsule contracture AND reoperation rates – this is based upon data from the Allergan FDA premarket approval studies.
- These implants are ideal for those with constricted lower pole (tubular breasts and lower pole underdevelopment) and asymmetric breasts.
- Better suited to those patients with a tight soft tissue envelope by preserving lower pole fullness and resisting deformation resulting in excessive upper pole fullness.
- The upper pole (portion) of the breast blends in to the upper breast and chest better than with a round silicone gel implant (or a teardrop saline implant for that matter!).
- Subtle differences in implant size and pocket dissection can have dramatic differences in results.
- Lower rupture rate – The gel does not shift, and therefore there is little to no shell folding and collapse. Shell folding is what is thought to be the cause of shell failure. However, if shell fails, there is less extrusion of the gel from the implant. As the shape is stable, there is little to no shell folding which is felt to be the cause of shell failure in saline and conventional silicone gel filled implants. This suggests that these implants may last longer.
- Less rippling that a round gel implant, which is again much less rippling that with a saline implant.
- Cost – this is theoretical at this point. Although the Allergan 410 is more expensive initially due to the greater complexity to manufacture. If the implant lasts longer than a round gel implant, then in the long term, the 410 may be a more cost-effective alternative. This again is just a theory…
Many people believe that this implant was designed to lessen leakage of silicone should a shell failure occur. This is not the purpose of this implant. The main reason to choose this implant is the unparalleled benefit in shape and the long term maintenance of that shape. The shape is created and maintained by the highly cohesive silicone gel inside the implant, not the shell. The fact that the gel doesn’t flow as easily out of a failed shell is simply a result of having a more highly cohesive gel, not the main goal of the implant.
I stated that the Allergan 410 implant is a wonderful device. however, it is not for everyone. Here are some disadvantages:
- Cost – for some patients, this is really a factor. They are stretching their budget for a breast augmentation and maybe cannot afford the extra cost of this device. For those, I tell them the truth: even if you have to “settle” for a round smooth silicone gel implant, rest assured, you will have a wonderful implant and a beautifully enhanced breast. Even though the Allergan 410 is the “Rolls-Royce” of breast implants, the round, smooth, silicone gel implant is hardly “chopped liver!” However, these implants may turn out to be more cost effective in the end as there is less shell folding and shell fatigue which will probably translate to a more long lasting implant than conventional round smooth silicone gel implants.
- Limitation of the range of implant sizes for a patient – as stated above, there is a little wiggle room on volume, but not much. The range of acceptable implant volume is narrower than for a round, smooth, silicone gel implant. This is not a bad thing, as I try to select an implant that most conforms to my calculated ideal volume for that breast based upon soft tissue planning techniques. This is not a problem for the patient. This is a problem for the surgeon who is not familiar with soft tissue based planning techniques and doesn’t know how to determine ideal breast volume with accuracy and precision. Based upon a show of hands in one of the courses at the 2013 ASAPS (American Society of Aesthetic Plastic Surgeons) meeting on the 410 implant, the percentage of surgeons who correctly employ soft tissue based planning in their breast augmentation practice is an extremely low percentage. This is probably why, nationwide, the re-operation rate and complication rates are higher for those who do not use this method of surgical planning.
- Shaped implants require precision in pocket dissection and placement. If a round implant spins, it is still round. No change in breast shape will result. This is not true for a shaped implant. If the implant turns, the breast will change shape. If the surgeon makes a pocket larger than the implant, and places a round implant, the implant may shift or spin within the pocket. Not a problem, the breast won’t change shape. If the surgeon creates a pocket larger than the implant and places an Allergan 410 implant (or a tear drop saline implant for that matter), the implant may shift or turn, changing breast shape. That is not good. So here, precise pocket dissection within less than a centimeter tolerance is important. The implant must fit easily but precisely into the pocket. This is not hard to do, if you know the principles of, and are experienced at atraumatic pocket dissection. I have been using an atraumatic technique to create the implant pocket since 2004, and also have extensive experience with shaped saline implants, prior to the approval of 410 silicone gel Gummy Bear implants. Placement is also an issue. I believe that shaped implants should have a slight tilt to them to achieve optimum aesthetic results, and this is based upon my experience with them. This is true whether using a saline or silicone gel shaped implant. As sometimes I also lower the inframammary (breast crease) fold, properly setting the crease level is essential with the Allergan 410. So for me, from my first Allergan 410 implant case forward, working with a teardrop-shaped implant was nothing new to me. The surgical technique, simply put, must be more refined, meticulous and precise.
- Larger incision size – Saline implants are inserted deflated and rolled up like a cigar, hence they can be inserted through a smaller incision, about 4 cm long. Silicone gel implants require a slightly longer incision, however, using the Keller funnel, again, a 4 cm incision is usually of adequate length. I do use the Keller funnel with the Allergan 410 implant, however, these silicone gel form stable implants cannot be deformed as much as a round silicone gel implant when inserted or you risk damage to the implant. These implants require at least a 4.5 to 5.5 cm incision, depending upon implant size. Larger implants may require an even larger incision. However, if care is taken during the planning stage, the incision will be made in the crease where they are less noticeable. No scar is completely invisible, but if the scar is placed in the crease, the biomechanical forces upon it will be less than elsewhere on the breast, rendering it less visible. Also, by its very nature lying in the crease will make it less visible. I use breast crease incisions in almost all of my augmentations now, and I have found them to be the best choice in terms of visibility, access to the breast, precision in pocket dissection, and lowest complication rate. Nothing is worse than a badly healed periareolar (around the nipple) scar. It leaves a scar on the most visible portion of the breast and is also associated with a higher capsule contracture rate. Transaxillary (armpit) incisions are used occasionally but are really not recommended for silicone gel implants. The larger incisions are not really well hidden in the armpit.
