Saline Filled versus Silicone Gel Filled Implants
Breast implants are implantable medical devices used to cosmetically enhance the size and shape of the breast. Breast implants are also used for breast cancer reconstruction to restore volume after mastectomy. Breast implants have a outer silicone shell filled with a filler material consisting of either saline solution or silicone gel. Saline solution (salt water solution) is found throughout the body and is completely harmless when absorbed. The newer generation silicone implant are filled with a cohesive gel, which is “thicker” than the older generation implants. Dr. Neil J. Zemmel believes both implants are safe for cosmetic and reconstructive purposes.
There are advantages to each type of implant. Saline implants are implanted during surgery and the filled. The fill volume can be finely tuned to achieve better symmetry and shape. Silicone implant are prefilled and once implanted cannot be adjusted. Furthermore the FDA has mandated a slightly longer incision for silicone implant placement. For this reason silicone implants cannot be placed endoscopically through a navel incision and an axillary incision.
Dr. Zemmel believes both types of implants give excellent results in properly selected patients. Silicone implant are reported to have an improved texture when compared to saline implants. The viscosity (thickness) of the cohesive gel implants mimics the feel of natural breast tissue better than saline filled implants. This effect is increased in thinner patients with less breast tissue and muscle covering the implant. Dr. Zemmel will discuss the differences between the implants in great detail during your complimentary consultation.
- History of Silicone Implants
- Advantages of the Form Stable Cohesive Implant
- Disadvantages of the so-called “gummy bear” cohesive implant
- The Safety of Silicone Gel Breast Implants
- Candidates for Silicone Breast Implants
- High Profile vs. Round vs. Anatomical Shaped Breast Implants
HISTORY OF SILICONE IMPLANTS
Breast implants have been popular since their introduction in the 1960s, but a large amount of attention was focused on silicone implants the late 1980s and early 1990s. During this period many woman claim to have developed illnesses related to silicone implants including autoimmune diseases such as arthritis, lupus, scleroderma, connective tissue diseases and even cancer. Large class action suits were filed. Thousands of women claimed that their symptoms of chronic fatigue, breast cancer, hair loss, were caused by leaking silicone implants. As a result of the law suites, without any supportive medical research, the FDA imposed a ban on the sale of silicone gel breast implants in 1992. At that point silicone could no longer be offered to the general public for cosmetic uses. Several implants manufacturers paid billions of dollars in claims and were force into bankruptcy.
However, the FDA allowed silicone gel implants to remain in use after 1992, but only if a patient met certain criteria and participated in clinical trials. In April of 2005, after hearing testimony from women and reviewing the available studies and data, the FDA’s scientific panel, voted that the FDA should approve Mentor’s gel implants. Mentor received a letter of approval in July of 2005 from the Federal Drug Administration (FDA) indicating that the company’s silicone gel implants could be approved for general use if the company met certain conditions. After a year and a half of further negotiation, the FDA approved silicone gel breast implants for breast augmentation in women aged 22 and over.
Thomas Cronin and Frank Gerow, plastic surgeons, from Houston, Texas developed the first implantable breast prosthesis in conjunction with Dow Corning Corporation in 1961. The First procedure was performed in 1962. The development of silicone implants can be categorized into 5 generations denoted the separate production methods.
First generation Silicone Implants
The original Cronin-Gerow implants were made of an anatomic tear drop shaped silicone shell filled with a thicker silicone gel. The implant was coated with Dacron patch to reduce subluxation of the implant.
Second generation Silicone Implants
Plastic surgeons then requested modification to the implants in order to produce and more natural shape and feel. These implants were then redesigned in the 1970s using a thinner outer shell and less viscous gel. These new implants had higher rupture rates and diffusion of the gel filler “gel bleed” through the intact implant shell was common. This resulted in a high rate of capsular contracture, which is scaring around the implant. These were the implants primarily involved into the lawsuits of the early 1990s.
