Bleed of and biologic response to triglyceride filler used in radiolucent breast implants

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.

Prospective Study on Trilucent Soybean Oil-Filled Breast Prosthesis

BACKGROUND

The use of Trilucent breast implants dates back to 1995. These implants were produced in an attempt to overcome the perceived shortcomings of other implants filled with saline and silicone gel. The filler material, which was derived from soybean oil, was said to be biodegradable and biocompatible. When this prosthesis was subsequently found to be prone to rapid aging and rupture of the silicone shell, the company that manufactured this implant decided to withdraw it from the market and offered to remove or replace all Trilucent prostheses.

METHODS

The authors present a clinical study of the Trilucent implant in which 36 patients received a total of 63 implants and 33 patients had 58 implants removed. The authors also examined the implant shell of the removed prostheses to investigate the possible cause of silicone implant aging and rupture.

RESULTS

Each of the implants removed was carefully inspected visually, and samples of the implant shell were analyzed by scanning electron microscopy. All the implants removed had a very bizarre appearance; they were variegated in color, with shades of yellow and brown, and were studded with whitish yellow nodules whose number grew in proportion to the time the prosthesis was implanted. Scanning electron microscopic analysis of the implant shell revealed a heterogeneous inner surface of the implant together with fissures and globoid deposits on the cut surface.

CONCLUSIONS

The authors' findings on Trilucent implants are similar to those reported in previously published studies for other types of breast implants for the first 2 years after implantation, after which a progressive, rapid deterioration was observed.

Trilucent Breast Implants: Voluntary Removal following the Medical Device Agency Recommendation. Report on 115 Consecutive Patients

In June of 2000, the U.K. Medical Device Agency recommended the removal of Trilucent implants as a precautionary maneuver in response to reports of local inflammatory reactions. This decision allowed the authors to operate on 115 consecutive patients between June of 2000 and January of 2001. On the preoperative examination, the authors found a very high incidence of rippling (66 percent), whereas capsular contracture was seen in only three patients (2.6 percent). Rippling was significantly more common in patients with subglandular implants. Five implants were found ruptured during the operation. This figure, together with the relative ease of implant breakage at removal, shows a premature deterioration of the implant shell. The authors also comment on implant bleeding, which seems common in this type of breast implant. The authors think that this is a possible cause for the rippling phenomenon, resulting from a reduction of the implant content. On the basis of these findings, the authors conclude that Trilucent implants are associated with a poor cosmetic outcome and a high rate of complications.

What Exactly Was Wrong with the Trilucent Breast Implants? A Unifying Hypothesis

Trilucent soybean oil-filled breast implants were initially announced as the ultimate prostheses for breast augmentation. However, after an increasing number of reports of local complications and hazardous metabolites attributable to lipid oxidation, first the United Kingdom Medical Devices Agency and later the Belgian National Ministry of Health urged all plastic surgeons to contact their patients and advise them to have the implants removed and, if desired, replaced with another type of prosthesis. In our plastic surgery department, 13 patients received bilateral implants with triglyceride-filled prostheses between February and July of 1996, for primary breast augmentation or replacement of previously implanted prostheses. For 12 of those 13 patients, the prostheses have been explanted, because of unilateral breast enlargement attributable to a ruptured prosthesis for five patients and following the recommendation of the Belgian National Ministry of Health for the other seven patients. Before explantation, all patients underwent standard clinical examinations, with assessments of breast shape, volume, and firmness. Blood analyses were performed, with a special focus on liver enzymes, as were urinalyses. Magnetic resonance imaging scans were obtained before explantation; for two patients, the scans revealed a fluid level separating two liquid layers in an intact prosthesis. This is the first report of such a finding. The removed implants were examined for any damage or shell deterioration and for changes in color and viscosity, the weights and volumes were measured and compared with the initial values for the implanted prostheses, and complete biochemical analyses of the accumulated fluid in cases of ruptured prostheses and of the filler material in cases of intact prostheses were performed. This small but well-documented series illustrates the multitude of problems associated with triglyceride-filled implants, including bleeding of the triglyceride filler; shell deterioration, as indicated by a loss of texture and extreme fragility of the implant (with rupture or delamination with a simple finger touch); an increase in osmotic pressure exerted by the degraded filler material; progressive weakening of the outer silicone shell, with influx of plasma proteins of up to 750 kDa, eventually resulting in rupture of the prosthesis; a lack of oxidative stability and the formation of toxic oxidation products; a lack of biocompatibility, with the formation of insoluble organic soap-like material; and a pronounced inflammatory reaction. It is concluded that the sequential and/or simultaneous occurrence of (1) implant bleeding, (2) lipid infiltration of the silicone elastomer, and (3) inflammation attributable to oxidation products provides an overall explanation or unifying hypothesis for the wide variety of adverse events related to soybean oil-filled implants.

