Pictorial ReviewThe ruptured PIP breast implant
Introduction
The silicone Poly Implant Prothèse (PIP) breast implant (also marketed as M-Implants and Rofil-implants) were made in France from 2001 until their production ceased in March 2010.1 It is estimated that in the UK about 47,000 women may have received a PIP implant,2 the majority of which were implanted in the private sector. According to the analysis of the French authorities, the silicone contained in these implants was of an industrial standard, rather than the medical grade originally tested for the award of the CE mark of approval.3 Soon after their withdrawal from the French market, the Medicines and Healthcare Products Regulatory Agency (MHRA) issued a device alert advising clinicians not to use PIP implants. Six months later there followed advice from the MHRA that clinicians should contact all patients who received a PIP implant and offer them a specialist consultation and “appropriate investigation” of the implant. The media spotlight probably inflated legitimate concern amongst patients with a PIP implant4, 5, 6, 7, 8, 9, 10 and led to a greatly increased demand for implant screening and subsequent resource burden for the National Health Service (NHS).11, 12 The advice from MHRA concerning PIP implants is a significant departure from the usual approach to breast implant imaging. Until now, breast implants of any brand or construction have only been imaged in the context of symptoms.
Concerns have been raised about the construction of both the implant shell and its silicone filler.1, 13, 14 The filler of the PIP implant contains a higher proportion of low molecular weight silicone than would be found in a medical-grade product, and it is this that is thought to be the culprit in early shell weakening and rupture.3 Official chemical analysis has also revealed considerable variation in the structure of the silicone compound, such that implant performance may be somewhat unpredictable.3
Mammography and sonography have a role in implant assessment for symptomatic women.15, 16, 17, 18, 19, 20, 21, 22, 23 However, the superior sensitivity and specificity of magnetic resonance imaging (MRI) as compared to mammography or ultrasound for the detection of prosthetic failure makes it the reference standard imaging investigation.16, 18, 23, 24 MRI also offers the advantage of being able to image both breasts and the axillae at once without exposure to ionizing radiation (Table 1).
Section snippets
Features of implant rupture
Ruptures are generally considered either intra-capsular or extra-capsular. In the former, silicone gel is no longer contained by the implant shell but is retained within the fibrous capsule that normally forms in the breast following prosthetic implantation. Intra-capsular ruptures are often silent as breast shape is unchanged, the patient is asymptomatic, and clinical examination is unremarkable. Extra-capsular ruptures occur where free silicone gel leaks outside of the breast's fibrous
Magnetic resonance imaging
MRI gives the best illustration of the varying characteristics of the ruptured implant, indeed several of the signs are specific to this technique. Numerous radiological signs have been described relating to breast implant rupture on MRI, notably the “linguine”, “keyhole” or ”noose”, “salad oil”, and “sub-capsular line” signs.24
The linguine sign is highly sensitive and specific for intra-capsular rupture (96% and 94%, respectively)15 and shows the collapsed walls of implant shell floating in
Ultrasound
Ultrasound is performed using a high-frequency (e.g., 12 MHz) linear-array probe. In many institutions the availability and cost of sonography make it an attractive first-line investigation of implant integrity.26, 27 Ultrasound also has the advantage of being able to reveal other unrelated breast disease. The ultrasound appearance of an intra-capsular rupture reflects MRI appearances. The linguine sign is again revealed as linear echogenic strands within the substance of the implant (Fig 1).
Mammography
Detection of extra-capsular implant ruptures can be difficult on mammography, and detection of intra-capsular silicone ruptures is often not possible (Fig 15). Furthermore, the compression required during mammography can exacerbate a pre-existing defect or convert an intra-capsular rupture to extra-capsular. For these reasons women may be unwilling to undergo mammography.
Conclusion
Although mammography and sonography have a role in assessing breast implants in symptomatic women, MRI is widely accepted as the reference standard. STIR and silicone-bright sequences are especially useful, and even when used in isolation and without contrast medium enhancement, provide high-quality and cost-effective images to assess implant integrity alone. Although there is a need for further data with surgical correlation, our experience to date suggests STIR and silicone-bright sequences
References (28)
- et al.
A late complication following the insertion of hydrogel breast implants
J Plast Reconstr Aesthet Surg
(2007) - et al.
The implications of PIP are more than just cosmetic
Lancet
(2012) - et al.
The PIP mammary prosthesis: a product recall study
J Plast Reconstr Aesthet Surg
(2012) - et al.
Imaging spectrum of breast implant complications: mammography, ultrasound, and magnetic resonance imaging
Semin Ultrasound CT MR
(2000) - et al.
Breast implants and health alert PIP: experience of the regional cancer center of Lille
Bull Cancer
(2012) - Medicines Healthcare Products Regulatory Agency. Medical Device Alert, MDA/2012/011. Issued 15 March 2012. Department...
- Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). The Safety of PIP Silicone Breast...
UK recommends PIP breast implants should not be removed
BMJ
(2011)French women to have PIP breast implants removed for free
BMJ
(2011)Additional 7000 UK women may have faulty PIP implants
BMJ
(2012)
Around 1000 women with private sector PIP implants seek NHS help
BMJ
Government puts pressure on private sector to pay for removal of PIP breast implants
BMJ
UK launches inquiry into safety of PIP breast implants
BMJ
Hundreds of thousands of pounds of NHS funds have been spent on care of private patients with PIP implants
BMJ
Cited by (10)
Prevalence, clinical characteristics, and management of silicone lymphadenopathy: A systematic review of the literature
2024, Journal of Plastic, Reconstructive and Aesthetic SurgeryACR Appropriateness Criteria® Breast Implant Evaluation: 2023 Update
2023, Journal of the American College of RadiologyACR Appropriateness Criteria <sup>®</sup> Breast Implant Evaluation
2018, Journal of the American College of RadiologyCitation Excerpt :Most implant ruptures are intracapsular, and these are most often asymptomatic. MRI findings of both intracapsular and extracapsular rupture have been described [7,9,10,22,31]. An incomplete intracapsular rupture has been referred to by a variety of names including the “inverted-loop sign,” “keyhole sign,” “teardrop sign,” and “hang noose sign.”
False-positive axillary lymph nodes due to silicone adenitis on <sup>18</sup>F-FDG PET/CT in an oncological setting
2016, Journal of Thoracic OncologyCitation Excerpt :In this case, given the context of an oncological diagnosis and increased 18F-FDG uptake in the contralateral axillary lymph nodes suggestive of nodal metastatic disease, a biopsy was performed and revealed silicone adenitis. This entity consists of inflammatory lymph nodes containing free silicone surrounded by inflammatory cells (most often macrophages), and in this case, it is due to silicone leakage from the breast implants as confirmed by morphological imaging.1–3 This case confirms previous reports that contralateral axillary lymph node involvement in the presence of an underlying lung carcinoma is rare.
Diagnosing PIP breast implant failure: A prospective analysis of clinical and ultrasound accuracy
2015, Journal of Plastic, Reconstructive and Aesthetic SurgeryCitation Excerpt :Any future study investigating the accuracy of ultrasound in PIP implants comparative to other brands would need to account for capsular contracture as a potential confounder. Our results are limited by the fact that ultrasound is user dependent.30 Not only is there a steep learning curve, but technical factors and suitability of equipment may also influence accuracy.10,31
MR Evaluation of Breast Implants
2014, Radiologic Clinics of North America