Are triglyceride breast implants really biocompatible?

Breast implant surface development: perspectives on development and manufacture

Capsular contracture poses a significant clinical and scientific research challenge for breast surgeons. Some researchers have pointed to the surface features of implant devices as being responsible for the potential tightening and hardening of the surrounding capsule. In this article, the authors review the history and development of breast implant design, specifically the data supporting improvements that have potential to mitigate the incidence of capsular contracture. The literature suggests that development of new implant surfaces designed to reduce a patient's foreign body response will improve the safety profile of implant devices and increase patient satisfaction in the long-term.

Post-mastectomy breast reconstruction: a history in evolution

Although the need for mastectomy has been evident for many years, postmastectomy reconstruction has been recognized as an achievable outcome for only a little over a century. A review of the evolution of both autologous and prosthetic options for reconstruction was undertaken. The earliest attempts at reconstruction used autologous techniques that were either unsuccessful, not reproducible, or were associated with significant morbidity. Prosthetic techniques became sought after, with silicone prostheses widely used until concerns about potential adverse effects led to the investigation of alternate options. With these concerns shown to be unfounded, silicone and saline prostheses evolved with successive generations of implants. Concurrent advances in reconstructive surgery led to a revival in autologous techniques for breast reconstruction, with microsurgical free-tissue transfer potentiating a new range of potential donor sites. The abdominal wall became the donor site of choice, and with the advent of perforator flaps, morbidity associated with flap harvest was minimized. In cases where the abdominal wall is unsuitable, flaps such as the superior and inferior gluteal artery perforator flaps, the musculocutaneous gracilis flap, and the "stacked" deep inferior epigastric artery perforator flap are frequently used options. The development of minimally invasive techniques for implant placement and flap harvest, such as endoscopy, continue to evolve, and research in tissue engineering offers a vision for a future without the need for a donor site.

Possible future development of implants and breast augmentation

Since the introduction of the silicone gel prosthesis in 1962, breast augmentation has become one of the most frequently performed operations in plastic surgery. As we strive for perfect results, it is important to continue to gather and review data evaluating innovative techniques and devices. Now we even have more options available for breast augmentation, whether we use them in combination or alone. By combining all of the available options (acellular dermal matrix products, silicone implant, fat grafting), we have been able to create "bioengineered breasts" with high patient and surgeon satisfaction. As always in plastic surgery, our concern is with safety; as newer technology and products are introduced to us, patient education, consent, and follow-up remain important.

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.

Trilucent breast implants: five years' experience from an Italian perspective

In June 2000 the Medical Devices Agency (MDA) issued a Hazard Notice recommending the explantation of Trilucent breast implants (TBP) as a precautionary measure. Following that recommendation, we reviewed our series of 52 patients (71 implants) operated on from 1994 to 1998 to recall and advise those still harboring TBP. We have analyzed all the recorded adverse events in our setting before June 2000 to estimate the adverse reaction frequency and their time relation (review series). We have also recorded the rate of preoperative symptoms and postoperative findings in 23 patients (29 implants) who underwent explantation after the MDA recommendation (explantation series). In addition, some histologic observations have been made. The rates of significant capsular contracture (Baker 3-4) and explantations were estimated using the Kaplan-Meier method of survival analysis, and the rates of wrinkling and palpability were compared at 1 and 5 years of follow-up. Overall, the rate of grade 3-4 capsular contracture was approximately 45% at 6 years of follow-up with no statistically significant difference among the reconstruction and augmentation groups. The analysis of survival curves showed an overall rate of approximately 55% of explantations at 6 years. Preoperatively, capsular contracture and volume modifications were the most frequent findings in the explantation series. Postoperatively, most implants opposed inadequate resistance to the operative stress and ruptured, showing a creamy content. Free oil has never been found in tissue surrounding the periprosthetic capsule. In conclusion, it appears that the TBP-claimed advantages over other available implants seem to be inconsistent and the MDA advice appropriate. The problems related to these implants have had a great impact on public opinion in Europe and have contributed to the implementation of the conformity assessment procedures to be followed for medical devices: on the 4th February 2003 breast implants were in fact reclassified as class 3 products, in order to provide the best guarantee for health protection. The publication of a communication by the European Parliament in November 2001 gives us hope for the future.

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.

Observations on a consecutive series of patients who have had Trilucent breast implants removed as recommended by the MDA Hazard Notice (May 2000)

A prospective study of 25 female cosmetic-surgery patients who had a total of 50 Trilucent breast implants forms the basis of this paper. All but one patient elected to have new implants, of which all but three patients had silicone implants (the others selected glucose saline implants). The Trilucent implants were more difficult to remove than expected because of a 'Velcro-like' attachment to the internal surface of their capsules. As a result, several implants were ruptured on removal (though none were ruptured on initial exposure). The sites of rupture suggest a structural weakness, possibly related to the microchip panel or folds in the implant shell. Varying degrees of encrustation of the implants and internal capsules were found, which did not appear to be related to the duration of implantation. Histological studies of the capsule changes generally showed lipids and giant cell infiltrations. It would seem that, contrary to expectations, leaking of the filler occurs early and is associated with varying degrees of cellular reactions. The adherence problem appears to be related to the amount and distribution of the leaked material. Only three patients in this series had problems with their Trilucent implants that required additional surgery. One of these remains a significant and unsolved problem.