Rupture of poly implant prothèse silicone breast implants: an implant retrieval study

Suppression of the fibrotic encapsulation of silicone implants by inhibiting the mechanical activation of pro-fibrotic TGF-β

The fibrotic encapsulation of implants involves the mechanical activation of myofibroblasts and of pro-fibrotic transforming growth factor beta 1 (TGF-β1). Here, we show that both softening of the implant surfaces and inhibition of the activation of TGF-β1 reduce the fibrotic encapsulation of subcutaneous silicone implants in mice. Conventionally stiff silicones (elastic modulus, ~2 MPa) coated with a soft silicone layer (elastic modulus, ~2 kPa) reduced collagen deposition as well as myofibroblast activation without affecting the numbers of macrophages and their polarization states. Instead, fibroblasts around stiff implants exhibited enhanced intracellular stress, increased the recruitment of α_v and β₁ integrins, and activated TGF-β1 signalling. In vitro, the recruitment of α_v integrin to focal adhesions and the activation of β₁ integrin and of TGF-β were higher in myofibroblasts grown on latency-associated peptide (LAP)-coated stiff silicones than on soft silicones. Antagonizing α_v integrin binding to LAP through the small-molecule inhibitor CWHM-12 suppressed active TGF-β signalling, myofibroblast activation and the fibrotic encapsulation of stiff subcutaneous implants in mice.

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.

Mechanical and surface chemical analysis of retrieved breast implants from a single centre

INTRODUCTION

Breast implants are associated with complications such as capsular contracture, implant rupture and leakage often necessitating further corrective surgery. Re-operation rates have been reported to occur in up to 15.4% of primary augmentation patients and up to 27% in primary reconstructions patients within the first three years (Cunningham, 2007). The aim of this study was to examine the mechanical and surface chemical properties as well as the fibroblast response of retrieved breast implants in our unit to determine the in vivo changes which occur over time.

METHODS

Ethical approval was obtained. 47 implants were retrieved. Implantation time ranged from 1 month to 388 months (Mean 106.1 months). Tensile strength, elongation, Young's modulus and tear strength properties were measured using Instron 5565 tensiometer on anterior and posterior aspects of the implant. Attenuated total reflectance-fourier transform infra-red spectroscopy (ATR-FTIR), wettability and scanning electron microscopy (SEM) analysis was performed on the shell surfaces. Bicinchoninic acid assay was performed to determine shell protein content. The fibroblast response was determined by seeding HDFa cells on the retrieved implants and cell metabolism measured using Alamar Blue™ assay.

RESULTS

Mechanical properties fall with increasing duration of implantation. There were no significant changes in ATR-FTIR spectra between ruptured and intact implants nor significant changes in wettability in implants grouped into 5 year categories. SEM imaging reveals surface degradation changes with increasing duration of implantation.

CONCLUSIONS

With increasing duration of implantation, mechanical properties of the breast implants fall. However this was not associated with surface chemical changes as determined by ATR-FTIR and wettability nor protein content of the shells. Thus the reduction in mechanical properties is associated with breast implant failure but further research is required to elucidate the mechanisms.

Engineering standards for trauma and orthopaedic implants worldwide: a systematic review protocol

INTRODUCTION

Despite multiple scandals in the medical implant sector, premarket testing has been the attention of little published research. Complications related to new devices, such as the DePuy Articular Surface Replacement (ASR, DePuy Synthes, USA), have raised the issue of how designs are tested and whether engineering standards remain up to date with our understanding of implant biomechanics. Despite much work setting up national joint registries to improve implant monitoring, there have been few academic studies examining the premarket engineering standards new implants must meet. Emerging global economies mean that the markets have changed, and it is unknown to what degree engineering standards vary around the world. Governments, industry and independent regulatory bodies all produce engineering standards; therefore, the comparison of surgical implants across different manufacturers and jurisdictions is difficult. In this review, we will systematically collate and compare engineering standards for trauma and orthopaedic implants around the world. This will help inform patient, hospital and surgeon choice and provide an evidence base for future research in this area.

METHODS AND ANALYSIS

This protocol is based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) guidelines. We will conduct a systematic review of trauma and orthopaedic engineering standards from four main sources of information as identified in our preliminary scoping searches: governments, industry, independent regulatory bodies and engineering and medical publications. Any current standard relevant to trauma and orthopaedic implants will be included. We will use a predefined search strategy and follow the recommendations of the Cochrane handbook where applicable. We will undertake a narrative synthesis with qualitative evaluation of homogeneity between engineering standards.

ETHICS AND DISSEMINATION

No ethics approval is required as no primary data are being collected. The results will be made available by peer-reviewed publication and reported according to PRISMA-P guidelines.

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.

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 .

Chemical and Structural Characterization of Several Mid-Term Explanted Breast Prostheses

The recent scandal of poly implant prostheses (PIP), which were found in some cases to be made of non-medical grade silicone (as reported by the European Scientific Committee on Emerging and Newly Identified Health Risks), had a great social impact. Thousands of patients asked for implant removal with significant costs for public health care systems. We analysed, by a multidisciplinary approach, sixteen different breast implants after explantation by using several analytical and structural techniques, such as Fourier Transform infrared spectroscopy (FT-IR), mass spectrometry equipped by ion coupled plasma (ICP-MS), gas-chromatography (GC-MS), and tensile testing. Traces of organic (fatty acid) and inorganic (Fe, Cr, Pt, Na, and other metals) substances were found in all samples, and, even if these values are under danger threshold levels, our study results highlight the possibility of bioaccumulation and tissue contamination, implying the need for continuous medical surveillance and monitoring of material aging.

