Safety of Silicone Breast Implants (1999) / Chapter Skim
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5 Reoperations and Specific Local and Perioperative Complications
5 Reoperations and Specific Local and Perioperative Complications
Pages 114-178
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From page 114... ...
Local and perioperative complications are important outcomes in their own right, and to the extent that they lead to significant further medical interventions or impair the achievement of expected and desirable results, they are also relevant to implant safety. Five-year reoperative or secondary surgery rates or average number of implants placed per breast or per woman provide approximations of the sum of these complications.
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From page 115... ...
This argues for careful prospective studies as the committee concludes at the end of this section. This chapter addresses the following topics because they have significant effects on implant safety: reoperation or secondary procedures as indicators of overall frequency of local and perioperative complications; aggregate complications in breast reconstruction; aggregate complications in breast augmentation; rupture and deflation; factors contributing to loss of implant shell integrity; detection of gel implant rupture; strength and durability of implant shells; frequency of implant rupture and deflation; description of implant fibrous tissue capsules and contractures; capsular, local breast, and distant tissue exposures to silicone and their complications; frequency of saline implant capsular contracture; barrier implants and contractures; effect of implant surface and contracture; effect of local adrenal steroids and contracture; presence of bacteria around implants, antimicrobial treatment and contracture or other complications; hematomas, their frequency and relationship to contractures; the effect of implant placement on contracture; and other relevant complications includ .
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From page 116... ...
is also reported as a complication, but gel fluid diffusion is intrinsic to the design and physical characteristics of gel-containing implants (see Chapter 3 of this report)
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From page 117... ...
In this cohort, 23% of augmented women and 42.4% of reconstructed women required secondary surgery ranging from explantation to evacuation of hematoma or seroma, to correction of implant placement or contracture, to biopsy during the five-year study period. These are underestimates because implant rupture was diagnosed by physician evaluation; and therefore a number of silent ruptures were likely missed.
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From page 118... ...
reported the results of a survey of 106 women representing 62.9% of a cohort of 167 women who could be located from the original 304 women who had undergone breast augmentation from 1973-1991. Their implants were primarily smooth silicone gel (70.8%)
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From page 119... ...
augmented women who agreed to participate in the study, out of 138 consecutive women with breast implant problems, the average was 3.19 gel implants per woman over an average of 11.9 years (Wells et al., 1995~. In another small cohort (N = 60)
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From page 120... ...
(1985) reported on 85 women undergoing immediate reconstruction after mastectomy with saline and double-lumen implants with
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From page 121... ...
Using expanders and gel implants for immediate and delayed reconstruction, Slavin and Colen (1990) had an overall complication rate of 60% (among them, 15% seromas, 13.3% skin necrosis, 8.8% extrusion, 6.7% infection)
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From page 122... ...
Expanders were mostly replaced by textured saline implants, and follow-up after completion of reconstruction averaged 19 months. There were 14 (8.1%)
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From page 123... ...
reported placing 2,018 saline implants, with 4.2% of patients needing revisions, 1.1% Class III-IV contractures, and 2.3% deflations of all implants, but only 0.56% deflations of recent model Heyer-Schulte inflatables. The follow-up of these implants
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From page 124... ...
SPECIFIC COMPLICATIONS The important events for the safety of breast implantation are those that require significant interventions and seriously detract from the desired cosmetic objective. These include gel implant rupture (especially extracapsular)
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From page 125... ...
In any event, no conclusive evidence was found that these different surgical approaches have significant influences on complications related to the safety of breast implants. Implant Rupture and Deflation All silicone gel implants are subject to the bleed or diffusion of gel fluid composed of relatively low molecular weight linear and cyclic sili
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From page 126... ...
Factors Contributing to Loss of Shell Integrity Silicone gel fluid is regularly found on and outside the shells of gelfilled implants. Implant rupture, a loss of integrity of the implant shell of varying severity, is diagnosed only when silicone gel itself is present outside the implant.
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From page 127... ...
