Tuesday, March 4, 2008

Silicone vs Saline Breast Implants

With the reintroduction of silicone implants into more general use and not simply in controlled studies, comparisons between silicone and saline are inevitable. Any comparison seems to be potentially biased, but I will try to give a fair one. To try to keep it simpler, I will stick to a comparison in augmentation use not reconstructive.

In general, normal saline implants are not thought of as first or second generation implants. Silicone gel implants are. Depending on who you read, silicone gel implants are either in their third or fifth generation. I'll give you the information from the first reference below (Supplement, page 45S):

ImplantDescription
1st generation,
1962-1970
Thick, two-piece shell
Smooth surface with Dacron fixation patches
Anatomically shaped (teardrop)
Viscous silicone gel
2nd generation,
1970-1982
Thin, slightly permeable shell
Smooth surface, no Dacron patches
Round shape
Less viscous silicone gel
3rd generation,
1982-1992
Thick, strong, low-bleed shell
Smooth and textured surface
Round shape
More viscous silicone gel
4th generation,
1993-present
Thick, strong, low-bleed shell
Smooth and textured surfaces
Round shape
More viscous (cohesive) silicone gel
Refined manufacturing processes
5th generation,
1993-present
Thick, strong, low-bleed shell
Smooth and textured surfaces
Round and diverse anatomical shapes
Enhanced cohesive & form-stable silicone gel

So when comparing implants, saline to silicone or 1st generation to 4th generation silicone, there may be a distinct difference in years of follow-up. There is no long-term data yet available for the 4th and 5th generation silicone gel implants. The data from these latest generation of silicone implants are approximately 3 to 4 years old. The data collection period on saline implants (during the moratorium on silicone gel implants) spanned more than 15 years in the United States, and the information gathered has shown that saline implants are safe and effective.

There is still a lot of data on silicone implants, but not any 10 year follow-up on the new cohesive gel implants. So we are giving patients the information we have now, not what time may prove out. The following table compares complication rates between the two types of implants (information from 3rd reference mainly).

SalineSilicone
Rupture rate
1-2 yrs
3 yr
5 yr
9-10 yr

1-4%
3-5%
16%
7%

8%
0.5%
1%
8-10%
Contracture rates
1-3 yr
7 yr
10 yr

4-9%
11-16%
16.6%

8.1%
5.6%
No comparison,
38.5-90% with earlier generation
Patient satisfaction97% at 6 yrs95% at 5 yrs,
87% at 7 yrs
Implant removal
(1-4 years)
8% at 2 years
12% at 4 years
5.1 % at 3 years
7.5% at 4 years
Detection of deflation/rupturePhysician/patient able to detectMRI at 3 yrs then every 2 yrs recommended by the FDA
Deflation rate0.34/1000 implants
Implant cost range1X2X
Incision size3-4 cm6-8 cm
Integrity at 10 yrs96.9-98%not collected yet, projected to be 83-85%
Implant removalSimpleComplicated

Consideration of incision size between the two types of implants is significant. Saline implants can be placed unfilled and so a small 3- to 4-cm incision can be used. Silicone implants must be placed through an incision almost twice that length, depending on the size of the implant used. The incision must be large enough that the silicone implant can be placed with ease, so that the gel is not fractured on placement. Brown et al found this to be at least 5 cm.

Cost is also a factor. The cost of saline implants is approximately 50 percent less than that for silicone implants. Satisfaction rates are high for both silicone and saline.

Hard to know what to make of the implant removal rates. Often the reasons for removal are to change size rather than to simply remove and leave out. That data is not often broken down further and it would be helpful if it were.

For me it is tough to justify going back to silicone gel implants in light of the satisfaction of the patient with saline, the difference in cost (both initial and long term as the MRI recommended by the FDA may not be covered by the patient's insurance), the size of the incision, the lack of clear advantage of silicone over saline.

Silicone implants do simulate the feel of breast tissue much better than saline implants ever will. They are therefore perceived as more natural to some patients. There may also be less palpable rippling and less potential for visible rippling with silicone implants. However, women with minimal subcutaneous tissue and/or poor skin turgor are difficult (if not impossible) to hide all rippling. The subpectoral placement can help this with either implant.

