Electron and light microscopy examination of capsules around breast implants.

An investigation, by scanning electron microscopy of the capsules formed around silicone breast implants revealed that they consist almost entirely of connective tissue. In contrast, the capsules around the Y-prostheses (with a polyurethane foam surface) showed a foreign body reaction. We believe that excessive capsule formation around silicone implants is, among other factors, most likely due to discrete or moderate bleeding with subsequent hematoma formation. Therefore, we favor a two-stage procedure for subcutaneous mastectomy with insertion of the implant at 4 to 6 months after the excision.