Chemical and physicochemical properties of the high cohesive silicone gel from Poly Implant Prothèse (PIP) breast prostheses after explantation: a preliminary, comparative analytical investigation

Biological and genetic landscape of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL)

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an uncommon form of non-Hodgkin lymphoma (cancer of the immune system) that can develop around breast implants. Breast implants are among the most commonly used medical devices for cosmetic or reconstructive purposes. In the past few years, the number of women with breast implants diagnosed with anaplastic large cell lymphoma (ALCL) has increased, and several studies have suggested a direct association between breast implants and an increased risk of this disease. Although it has been hypothesized that chronic stimulation of the immune system caused by implant materials and biofilms as well as a possible genetic predisposition play an important role in this disease, the cellular and molecular causes of BIA-ALCL are not fully understood. This review aims to describe the current understanding around the environmental and molecular drivers of BIA-ALCL as well as the genetic and chromosomal abnormalities identified in this disease to date.

Is breast implant-associated anaplastic large cell lymphoma a hazard of breast implant surgery?

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) may occur after reconstructive or aesthetic breast surgery. Worldwide, approximately 1.7 million breast implant surgeries are performed each year. To date, over 500 cases of BIA-ALCL have been reported around the world, with 16 women having died. This review highlights the most important facts surrounding BIA-ALCL. There is no consensus regarding the true incidence rate of BIA-ALCL as it varies between countries, is probably significantly under-reported and is difficult to estimate due to the true number of breast prostheses used largely being unknown. BIA-ALCL develops in the breast mostly as a seroma surrounding the implant, but contained within the fibrous capsule, or more rarely as a solid mass that can become invasive infiltrating the chest wall and muscle, in some instances spreading to adjacent lymph nodes, in these cases having a far worse prognosis. The causation of BIA-ALCL remains to be established, but it has been proposed that chronic infection and/or implant toxins may be involved. What is clear is that complete capsulectomy is required for treatment of BIA-ALCL, which for early-stage disease leads to cure, whereas chemotherapy is needed for advanced-stage disease, whereby improved results have been reported with the use of brentuximab. A worldwide database for BIA-ALCL and implants should be supported by local governments.

Biomechanical analysis of intact versus ruptured Poly Implant Prothèse breast implants

Despite there being many studies that have evaluated breast implant rupture, there is no consensus about causes and incidence. Most studies lack a multifactorial analysis of what causes breast implants to rupture. To fill this gap, an experimental protocol was developed to compare ruptured and intact Poly Implant Prothèse (PIP) breast implants from the same woman. These conditions guarantee that the physical/biological variables are the same for each pair of ruptured and intact implants. A total of 1008 samples from 22 PIP explants (11 intact and 11 ruptured) and three control PIP implants were analysed. The mechanical properties (tensile strength) of the ruptured and intact implants were compared according to brand, lot, implantation time and demographic conditions. In general, statistically significant differences were found between the intact and ruptured PIP implants. Ruptured implants were thinner (0.73 ± 0.10 mm versus 0.91 ± 0.11 mm) and weaker (7.42 ± 2.65 MPa versus 9.59 ± 2.37 MPa) than intact implants. Intact and ruptured implants have shown distinct mechanical behaviours and variations in thickness. Our understanding is that these differences may be associated with the typical manufacturing process of breast implant shells. These results stress the importance of thorough control of the shell thickness. Given its relevance, shell thickness should be used as a quality control measure for homologation purposes. Thus, the homogeneity of the shell should be considered as a relevant parameter during the manufacturing process. This will translate into an improved quality of life for patients and will potentiate safer and longer lasting products.

Poly Implant Prothèse Silicone Breast Explants: Chemical Analysis of Silicone Gel and Implant Shell

Background:

Poly Implant Prothèse (PIP) silicone breast implants were removed from the market between 2010 and 2012 because of the use of nonmedical grade silicone filler. The chemical and physico-chemical properties of PIP implants have been analyzed by several groups. In addition, our previous study illustrated that PIP implant shells were more permeable. Therefore, we analyzed the chemical composition of the envelope and gel of PIP silicone breast explants. Also, the composition of absorbed material into the implant was analyzed.

