Effects of fibrin, thrombin, and blood on breast capsule formation in a preclinical model

A Forgotten Entity following Breast Implant Contracture: Does Baker Need a Change?

Although capsular contracture represents one of the most important complications after breast augmentation, local inflammation and fibrosis can lead, in very rare cases, to capsular calcification, an often-forgotten radiological sign of capsular contracture. In this article, the authors present a clinical case of breast implant calcification in an 81-year-old patient. Although this complication has been rarely described, the literature was reviewed to clarify the role of the local microenvironment in capsular contracture and calcification. At present, capsular contracture patients are classified using the conventional Baker score and the histological Wilflingseder classification. As it was not possible to consider capsular calcification when classifying our patient using the traditional scores, the authors propose an updated version of the current scale.

The role of fat grafting on contracted breast implant capsules: A retrospective comparative histological and immunohistochemical study

Capsular contracture, a common complication of breast implant reconstruction following postmastectomy radiotherapy (PMRT), represents a challenge for plastic surgeons. Regenerative surgery with multiple autologous fat grafts (lipobed) before replacing the implant has been proven to be a satisfactory approach in the radio-damaged breast. Currently, in literature, there are no data available on the histological features of irradiated capsules after regenerative surgery. We enrolled 80 patients after immediate subpectoral alloplastic breast reconstruction, with indication for revision surgery due to grade IV capsular contracture developed after PMRT. Forty patients were undergoing multiple fat grafting (lipobed group, mean age 48) and 40 patients were not undergoing multiple fat grafting (non-regenerative surgery (NRS) group, mean age 49). The removed capsules were addressed to histological and immunohistochemical assessment. The capsules of the lipobed group patients compared with NRS group patients showed: a lower mean thickness (602.17 versus 670.43 µm; P = 0.013), a lower collagen fiber alignment (median value of angle deviation: 30.34 versus 18.38; P = 0.001), a lower immunohistochemical positivity for myofibroblasts (α-smooth muscle actin [α-SMA] expression: 12.5% versus 52.5%; P = 0.00), a higher immunohistochemical positivity for estrogen receptor-β (ER-β; 80% versus 20%; P = 0.00), and a lower immunohistochemical positivity for estrogen receptor-α (ER-α; 53.3% versus 16.7%; P = 0.00). The histological and immunohistochemical differences found are possibly due to alterations in the extracellular microenvironment determined by grafted fat.

The Histological Composition of Capsular Contracture Focussed on the Inner Layer of the Capsule: An Intra-Donor Baker-I Versus Baker-IV Comparison

Background

Capsular contracture remains one of the major complications after breast implantation surgery. The extent of capsular contraction is scored using the Baker scale. The aim of this study was to compare intra-individual Baker-I with Baker-IV capsules, and in particular the prevalence and histological properties of the inner capsule layer.

Methods

Twenty capsules from ten patients were included after bilateral explantation surgery due to unilateral capsular contracture (Baker-IV) after cosmetic augmentation with textured implants. All capsules underwent (immune-)histochemical analysis: haematoxylin–eosin (morphology), CD68 (macrophages), cytokeratin (epithelial cells) and vimentin (fibroblasts), and were visually scored for cell density and the presence of an inner layer and measured for thickness.

Results

Baker-IV (n = 10) capsules were significantly thicker compared to Baker-I (n = 10) capsules (P = 0.004). An inner layer was present in 8 Baker-I capsules. All Baker-I capsules were vimentin and CD68-positive and cytokeratin-negative. Positive vimentin was seen throughout the inner layer, and CD-68 staining was observed adjacent to the intermediate capsule layer. In contrast, only 2 Baker-IV capsules had an inner layer, of which only 1 showed the same profile as Baker-I capsules (P = 0.016). No cytokeratin positivity was seen in any capsule. In Baker-IV capsules, outer layers showed more positivity for both vimentin and CD68.

Conclusion

The inner layer is morphologically consistent with synovial metaplasia and is more prevalent in healthy, uncontracted Baker-I capsules. This inverse relation between the presence of the inner layer and higher Baker classification or pathological contracture could indicate a protective role of the inner layer against capsular contracture formation.

Level of Evidence III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Follistatin and the Breast Implant Capsule

Supplemental Digital Content is available in the text.

