In the United States, around 400,000 silicone breast implant procedures are performed every year. While the procedure and the implants are considered safe, some patients have an immune response and can suffer complications, including fibrosis and lymphomas.
When procedures first started to be performed in the 1960s, some patients experienced capsular contracture, which involves the formation of scar tissue around the implant which results in deformities and pain. The earlier implants were smooth, but in the 1980s, textured implants were introduced which reduced the risk of capsular contracture. However, these textured implants were found to cause Breast Implant Associated Anaplastic Large Cell Lymphoma (BIA-ALCL) and the implants were eventually recalled in 2019.
Now a team of researchers at Massachusetts Institute of Technology, Rice University, University of Texas, MD Anderson Cancer Center, and Baylor College of Medicine have demonstrated the roughness of the surface of silicone breast implants is what causes an immune response, and the tissue that surrounds the breast implants alters the patient’s immune response to the implant.
The researchers conducted experiments on mice using clinically approved implants with varying degrees of roughness. The implants were put into the mammary fat pads of mice with full scale implants used in rabbits. The researchers then studied the formation of fibroid tissue for up to a year. The researchers found implants with a mean roughness of 4 microns were the least likely to cause inflammation and the formation of fibroid scar tissue.
Follow on studies were conducted to determine how human patients responded to different types of breast implants. The results were similar, with patients with highly textured implants showing signs of a chronic, long term immune response several years after having the implants. Many had formed thick scar tissue around the implants.
“The surface topography of an implant can drastically affect how the immune response perceives it, and this has important ramifications for the design,” said Omid Veiseh, PhD, assistant professor of bioengineering at Rice University. “We hope this paper provides a foundation for plastic surgeons to evaluate and better understand how implant choice can affect the patient experience.”
You can read more about the study in the paper – The surface topography of silicone breast implants mediates the foreign body response in mice, rabbits and humans – which was recently published in Nature Biomedical Engineering. DOI: 10.1038/s41551-021-00739-4
Image source: Source: FDA, Public domain, via Wikimedia Commons