Methods:

This study was conducted on 3 PIP implants explanted from 2 patients. The envelope was analyzed using Raman microscopy, whereas the gel was analyzed using near-infrared spectra, nuclear magnetic resonance spectroscopy, and gas chromatography coupled to mass spectrometry. Absorbed material was investigated with Fourier-transform infrared spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis.

Results:

The 3 implants appeared to be Rofil implants, and all implants displayed a yellow color. None of the envelope showed a barrier layer. Amounts of D4, D5, and D6 were found to be below 100 ppm. Water was found in all 3 implants and also proteins were absorbed into the implants.

Conclusions:

The current study shows that the analyzed implants originate from the manufacturer Rofil but have PIP1 hallmarks. Apparently, these are own brand labeling implants. The presence of water and proteins in the explants indicate exchange of small and large molecules into the explants, even in the implant with a visually intact envelope. Because of the PIP1 hallmarks of the Rofil implants, patients with such implants are advised to be counseled by their physicians.

Poly Implant Prothèse silicone breast implants: implant dynamics and capsular contracture

Background

The Poly Implant Prothèse (PIP) implants were withdrawn from the market in 2010 due to the use of low-grade silicone, causing a high risk for implant rupture. The aim of this study was to investigate the implant dynamics of PIP breast implants, as well as to determine the rate and predictors of implant gel bleeding, rupture, and capsular contracture in PIP implants.

Methods

Eighty women with a total of 152 PIP implants who underwent a reoperation in 2012 were enrolled in this study. Physical investigation included assessing the Baker score and demographics were retrospectively traced in medical records. The pre- and post-operative volumes of the implants were calculated and their state was determined intraoperatively by the surgeon.

Results

The implants were removed after a mean implant duration of 11 ± 2.1 years. Gel bleed and implant rupture occurred in respectively 42 and 25% of the implants. Intact implants had post-operative volume increase as well as decrease. There was a correlation between gel bleeding and more post-operative implant volume increase (P ≤ 0.05). Capsular contracture had a protective effect against post-operative implant volume increase (P ≤ 0.05), while a post-operative implant volume increase provided a protective influence in developing capsular contracture (P ≤ 0.05). Additionally, implant rupture led to a higher risk of capsular contracture (P ≤ 0.05).

Conclusions

We managed to illustrate that PIP implant shells were too permeable and that there is a correlation between gel bleeding and the increase of the post-operative implant volume. Implant rupture led to a higher risk for developing capsular contracture.

Level of evidence: Level III, risk / prognostic study.

Electronic supplementary material

The online version of this article (10.1007/s00238-018-1427-y) contains supplementary material, which is available to authorized users.

Evolution of consciousness of exposure to siloxanes-review of publications

The purpose of this description is to review scientific literature from 1944 to 2017 as a source of information on the reasons for the increased interest in siloxanes (silicones). Not only the research area, but first, the changes in the tendency of research aims are important issues in the evaluation. On the one hand, the authors emphasize the unique properties of linear and cyclic siloxanes, providing many examples of beneficial applications, and on the other hand, there are some warnings of overcoming of the safety barrier of their presence in human environment. Analyzing the results from the SCOPUS database, it can be argued that the increased interest of scientists and government agencies particularly relates to the analysis of siloxanes in biological and environmental samples. This is caused not only by the widespread use of various siloxanes in the pharmaceutical, medical, cosmetic and food industries, but also by the direct contact of these compounds with tissues, as well as an increased access to knowledge and modern research tools that have developed the awareness of hazards. The development of research methods enables not only constant monitoring of progressively lower siloxanes concentrations in various samples, but because of the specificity of these methods, it also enables an identification of specific siloxane compounds and evaluation of their effects on humans and environment. This paper discusses the issues of the evolution of consciousness of exposure to siloxanes due to their increased synthesis and widespread use in many areas of human life, which contributes to environmental pollution.

In vitro degradation of polydimethylsiloxanes in breast implant applications

BACKGROUND

The durability of breast implant material is associated with failure probability, increasing with time from implantation. The current study avoided the bias introduced by biological factors, to systematically investigate the degradation over time of shell materials. The same fundamental physical and chemical conditions were maintained (temperature and pH) throughout the study, to decouple biological aspects from the degradation process.

METHODS

Six virgin implants of 2 brands were submitted to the in vitro degradation process, mechanical testing of shell materials, surface change analysis (via scanning electron microscopy [SEM]) and chemical composition analysis by Fourier transform infrared (FTIR) spectroscopy.

