ANALYSIS OF SILICON LEVELS IN CAPSULES OF GEL AND SALINE BREAST IMPLANTS AND OF PENILE PROSTHESES

Although a potential link between silicone-gel breast implants and aut oimmune connective tissue disease has been suggested, none has been pr oven. The potential role of silicone as an immune adjuvant remains ver y controversial. Currently available techniques do not allow precise m easurements of silicone in tissues. However, all compounds containing silicon (including silicone) can be measured accurately. The present s tudy was designed to measure silicon levels in the fibrous capsules of patients with silicone-gel breast implants, saline breast implants, a nd silicone inflatable penile prostheses. Baseline control silicon lev els were obtained from the breast tissue of patients undergoing breast reduction, who had no exposure to breast implants. All silicon measur ements were carried out using atomic absorption spectrometry with a gr aphite furnace. Silicon was measured in a normal heptane extract of si licone from dried tissue. The mean silicon levels in 16 breast tissue control samples from 8 patients undergoing breast reduction varied fro m 0.025 to 0.742 mu g/gm with the median mean being 0.0927. The median silicon level in capsules from six patients with saline implants was 7.7 mu g/gm (range, 1.9-36.6 mu g/gm). The median silicon level in cap sules from five patients with silicone inflatable penile prostheses wa s 19.5 mu g/gm (range, 1.9-34.8 mu g/gm). Although the levels of silic on in capsules of patients with saline breast prostheses and penile im plants were higher than in control samples, they were much lower than those from the capsules of the 58 gel implants (median, 9,979 mu g/gm; range, 371-152,000 mu g/gm). Of the 58 silicone-gel breast implants ( from 20 patients with bilateral implant removal and 18 patients with u nilateral removal) that had been inserted from 1974 to 1990, 28 were i ntact, 8 had pinhole leaks, and 22 were ruptured. Median capsule silic on levels and ranges for all 58 implants, for intact only, for leaking , and for ruptured were, respectively, as follows: 9,979 (371-152,000) ; 10,477 (371-88,703); 6,599 (3,235-65,396); and 9,922 (1,762-152,387) mu g/gm. There were no significant differences in silicon levels asso ciated with implant status, duration in situ, or year of implantation.