Reaction to silicone implants in the guinea pig

Many papers have been published on the lack of reaction around silicone implants both in the experimental animal and the human. A study with human silicone implants with silicone gel interior shows loss of the silicone fluid from intact silicone sac. A solid silicone disc subjected to 5 pounds weight for one week loses silicone to the underlying paper. In the guinea pig, some capsules surrounding solid silicone implants, silicone sacs with saline, and silicone sac with silicone gel show vacuole or amorphous materials (silicone) with a thickening of the capsule and associated inflammatory reaction. These vacuoles or amorphous material resembles the silicone found in capsules around intact human silicone jell prosthesis. The presence of silicone with associated thickening of the capsule and inflammatory reaction may be one cause of firmness in the human after breast augmentation by silicone implants.