Calcification properties of saline-filled breast implants

Complicated calcified alloplastic implants in the nasal dorsum: A clinical analysis

BACKGROUND

In rhinoplasty, calcification around silicone implants is frequently observed in the tip dorsum (TD) area. Additionally, based on a review of various literature, it is presumed that calcification in silicone implants occurs due to both inflammatory chemical reactions and physical friction against the tissue. The calcification of nasal silicone implants not only results in the functional loss of the implants, but also leads to material deformation. However, there is a lack of research on calcification of nasal silicone implants in the current literature.

AIM

To elucidate various clinical characteristics of calcification around nasal silicone implants, using histological and radiological analysis.

METHODS

This study analyzed data from 16 patients of calcified nasal implants, who underwent revision rhinoplasty for various reasons after undergoing augmentation rhinoplasty with silicone implants. The collected data included information on implant duration, implant types, location of calcification, presence of inflammatory reactions, and computed tomography (CT) scans.

RESULTS

The most common location of calcification, as visually analyzed, was in the TD area, accounting for 56%. Additionally, the analysis of CT scans revealed a trend of increasing Hounsfield Unit values for calcification with the duration of implantation, although this trend was not statistically significant (P = 0.139).

CONCLUSION

Our study shows that reducing the frequency of calcification may be achievable by using softer silicone implants and by minimizing the damage to perioperative tissues.

The Spectrum of Non-neoplastic Changes Associated With Breast Implants: Histopathology, Imaging, and Clinical Significance

Breast implant-associated anaplastic large cell lymphoma has been recognized as a distinct entity in the World Health Organization classification of hematolymphoid neoplasms. These neoplasms are causally related to textured implants that were used worldwide until recently. Consequently, there is an increased demand for processing periprosthetic capsules, adding new challenges for surgeons, clinicians, and pathologists. In the literature, the focus has been on breast implant-associated anaplastic large cell lymphoma; however, benign complications related to the placement of breast implants occur in up to 20% to 30% of patients. Imaging studies are helpful in assessing patients with breast implants for evidence of implant rupture, changes in tissues surrounding the implants, or regional lymphadenopathy related to breast implants, but pathologic examination is often required. In this review, we couple our experience with a review of the literature to describe a range of benign lesions associated with breast implants that can be associated with different clinical presentations or pathogenesis and that may require different diagnostic approaches. We illustrate the spectrum of the most common of these benign disorders, highlighting their clinical, imaging, gross, and microscopic features. Finally, we propose a systematic approach for the diagnosis and handling of breast implant specimens in general.

