In Vitro Measurement of Silicone Bleed From Breast Implants

Abstract

A method to measure gel bleed from intact silicone gel-filled breast implants was developed. This nondestructive technique permits accurate and reproducible serial measurements of silicone bleed from smooth wall breast implants (n=10) under simulated physiologic conditions in vitro. Gel bleed rates from new low bleed gel-filled implants and intact explants (unbarriered, low bleed, double lumen) were determined. These results demonstrate the reliability of this method to quantify silicone gel bleed and may permit a meaningful comparison of bleed rates from implants in the future.

Exhaustive soxhlet extraction for the complete removal of residual compounds to provide a nonleaching silicone elastomer

“…Continual washing of the swollen elastomer network with fresh solvent in a Soxhlet extraction system removes residual compounds. It has been reported previously, and further supported by leaching data in this study, that 72 h is a sufficient time for complete removal of residual compounds 16,20 [and unpublished data from the authors]. The leaching conducted over two time points (Table II) essentially shows no detectable Si containing compounds for extracted samples after 3 or 18 days.…”

Bioavailability of Octamethylcyclotetrasiloxane (D 4 ) after Exposure to Silicones by Inhalation and Implantation

“…PDMS is commonly used in orthopedic and breast implants (5). Although breast implants are composed mostly of stable high molecular weight siloxanes (HMWS), low molecular weight siloxanes (LMWS) still exist in the polymer as impurities (5)(6)(7)(8)(9). LMWS consist of both cyclic and linear molecules with repeating units of dimethylsiloxane, of which D 4 is a major component (47%) (7)(8)(9).…”

“…Although breast implants are composed mostly of stable high molecular weight siloxanes (HMWS), low molecular weight siloxanes (LMWS) still exist in the polymer as impurities (5)(6)(7)(8)(9). LMWS consist of both cyclic and linear molecules with repeating units of dimethylsiloxane, of which D 4 is a major component (47%) (7)(8)(9). Residual LMWS ranged from 0.2 to 2% by weight for the silicone gel and 0.01% to 0.1% for the silicone envelope (1.04-10.4 mg) (5)(6)(7)(8)(9).…”

“…LMWS consist of both cyclic and linear molecules with repeating units of dimethylsiloxane, of which D 4 is a major component (47%) (7)(8)(9). Residual LMWS ranged from 0.2 to 2% by weight for the silicone gel and 0.01% to 0.1% for the silicone envelope (1.04-10.4 mg) (5)(6)(7)(8)(9). Numerous studies have documented the migration of significant amounts of LMWS out of breast implants into surrounding breast tissues and to the liver (8)(9)(10)(11).…”

“…Residual LMWS ranged from 0.2 to 2% by weight for the silicone gel and 0.01% to 0.1% for the silicone envelope (1.04-10.4 mg) (5)(6)(7)(8)(9). Numerous studies have documented the migration of significant amounts of LMWS out of breast implants into surrounding breast tissues and to the liver (8)(9)(10)(11). This would add to the dermal or inhalation exposures from personal care products in a typical woman.…”