Implants breast

Siheone has been shown to have excellent biocompatibility, hemocompatibihty and desired permeability properties. These properties make it ideal for use as silicone tubing and membranes used in kidney dialysis and heart bypass machines with high oxygen diffusivity and ions. It has also found application in several mechanical heart valves. 

According to the American Society of Plastic Surgeons National Clearinghouse of Plastic Surgery Procedural Statistics, there were 296,203 breast augmentation procedures and 93,083 breast reconstruction procedures performed in the United States in 2010 [ 14]. Approximately half the procedures used saline-filled implants and half used silicone gel-filled implants. The history of breast implants has been very dynamic since its introduction in 1895, and the acceptance level in society has varied with influences from the media and regulatory bodies [15]. There are two main types of breast implants 1) non-silicone shell materials, or 2) silicone elastomer shells filled with either a) silicone gel or b) saline. The historical use of these implants is described below. 

Vincenz Czerny reportedly performed the first augmentation mammoplasty in 1895 using a benign lipoma taken from patients hip. In the early and mid-20th century, many different materials were used for implantation or injection into the breast of patients including paraffin, petroleum jelly, ground rubber and silicone oils. Most of the prehminary 

2 Silicone Elastomer Shells with Silicone Gel or Saline 

In 1962, Cronin and Gerow implanted silicone shells into dogs, which was a significant change in breast augmentation. The breast implant was crosslinked and reinforced silicone rubber shell that encapsulated a silicone gel or saline solution. The silicone gel comprised crosslinked silicone elastomer, mainly PDMS and a low molecular weight silicone fluid (also PDMS). There were many variations in the PDMS functionalities by different manufacturers to attain desired gel properties. Saline-filled implants were first manufactured as Simaplast in 1965 but did not have the same confluence due to the water-like viscosity of saline as compared to a more viscous gel. 

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Silicone mbbers have been widely used for medical applications, particularly for body implants in structural cosmetic surgery. One high-profile application has been that of breast implants, but the award in early 1994 of enormous damages by a US court in respect of faulty implants may discourage development of this application. 

EC Reclassifies breast implants as Class 111 devices by way of derogation from the general classification rules... 

Garrido, L. and Young, V.L. Analysis of periprosthetic capsular tissue from women with silicone breast implants by magic-angle spinning NMR, Magn. Res. Med., 42, 436, 1999. 

Siggelkow, W. et al. In vitro analysis of modified surfaces of silicone breast implants. Inti. J. Artif. Org., 27, 1100, 2004. 

Peters, W. et al. Calcification properties of saline-filled breast implants. Blast. Reconstr. Surg., 107, 356, 2001. 

Draft Guidance for Industry and FDA Staff Saline, Silicone Gel and Alternative Breast Implants. Washington DC, January 13, 2004. 

Center for Veterinary Medicine FDA Bioengineered food FDA Breast Implants... 

From the large number of papers dealing with silicone-based breast implants, a well-referenced review on the scientific considerations regarding a silicone syndrome, 531 supplemented with a few other recent papers, can... 

The first ever injectable crude biomaterial, that is a dental implant, appeared early in ad 6oo (Fig. 12.1). During those times, Mayan people trimmed seashells into artificial teeth to replace missing teeth (Michael, 2006 Ratner et al., 2004). Early biomaterials also led to problems, including sterilization, toxicity, inflammation, and immunological issues. Since the Mayan s initial use of artificial teeth, biomaterials have evolved to be used in modem artificial hearts, hip and knee pros-theses, artificial kidneys, and breast implants. Materials used in these applications include titanium, silicons, polyurethanes, teflon, polybiodegradable polymers, and most recently bio-nanomaterials (Pearce et al., 2007)... 

Over the past several decades, there has been some concern over the potential hazards and safety of the cosmetic use of silicone body implants—breast implants, in particular. Several manufactures have been sued over the failure of the implants, and the federal government... 

Use Safety caps on medicine bottles White paint from lead oxide to titanium oxide breast implants from silicone oil to salt water... 

Silicone oils have very desirable visco-elastic properties, and are very stable. They have been used for many years for breast implants, as a cosmetic to improve appearance. There are many lawsuits charging that silicone oil can leak out of the containing sacks and cause adverse physiological reactions. The current customers either abandon the breast implant or use salt water implants, which do not have the same desirable viscoelastic properties. 

On the other hand, silicone s reputation nosedived when Dow Coming, the major manufacturer, was forced to hand out billions of dollars of compensation in response to lawsuits claiming that leakage of silicone breast implants had damaged the health of many women. These implants contain silicone oil within a sac of rabbeiy silicone. The charge was that silicone had led to autoimmune diseases in implantees. There is still no clear evidence that the compound is harmful in any way, but nevertheless in 1992 a moratorium was imposed in the USA on its use for implants. 

Many women who have received silicone-fluid-filled breast implants have claimed to suffer from implant-related diseases, apparently caused by small leakages of the fluid into the body tissue. Successful lawsuits on those grounds in the United States have driven Dow Corning, the principal manufacturer of the implants, to file for bankruptcy protection. Food and Drug Administration Commissioner David A. Kessler, however, has reported to a congressional subcommittee that, as of July, 1995, there was no scientific evidence that silicone implants are a significant cause of disease. See M. S. Reisch and R. L. Rawls, Silicone gel breast implants. Chem. Eng. News, December 11, 10-17 (1995). 

This subject was studied in relation to the silicone breast implant controversy of the 1990s. Silicone-fiUed artificial breasts were coated with thin layers of a TDI-based polyurethane foam to encourage stabilization by cell ingrowth. Residual toluene diamine (TDA) was found in prepolymer-based polyurethanes at the part-per-biUion level and, more importantly, hydrolysis that would lead to the release of more TDA in vivo was suspected. 

MEASURING SILICONES LEAKING FROM BREAST IMPLANTS... 

Selected ion monitoring gas chromatogram of plasma extract showing traces of siloxanes 5 years after 5-year-old breast implants were removed. [From D Flassbeck. B. Pffeiderer, R. Grumping, and A. V. Hirner,... 

Determination of Low Molecular Weight Silicones In Women After Exposure to Breast Implants by GC/MS,"... 

High-molecular-mass poly(dimethylsiloxane), [(CH3)2SiO] , is used as a stationary phase in gas chromatography (Table 24-1) and as the gel in breast implants. Approximately 1-2% of silicones in breast implants are low-molecular-mass materials that can leak from intact implants and travel through the circulatory and lymph systems to take up residence in lipid-rich tissues. 

BPE, and chiral bisphosphane ligands, 10, 7 (+)-Brasilenyne, via ring-closing diene metathesis, 11, 221 Breast implants, silicone applications, 3, 680 Brevetoxin B, via ring-closing diene metathesis, 11, 237 m -Brevicomin, synthesis, 9, 13... 

Smith HR. Do silicone breast implants cause autoimmune rheumatic diseases Journal of Biomaterials Science, Polymer Edition 1995, 7, 115-121. 

Silicon (Si) Silicon is a lustrous silvery gray material. Because silicon conducts electricity, but not as well as a metal, silicon is classified as a semimetal. Crystals of pure silicon that have been doped with arsenic or gallium are known as semiconductors and are used to fabricate computer chips. Silicone rubbers are polymers containing silicon, oxygen, and various hydrocarbon groups, and are used in applications ranging from sealants to breast implants. 

Figure 7.10 Images of a section from a worn silicon-breast implant envelope (a) T2-weighted imaged, (b) image of dipolar encoded longitudinal magnetisation...

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