title: Analytical investigations on elastomeric shells of new Poly Implant Prothèse (PIP) breast and from sixteen cases of surgical explantation.
abstract: In this study we have analysed the chemical composition of the extractable components from the elastomeric shells from n=27 explanted implants (n=16 patients), n=2 new PIP implants, and from explanted Eurosilicone and McGhan implants (n=2 for each brand). Empty elastomeric PIP shells (n=2) were also available for analysis. Prostheses were explanted between 2011 and 2012, after 3-11 years of implantation. Patients presented pre- and post-operation complications of different degrees. First we evaluated the micro-structural features of the shells by phase contrast microscopy, and compared the results with those obtained using attenuated total reflectance infrared spectroscopy (ATR-FT-IR), head space gas chromatography coupled to mass spectrometry (HS-GC-MS) and GC-MS in direct injection mode. The results of these studies confirm and explain the conclusion of previous international investigations that evidenced a linear decrease of rupture rate for prostheses implanted after 2006. The analytical identification of a series of UV sensitive radical photo-initiators (0.1%-0.2% w/w), belonging to the benzophenone family, in the shells of new and explanted prostheses produced after 2006 (associated with a strong smell absent in those produced earlier), in parallel to (ii) the removal of the anti bleed barrier from their manufacturing procedure (introduced after 2001), strongly suggested that from 2007, the PIP company used a polymerisation process different from that declared, probably as a consequence of the first reports of rupture problems. In addition, the HS-GC-MS experiments demonstrated that at body temperature the diffusivity of low molecular weight (LMW) silicones present in the PIP filler silicone is significantly higher than that of LMW silicones in an approved implant.
authors.affiliation: Department of Pharmaceutical Sciences, University of Milan, Milan, Italy. Electronic address: giangiacomo.beretta@unimi.it.
authors.forename: Giangiacomo
authors.initials: G
authors.lastname: Beretta
authors.affiliation: Department of Veterinary Science and Public Health, University of Milan, Milan, Italy. Electronic address: sara.panseri@unim.it.
authors.forename: Sara
authors.initials: S
authors.lastname: Panseri
authors.affiliation: Department of Veterinary Science and Public Health, University of Milan, Milan, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Manzo
authors.affiliation: Department of Pharmaceutical Sciences, University of Milan, Milan, Italy.
authors.forename: Rufaida
authors.initials: R
authors.lastname: Hamid
authors.affiliation: Aurora Clinics, Princes Risborough, UK. Electronic address: adrian@aurora-clinics.uk.
authors.forename: Adrian
authors.initials: A
authors.lastname: Richards
authors.affiliation: FMH Plastic, Reconstructive and Aesthetic Surgery, Lugano, Switzerland. Electronic address: m.malacco@tin.it.
authors.forename: Matteo
authors.initials: M
authors.lastname: Malacco
mesh_terms: D001577:Benzophenones / Q000737:chemistry; D001831:Body Temperature; D018427:Breast Implants; D020724:Elastomers; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D012828:Silicones / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000379:methods
chemical_list: D001577:Benzophenones; D020724:Elastomers; D011108:Polymers; D012828:Silicones; C036925:elastomeric polymer; C047723:benzophenone
keywords: Analysis; Elastomeric shell; PIP implants; Poly Implant Prothèse; Toxicology