The Evolution of Breast Implants

The present review traces the evolution of breast implants over the past 50 years. During the early years (from 1951 to 1962), a number of different sponges were used for breast augmentation. The first of these was Ivalon, a polyvinyl alcohol sponge. Other sponges were introduced subsequently, including Etheron (a poly-ether sponge popularized by Dr Paule Regnault in Montreal) and Polystan (fabric tapes that were wound into a ball). Subsequently, polyethylene strips enclosed in a fabric or polyethylene casing were also used for breast augmentation. All of these materials had similar outcomes. Although the initial results were encouraging, within one year of augmentation, breasts became very firm and lost over 25% of their volume. This was due to capsular contracture, a process that would lead to the collapse of the sponge and would continue to plague plastic surgeons and their patients for the next 50 years. In 1963, Cronin and Gerow introduced the silicone gel ‘natural feel’ implant, which revolutionized breast augmentation surgery. Approximately 10 companies have manufactured many types of silicone gel breast implants over the years. They obtained their raw materials for gels and shells from a similar number of other companies that entered and left the market at intervals. Many of the suppliers and manufactures changed their names and ownership over the years, and most of the companies no longer exist. No formal process of United States Food and Drug Administration premarket testing was in effect until 1988. There have been three generations of gel implants and a number of other lesser variations. First-generation implants (1963 to 1972) had a thick gel and a thick wall. They have generally remained intact over the years. Second-generation implants (1973 to the mid-1980s) had a thin gel and a thin wall. They have tended to disrupt over time. Third-generation implants (mid-1980s to 1992) had a thick wall and a thick gel. Except for those made by Surgitek, these implants remain intact. The breast implant business was competitive and companies introduced changes such as softer gels; barrier low-bleed shells; greater or lesser shell thickness; surface texturing; different sizes, contours and shapes; and multiple lumens in search of better aesthetics. Ultimately, more than 240 styles and 8300 models of silicone gel breast implants were manufactured in the United States alone. Inflatable breast implants were introduced in Toulons, France in 1965 (the Simaplast implant). There have been three main eras of inflatable implants: seamed, high-temperature vulcanized and room temperature vulcanized implants. In 1973, spontaneous deflation rates of 76% to 88% over three years were reported for many types of inflatable implants. Because of this, most plastic surgeons abandoned their use. From 1963 until the moratorium on gel implants (January 6, 1992), about 95% of all breast implants inserted were silicone gel filled. Only 5% were saline filled. Since the moratorium, this ratio has been reversed and 95% of all implants have been saline-filled, with only 5% being gel filled. Polyurethane-coated (PU) silicone gel implants were introduced in 1968. Over the next 20 years, they were shown to reduce the prevalence of capsular contracture to 2% to 3%. Other forms of surface texturing (Biocell, Siltex, multistructured implant) also appear to reduce capsular contracture with gel implants, but the reduction has been much less dramatic than that seen with PU implants. Contoured (anatomical) shaping appears to have advantages in some patients with gel implants. No such advantage has been seen for texturing or shaping with saline-filled implants. The story of gel implants has culminated in the largest class action lawsuit in medical history, with US$4.2 billion being awarded to women with silicone gel implants. During the past decade, there has been a tremendous amount of research on the reaction of a woman's body to gel implants. A plethora of studies have demonstrated that silicone gel implants are not associated with the development of any medical diseases. Silicone gel-filled implants have therefore been approved for use under Health Canada's Special Access Program. Silicone gel-filled implants may now be used in certain patients in whom they would provide advantages over saline implants. Silicone gel implants have not been approved for unrestricted general use. The evolution of breast implants occupies the past half century. It has been a stormy course, with many exciting advances and many bitter disappointments. The universe of breast implants is large and the variation among the implants is substantial. The purpose of the present review is to trace the evolution of breast implants over the past 50 years.

Calcinosis cutis long after rhinoplasty with silicone

Rhinoplasty is a plastic surgery procedure to reconstruct the nose. Silicone alloplastic materials are most widely used as implants for rhinoplasty, but calcification on the surface occurs with long-term usage. Herein, we report a case of gruel-like calcification approximately 50 years after silicone implant rhinoplasty. In this case, calcification on the silicone surface might have transformed into gruel-like deposits, which presented as a subcutaneous mass at the dorsal area of the nose. The precise mechanism is unclear; a pH change in the tissue might have occurred during the process of inflammation, leading to the dissolution of calcified deposits.

The association of matrix Gla protein isomers with calcification in capsules surrounding silicone breast implants

Implanted silicone medical prostheses induce a dynamic sequence of histologic events in adjacent tissue resulting in the formation of a fibrotic peri-prosthetic capsule. In some cases, capsular calcification occurs, requiring surgical intervention. In this study we investigated capsules from silicone gel-filled breast prostheses to test the hypothesis that this calcification might be regulated by the small vitamin K-dependent protein, matrix Gla protein (MGP), a potent inhibitor of arterial calcification, or by Fetuin-A, a hepatocyte-derived glycoprotein also implicated as a regulator of pathologic calcification. Immunolocalization studies of explanted capsular tissue, using conformation-specific antibodies, identified the mineralization-protective γ-carboxylated MGP isomer (cMGP) within cells of uncalcified capsules, whereas the non-functional undercarboxylated isomer (uMGP) was typically absent. Both were upregulated in calcific capsules and co-localized with mineral plaque and adjacent fibers. Synovial-like metaplasia was present in one uncalcified capsule in which MGP species were differentially localized within the pseudosynovium. Fetuin-A was localized to cells within uncalcified capsules and to mineral deposits within calcific capsules. The osteoinductive cytokine bone morphogenic protein-2 localized to collagen fibers in uncalcified capsules. These findings demonstrate that MGP, in its vitamin K-activated conformer, may represent a pharmacological target to sustain the health of the peri-prosthetic tissue which encapsulates silicone breast implants as well as other implanted silicone medical devices.