- Allergan 410 implants are firmer – not as firm as a saline implant, but definitely a little bit firmer than a standard gel implant. The Allergan 410 must be firmer by definition or it couldn’t maintain its shape. This factor doesn’t appear to be a big issue for most patients. Those patients more likely to complain about firmness are those with mobile, lax, soft breasts – the typical breast that over-deflated following pregnancy. The Allergan 410 may not be appropriate for use in these patients. This is left up to the discretion of the surgeon and the patient.
- Risk for rotation – I addressed this above. Although there is a risk for rotation, if pocket dissection is truly precise, then this risk should be quite low and should not deter a woman from selecting this implant. As I stated above in my experience with saline teardrop implants, this issue occurred in less than 1% of my cases. For the Allergan 410, the rotation rate is also less than 1%. In a tight breast the anticipated risk of rotation is less than if the implant is placed into a lax breast. The textured surface of the implant “adheres” to the chest wall and underside of the breast/muscle in a way similar to velcro. If the breast is tight, it will hold the implant in place so that adherence can take place. A lax breast may not be as effective in holding the implant in place and adherence may not occur. The adherence is not true tissue ingrowth into the implant, but rather, as I stated earlier, more of a velcro phenomenon, so implant removal, should it ever be necessary, is not in the least hindered by the textured surface.
- Not for use in oversize cases – I am not a surgeon who likes to do oversize cases, but consider it said that this is not the implant to use. I believe that using this implant in oversize cases will result in difficulty with wound closure and risk to damage of the device during the insertion process.
- Not recommended for repeat cases – my concern here is that placing the implants in an already expanded pocket will increase the risk for rotation of the implant as the pocket is by definition already lax to begin with.
- Woman who desires a natural looking breast with a size that fits her body.
- Possesses a tighter soft tissue envelope
- Allows objective sizing using soft tissue based planning
- Patient requests this implant
- Primary (first time) augmentation
- A woman who is safety-conscious and wants a device with the least likelihood of failure (although more time may be needed to definitely prove this)
- Women with asymmetric breasts or tight/constricted/tubular breasts. The 410 resists flattening of the lower pole of the breast with a resultant upper breast bulge. The lower breast fills out where you want it to.
- Deterred by the increase cost of the implant
- Doesn’t like the increased firmness of the implant
- Fear of potential rotation of the implant, albeit rare
- Not amenable to precise sizing using soft tissue based planning
- Desire a disproportionately large breast (over augmentation)
- Will not accept a slightly larger incision
- Fear of the “newness” (even though it has been in use abroad for about twenty years) of the implant
- Patient with lax, soft, mobile, sagging breasts or very thin tissue
- You want a “fake”, unnatural, round look; in other words, you want to look like you have breast implants
For a given base width, the Allergan 410 is available in moderate height and full height. It is also available in moderate projection and full projection. Each implant is identified by two letters followed by a three digit number. The two letters are either “M” or “F” indicating either “moderate” or “full”. The first letter is for height and the other is for projection. The three digit number is the volume in cc’s.
I select the implant height based upon the height of the upper chest when measured. I select the implant projection based upon the laxity or tightness of the soft tissue envelope, again when measured. The base width is also measured along with other soft tissue parameters.
Therefore, there are four shapes avaialble for a given implant size: FF, FM, MF, MM (i.e.: FM = Full height, moderate projection)
It cannot be overemphasized that proper implant selection (volume, height and projection) are paramount to success and this cannot be accomplished accurately without appropriate soft tissue based planning.
Younger patients, particularly those that have not yet become pregnant have firmer breast tissue, so for these patients, a more cohesive breast implant like the Allergan 410 may not be at all an issue. For those with more compromised tissue such as those that have lactated, or perhaps lost a significant amount of weight, an implant like the Allergan 410 may represent more of a change from what they are already accustomed to. Firm breasts are closer to the aesthetic goals that most women are trying to achieve. If you want to minimize rippling, want an implant less prone to breakage and silicone leakage, and want a shape that lasts, then you have to accept the additional firmness of a form stable implant like the Allergan 410.
Placing an oversized implant in to a breast is what gives the breast a round, unnatural look. This will happen with conventional round, smooth silicone gel implants, and will even happen with an anatomical implant like the Allergan 410. This is why volumetric assessment via soft tissue based planning is so important.
When using a shaped implant, it is best to place them into a fresh pocket that is tight so as to prevent rotation. However, these implants can be used in re-operation cases as well. No implant will be invisible when the overlying tissue is too thin or the implant size is too large, however, the Allergan 410 may be one of the best options in the case of very thin overlying tissues as long as the implant size is chosen according to soft tissue based planning methods. I have used shaped saline implants in many revision cases years ago, before silicone gel implants were approved in this country. I always warned my patients about rotation, but this did not happen very frequently. I do believe that the incidence of rotation would be greater than the rotation rate seen in first time (primary) augmentations, but I cannot honestly quote percentages here.
All that said, this implant can work well in some revision surgeries, but in others where the pocket is anticipated to be very loose may do better with a round silicone gel implant.
My personal opinion on this implant is that if you are a candidate for this device, do not mind a slightly firmer implant and a slightly larger incision, this implant will give you a more natural shape and will retain that shape longer. I am very impressed with it so far and it would be my first choice for women who are a candidate for it. They may take longer to settle than a saline or round silicone gel implant.
Every woman presents to me with a different set of breast shape and tissue characteristics. The more tissue the woman has, and the thicker and firmer that tissue is, the more natural that breast will feel with a given implant inside, and this is true no matter which breast implant you choose.