Background:

Breast capsular contracture remains an elusive problem faced by plastic surgeons and is the leading long-term complication after breast implantation. Follistatin (Fst) is a protein with known anti-inflammatory and antifibrotic properties and has the potential to limit the severity of diseases associated with inflammation and fibrosis such as capsular contracture. The aim of this study was to examine the effect of Fst288 on capsular fibrosis around silicone implants in a mouse model.

Methods:

BALB/c mice were implanted subcutaneously with untreated silicone implants (baseline control). In the experimental group, immediately after silicone implant insertion, the implant pocket received either a single injection of 1 µg Fst288 or normal saline (internal control). The animals were killed at 3, 5, 7, 14, 28, and 90 days after surgery, and serum, implants, and the surrounding tissue were removed for histological and immunohistochemical analyses.

Results:

Fst288 treatment resulted in significant decreases in capsule thickness at 28 days (P < 0.05) and 3 months (P < 0.001), decreased collagen production at 14 days (P < 0.05) and 3 months (P < 0.01), decreased angiogenesis at 3 months (P < 0.001), decreased α-smooth muscle actin levels at 3 months (P < 0.05), and a decrease in the number of CD45+ cells at days 5 (P < 0.05) and 7 (P < 0.01), respectively, when compared with control implants.

Conclusions:

A single injection of Fst288 at the time of silicone implant insertion into the mice results in a significant reduction in pericapsular inflammation and capsular fibrosis.

Capsular Contracture after Breast Augmentation: An Update for Clinical Practice

Capsular contracture is the most common complication following implant based breast surgery and is one of the most common reasons for reoperation. Therefore, it is important to try and understand why this happens, and what can be done to reduce its incidence. A literature search using the MEDLINE database was conducted including search terms 'capsular contracture breast augmentation', 'capsular contracture pathogenesis', 'capsular contracture incidence', and 'capsular contracture management', which yielded 82 results which met inclusion criteria. Capsular contracture is caused by an excessive fibrotic reaction to a foreign body (the implant) and has an overall incidence of 10.6%. Risk factors that were identified included the use of smooth (vs. textured) implants, a subglandular (vs. submuscular) placement, use of a silicone (vs. saline) filled implant and previous radiotherapy to the breast. The standard management of capsular contracture is surgical via a capsulectomy or capsulotomy. Medical treatment using the off-label leukotriene receptor antagonist Zafirlukast has been reported to reduce severity and help prevent capsular contracture from forming, as has the use of acellular dermal matrices, botox and neopocket formation. However, nearly all therapeutic approaches are associated with a significant rate of recurrence. Capsular contracture is a multifactorial fibrotic process the precise cause of which is still unknown. The incidence of contracture developing is lower with the use of textured implants, submuscular placement and the use of polyurethane coated implants. Symptomatic capsular contracture is usually managed surgically, however recent research has focussed on preventing capsular contracture from occurring, or treating it with autologous fat transfer.

Histologic, Molecular, and Clinical Evaluation of Explanted Breast Prostheses, Capsules, and Acellular Dermal Matrices for Bacteria

BACKGROUND

Subclinical infections, manifest as biofilms, are considered an important cause of capsular contracture. Acellular dermal matrices (ADMs) are frequently used in revision surgery to prevent recurrent capsular contractures.

OBJECTIVE

We sought to identify an association between capsular contracture and biofilm formation on breast prostheses, capsules, and ADMs in a tissue expander/implant (TE/I) exchange clinical paradigm.

METHODS

Biopsies of the prosthesis, capsule, and ADM from patients (N = 26) undergoing TE/I exchange for permanent breast implant were evaluated for subclinical infection. Capsular contracture was quantified with Baker Grade and intramammary pressure. Biofilm formation was evaluated with specialized cultures, rtPCR, bacterial taxonomy, live:dead staining, and scanning electron microscopy (SEM). Collagen distribution, capsular histology, and ADM remodeling were quantified following fluorescent and light microscopy.

RESULTS

Prosthetic devices were implanted from 91 to 1115 days. Intramammary pressure increased with Baker Grade. Of 26 patients evaluated, one patient had a positive culture and one patient demonstrated convincing evidence of biofilm morphology on SEM. Following PCR amplification 5 samples randomly selected for 16S rRNA gene sequencing demonstrated an abundance of suborder Micrococcineae, consistent with contamination.

