The privately held Sientra Inc. on Friday joined the publicly traded Allergan Inc. and Johnson & Johnson (Mentor Worldwide LLC) as the only three companies to have won U.S. Food and Drug Administration approvals to market controversial silicone gel-filled breast implants.

The FDA conditionally OK'd Sientra's breast implant, first, to enhance breast size in women at least 22 years old (augmentation) and, second, to rebuild breast tissue in women of any age (reconstruction), according to the agency, based in Silver Spring, Md.

As a condition of approval, Sientra will be required to conduct post-approval studies that will assess the product's long-term efficacy and safety, as well as the risks of rare disease outcomes.

Silicone gel-filled breast implants are medical devices implanted under either the breast tissue or the chest muscle for breast augmentation or reconstruction, the FDA explained in a statement. With silicone outer shells filled with silicone gel, these implants come in different sizes, and they have either smooth or textured shells.

Breast augmentation includes primary breast augmentation to increase breast size, as well as revision surgery to correct or improve the result of a primary breast augmentation surgery.

Breast reconstruction includes primary reconstruction to replace breast tissue that has been removed because of cancer or trauma or that has failed to develop properly due to a severe breast abnormality. Breast reconstruction also includes revision surgery to improve the result of a primary breast reconstruction surgery.

Breast augmentation was the most popular cosmetic surgery in the United States last year, as the number of procedures expanded 4 percent, to 307,000, according to the American Society of Plastic Surgeons.

Breast reconstruction also was popular last year, as the number of such surgeries swelled 3 percent, to 96,000, the ASPS reported.

The FDA reported its Sientra approval was based on three years of clinical data from 1,788 participants. Complications reflected those found in previous studies of other breast implants. Among them were tightening of the area around the implant (capsular contracture), re-operation, implant removal, uneven appearance (asymmetry), and infection.

In June 2011, the FDA released a report that included preliminary safety data from post-approval studies from earlier breast implant approvals. The experience collecting and analyzing data from these studies informed the design and structure of post-approval studies for Sientra breast implants.

In addition to other post-approval conditions, the FDA said, Sientra will:

  • Continue to follow the 1,788 clinical-trial participants in their premarket study for an additional seven years;
  • Conduct a 10-year study of 4,782 women receiving Sientra silicone gel-filled breast implants to collect information on long-term local complications such as capsular contracture, as well as less common disease outcomes, such as rheumatoid arthritis and breast and lung cancer; and
  • Conduct five case-control studies that will evaluate the association between Sientra's silicone gel-filled breast implants and five rare diseases: rare connective tissue disease, neurological disease, brain cancer, cervical/vulvar cancer, and lymphoma.

Both Sientra and J&J's Mentor unit are based in Santa Barbara, Calif., while Allergan is headquartered in Irvine, Calif.