Lay experts and the politics of breast implants

This paper discusses the controversy around breast implants in the United States and Europe. It focuses on the emergence of consumer and support groups for women and offers an analysis of the role they have played in recent policy developments in UK and Europe. The politics of breast implants is seen as a politics of knowledge in which scientific expertise has consistently been deployed in ways that minimize the credibility and legitimacy of women's accounts of their bodies and illness experiences. These women have been doubly disadvantaged in a policy debate that turns on scientific controversy and uncertainty. This implies a gendered dynamic to the changing relations of knowledge and expertise. The paper contributes to an understanding of the relations between regulators, manufacturers, users, and clinicians in the global medical device industry and to wider debates around the public understanding of science.

Breast augmentation with bilateral deepithelialized TRAM flaps: an alternative approach to breast augmentation with autologous tissue

Since the 1980s, many patients have benefited from the use of the transverse rectus abdominis musculocutaneous (TRAM) flap for postmastectomy reconstruction. In addition to cancer reconstruction, this technique has recently been used to treat patients with breast implant intolerance and for reconstruction after siliconoma resection. However, physicians and patients alike believe that such an extensive procedure should not be used for aesthetic purposes, and to the authors' knowledge, no study has been reported on the use of pedicled TRAM flaps for aesthetic augmentation mammaplasty. In the past several years, a number of the authors' patients have requested simultaneous breast augmentation and abdominoplasty. These patients objected to the use of prosthetic implants because of potential complications such as implant failure, capsular contracture, wrinkling, and palpability. Therefore, from 1995 to 2000, the authors performed 14 cases of bilateral breast augmentation with deepithelialized, pedicled TRAM flaps. In this series, the donor-site complication rate was similar to that of the traditional TRAM flap. Surprisingly, no cases of complete or partial flap loss were clinically detected. The only complaints were pedicle bulges at the costal margins. These patients were all extremely satisfied with the results. It was concluded that the TRAM flap is safe for augmentation in a subset of carefully selected women with hypoplastic or atrophic breasts. The authors discuss patient selection, technique, and their experience with this method of breast augmentation.

The history of Trilucent implants, and a chemical analysis of the triglyceride filler in 51 consecutively removed Trilucent breast prostheses

This study set out to detect specific classes of potentially genotoxic aldehydes resulting from soybean-oil peroxidation in oil samples from 51 Trilucent implants in 26 patients and two factory-retained prostheses. The chemical analysis was performed independently of AEI inc. All of the implants showed evidence of shell deterioration suggestive of lipid absorption, and of lipid bleed throughout the implant shell. The mean implant weight loss was found to be almost 2% per year. Although none of the implants had actually ruptured in-situ, we identified specific problems with anterior and posterior patch delaminations, making the implant prone to rupture. Our data suggest that the soybean oil in all the explanted Trilucent implants and the two factory-retained prostheses had undergone peroxidation, yielding aldehyde by-products in millimolar concentrations. These concentrations are over 1000 times that thought to be potentially genotoxic. The clinical implications of these findings remain unclear. Capsular tissue was submitted to AEI Inc for histological and chemical analysis, but the data have not been forthcoming, which is disappointing as this may provide further evidence for the risks of long-term complications in these patients.

Experience of explantation of Trilucent breast implants

On 6 June 2000, the Medical Devices Agency (MDA) recommended that all Trilucent (soya-bean-oil filled) breast implants should be removed. This accelerated a trend that had already begun in our unit. This study follows our previous report on a 3 year series of women with Trilucent breast implants. The aim was to present our operative findings at explantation, and to correlate them with the preoperative signs and symptoms, the postoperative complications and the details of the hospital stay. In total, 44 patients (82 implants) underwent explantation, of whom 34 were cosmetic cases and 10 were reconstructive. Five patients had their implants removed before the MDA announcement. Implant rippling was the most common problem reported (25%), followed by pain (18%), implant deflation (9.1%) and capsular contracture (4.5%). Free oil was seen around the implant in 15 cases; four of these presented with clinical deflation, and three with rippling. The remaining eight patients were asymptomatic. We conclude that these implants tend to bleed, as evidenced by the presence of free oil around the implant in 34% of patients. The absence of free oil in 73% of the patients who presented with rippling suggests that the leaking oil is often metabolised and absorbed. The findings of this study are significant for women in whom free oil was found around the implant during explantation, and for those who still have Trilucent implants in place, for whatever reason, in spite of the MDA recommendation.