Poly Implant Prothèse and Rofil Substandard Breast Implant Explantations from a Large German Single Centre from 2011 to 2014: A Comparative Study

BACKGROUND

Following a Europe-wide scandal, substandard breast implants containing silicone for industry purposes produced by Poly Implant Prothèse (PIP&Rofil) were explanted due to its potential health risks.

OBJECTIVE

We investigated whether these implants actually imposed a threat to patients' health.

METHODS

In this retrospective single-centre case-control study, we compared patients with breast augmentation receiving implant explantation (01/2011-01/2015). Data were collected retrospectively from the patients' records. Patients were split into two groups: PIP&Rofil and implants of other manufacturers.

RESULTS

A total of 307 patients with 495 breast implants met the inclusion criteria, 64 patients with 115 PIP&Rofil implants and 243 patients with 380 implants of other manufacturers. Comparison of descriptive statistics between the two groups revealed that for a variety of indicators (e.g. patient age, breast cancer, aesthetic vs. reconstructive indication, implant volume, submuscular vs. subglandular implant position) PIP implants differ from non-PIP implant patients. Raw mean comparison showed higher rupture rates for non-PIP implants, 28.42 % (PIP 23.48 %). However, when controlling for implant indwelling time, PIP implants had shown higher rupture rates. Both groups had similar rates of capsular contracture (PIP: 71.30 %, Others: 72.63 %) with different distribution of Baker Scores (Baker 2/3/4: PIP 5/8/13 and non-PIP 3/24/135).

CONCLUSION

Concerning patient symptoms, we did not find any objective reason to justify implant explantation of PIP&Rofil implants as a solely precautionary measure. As PIP&Rofil implants showed shorter retention periods until rupture and ruptured implants can cause symptoms or health problems, PIP&Rofil implants should be regularly monitored and explanted if there is evidence of rupture.

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.

Poly implant prothèse asymmetrical anatomical breast implants: a product recall study

BACKGROUND

In 2010 high rupture rates were unexpectedly found among prostheses produced by the French manufacturer Poly Implant Prothèse. Since then, several studies have been performed concerning the round implants, but there are still few data available on anatomical implants.

METHODS

From 2003 to 2006 Poly Implant Prothèse implants were employed at the authors' institute for immediate or delayed reconstruction after mastectomy. All implants were anatomical and asymmetrical. In November of 2010, the authors began offering free consultation with a plastic surgeon and radiologist. Demographic data, type of reconstruction, implant lifespan, indications for implant removal, and rupture rate were recorded.

RESULTS

A total of 578 women underwent postmastectomy immediate or delayed reconstruction with 658 Poly Implant Prothèse implants from 2003 to 2006 at the authors' institute. The authors explanted 409 of 443 prostheses, and 34 were explanted at other centers. Eighty-nine patients died and 120 are alive with the implants in place. The mean implant lifespan was 57.5 months, 76 ruptured implants were explanted (18.5 percent), and in 22 cases (5.4 percent), leakage of silicone gel was detected.

CONCLUSIONS

Poly Implant Prothèse implant failure is to be ascribed to shell structure, although the primary safety issue concerned the gel (an industrial-grade and low-cohesive silicone). These issues produce the known rupture rates in the manufacturer's round implants. The authors' use of only anatomical and asymmetrical implants, with their more cohesive silicone gel and more rigid shell allowing a stable form and projection along with a natural feel and touch, probably reduces the rupture rate and silicone spread, although these events remain unacceptably high compared with similar products of other brands.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

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.

Soft, Brown Rupture: Clinical Signs and Symptoms Associated with Ruptured PIP Breast Implants

Supplemental Digital Content is available in the text.

Background:

Preoperative signs and symptoms of patients with Poly Implant Prothese (PIP) implants could be predictive of device failure. Based on clinical observation and intraoperative findings 4 hypotheses were raised: (1) Preoperative clinical signs including acquired asymmetry, breast enlargement, fullness of the lower pole, decreased mound projection, and change in breast consistency could be indicative of implant rupture. (2) Device failure correlates with a low preoperative Baker grade of capsule. (3) Brown-stained implants are more prone to implant failure. (4) The brown gel could be indicative of iodine ingression through a substandard elastomer shell.

Methods:

Preoperative clinical signs were compared with intraoperative findings for 27 patients undergoing PIP implant explantation.

Results:

Acquired asymmetry (P = 0.0003), breast enlargement (P = 0.0002), fuller lower pole (P < 0.0001), and loss of lateral projection (P < 0.0001) were all significantly predictive of device failure. Capsule Baker grade was lower preoperatively for ruptured implants. The lack of palpable and visible preoperative capsular contracture could be secondary to the elastic nature of the capsular tissue found. Brown implants failed significantly more often than white implants. Analysis of brown gel revealed the presence of iodine, suggesting povidone iodine ingression at implantation.

Conclusions:

Preoperative signs can be predictive of PIP implant failure. Brown-stained implants are more prone to rupture. The presence of iodine in the gel suggests unacceptable permeability of the shell early in the implant’s life span. A noninvasive screening test to detect brown implants in situ could help identify implants at risk of failure in those who elect to keep their implants.