Both of these maneuvers have been associated in some reports with implant rupture or deflation and rarely with other complications such as infection, gel migration, silicone granulomas and exudation of gel from the skin and nipple, or conversion of intra- to extracapsular rupture. During mammography, this is very unusual and rarely, if ever, has been proved conclusively and should not discourage mammographic screening for breast cancer (Addington and Mallin, 1978; Andersen et al., 1989; Apesos and Pope, 1985; Argenta, 1983; Bassett and Brenner, 1992; Beraka, 1995; Brandt et al., 1984; Cocke, 1978; Cohen et al., 1997; De Camara et al., 1993; Edmond and Versaci, 1980; Eisenberg and Bartels, 1977; Eklund, 1990; Feliberti et al., 1977, Goin, 1978; Gruber and Tones, 1981; Hawes, 1990; Huang et al., 1978; Hueston and Hare, 1979; Laughlin et al., 1977; Pay and Kenealy, 1997; Pickford and Webster, 1994; Renfrew et al., 1992; Robinson et al., 1995; Scott et al., 1988; Wilflingseder et al., 1983; Williams, 1991; Zide, 1981~.
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From page 128... ...
of women with contractures, 28% of their series of 482 women who received silicone gel implants between 1973 and 1978. They noted that 18% of women with contractures were satisfied despite contracture and declined further intervention.
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From page 129... ...
For unknown reasons, larger volume changes have been reported to develop over the years in rare cases (Botti et al., 1994; Robinson and Benos, 1997~. Volume changes in intact saline implants might reflect correction of an osmotic imbalance due to variation in human body fluid and saline filler osmolality by movement of water into the implant lumen (Frisch, 1997, 1998~.
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From page 130... ...
Abrasion and compression cause deflation of saline implants in ways similar to their effect on gel implants. However, saline implants lack the solidity and supportiveness of the gel interior and the lubrication of silicone fluid on the shell surface.
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From page 131... ...
The diagnosis of rupture of a gel implant is important because the release of silicone gel and fluid into the tissues may result in local complications. An intracapsular rupture may become extracapsular, and both are generally, but not always (Hardt, IOM Scientific Workshop, 1998)
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From page 132... ...
who noted changes by scanning electron microscopy such as accentuation of defects in the surfaces of saline implants subjected to 3/4pound tension. Although not universally agreed upon, it appears that the elastomer shell is relatively stable in viva once the effects of gel fluid permeation, that can decrease the tensile strength of shells not protected by barriers to gel fluid diffusion by around 30%, are taken into consideration (FDA, 1992a, p.
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From page 133... ...
control gel implants of ages up to 28 years, manufactured primarily by Dow Corning, both as is and after gel fluid extraction. They also reported that gel fluid permeation in viva decreases various parameters of shell strength.
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From page 134... ...
They indicate that rupture will depend on the manufacturer, type and model and even the lot of saline and gel implants, as well as on underlying physical parameters such as designed thickness and chemical formulation. Any analyses of rupture resistance and shell strength or of rupture prevalence in cohorts of women should try to control for these confounding variables.
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From page 135... ...
The medical literature on rupture of gel implants includes reports of prevalence ranging from 0.3 to 77% (Beckman et al., 1997b; Berg et al., 1993, 1995; Chung et al., 1996; Cohen et al., 1997; Davis et al., 1995; De Camara et al., 1993; Destouet et al., 1992; Dowden, 1993; Duffy and Woods, 1994; Gabriel et al., 1997; Gorczyca et al., 1992; Harris et al., 1993; Ko et al., 1996; Malata et al., 1994a; Middleton, 1998b; Nelson, 1981; Netscher et al., 1995a; Park et al., 1996b; Peters et al., 1996; Phillips et al., 1996; Robinson et al., 1995; Rohrich et al., 1998a; Rolland et al., 1989a; Slavin and Goldwyn, 1995; Weizer et al., 1995; Yeoh et al., 1996; Young et al., 1996a, 1998~. These are reports of either the percentage of women who have one or both
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From page 136... ...
(1997) reported their experience with 709 implants in 407 women who responded to a questionnaire mailed to 454 women who had received saline inflatable implants in their two facilities in France and the United States between 1981 and 1995 (489 smooth Mentor and 220 textured Mentor Siltex breast implants)
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From page 137... ...
They commented that their "study confirms the obvious: Inflatable breast implants deflate with time." Rubin (1983) reported his own experience with saline inflatable implants.
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From page 138... ...
The low sensitivity of these detection methods (and, especially for Dow Corning, the short follow-up) inevitably means an underestimate of implant rupture (Bowlin et al., 1998; McGhan Medical Corporation, 1998; Purkait, Mentor Corp, IOM Scientific Workshop, 1998~.
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From page 139... ...
The reported high rupture prevalences cited above reflect experience with a great many thin-shell, compliant gel models according to the dates of explantation from these reports. Clearly it is possible to build an implant of sufficient strength to endure a long time, as the experience with first-generation 1960s thick-shell, thick-gel implants shows (Brandon et al., 1999; Peters et al., 1996~.
