"Gummy bear" breast implants are breast implants that are filled with a semi-solid, highly cohesive (it stays stuck together) silicone gel, surrounded by a thick, strong, multi-layered outer silicone shell.
Highly cohesive silicone gel breast implants -- also known as gummy bear breast implants, cohesive gel implants, or high-strength gel implants -- have not yet been FDA-approved for use in the U.S., though they have been in use in several other countries since 1995. U.S. clinical trials began in 2004, and data is currently being reviewed by the FDA for implants made by two companies, Mentor and Allergan.
The most significant difference between these implants and traditional silicone gel breast implants is the thick consistency of the filler material, which remains intact and retains its shape, even when cut (like a gummy bear, hence the nickname). These properties, together with a stronger outer shell, are intended to lessen the chance of “gel bleed.”
Gummy bear implants are available only in an anatomical, or “tear-drop” shape, meaning they are fuller at the bottom than at the top. Therefore, it is important that the implants not move around inside the body, since a position shift could result in an odd appearance. To help secure the implants in place, the outer shell has a textured surface to encourage better tissue adherence.
While the general theory behind these implants is an expected lower risk of silicone leakage and migration, these expectations cannot be proven (or disproved) until the 10-year post-implantation findings can be reviewed. (As of October 2009, only the 3-year data is in.)
Advantages of Gummy Bear Breast Implants
The consistency of gummy bear implants is considered by most to be closer to breast tissue than saline breast implants.
Gummy bear breast implants retain their form, bouncing back into shape after manipulation or movement. This lessens the chance that the shell will fold or ripple -- an important characteristic since folding and rippling are the primary causes of implant rupture.
Capsular contracture (the most common complication after breast augmentation surgery) reportedly occurs less often with cohesive silicone-gel breast implants. It is believed this may be due to a combination of the cohesive material and the textured outer shell.
It is believed that if the outer shell of a gummy bear implant were to rupture, the silicone would not leak out and possibly migrate to other parts of the body, but rather stay in place, retaining its shape and integrity.
Disadvantages of Gummy Bear Implants
The most obvious disadvantage is that these implants do not yet have a long-term track record of follow-up data demonstrating their safety and effectiveness.
Because the implant is more solid and less flexible, a larger incision is necessary. This rules out certain incision placement options, like the belly button (transumbilical, or TUBA) approach. The peri-areolar (around the nipple) incision is likely to work only in patients with large areolas, and the transaxillary (under-the-arm) approach is technically very difficult (and many doctors agree, unadvisable). The inframammary (in the natural fold under the breast) incision is the most commonly used approach when inserting gummy bear implants.
Surgeon selection is even more critical, because the procedure differs from standard breast augmentation surgery. Extra care must be taken to create as tight-fitting a “pocket” (the space inside the body where the implant sits) as possible. In patients with floppy, loose, or empty types of breasts, or in those having secondary breast augmentation (revision or replacement) surgery, the looser tissue or larger pre-existing pocket may allow the implant to move around too much.
A small percentage of patients feel that highly cohesive gel implants feel slightly firmer and less natural than traditional silicone implants. This increased firmness is more likely to be noticed in patients with little natural breast tissue.
The cost of gummy bear implants is higher than saline or traditional silicone.
What If My Gummy Bear Implant Ruptures?
The bad news is that we do not really know what may happen, because of the lack of long-term data available. The hope is that the filler gel would not migrate in any significant amount, due to its stiffer, more cohesive nature.
It is not yet known if an MRI would be able to detect rupture with this type of implant. When an implant is placed in the body, the body forms a barrier called a capsule around the implant. If a highly cohesive implant were to leak, it is presumed that the filler material, with its gummy bear consistency, would probably remain within the capsule. It is possible that the capsule might stiffen or thicken, and a patient may notice a difference in the feel of the breast.
Though years of studies have shown no link between silicone leakage and any systemic disease, there is a risk associated with silicone leakage and migration: the formation of granulomas. While granulomas themselves are benign, they can lead to infections as well as mimic calcification and cancers. This is important because it could possibly lead to either a misdiagnosis, or a missed diagnosis.
Where Can I Get Gummy Bear Implants?
Though FDA trials are ongoing, enrollment in the trials is closed. Patients who have already received these implants are being followed to collect data on their safety and effectiveness. Therefore, gummy bear implants are not yet available to the general public in the U.S, though they are available in some European countries.
Breast Implant Questions and Answers; Consumer Information Sheet, U.S. FDA; 2006
Long-Term Safety and Effectiveness of Style 410 Highly Cohesive Silicone Breast Implants; P.Hedén, G.Bronz, J.J. Elberg, R.Deraemaecker, D.K. Murphy, A.Slicton, R.J.Brenner, C.Svarvar, J.Van Tetering, L.P.Van Der Weij; Aesthetic Plast Surg. 2009 May;33(3):430–436
Mending the Myths: Facts about Silicone Gel-Filled Breast Implants; Allergan Corp; 2009