Volume 9,
Issue 2, 2000
Analysis
of Explanted Silicone/Silica Composite Breast Implants
Harold J. Brandon1,2, V. L.
Young2, K.L. Jerina1,
and C.J. Wolf3
1
Department of
Mechanical Engineering, Washington University Campus Box 1185, One Brookings Drive, St.
Louis, MO 63130 USA
2
Division of
Plastic Surgery, Washington University, St. Louis Missouri USA
3Department of Chemical Engineering,
Washington University, St. Louis Missouri USA
(Received 9/99; accepted 2/00)
ABSTRACT
A study was conducted to examine the physical,
mechanical and chemical properties of composite (silicone/silica) breast implants as a
function of implantation time. In the study the properties of SILASTC®II gel-filled explants with in vivo duration times
ranging from 4 months to 10 years were compared to lot-matched control (unimplanted)
samples. Tensile strength properties were measured for both explant and control shells
using identical testing protocols. The tensile strength properties of shells which were
extracted with hexane to remove non-cross linked silicones were also measured. In
addition, swelling measurements were used to determine the average molecular weight
between cross-links (and/or entanglements). The tensile strength properties obtained from
the present study were correlated with implantation time. The results of the study suggest
that the silicone elastomer shells do not undergo appreciable degradation during in vivo
aging.