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From page 140... ...
Contracture, which is more common in gel implants, may be a risk factor for rupture (Fen", IOM Scientific Workshop, 1998) , although there is insufficient evidence for this (Lantieri et al., 1997~.
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From page 141... ...
Keeping in mind the results of explant series of modern implants and other recent observations as noted above, the committee is of the opinion that, with a conservative guess at upward adjustment to account for underdiagnosis, a modest number (perhaps less than 10%) of modern gel implants will have ruptured by five years and that ruptures will continue to accumulate and prevalence will increase in ensuing years.
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From page 142... ...
Different types of breast implants will produce differing capsules. Some have speculated that damage to the breast during implant placement, which could lead to fat necrosis, mammary gland degeneration, and muscle atrophy, may also contribute to capsule thickness and contracture (Smahel, 1978b)
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From page 143... ...
On direct visual observation, the usual implant capsule is a variably thin, grayish, glistening membrane. Microscopically, smooth-surfaced gel or saline implant capsules may have a flattened unicellular lining or a layer of pseudoepithelial cells next to the implant, overlaid with a regularly and linearly oriented dense collagen network that progresses to looser, better-vascularized connective tissue merging with the surrounding breast tissue.
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From page 144... ...
Synovium has been described around all kinds of breast implants including smooth saline implants (McConnell et al., 1997~. Fragments of the elastomer shell are seen in capsules around saline implants (Teeny and Smahel, 1981; Vargas, 1979)
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From page 145... ...
Calcium phosphate was reported as hydroxyapatite in both heterotopic bone and spherulitic aggregates of crystal in the capsule near the implant surface. Although most reports of calcification, and the data in this IOM report refer to silicone gel implants, calcification in the form of hydroxyapatite crystals is occasionally described stuck to the surface of saline implants (Peters et al., 1998; Schmidt, 1993~.
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From page 146... ...
Some have argued for an adaptive immune component in silicone breast implant tissue reactions (Kossovsky, 1993~. Others have tried to immunize animals to silicone gel, elastomer, or fluid using powerful adjuvants and have failed to observe a difference in the tissue reaction to subsequent silicone implants in either normal or immune deficient (nu/nu)
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From page 147... ...
, and consistent with this presumed reaction to exposure to silicone gel and gel fluid, capsules around saline implants are thinner than those around gel and textured implants. Capsules around textured implants tend to take on the imprint of the pillared surface of these shells of those implants, with a greater likelihood of fluid accumulation in cysts within the capsule or in the space around the implant (Teeny and Smahel, 1981; Malata et al., 1997; Rothfuss et al., 1992~; probably due to the presence of synovial linings with secretory function.
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From page 148... ...
Contracture may also lead to other interventions that carry risk, such as closed capsulotomies with possible hematoma or rupture, migration of silicone gel and a need for further surgery, or it may impair the use of diagnostic technologies such as screening or diagnostic mammography for the detection of cancer and other conditions, by making it much more difficult or impossible to achieve adequate breast compression and visualization of much of the breast tissue. The foreign body reaction, formation of a fibrous capsule, and its contracture are likely no more common in breast than in other implants, but the soft tissue, cosmetic role of the breast implant means that these reactions or complications have a substantially greater effect on the safety and performance of this implant, as just discussed.
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From page 149... ...
Not everyone agrees that contracture is random, however, even though contractures observed in patients in clinical practice seem to be a mixture of unilateral and bilateral, and in some reports all contractures are unilateral (Milojevic, 1983~. The finding of Class III contractures on one side and Class I on the other in monozygotic twins with identical implants three years postoperatively is also interesting, although anecdotal, evidence (Poppi, 1985~.
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From page 150... ...
, and needless to say, augmentation was not in great demand at that time (see discussion of prevalence in Chapter 1~. The introduction of silicone gel implants with Dacron patches in the early 1960s reportedly lowered the incidence of serious contractures to around 75% (Gylbert et al., 1989)
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From page 151... ...
report of 71% Class IV contractures in 639 women with silicone gel implants at 440 days on average after placement. Tissue Exposure to Silicone and Contracture There are some data defining the amount and characteristics of the silicone gel fluid diffusing through the barrier and nonbarrier shells of implants from some manufacturers, but they are far from complete (see Chapter 3 and below)
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From page 152... ...
