A new breast implant called the Natrelle 410 Highly Cohesive Anatomically Shaped Silicone-Gel Filled Breast Implant to increase breast size in females 22 and older and to rebuild breast tissue of women of all ages, has been approved by the US FDA.

The Natrelle 410 implants are manufactured by Allergan, Inc.

Seven years of data were gathered and analyzed from 941 females before the FDA made their decision to approve the implant for augmentation and reconstruction.

The majority of complications and outcomes are similar to those found in previous studies on breast implants, and include:
  • re-operation
  • implant removal
  • asymmetry - an uneven appearance
  • capsular contracture - tightening of the area around the implant
  • infection
The FDA team of experts also examined cracks, known as fissures, in the gel of some Natrelle 410 implants. This feature, known as gel fracture, is distinct to this implant.

Jeffrey Shuren, M.D., director of the FDA's Center for Devices and Radiological Health, explained:

"It's important to remember that breast implants are not lifetime devices. Women should fully understand the risks associated with breast implants before considering augmentation or reconstruction surgery, and they should recognize that long-term monitoring is essential."

The data we reviewed showed a reasonable assurance of safety and effectiveness. We will be looking at the results from post-approval studies that will focus on their long-term safety and effectiveness."

The Natrelle 410 implant's silicone gel consists of more cross-linking than the silicone gel in Allergan's previously approved Natrelle implant. This enhanced cross-linking provides a firmer gel.

Cross-linking refers to the bonds that connect one silicone chain to another. According to the FDA "The clinical significance of this type of silicone gel is not known".

The Agency added "Allergan's studies did not compare the safety and effectiveness of the Natrelle 410 implant to other previously approved silicone gel-filled breast implants on the market. Therefore, these implants cannot be directly compared to any previously FDA-approved implant."

The FDA has instructed Allergan to carry out some post-approval studies to evaluate the safety and efficacy outcomes, and to determine what the long-term risks of disease or problems might be.

The scientists said:

"Lessons learned from previous post-approval studies on silicone gel-filled breast implants informed the design of post-approval studies for the Natrelle 410."

The FDA approved the new implant on condition that Allergan follow a list of instructions.

They include:
  • As part of their continued access report, the company must keep observing, for an extra 5 years, an estimated 3,500 females who received the Natrelle 410 implants.
  • Carry out a 10-year study on over 2,000 women, the aim being to gather data on the possible long-term local complications associated with Natrelle 410 silicone gel-filled implants (post-approval).
  • Assess the potential link between the Natrelle 410 implants, as well as other silicone gel-filled breast implants, and 5 rare diseases (brain cancer, lymphoma, cervical/vulvar cancer, neurological disease, and rare connective tissue disease) during five case control studies.
  • Determine females' perceptions of the patient labeling.
  • When the Natrelle 410 implants are removed from the patients and sent back to the manufacturer, they need to be analyzed.
Silicone gel-filled breast implants are inserted under the breast tissue or under the chest muscle to either increase the size of the breast, or for reconstruction.

The implants have a silicone outer shell that is made up of silicone gel and come in various sizes and styles- the shells can be either textured or smooth.

Breast reconstruction, for example, may involve rebuilding a breast after a malignant tumor was surgically removed. It might also include patients who experienced some kind of trauma where breast tissue was lost. "Breast reconstruction also includes revision surgery to correct or improve the result of a primary breast reconstruction surgery."

There are three companies in the USA that make silicone breast implants - Allergan, Sientra and Mentor.

Sientra's silicone gel-filled breast implant for breast augmentation and reconstruction was approved by the FDA in March 2012.

Written by Sarah Glynn