Pathological calcification and replicating calcifying-nanoparticles: general approach and correlation

Calcification, a phenomenon often regarded by pathologists little more than evidence of cell death, is becoming recognized to be important in the dynamics of a variety of diseases from which millions of beings suffer in all ages. In calcification, all that is needed for crystal formation to start is nidi (nuclei) and an environment of available dissolved components at or near saturation concentrations, along with the absence of inhibitors for crystal formation. Calcifying nanoparticles (CNP) are the first calcium phosphate mineral containing particles isolated from human blood and were detected in numerous pathologic calcification related diseases. Controversy and critical role of CNP as nidi and triggering factor in human pathologic calcification are discussed.

Silsesquioxane nanocomposites as tissue implants

BACKGROUND

Silicone implants are being used increasingly worldwide, especially in breast augmentation procedures. The most common morbidity observed is capsular contracture, which occurs in 15 percent of cases. To overcome this problem, the authors have developed a novel nanocomposite based on polyhedral oligomeric silsesquioxane-poly(carbonate-urea)urethane (POSS-PCU) for use as tissue implants.

METHODS

These polymers were implanted in six healthy sheep (n = 6) for 36 months and a siloxane served as the positive control. After explantation, these polymers were extracted, as was the surrounding capsule, if any. Attenuated total reflectance Fourier transform infrared spectroscopy analysis was performed to look for signs of surface degradation on the polymers and histopathologic and electron microscopic examinations were performed to study the interaction between the biomaterial and the host environment in greater detail.

RESULTS

After implantation, the authors observed minimal inflammation of the nanocomposite within the sheep model as compared with the siloxane control. Contact angle measurements and fibrinogen enzyme-linked immunosorbent assay tests were then conducted on the POSS-PCU nanocomposite to determine the reason for this behavior. The increased fibrinogen adsorption on POSS-PCU, its amphilicity, and large contact-angle hysteresis indicated that POSS-PCU inhibits inflammation by adsorbing and inactivating fibrinogen on its surface. In complete contrast, the control siloxane in the same setting demonstrated very significant inflammation and degradation, resulting in capsular formation. Naturally, there was no evidence of degradation of the nanocomposite compared with the siloxane control.

CONCLUSIONS

POSS-PCU nanocomposites have enhanced interfacial biocompatibility and better biological stability as compared with conventional silicone biomaterials, thus making them safer as tissue implants.

Explantation of 41-Year-Old Implants Following Primary Breast Augmentation

The long-term affects of primary breast augmentation is a topic of controversy. This case report will highlight the long-term outcome in a woman with Ivalon sponge breast implants and the reasons for explantation. The focus of the manuscript will include mammography, capsular contracture, and late hematoma.