RESULTS

FTIR results showed that the principal chemical bonds of the material remained intact after 12 weeks of degradation. Apparently the implants' shell structures remained unchanged. Despite this observation, there were statistically significant differences between strain at failure at different time points for the shells of both brands, translated into a stiffening of the material over time.

CONCLUSIONS

Material stiffening is reported as an indicator of material degradation. This altered mechanical behavior, added to the mechanical friction from tissue-tissue and tissue-implant contact and to the external mechanical loading (physical activity), may alter the material performance in women's bodies. Ultimately these changes may affect the implants' durability. Further work is needed to understand the biological aspects of the degradation process and their impact on implant durability.

An experimental analysis of shell failure in breast implants

Breast implant durability and the mechanisms of rupture are important topics in the medical community, for patients, manufactures and regulatory medical agencies. After concerns about the Poly Implant Prosthesis (PIP) implants, the need for understanding the adverse outcomes and the failure mode to improve the breast implants increased. The objective of this research is to analyze and describe the rupture characteristics of failed explanted PIP implants to study the modes and causes of rupture. Eleven explanted PIP implants were analyzed by visual inspection and scanning electron microscopy (SEM). To simulate hypothetical ruptures caused by cyclic mechanical stress (fatigue) in the implant shell, two control implants were submitted to fatigue tests, and analyzed with SEM. Small ruptures (either Hole or split) striations were found, which normally appear due to fatigue phenomena. Similar striations were also found in specimens (control) tested under laboratory controlled conditions. In the context of this work, the striations found in explants constitute a significant finding as they point to the occurrence of fatigue phenomena associated with mammary implants rupture. This research, also demonstrates that rupture surface analysis of explanted breast implants has the potential to become a useful indicator for assessing implant rupture mechanisms.

Mechanical Performance of Poly Implant Prosthesis (PIP) Breast Implants: A Comparative Study

BACKGROUND

There is societal concern regarding potential health problems associated with breast implants. Much of this distrust climate was a reaction to the Poly Implant Prosthesis (PIP) scandal. Studying the mechanisms of implant rupture is an important step for their improvement. The mechanical behaviour of breast implant shells was studied on explanted and virgin implants. Implants from both PIP and another brand (brand X), currently in the market, were considered.

METHODS

To study the mechanical behaviour of the shell, a total of 940 samples from 11 explants and 5 control implants were analysed. The experimental protocol follows the ISO standards for shell integrity and determination of tensile stress-strain properties. Pearson correlation analyses and the multi-factor ANOVA statistical tests were performed using mechanical test data.

RESULTS

Both PIP control and explants had significant variations of stress (P = 0.0001) and shell thickness (P = 0.000) throughout the implant. The stress was directly related to shell thickness. Shell thickness varied significantly for PIP implants, exceeding the manufacturer's specifications. Regarding the other brand, thickness variation was within manufacturer's specifications.

CONCLUSIONS

The heterogeneous nature of PIP implants was confirmed. The implant shell thickness should be considered as a relevant parameter during the manufacturing process, for quality control purposes. These results may contribute to dispel mistrust and doubt surrounding breast implants, among the medical community and patients.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of the Explantation Rate of Poly Implant Prothèse, Allergan, and Pérouse Silicone Breast Implants within the First Four Years after Reconstructive Surgery before the Poly Implant Prothèse Alert by the French Regulatory Authority

Background. In March 2010, ANSM (Agence Nationale de Sécurité du Medicament), the French Medical Regulatory Authority, withdrew Poly Implant Prothèse (PIP) breast implants from the market due to the use of non-medical-grade silicone gel. The aim of this study was to compare the removal rate (and reasons thereof) of breast implants produced by different manufacturers before the ANSM alert. Materials and Methods. From October 2006 to January 2010, 652 women received 944 implants after breast cancer surgery at the Gustave Roussy Comprehensive Cancer Center, Paris (France). The complications and removal rates of the different implant brands used (PIP, Allergan, and Pérouse) were evaluated and compared. Results. PIP implants represented 50.6% of the used implants, Allergan 33.4%, and Pérouse 16%. The main reasons for implant removal were patient dissatisfaction due to aesthetic problems (43.2%), infection (22.2%), and capsular contracture (13.6%). Two years after implantation, 82% of Pérouse implants, 79% of PIP, and 79% of Allergan were still in situ. There was no difference in removal rate among implant brands. Conclusion. Before the ANSM alert concerning the higher rupture rate of PIP breast implants, our implant removal rate did not predict PIP implant failure related to the use of nonapproved silicone gel.