. Other technologies can locate and identify silicon in microscopic sections using energy dispersive x-ray analysis or scanning electron microscopy (Winding et al., 1988~.
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From page 153... ...
, and 0.13,ug/ml (Teuber et al., 1995a, 1996~. These values have been compared to measurements from women with silicone gel breast implants.
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From page 154... ...
in other human tissue than capsules around gel implants, and studies reporting these capsular levels also report levels in tissue in the few microgram range (see below)
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From page 155... ...
Very high silicon levels are reported in capsules around silicone gel implants and intact and ruptured implant capsules: 15-9,800 ,ug/g of PDMS in formalin=fixed tissue (Baker et al., 1982~; 75-9,000 ,ug/g tissue (Evans and Baldwin, 1996~; average levels in capsule around silicone gel implants of 1,439 ,ug/g tissue, with a median of 490 ,ug/g tissue (Evans and Baldwin, 1997b) ; 29-496 ,ug/g dry weight in presumably intact implant capsules (Leung and Edmond, 1997~; a median of 11,492,ug/g and a mean of 11,613,ug/g in intact implant capsules with a median of 85,ug/g and a mean 490 ,ug/g in breast tissue.
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From page 156... ...
There is no correlation between implant age and capsular silicon level in most reports (Baker et al., 1982; Barnard et al., 1997; Evans and Baldwin, 1997b; Peters et al., 1996; Schnur et al., 1997) , although one analysis of intact gel implants found a significant correlation between implant age and silicon levels (McConnell et al., 1997)
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From page 157... ...
This does not mean that all implant silicone is accounted for. Small amounts of low molecular weight compounds from gel fluid are likely to diffuse or be transported away from their source and to be subject to lung, hepatic, or renal clearance, as some elevated blood levels (if accurate)
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From page 158... ...
Frequency of Capsular Contracture Saline Implants Compared to Gel Implants As noted earlier, reports of the frequency of capsular contracture suffer from many of the same problems as studies of breast implant rupture in the plastic surgery literature. Reports use different units (percentage patients, percentage breasts)
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From page 159... ...
Their aggregate figures for contractures per patient were 56.8% of women with gel implants and 40.5% of women with saline implants. Other substantial numbers of Class III-IV contracture of capsules around gel-filled implants have been reported: 79% at 15-21 years after submammary augmentation (Gylbert et al., 1989~; 44% of gel submuscular implants (Hakelius and Ohlsen, 1997~; 40% of augmented breasts with "firmness" leading to reoperation in more than a third (Domanskis and Owsley, 1976~; 45% of augmented breasts with Class II-IV contractures needing capsulotomies (Brands et al., 1984~; 56% Class III-IV contractures of 60 breasts augmented with double-lumen implants in the placebo arm of an antibiotic treatment trial (Gylbert et al., 1990a)
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From page 160... ...
The 1990 Dow Corning figures at two years were 17.6% Class III-IV contracture for Silastic II, and 8.6% for Silastic MSI implants in augmentation (Bowlin et al., 1998~. All of these studies have so many variables, such as different vintages and manufacturers of implants, follow-up, placement, texturing, and indications for implantation among others, that it is not possible to draw a firm conclusion about the frequencies of contracture in capsules around saline- or gel-filled implants, but the evidence suggests that women can expect more contractures around gel implants than around saline implants if these are the only variables.
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From page 161... ...
Saline-filled and barrier-coated implants appear to be associated with lower tissue silicone exposure and fewer and less severe contractures compared to conventional gel implants in a preponderance of the studies cited above. Fibrous capsules form around any foreign body, and contracture of these capsules is undoubtedly multifactorial, however.
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From page 162... ...
(1996) found 3-9% Class III-IV contractures around textured implants and 10-20% around smooth-surfaced gel implants from the same manufacturer, measured by three techniques (two of which provided a statistically significant difference)
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From page 163... ...
In a comparison study of patients with textured and smooth surfaced, but otherwise identical, gel-filled implant placed in opposite sides, the textured implant was unequivocally preferred by the women and rated better by surgeons in terms of contracture (Hakelius and Ohlsen, 1997~. The Dow Corning 1990 multisite study of its smooth and textured gel implants reported half as many Class III-IV contractures around the textured as around the smooth implants (Bowlin et al., 1998~.
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From page 164... ...