Another second-generation modification was the use of polyurethane foam coating on the implant shell. This coating was effective in lowering the rate capsular contracture by causing reduced formation of scar tissue around the implant. These implants were later removed from the market due to concern of potential adverse health effects from the breakdown products from the polyurethane. The FDA performed a large study assessing the risk of cancer in these patients and found that cumulative risk of cancer was so insignificant as not to justify removal of the devices from patients. Polyurethane implants are still used in Europe and South America.
Double lumen shell designs were also introduced during second-generation implant design. These implants were a silicone breast implant inside a saline breast implant. The double lumen design was an attempt to provide the cosmetic benefits of gel in the inner compartment, while the outside compartment contained saline. Implant volume could be adjusted after surgical placement. The current versions of these devices, the Becker Breast Implant, are used primarily for breast reconstruction.
Third & fourth generation Silicone Implants
The 1980s saw the development of third and fourth generation breast implants. This was a series of advances in manufacturing with polymer coated shells to decrease gel diffusion across the implant shell wall. The gel filler was also redesigned to be more cohesive. The increased cohesion of the gel reduced potential leakage after shell rupture when compared to earlier devices. The shell was also redesigned with an increased durability when compared to the earlier second generation implants. A variety of both round and anatomic shapes (tear drop shaped) were available during this period. Anatomic implants are textured to increase tissue adherence, reducing rotation and to reduce the rate of capsular contracture. Round implant are available in both smooth and textured surfaces.
Fifth generation (“Highly Cohesive Gel” and “Gummy Bear” Silicone Gel Breast Implants)
Form stable (highly cohesive) implants are made of silicone polymer shells filled with a more cross-linked form of silicone. These newer implants are designed to retain their shape during a rupture and decrease gel leakage and movement. Highly-cohesive implants are currently being studies in the United States. These implants have been used since the mid 1990s in Europe. Preliminary studies of these devices have shown significant improvements in safety and efficacy over prior implants with decreased rates of rupture and capsular contracture.
Advantages of the Form Stable Cohesive Implant:
Shape: Cohesive breast implants may retain their shape better than other previous breast implant designs. Forth generation silicone or standard saline breast implants are subject gravity and the normal motion of the breast and body. These implants may experience distortion over time. Form stable cohesive gel implants have a distinct shape that is imparted to the overlying breast.
Capsular Contracture: The European experience has been that high grade capsular contracture seems to occur less frequently with cohesive implants. It is not clear if this is a short or long term effect. Some researchers speculate that it is related to less diffusion of silicone than with non-cohesive fillers, while others believe it is due to the increased firmness of the implant, which prevents the tissue from contracting around it.
Rupture and Gel Leakage: All breast implant shells are subject to rupture like any other surgical device. All breast implants have a lifetime. Folding and rippling of the breast implant shell is thought to contribute to the rate of shell rupture. With a thicker shell and more cohesive gel, fatigue fractures may occur at a low rate thereby reducing breast implant rupture. The highly cohesive gel will likely have a low rate of migration.
Implant Rippling: Since the filler material does not shift from one pole of the implant to another, upper pole breast implant collapse seems less likely.
Disadvantages of the so-called “gummy bear” cohesive implant:
Texture: Depending on the patient overlying soft tissue thickness (i.e. thickness of skin, breast tissue and muscle, patients may experience more over firmness in texture when compared to 4th generation silicone breast implants. This may or may not be desirable to some patients. This effect may also be off set by the potential reduction in capsular contracture.
Shape: Because the shape of the implant is more fixed, and subject to less motion and gravity, implants will retain their shape. This may lead to a slightly less natural result especially in larger sizes. Patients and surgeons must be particularly aware of the importance of preoperative sizing.
Rotation Deformity: Because some form stable breast implants are anatomic in shape (i.e. tear drop shaped) accurate submuscular pocket dissection is essential. If the breast implant pocket is too large for the implant rotation may occur which can cause distortion at the superior pole of the breast. This usually requires surgical correction.
