Hyaluronic acid-filled mammary implants: an experimental study

Issues of radiolucency and biocompatibility of currently available mammary implants have prompted the search for alternatives. Several new filler materials have been suggested recently but have involved the use of materials foreign to the body. We have studied the use of a naturally found polysaccharide molecule, hyaluronic acid, as an alternative filler material to silicone gel. We tested hyaluronic acid-filled implants using standard mammographic techniques, applanation tonometry, and in an in vivo animal model (n = 24) up to 1 year after implantation. The present study demonstrates that hyaluronic acid-filled implants have softness comparable with that of silicone gel and saline implants and are more radiolucent, allowing better visualization of breast structures around the implant. Furthermore, in vivo studies fail to demonstrate any adverse reactions to the material over a period of 1 year. Hyaluronic acid has unique properties in modulating the process of wound healing, and these properties may be applied to the tissues surrounding the implants as a result of leaching of hyaluronic acid through the covering shell. Although further studies using larger volumes of filler, characterization of the hyaluronic acid within the implant, quantification of the exact amounts of hyaluronic acid leached into surrounding tissues, and a more appropriate primate model need to be undertaken, this pilot study points out that there may be more biologically compatible materials for the use in breast implants that warrant further investigation.