Michael Simca Middleton PhD, MD, Presenter: Research Consultant, Siemens AG Research Consultant, Confirma, Inc Grant, General Electric Company Stockholder, General Electric Company Grant, Bayer AG Research Consultant, Merge Healthcare Research Consultant, Allergan, Inc Research Consultant, Merck & Co, Inc Research Consultant, Naviscan, Inc Speaker, SenoRx, Inc Speaker, C. R. Bard, Inc

Michael Patrick McNamara MD, Abstract Co-Author: Stockholder, Apple Inc Research Consultant, Carestream Health, Inc

Christopher E. Comstock MD, Abstract Co-Author: Nothing to Disclose

In part related to legal settlements, there have been recommendations to evaluate silicone gel-filled implants with MRI each 1-3 years, and to replace them after 10 years. The purpose of this study is to re-examine those recommendations by comparing the MRI-determined failure prevalence of a cohort of thin-shell implants placed between 1973 and 1983, to a cohort of more recently placed thicker-shell implants placed between 1986 and 1996.

With retrospective IRB approval, including waiver of written informed consent and waiver of HIPAA authorization, MRI examinations of a series of 29 consecutive sets of thin-shell silicone gel-filled breast implants placed between 1973 and 1983 that were between ten and twenty years of age at the time of MRI, were compared to a series of 29 consecutive sets of thicker-shell silicone gel-filled breast implants placed between 1986 and 1996 that were ten to twenty years of age at the time of their MRI. Failure prevalence was compared for these two groups. Shell thickness was determined based on product identification. Failure criteria were those used for the FDA Breast Implant Study (Brown et al in 2000 (AJR 175:1057). Case selection was based on review of consecutive MRI studies performed between 1992 and 2006 for which shell thickness (older style thin, versus later style thicker) could be determined (Middleton and McNamara, Breast Implant Imaging, ©2003 Lippincott).

The older thin-shell group had 64% of implants ruptured, and 79% rupture by patient (one or both ruptured). The later thicker-shell group had 33% of implants ruptured, and 52% rupture by patient (one or both implants ruptured). These failure prevalence differences are statistically significant (p<0.01).

In this preliminary study, older thinner-shell implants referred for suspected rupture are more likely to be ruptured than later thicker-shell implants.

Recommendations for MRI, and removal, are based largely on failure reports for older thin shell implants, and so might need to be reconsidered if our results are confirmed under more rigorous study.

Middleton, M, McNamara, M, Comstock, C, Do Silicone Gel-filled Breast Implants Need to Be Evaluated with MR Imaging and Replaced So Frequently?.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11016976.html