Finances: These breast implants cost significantly more than saline and 4th generation silicone breast implants.
Incision Length: These breast implants are not deformable and therefore they cannot be place through small incisions (i.e. 2-3cm). Depending upon the size of the implant, incision length must be between 4-5 cm. Inframammary and periaerolar incisions are preferable.
Today’s 4th and 5th generation silicone gel breast implants are made with a much more sophisticated process than in previous generations. Dr. Zemmel feels comfortable placing newer generation silicone implants to provide you with a reliable, natural result. During your initial consultation, Dr. Zemmel will provide you with a complete overview of the different types of breast implants, and together you will choose the best one for you.
The Safety of Silicone Gel Breast Implants
Several large retrospective studies have been conducted to examine the claims relating systemic symptoms of connective tissue disease, fibromyalgia, and neurological issues to silicone implants. These studies have found localized risks associated with all breast implants (i.e. risk of infection, capsular contracture and gel leakage) but no conclusive evidence to support the claims systemic illness. Many studies conducted by the Institute of Medicine and other experts have found no connection between silicone breast implants and these diseases.
Candidates for Silicone Breast Implants
Prior to the FDA approval in November 2006, silicone gel breast implants were not available for general use and women could only obtain silicone breast implants as part of an FDA-sanctioned adjunct study. Patients who may qualify must meet the following criteria:
Cosmetic breast augmentation patients must be at least 22 years of age. Cosmetic breast augmentation includes primary augmentation to increase the size of the breast, and secondary surgical revision to correct or improve the result of a primary breast augmentation surgery.
Breast reconstruction includes primary reconstruction to recreate breast tissue that has been excised due to trauma or cancer or that has failed to develop properly. Breast reconstruction also includes secondary revisional surgery to improve the result of a primary breast reconstruction surgery.
Textured vs. Smooth Surfaces
Breast implants may have a rough, textured surface or may have a smooth surface. The textured implants were designed to increase tissue adherence. The textured surface acts “like Velcro” to the tissue interface. The goals of textured surfaces are to decrease potential rotation of the implant and to decrease the rate of capsular contracture. This effect appears only when the implant is placed above the pectoralis major muscle of the chest wall. Textured implants have not been shown to provide any reduction in complications versus smooth implants when placed in the submuscular space.
Textured implants also have disadvantages. Textured implants are produced by making the surface of a smooth implant textured on its outer surface. This process produces a shell thicker and harder. This can potentially make the implant more visible under the skin. The implant may also be felt more easily. Textured implants also have a higher rate of traction rippling and rupture.
Because of these potential complications Dr. Zemmel uses smooth surfaced implants. Dr. Zemmel places all breast implants in the submuscular position. Dr. Zemmel believes that submuscular placement and smooth surfaced implants provide a much more natural look and normal feel when compared to other implant types.
High Profile vs. Round vs. Anatomical Shaped Breast Implants
Dr. Zemmel uses smooth round implant almost exclusively. These breast implants provide excellent shape, contour and volume restoration. Implants that are tear drop shaped are known as anatomic implants. These implants are designed to better mimic the shape of the breast and to provide greater upper pole fullness. They are also textured. These two factors combined can lead to greater traction rippling and rotation of the implant which can lead to shape distortions. This does not occur with a smooth round implant.
Dr. Zemmel also gives his patients the option of a moderate or high profile implant. High profile implants are narrower and project father than moderate profile implants for any given volume. This allows Dr. Zemmel to give a higher volume implant without a large increase in implant diameter. Dr. Zemmel believes this gives his patients a thinner more contoured look without achieve a “shelf-like” appearance of the chest. Women with more petite frames can therefore undergo the same increase in volume without a large diameter implant. Some women who could benefit from a concurrent breast lift may avoid this extra procedure by opting for a high profile implant placed via a dual plane technique.
Directions to Our Office
Dr. Zemmel is proud to provide his plastic surgery services to patients traveling from nearby cities. For your convenience, we have provided driving directions to our practice from the following locations: