Capsular contracture has multiple causes, all of which lead to increased inflammation and scarring. There have been five generations of silicone breast implants; the most recent are filled with a highly cohesive gel thought to reduce capsular contracture. No independent data exist to support this claim.
Eight Göttingen swine were each implanted with eight 50-cc custom gel implants. In phase 1 of the study, the implant shells were photochemically altered to produce a low-bleed shell or a high-bleed shell to simulate a second-generation implant. In phase 2, both the third/fourth generation and the newest, fifth generation (highly cohesive gel) devices were implanted. Half the implants were punctured with a 3-ml punch biopsy to simulate a ruptured implant. Capsule and implant specimens were harvested at 1 and 3 months and analyzed with a Bose strain gauge. Intracapsular fluid was tested for silicon levels with atomic emission spectrometry. Histologic analysis was prepared with hematoxylin and eosin, Masson trichrome, and α-smooth muscle actin immunohistochemistry stains.
Gel bleed correlated with capsule stiffness in a dose-dependent manner (p < 0.05). High-bleed second-generation implants had the stiffest capsules, and nonruptured third- and fourth-generation implants had the softest. Histologic examination revealed an intermediate layer of spindle-like cells staining positive for α-smooth actin in the most contracted capsules.
There is a dose-dependant relationship between silicone gel bleed and capsule compliance that is independent of the cohesivity of the silicone. Capsule thickness and a fibrotic, α-smooth muscle actin–positive layer are present within the most contracted capsules.
From the Division of Plastic Surgery, Emory University.
Received for publication April 18, 2012; accepted April 23, 2012.
Disclosure:Dr. Losken is a speaker for LifeCell Corporation. The other authors have no financial interests to declare.
Hunter R. Moyer, M.D., Atlanta Plastic Surgery, 975 Johnson Ferry Road, NE, Suite 100, Atlanta, Ga. 30342, firstname.lastname@example.org