Conflicting in vitro studies found that steroid diffusion out of the implant was very slow a few months to years in duration and likely varies with the physical and chemical characteristics of the implant shell. Continuing steroid diffusion probably results in exposure of surrounding capsular and breast tissue to pharmacologic concentrations of steroids over prolonged periods of time as clinical experience suggests.
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From page 165... ...
(1978) found Class II-IV contractures in 26% of women with implants for augmentation in a series treated with 60 mg of triamcinolone in the pocket around smooth gel implants, compared with 35% contractures in the no-treatment group.
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From page 166... ...
compared textured gel implants from two manufacturers with polyurethane-coated implants and smooth double-lumen implants with and without 20 mg methylprednisolone in submammary augmentation. Although the follow-up was short in some groups, in general the Class III-IV contractures were zero and 3.9% around polyurethanecoated implants and steroid-added double-lumen implants compared to 25% with the no-treatment smooth double-lumen implants.
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From page 167... ...
The committee believes that, at a minimum, before this treatment can be recommended, the behavior of a particular implant as a delivery vehicle and the therapeutic results and complications of a defined dosage to tissue in properly controlled and randomized studies would have to be determined. Role of Infection and Antimicrobial Treatment The safety of breast implants is affected by infections in a number of ways.
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From page 168... ...
. Some of these latter organisms, and occasionally fungi, may also be found within saline expanders and inflatable implants, where they can survive and even proliferate possibly supported by glucose that diffuses into, and has been measured within, the implant (Blats, IOM Scientific Workshop, 1998; Chen et al., 1996; Coady et al., 1995; Nordstrom et al., 1988; Young et al., 1997~.
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From page 169... ...
five-year experience of infection with gel implants was 0.7% of augmented breasts and 0% of reconstructed breasts. The Mentor adjunct study (1992)
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From page 170... ...
were found to inhibit bacterial growth in vitro due to the diffusion of free iodine through the shell. Saline implants placed in mouse tissue pockets contaminated with S
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From page 171... ...
breast implants, noted that 76% (62 out of 82) of those with Class III-IV contractures, but only 28% (19 of 68)
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From page 172... ...
of the Class III-IV contracture rates for modern saline implants, and some studies have been negative (e.g., Peters et al., 1997~. The differences in contracture frequency with saline versus gel and textured versus smooth implants are not readily explained by a bacterial theory of causation.
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From page 173... ...
and so on, for augmentation and reconstruction with both gel and saline implants. These reports are typical for hematomas that are observed within days after implantation.
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From page 174... ...
This effect is reported in a number of additional studies that cite significant decreases in contracture when comparing women with submuscular implants to women with submammary implantation of different kinds of gel-filled implants. These include decreases from 11.1% to 3% of Class III-IV contractures with some standard and some low-bleed gel implants (Biggs and Yarish, 1990~; 40% to 5% of patients with severe contracture (Mahler and Hauben, 1981~; 83.8% to 27.1% of Class III-IV breasts with gel implants of 12 years' duration or less (Peters et al., 1997~; 41% to 8% of Class III-IV contractures with gelfilled implants (Puckett et al., 1987~; improvement from 30% Class I contracture to 95% Class I contracture around gel-filled implants (Scully, 1981~; average self-assessed Baker score at five years of 2.9, submammary to 2.1, submuscular using gel-filled implants (Fiala et al., 1993)
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From page 175... ...
submammary placements with Class II contractures (Hester et al., 1988~. A few studies compared contractures after subcutaneous implantation with those after submuscular implantation of gel-filled breast implants.
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From page 176... ...
For example, although the reference list includes about 30 citations on the effects of radiation therapy in women with breast implants, implants themselves have good stability to clinically relevant dose levels of irradiation, they do not significantly interfere with the radiation beam and radiation therapy, and evidence that radiation can increase implant capsular contracture is limited (see Chapter 3 for discussion)
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From page 177... ...
Pain is also associated with some gel implant ruptures, up to 93% in some reports (Akin et al., 1994b; Andersen et al., 1989) , is reported in association with polyurethane implants (Tabaley and Das, 1986; Smahel, 1978a; Wilkinson, 1985)
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From page 178... ...
Much remains to be learned about the basic biology of foreign body, silicone, and other polymer interactions with tissue, although progress has been made recently. The committee drew conclusions about ruptures and deflations, the role of silicone in contracture, saline versus gel implants, barrier shells and shell texturing, submuscular placement of implants, the roles of infection and hematomas, the use of adrenal steroid, pain and other outcomes that can affect reoperations and local and perioperative complications.
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