The Evolution of Breast Implants

Abstract

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.

Autoinflation of Saline-Filled Inflatable Breast Implants

“…Introducing a metal catheter into the leaflet valve mechanism fills this type of implant. These particular implants, like all other leaflet valve saline implants, are now known to have a high deflation rate (19)(20)(21). Similar high deflation rates have also been found among leaflet valve saline-filled implants that were made by other manufacturers, including Dow Corning Corporation (USA) and McGhan, INAMED Aesthetics (USA) (19,20).…”

“…These particular implants, like all other leaflet valve saline implants, are now known to have a high deflation rate (19)(20)(21). Similar high deflation rates have also been found among leaflet valve saline-filled implants that were made by other manufacturers, including Dow Corning Corporation (USA) and McGhan, INAMED Aesthetics (USA) (19,20). The failure of these leaflet valve saline-filled implants was likely due to a faulty valve mechanism, possibly secondary to fibrous tissue growing into the leaflet valve (19,21).…”

The Medical Devices Special Access Program in Canada: A Scoping Study

“…Many authors indicated that patient eligibility was dependent upon the clinical indication ( Amat-Santos et al 2015 ; Basmadjian et al 2016 ; Campelo-Parada et al 2016 ; Chu et al 2016 ; de Varennes et al 2016 ; Gonzalez-Barlatay et al 2017 ; Peters 2002 ; Rodés-Cabau et al 2010; Sapp et al 2013 ; Saw et al 2015 , 2017 ; Webb et al 2006 ). Peters (2002) explained that MDSAP “provides approval for the use of silicone gel implants for the following patients: mastectomy, augmentation after failed saline implants (usually with ripples and folds) and primary augmentation if a saline failure is strongly predicted. Health Canada has not approved the use of gel implants for general use.” More recently, de Varennes et al (2016) reported that “These cases were not ‘run-of-the-mill’ AVRs [aortic valve replacements].…”

“…The MDSAP approves the use of unlicensed alternatives to licensed medical devices when they are perceived to be clinically superior ( Almashham et al 2008 ; Abraham et al 2012 ; Bagur et al 2016 ; Campelo-Parada et al 2016 ; Humpl et al 2010 ; Nietlispach et al 2010 ; Raymond et al 2001 ; Regueiro et al 2017 ; Ricci et al 2017 ; Saw et al 2017 ). Peters' (2002) review of breast implants noted the availability of two types of implants: saline-filled (comprising 95% of implants), which were licensed, and gel-filled (5%), which, at the time, were unlicensed. Gel-filled implants were being used for “patients with exceptional circumstances, who received approval on compassionate grounds, because the quality of their final results would be more compromised with saline implants … than with gel implants.”…”

Silicone Granulomas of the Eyelids—A Case Series Illustrating a Distant Migratory Phenomenon

“…First-generation silicone gel implants entered the market in 1964 and were composed of a thick rubber-like silicone elastomer envelope filled with a silicone-based gel and led to abnormal firmness and high rates of capsular contracture and calcifications. 25,26 Second generation implants in the 1970s to 1980s 27 featured thinner shells and a less viscous gel but had higher rates of rupture 25,27,28 and diffusion of silicone through the shell, a phenomena known as “bleeding.” Given safety concerns, silicone breast implants were pulled from the United States market from 1992 until 2006, after which third generation implants helped minimize these deleterious effects with a thicker or multilayered shell and a more cohesive gel composed of larger silicone particles. Fourth and fifth generation implants with even higher cohesion are currently used in the United States.…”