Histological examination of the capsules surrounding Trilucent breast implants

Following a statement by the UK Medical Devices Agency (MDA), soya-oil-filled Trilucent implants for breast augmentation were withdrawn from sale in March 1999. The most recent report on the toxicity of the Trilucent implant suggests that one of the breakdown products of the filler is an aldehyde with an explicit risk of genotoxic and teratogenic effects. Explantation of all these prostheses was advised by the MDA in June 2000. No guidance regarding capsulectomy was put forward by any publication. The operation of capsulectomy confers an increased morbidity compared with simple prosthetic replacement. This study looks at the capsules of 18 consecutive patients who had received Trilucent implants for cosmetic breast augmentation, and who had undergone explantation and capsulectomy. The mean duration of implantation was 3 years (range: 2 years to 4 years 9 months). The capsules were examined histologically. The significant features of all the capsules included a florid foreign-body type reaction, synovial metaplasia, a villous hyperplasia and the presence of refractile material within the substance of the capsule. It is postulated that the refractile material is filler material that has bled through the wall of the intact Trilucent implant, and as such would represent a potential genotoxic hazard. Until such time as this potential hazard has been investigated fully and a conclusion reached, we recommend acceptance of the increased morbidity, and the performance of capsulectomies when explanting Trilucent implants.

Trilucent breast implants: a 3 year series

The use of Trilucent breast implants in the UK dates back to 1995 and their introduction coincided with the medium-term effects of the silicone-implant controversy. We present a review of 3 years' experience of the Trilucent implant (1996-1998) during which 29 patients with a mean age of 39.4 years had a total of 50 implants. The aim of the study was to analyse the results in these patients in terms of complications, reoperation rate and patient satisfaction. Using a combination of retrospective chart analysis and postal survey, we found an incidence of implant deflation of 10% (5/50). The overall reoperation rate was 20% (10/50). The postal survey yielded a mean satisfaction score of 7.1 (on a scale of 0-10) from the 20 respondents out of the 29 patients (68.9%). In view of the high complication rate, we discontinued the use of Trilucent implants in advance of their withdrawal by the Medical Devices Agency (MDA) in March 1999. However, these findings may now be considered of added interest, particularly with regard to patients who are opting to keep their Trilucent implants despite the recommendation of the MDA in June 2000 that such implants should be removed.

Patient satisfaction with Trilucent breast implants

We report our findings in a retrospective study of patient satisfaction with soybean oil-filled mammary implants. Sixty-two women who had breast augmentation with Trilucent breast implants were sent a questionnaire to assess their satisfaction with implant placement; 19 of the 62 attended for clinical examination. Overall satisfaction with triglyceride implant placement was high: very pleased 45% (18/40), pleased 32.5% (13/40), content 12.5% (5/40). The majority of women felt that it had enhanced their body image and lifestyle (82.5%).

Local tissue reactions to oil-based breast implant bleed

We present two cases (three implants) of symptomatic local tissue reactions to Trilucent breast implant bleeds. The implant shells had changed their colour and texture. Capsule histology showed foreign body reaction and inflammatory changes. These findings question the safety of these implants.

Breast implant classification with MR imaging correlation: (CME available on RSNA link)

Rupture is now recognized as an important and common complication of breast implants. Magnetic resonance (MR) imaging is the most accurate method for evaluating implant integrity but requires an understanding of the numerous variations in implant construction that are encountered clinically. To assist in diagnosis, the authors provide an MR-oriented breast implant classification scheme based on data from 4,014 patients (>9,966 current or previous implants), the literature, and other primary documentation. This scheme consists of 14 implant types: 1) single-lumen silicone gel-filled, 2) single-lumen gel-saline adjustable, 3) single-lumen saline-, dextran-, or polyvinyl pyrrolodone-filled, 4) standard double-lumen, 5) reverse double-lumen, 6) reverse-adjustable double-lumen, 7) gel-gel double-lumen, 8) triple-lumen, 9) Cavon "cast gel", 10) custom, 11) solid pectus, 12) sponge (simple or compound), 13) sponge (adjustable), and 14) other. The MR imaging and mammographic appearance of many implant types is correlated with their actual appearance after explantation. A brief history of prosthetic breast augmentation and reconstruction is also provided to allow this classification method to be placed in historical perspective. Knowledge of the variety of breast implant types will help reduce misdiagnoses by providing imagers with better understanding of the expected appearances of breast implants. This classification scheme will allow stratification of data for studying incidence, prevalence, and risk factors for and causes of implant failure, as well as permitting better correlation with patient symptoms and surgical outcome.