The clinical implications of poly implant prothèse breast implants: an overview

Mammary implants marketed by Poly Implant Prothèse (PIP) were found to contain industrial grade silicone and this caused heightened anxiety and extensive publicity regarding their safety in humans. These implants were used in a large number of patients worldwide for augmentation or breast reconstruction. We reviewed articles identified by searches of Medline, PubMed, Embase, and Google Scholar databases up to May 2014 using the terms: "PIP", "Poly Implant Prothèse", "breast implants" and "augmentation mammoplasty" "siloxanes" or "silicone". In addition the websites of regulating bodies in Europe, USA, and Australia were searched for reports related to PIP mammary implants. PIP mammary implants are more likely to rupture than other implants and can cause adverse effects in the short to the medium term related to the symptoms of rupture such as pain, lumps in the breast and axilla and anxiety. Based on peer-reviewed published studies we have calculated an overall rupture rate of 14.5% (383/2,635) for PIP implants. However, there is no evidence that PIP implant rupture causes long-term adverse health effects in humans so far. Silicone lymphadenopathy represents a foreign body reaction and should be treated conservatively. The long-term adverse effects usually arise from inappropriate extensive surgery, such as axillary lymph node dissection or extensive resection of breast tissue due to silicone leakage.

Chemical fingerprinting of silicone-based breast implants

With millions of women worldwide carrying them, silicone-based breast implants represent a large market. Even though silicone breast implants already have a history of use of more than 50 years, the discussion on their safety has not yet come to an end. To improve safety assessment, regulatory authorities should have the availability of a set of tests to be able to determine parameters of implant identity and quality. Therefore, the gels and envelopes of various brands and types of silicone-based breast implants have been subjected to infrared, Raman and NMR spectroscopy. We show that by using a combination of complementary spectroscopic techniques breast implants of various origins can be distinguished on typical chemical hallmarks. It was found that typical silicone-based implants display a surplus of vinyl signals in the gel, cyclosiloxane impurities are tolerable at low levels only and a barrier layer is present in the implant envelope. The techniques presented here and the results obtained offer a good starting point for market surveillance studies.

PIP breast implant removal: a study of 828 cases

In March, 2010, the French Health Products Safety Agency suspended the sale of prefilled silicone breast implants manufactured by Poly Implants Prosthèse Prothese (PIP) because of a high failure rate and the use of an inappropriate silicone gel that did not comply with CE marking. These findings led to an international medical crisis. In France, 30,000 female patients had PIP implants. In our Department, 1150 PIP breast implants had been implanted in 630 patients since 2001. A retrospective study was conducted to define the rupture rate of these implants and the complications that arise. The women included in the study underwent implant removal from May 2010 to September 2012 for preventive or curative reasons. Data were collected from medical records that included: results of clinical examination, breast ultrasound before removal, rates of implant rupture, results of biopsy of periprosthetic capsule and pericapsule tissue and postoperative complications. A total of 828 PIP breast implants were removed in 455 patients. The rate of ruptured implants was 7.73% (64/828), corresponding to 11.6% of patients. A periprosthetic effusion was associated with rupture in 44% of cases. Breast ultrasound indicated a rupture for 87 implants; 32% were true positives and 3% were false negatives. Periprosthetic capsule biopsy demonstrated the presence of a foreign body, which seemed to be silicone, in 26% of cases and the presence of inflammation in 13% of cases. No siliconoma-type lesion was identified in the pericapsular tissue at biopsy. A total of 14 implants presented perspiration at removal. A statistically significant difference was found between the rates of rupture for texturised implants as compared to the smooth-surfaced implants. There were eight post-revisional-surgery complications (1%) and three cases of breast adenocarcinoma. The preventive explantation of PIP breast implants is justified given the high failure rate (7.73%) and given patients' exposure to silicone gel that did not comply with CE standards in the absence of rupture, through the early perspiration of implants.