Aging of retrieved gel breast implants: a comparison between two product generations

In order to get a marketing authorization, breast implants (BI) must meet a number of standard requirements. French and European standards ISO 14607 list a number of official tests to be performed before an implant can be used clinically. However, the BI material characteristics evolution over implantation time remains a research field which is unexplored. The goal of the present study is to compare the mechanical ageing of two breast implant generations and assess if the use of one generation rather than the other is advantageous in terms of durability. For that purpose, 21 explanted BI were analyzed in terms of biomechanical characteristics and compared. Twelve BI were textured anatomic specimens of 5th generation and 10 BI were round textured specimens of 4th generation. All the specimens were produced by the same manufacturer. Implantation time ranged from 3 to 130 months. Both the shell and the gel of every specimen were analyzed. Results show that the mechanical properties go down with the implantation time for all the implants. Moreover, the shell of round implants appear to be less resistant than the shell of anatomic specimens with 25% lower rupture forces. With regard to the gel, whatever the specimen, results show that the properties change with implantation time. The color changes from transparent to milky to finally become yellow, while the cohesion goes down especially for the round specimens. Globally, the study brings out that BI get degraded with implantation time and provides information which could help predicting the durability of the implant.