Sientra’s Silimed Brand “Gummy Bear” Silicone Gel Breast Implants Pose Safety Questions

gummy-bear-bubblegumMingxin Chen, MHS and Diana Zuckerman, PhD, The National Center for Health Research

In December 2012, the U.S. Food and Drug Administration (FDA) approved Sientra’s for its “Silimed silicone gel breast implants.” These implants are also called “gummy breast implants” because they are made of a thicker gel that is said to resemble candy gummy bears.

To gain approval, the company was required to submit the results of a clinical trial to prove that the implants were safe and effective. A 5-year study of these implants was published in the November 2012 issue of Plastic and Reconstructive Surgery, authored by three Sientra employees and several plastic surgeons who were paid by Sientra to conduct the research.1 The study included 1,788 participants with 3,506 breast implants.

Re-operation, Rupture, and Capsular Contracture

The three major complications measured were need for a re-operation, rupture, and capsular contracture. They can occur at any time, and become more common as the implants age. Capsular contracture refers to the formation of scar tissues around breast implants which becomes hard and potentially painful as the patients’ immune system reacts to the implant. MRIs were conducted on 571 of the 1788 participants to assess rupture that has no obvious symptoms.

The study indicated that the overall risk of rupture during the five years of the study was 2%, but that is misleading because the rupture rate was higher when “silent ruptures” measured by MRI were counted. MRI is the most accurate way to determine if an implant is ruptured, and more than 4% of first-time augmentation patients had a rupture within 5 years, which is much higher than expected. The risk of capsular contracture was 9% overall, and did not vary much for the different types of patients.

In contrast, the risk of reoperation varied considerably: 43% for first time reconstruction patients, 48% for reconstruction revision patients, compared to 17% for first time augmentation patients and 30% for augmentation revision patients. Revision patients are those whose previous implants were replaced with the Sientra implants.

Other Complications

There were many other complications affecting appearance and health. Most complications are highest for patients whose implants are for reconstruction after mastectomy; for example, 11% have asymmetry, 5% have an infection; 4% have breast pain, 4% of the implants are not in the correct position, and 3% have abnormal scarring. Complications are even higher for reconstruction patients who had earlier implants replaced by Sientra implants: 15% have breast asymmetry, 7% have implants in the wrong place, 5% have breast lumps or cysts, and 4% have breast pain.

For first-time augmentation patients, 3% have nipple sensation changes (either losing sensation or painfully sensitive) and 3% have sagging breasts. As noted earlier, reoperation, capsular contracture, and rupture are more common. Other complications, such as pain and swelling, add up, but each of these others complication is below 3%. Among revision augmentation patients, 5% have implants in the wrong position, 3% develop sagging breasts, 3% have wrinkling around the implant, and 3% have breasts that look asymmetrical.

Despite these high level of complications within only five years was high, the authors defended the implants. For example, they stated that over half of the patients who removed or replaced their implants did so for cosmetic reasons, predominantly patient request for style/size change. Regardless of the reason however, additional surgery is expensive and puts the patient at risk. And for breast cancer patients who chose mastectomy and implants so they would not have to think about cancer, these surgeries are a very unwelcome reminder.

The authors claimed Silimed is superior to the other two implant brands, Allergan and Mentor, in terms of risk of complications, as its risk of capsular contracture among first-time and revision augmentation patients within 5 years is 9% and 8%, in comparison with Allergan’s 13% and 17%, and Mentor’s 9% and 20%, both within 4 years.

Sientra, based in Santa Barbara, California, is the third largest global manufacturer of silicone implantable devices. The approval of the first gummy bear implants was welcomed by plastic surgeons, who pointed out that these implants had been manufactured and distributed outside of North America for 15 years.  However, the FDA approved the implants based on only 3 years of data, rather than the longer studies that would have been possible since the implants were on the market for 15 years.

  1. Stevens, W. G., Harrington, J., Alizadeh, K., Berger, L., Broadway, D., Hester, T. R., . . . Beckstrand, M. (2012, November). Five-Year Follow-Up Data from the U.S. Clinical Trial for Sientra?s U.S. Food and Drug Administration–Approved Silimed® Brand Round and Shaped Implants with High-Strength Silicone Gel. Plastic and Reconstructive Surgery, 130(5), 973-981.