The Food and Drug Administration recommends a magnetic resonance imaging scan at 3 years after surgery using silicone gel implants, and then every 2 years thereafter. MRI is an excellent imaging modality in localizing free silicone and evaluating an implant for rupture. It has a sensitivity and specificity of greater than 90%. I don't order one if it won't change my plan of care. If the patient and I have already decided that (for whatever reason--age of implant, etc) that she needs to go to surgery, then why add the cost? The FDA's recommendations are to pick up "silent" ruptures.

Regardless of which type of implant is used for augmentation mammoplasty there are risks that are inherent to the surgery and are non-implant related. These include bleeding, infection, malposition of the implant, changes in nipple and breast sensation, and scar formation.

Breast implants interfere with mammography detection of breast cancer and require additional views and skilled technologists to compensate. So make sure you have your mammogram done at a facility that does a lot (more than a few a week) of women with implants.

With either implant, there WILL be future surgery. I posted about this with saline implants here.

REFERENCES
Silicone Breast Implants: Outcomes and Safety; Suppliment to Plastic and Reconstructive Surgery, Vol 120, No 7, Suppl 1, December 2007

The FDA approves saline-filled breast implants: What does this mean for our patients?; Plast. Reconstr. Surg. 106: 903, 2000; Rohrich, R. J.

Breast Augmentation Today: Saline versus Silicone--What Are the Facts?; Plastic & Reconstructive Surgery. 121(2):669-672, February 2008; Rohrich, Rod J. M.D.; Reece, Edward M. M.D., M.S.

Cohesive Silicone Gel Breast Implants in Aesthetic and Reconstructive Breast Surgery; Plast. Reconstr. Surg, 116, 768, soo5; Brown MH, Shenker R, and Silver SA

Rupture and aging of silicone gel breast implants. Plast. Reconstr.
Surg. 91: 828; discussion 835, 1993; de Camara, D. L., Sheridan, J. M., and Kammer, B. A.

Mentor Corporation. Saline-Filled Breast Implant Surgery: Making
an Informed Decision. Product Insert; Mentor Corporation,
Santa Barbara, California: 2005.

FDA Breast Implant Home Page

6 comments:

Dr. Smak said...

Ramona-
Thanks for this info. I was unaware of the recommendations regarding MRI with the silicone implants. A lot of my patients with implants no longer follow with their surgeons. Does the FDA notify women of this recommendation? I was under the impression that they keep a registry of who has what implants for recall purposes.

rlbates said...

When I participated in some of the studies it was up to the doctors to notify patients. Of course, this only works when the patients notify you of address changes, etc.

Anonymous said...

I have a question regarding insurance and MRI's. Most insurance companies will cover breast MRI's if they are deemed medically necessary. Since the FDA recommends having these periodic checkups to detect ruptures, I would assume that counts as medically necessary. However, I've also heard that insurance companies may drop you, raise your premiums, or not cover any sort of breast medical problems in the future (even breast mammograms, etc). This sounds unethical and discriminatory. Can insurance companies really do this? Or is that completely bogus? I wanted to my daughter to try to go through her insurance for her periodic breast MRI's (cost ranges from $1500-3000_, but at that same time I don't want her to jeopardize her health insurance. Does anyone know more information about this?

rlbates said...

Anon, MRI's to check on a woman's silicone implants are not considered medically necessary even though the FDA recommends them. I'm not 100% certain, but I don't think the insurance company will drop the woman just because she has implants BUT they can put a rider on anything related to the implants. The rider will prevent them from needed to cover the surgery when the implants fail or hard capsule form or if an infection occured.

Melissa said...

Wonderful post filled with tons of useful information. Thank you.

Anonymous said...

Thank you for this very informative page regarding silicone vs. saline. I am debating on which I want and this page definitely helped me decide on saline. Even though silicone might look/feel more natural ( clearly a pro) it does not justify all the added expense of MRI's over the years and the potential worry of a rupture. I personally don't want to not know if it ruptures...it could damage the breast tissue permanently! So thank you, saline it shall be!