Polypropylene breast implants, also known as string breast implants, are a form of breast implant using polypropylene developed by Dr. Gerald W. Johnson. Due to a number of medical complications, the device has been banned in the European Union and United States.
Polypropylene implants absorb water very slowly, about <0.01% in 24 hours.[1] The polypropylene, which is yarn-like, causes irritation to the implant pocket which causes the production of serum which fills the implant pocket on a continual basis. This causes continuous expansion of the breast after surgery. Growth can only be alleviated by removal of serum by syringe. Problems can also arise if the breasts enlarge at different rates. This can be corrected by removal of serum or introduction of sterile saline. Continual breast growth will eventually result in "extreme, almost cartoonish breast sizes."[2]
String implants were only available for a very short time before being removed from the market by the FDA around 2001.[3]
Polypropylene implants have created the largest recorded increases in breast size due to surgical augmentation. They are rarely seen outside the adult entertainment industry. Big-bust entertainers Chelsea Charms, Maxi Mounds, Kayla Kleevage and Minka are some of the best known recipients of polypropylene breast implants. .