Study Suggests Vaginal Mesh Implants Trigger InflammationSep 1, 2016
New research provides evidence that transvaginal mesh implants trigger an inflammatory response in the body. Pelvic mesh devices were approved by the U.S. Food and Drug Administration (FDA) to treat pelvic organ prolapse and stress urinary incontinence, conditions caused by the weakening of the pelvic walls and muscles. In recent years, however, mesh inserts have come under scrutiny due to reports of complications. Thousands of women have filed lawsuits alleging the devices caused severe injuries.
Findings were presented at the American Urogynecologic Association Joint Scientific Meeting in Washington, D.C. as well as the 36th Annual Meeting of American Urogynecologic Society PFD week in Seattle, Washington. The researchers compared 27 women undergoing surgery for vaginal mesh complications to 30 women undergoing benign gynecologic surgery without mesh. In 15 cases, women were having the mesh removed due to exposure; 12 suffered from pain without exposure.
The study looked at the presence of macrophages, a type of cell that digests foreign material. An M1 macrophage is associated with inflammation while an M2 macrophage is involved in tissue remodeling. Excessive M2 activity can lead to fibrosis and mesh encapsulation, the authors note. In comparing the macrophage activity between the groups, researchers found that "macrophages surrounded each mesh fiber in both groups, with predominance of the M1 subtype."
Researchers also identified an increased in MMP-9, which indicates degradation. They concluded. "In women with complications, mesh induces a proinflammatory response that persists years after implantation. The increase in MMP-9 in mesh explants that were removed for exposure indicates degradation; the positive association between interleukin-10 and M2 macrophages in mesh explants that are removed for pain is consistent with fibrosis."
Women who filed lawsuits over transvaginal mesh allege that device makers failed to warn about the risk of complications, including pain, exposure, erosion, bleeding and other complications. Some plaintiffs allege having to undergo a number of surgeries to remove the implant without success. Plaintiffs’ lawsuits state that transvaginal mesh was approved without adequate clinical testing because it was approved through 510(k), a process that allows devices onto the market if device makers can prove that it is "substantially equivalent" to a previously approved device.
The FDA issued its first warning on transvaginal mesh in 2008. By 2012, the agency warned that complications associated with transvaginal mesh are "not rare".