Let’s start with a little history of breast implants to see how far we have come.
The earliest known breast augmentation was attempted in 1895 by Vincenz Czerny, using a woman's own fatty tissue. Paraffin injections were used in 1889, with horrible results. Other substances were tried, including ivory, glass balls, ground rubber, and ox cartilage. Synthetic materials such as Ivalon sponge in a polyethylene sac, polyether foam sponge (Etheron), polyethylene tape (Polystan) or strips wound into a ball, polyester (polyurethane foam sponge). Silastic rubber and teflon-silicone prostheses were also used. The results were severe foreign body reactions. Flap-based augmentation by rotating the patient's chest wall tissue into the breast to add volume was attempted by Berson in 1945 and Maliniac in 1950. Silicone injections were used in the 1950-60s causing silicone granulomas and hardening of the breasts that were so severe that women needed to have mastectomies for treatment. The advent of silicone gel and saline implants in the 1960 resulted in safe predictable results for many women and became the basis of the procedure of breast augmentation as we know it today.
Saline-filled breast implants were first manufactured in France in 1964. The early implants were prone to leaks as much as 25% of the time. Current saline devices are manufactured with thicker, room temperature vulcanized shells than earlier generations of devices. The implants are filled with saline solution (the same solution used in intravenous injections) after the implant is placed in the body. Since the implants are empty when they are surgically inserted, the scar is smaller than is necessary for silicone gel breast implants (which are filled with silicone before the surgery is performed). Saline-filled implants were most common implant used in the United States during the 1990s due to restrictions that existed on silicone implants, but were rarely used in other countries. The amount of saline that is used can affect the shape, firmness and feel of the breast. Saline implants are usually filled at the time of surgery allowing for modifications in implant size. Should the implant shell leak, a saline breast implant will collapse and the saline will be absorbed and naturally expelled by the body. Good to excellent results may be obtained, but as compared to silicone gel implants, saline implants are more likely to cause cosmetic problems such as rippling, wrinkling, and to be noticeable to the eye or the touch. Particularly for women with very little breast tissue, or for post-mastectomy breast reconstruction, silicone gel implants are considered as superior. In patients with more breast tissue in whom sub-muscular implant placement is used, saline implants can look very similar to silicone gel.
The first silicone breast prosthesis was developed by Drs. Cronin and Gerow with the Dow Corning Corporation in 1961. Silicone breast implants are pre-filled with an elastic gel in the manufacturing process. The gel feels and moves much like natural breast tissue. The size of the implant has to be predetermined because there cannot be any adjustment of the size during surgery. The implant requires a longer incision to insert it into the surgical space because it is pre-filled. If the implant leaks, the gel may remain within the implant shell, or may escape into the space surrounding the implant. A leaking implant filled with silicone gel may not collapse. If you choose these implants, you may need to visit your plastic surgeon regularly to make sure the implants are functioning properly. Silicone implants have evolved over the past fifty years with improvement in shell and elastomer technology. The silicone gel implant of today is much safer than the original implants.
First generation silicone gel implants
These implants had a thick outer shell, a Dacron patch on the back for fixation and an anatomic "tear drop" shape. The gel was thick and viscous and felt more firm than the surrounding breast tissue. The implants did not move freely like a natural breast and were subject to a very high rate of capsular contracture (thickened scar tissue) because of the reaction to the Dacron patch.
Breast implants were redesigned in the 1970s with thinner, less cohesive gels and thinner shells in order to feel more natural. Unfortunately, these implants had a greater tendency to rupture or "gel bleed" silicone through an intact implant shell. This led to greater complications such as capsular contracture and implant rupture. Implants of this generation were involved in the American class action-lawsuits against Dow-Corning and other manufacturers in the early 1990s.
From the mid 1980s, advances in manufacturing principles with elastomer-coated shells to decrease gel bleed, and thicker, more cohesive gel to avoid implant rupture improved the safety of these devices... A variety of both round and tapered anatomic shapes are available from different implants in this group.
"Gummy bear" or solid, high-cohesive, form-stable implants is in preliminary stages in the United States but these implants have been widely used since the mid 1990s in other countries. The semi-solid gel in these implants largely eliminates the possibility of silicone migration. Studies of these devices have shown significant potential improvements in safety and efficacy over the older implants with low rates of capsular contracture and rupture.