Autoinflation of saline-filled inflatable breast implants

Spontaneous autoinflation of saline-filled breast implants is a rare phenomenon; only 20 cases have been reported in the world literature. Over the past seven years, three patients have presented with significant unilateral autoinflation of their smooth, single-lumen, round, saline-filled implants. This developed at various times: progressively over 23 years with a Simaplast implant; between the ninth and 10th year after augmentation with a leaflet valve implant; and slowly over the first four years with a leaflet valve implant. The etiology of the autoinflation was shown to be different for the two types of implants. The Simaplast implant had likely been injected with a hypertonic filling solution - one that was twice as concentrated as 'normal saline'. This would have created an osmotic gradient, which would have facilitated autoexpansion by diffusion. The implant solution remained clear and transparent. In addition, there were no detectable levels of glucose, uric acid or albumin in the fluid. By contrast, auto-inflation of the leaflet valve implants likely resulted from mechanical alterations of the valve mechanism. This type of implant is known to have a high deflation rate, with frequent partial deflations. It is interesting that one of the patients with the leaflet valve implants presented with an autoexpansion on one side and a partial deflation on the other side. Both implants were from the same lot number. The same mechanism that caused partial deflations may have also allowed fluid from the implant pocket to pass through the valve into the lumen of these implants. This could allow glucose, protein and cellular elements to enter into the lumen (these would not pass through an intact elastomeric shell) which would create an osmotic gradient, allowing water to enter the elastomeric shell by diffusion. The fluid in these leaflet valve implants was brownish yellow, very viscous and turbid. It contained elevated levels of glucose and uric acid which would not have passed through the elastomeric shell. Over the past 10 years, four different theories have been proposed in an attempt to explain the etiology of autoinflation. However, the findings of the present study indicate that there are only two mechanisms - a hypertonic filling solution and alterations of the valve mechanism.

Mineralization followup with the use of NMR spectroscopy and others

High-resolution solid state NMR spectroscopy appears to be a powerful method for a better understanding of bone structures and bone substitutes and implants. It is particularly efficient to estimate osteoformation via bioceramic bone colonization. Pathological calcification occurring in bioprosthetic heart valves and breast prostheses can be characterized as a complement to X-ray spectrometry.

Histological analysis of silicone breast implant capsules and correlation with capsular contracture

BACKGROUND

A study was undertaken to investigate long-term histological changes in the environment of breast implants and their correlation with complains at the time of capsular contracture defined by the Baker score.

METHOD

The collagenous capsules of 53 silicone breast implants from 43 patients (23 smooth and 30 textured devices) were evaluated histologically for capsular thickness, the presence of histiocytes, the amount of silicone and calcification in the capsule, and the presence of synovial-like metaplasia of the inner surface of the capsule with light microscopy and polarised light. All parameters were correlated with the Baker score.

RESULTS

A significantly higher degree of the Baker score was found with increasing patient age (p<0.001), implant duration (p<0.02), and capsular thickness (p<0.009). A trend towards greater capsular thickness was documented in patients who had a breast augmentation for cosmetic reasons. Synovial-like metaplasia was seen in 28 capsules (52.8%). The highest incidence was found in textured implants with a duration of less than 5 years. Histiocytic inflammation was more common in patients with clinical symptoms (p<0.001) and around subglandular implants (p<0.096).

CONCLUSIONS

The histological findings of breast capsules were related to: the nature of the device surface (smooth versus textured), implant duration, and the degree of capsular contracture. Capsular contracture (Baker score of 3 or 4) was related to implant duration, capsule thickness, patient age, and inflammation.

Survival properties of third-generation silicone gel breast implants

From 1992 through 2001, 100 third-generation silicone gel breast implants were removed from 50 women who had undergone cosmetic breast augmentation. The main reasons for explantation were: ptosis in 16 patients (32%); to further increase implant size in 15 patients (30%); suspected silicone-related health problems in 11 patients (22%); medical disease in five patients (10%); and breast firmness and pain in three patients (6%). Of the 100 third-generation gel implants, 42 were manufactured by McGhan Medical, 38 by Surgitek, 10 by Cox-Uphoff and 10 by Dow Corning. The 42 McGhan implants had been in place for two to 15 years (mean 8.8 years), the 10 Cox-Uphoff implants for seven to 14 years (mean 9.4 years), and the 10 Dow Corning implants for five to 12 years (mean 8.1 years). All the McGhan, Cox-Uphoff and Dow Corning implants were clinically intact at explantation. By contrast, of the 38 Surgitek third-generation implants, which had been in place for three to 13 years (mean 7.9 years), only 28 were intact. Ten (26%) had already disrupted. A comparison of Kaplan-Meier survival curves indicated that the 62 third-generation gel implants manufactured by McGhan, Cox-Uphoff and Dow Corning were much more durable than 271 previously explanted second-generation gel implants. By contrast, the 38 third-generation Surgitek gel implants were less durable than the 271 second-generation implants.