Since the 1990’s, the Department of Health and Human Services (HHS) began one of the most extensive research studies to examine potential complications during or after silicone-based breast implant surgeries. After reviewing years of evidence and research found that "Evidence suggests diseases or conditions such as connective tissue diseases, cancer, neurological diseases or other systemic complaints or conditions are no more common in women with breast implants than in women without implants”. They concluded that local complications are "the primary safety issue with silicone breast implants", making a clear distinction between local complications and systemic health concerns. Bothersome results such as rupture, pain, capsular contracture, disfigurement, and infection, were stated to be possible local complications that could require medical intervention or repeat surgeries.
The manufacturers continued to improve their gel-filled products, developing more cohesive gel implant, and continued with their studies. On November 17, 2006, the FDA lifted its restrictions on the use of silicone gel-filled breast implants produced by the two manufacturers for breast reconstruction and for cosmetic breast augmentation. Currently the FDA has approved silicone gel-filled breast implants and over a million women around the world have already received these implants.
Surgeries involving breast implants, whether for cosmetic or reconstructive surgery, carry risk common to many types of surgery. These include adverse reactions to anesthesia, post-operative bleeding (hematoma) or fluid collection (seroma), surgical site infection or breakdown, breast pain or alterations in sensation , unfavorable scarring (6-7%), interference with breast feeding, visible wrinkling, asymmetry, thinning of the breast tissue, and symmastia (disruption of the natural plane between breasts which is sometimes referred to as 'bread loafing'). Complications and reoperations related to surgeries with breast implants or tissue expanders can add significant long term costs to patients and health care systems.
Specific complications related breast implants that have received notable attention involve surveillance and treatment for implant rupture and the phenomena of capsular contracture.
Breast implants can potentially remain intact for decades in the body, but all such devices will fail at some point. When saline breast implants break, they often deflate quickly and can be easily removed. Prospective studies of saline-filled breast implants showed rupture/deflation rates of 3-5% at 3 years and 7-10% at 5 years for augmentation patients. Newer saline implants are estimated to have a failure rate of 1% per year implanted.
Some of the suspected mechanisms for rupture are damage during implantation or other procedures, degradation of the implant shell, and in rare instances from the pressure of traditional mammograms.
The design and the age of the implant are the most important factors in rupture. The best available literature with longer term available MRI data on single lumen 3rd/4th generation silicone gel implants comes from Europe. Silent rupture rates of implant occur between 8% to 15% over a ten year period. Gel migration is much less of a concern with the newer cohesive gel implants. MRI evaluation of the highly-cohesive (5th generation) gel implants suggests improved durability, with a rupture rate reported at 1% or less. When silicone implants break they rarely deflate, and the silicone from the implant can leak out into the space around the implant. An intracapsular rupture can progress to outside of the capsule (extracapsular rupture), and both conditions are generally agreed to indicate the need for removal of the implant.
Capsular contracture occurs when thickened collagen fibers form as an immune response around the implant and the capsule tightens and squeezes the implant. This contracture is a complication that can be very painful and distort the appearance of the implanted breast. Some factors that contribute to this problem include bacterial contamination, silicone rupture or leakage, and hematoma. Methods which have reduced capsular contracture include submuscular implant placement, limiting handling of the implants and skin contact prior to insertion and irrigation with triple-antibiotic solutions. Correction of capsular contracture may require surgical removal or release of the capsule, or removal and possible replacement of the implant itself. Nonsurgical methods of treating capsules include massage, external ultrasound, and treatment with pathway inhibitors (Accolate, Singulair).
The presence of radio-opaque breast implants may interfere with mammography. A number of studies looking at breast cancers in women with implants have found no significant difference in stage of disease at time of diagnosis. Conversely, the use of implants for reconstruction after mastectomy for breast cancer also appears not to have a negative effect on cancer-related mortality.
Regardless of the type of implant, it is likely that women with implants will need to have one or more additional surgeries (re-operations) over the course of their lives.. Most commonindications for re-operations have included major or minor complications, capsular contracture treatment, and replacement of ruptured/deflated implants.
Which is better, silicone gel or saline filled breast implants? The answer is not that simple. Your decision should be made after a thorough discussion of the pros and cons with your plastic surgeon during your consultation. The following is a summary of some of the differences:
1. Can be inserted via a small incision usually less than an inch.
2. Saline implants are more likely to leak than silicone gel implants
3. Thin women will require sub-muscular placement to avoid implant visibility and rippling
4.Saline implants are adjustable at the time of surgery
5.Saline implants better for asymmetrical breasts
6.May be less likely to have capsular contracture
Silicone gel implants
1. Require a longer incision at least two or more inches
2. Less likely to leak than saline implants but there may be problems with gel migration
3.New implants made of cohesive gel that does not leak out of the implant
4.Feel more natural than saline
5. Better for thin individuals
6.Less likely to show rippling
7.More expensive than saline implants
8.May require more follow up