CONCLUSIONS

Our data suggest that bacterial biofilms likely contribute to a proportion, but not all diagnosed capsular contractures. Biofilm formation does not appear to differ significantly between ADMs or capsules. While capsular contracture remains an incompletely understood but common problem in breast implant surgery, advances in imaging, diagnostic, and molecular techniques can now provide more sophisticated insights into the pathophysiology of capsular contracture.

LEVEL OF EVIDENCE

4 Therapeutic.

Effect of Antiadhesion Barrier Solution and Fibrin on Capsular Formation After Silicone Implant Insertion in a White Rat Model

INTRODUCTION

One of the most serious complications of breast reconstruction and augmentation using silicone implants is capsular contracture. Several preventive treatments, including vitamin E, steroids, antibiotics, and cysteinyl leukotriene inhibitors, have been studied, and their clinical effects have been reported. However, the problem of capsular contracture has not yet been completely resolved. This study was performed to compare anti-adhesion barrier solution (AABS) and fibrin in their ability to prevent fibrotic capsule formation and simultaneously evaluated their effect when used in combination by capsular thickness analysis and quantitative analysis of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and type I collagen within the fibrous capsule.

MATERIALS AND METHODS

This study used female six-week-old Sprague-Dawley rats. Eighty rats were equally subdivided into the four following groups: AABS-treated, fibrin-treated, AABS and fibrin combined-treated, and untreated control groups. Each rat received two silicone chips under the panniculus carnosus muscle layer. The test materials were applied around the silicon chips. Four weeks later, the implantation sites including the skin and muscle were excised to avoid the risk of losing the fibrous capsule around the implants. The capsular thickness was analyzed by Masson's trichrome stain. Quantitative analysis of type I collagen, MMPs, and TIMPs was performed by real-time PCR, Western blot, and zymography.

RESULTS

The mean capsular thickness was 668.10 ± 275.12 μm in the control group, 356.97 ± 112.11 μm in the AABS-treated group, 525.96 ± 130.97 μm in the fibrin-treated group, and 389.24 ± 130.51 μm in the AABS and fibrin combined-treated group. Capsular thickness was significantly decreased in all experimental groups (p < 0.05). Capsular thickness was greater in the fibrin-treated group than in the AABS-treated group (p < 0.05). There was no statistically significant difference in capsular thickness between the AABS and fibrin combined-treated group and the AABS- or fibrin-treated group (p > 0.05). Compared to the control group, the experimental groups had significantly lower expressions of type I collagen and MMP-1 (p < 0.05), but there was no statistically significant difference in expressions of type I collagen and MMP-1 between the AABS-, fibrin-, and AABS and fibrin combined-treated groups (p > 0.05). The expressions of MMP-2 and TIMP-2 were not significantly different between the control and the experimental groups (p > 0.05).

CONCLUSION

AABS is more effective in reducing capsular thickness compared with fibrin treatment in a white rat model.

The "PIP problem": clinical and histologic characteristics

Implants from Poly Implant Prothése (PIP), the French manufacturer, showed increased risk of implant rupture and silicone leakage through the shell. Concerns also exist about the potential irritant behavior of silicone gel filler in these implants. This report presents the clinical, histologic, and microbiologic characteristics of a capsule and a siliconoma from a patient with a ruptured PIP implant. A 41-year-old woman submitted to breast augmentation in 2005 with PIP silicone gel implants presented with a recent history of progressive asymmetric breast enlargement and an enlarged lymph node on her right axilla. No capsular contracture was observed. A breast ultrasonography showed intra- and extracapsular ruptures of the right implant. The woman underwent explantation. Histologic analysis of the breast capsules showed a thin capsule with a chronic, mild inflammatory response. Microbiologic analysis showed no bacterial agent. The irritant behavior of the PIP silicone gel previously described was not able to produce capsular contracture or an exuberant inflammatory reaction. Studies to evaluate the potential risks of the silicone gel and to define the hazards for women implanted with those prostheses are urgently needed.

The impact of triamcinolone acetonide in early breast capsule formation in a rabbit model

BACKGROUND

The etiology and clinical treatment of capsular contracture remain unresolved as the causes may be multifactorial. Triamcinolone acetonide applied in the pocket during surgery was reported to be ineffective in prevention of capsular contracture. However, if injected 4-6 weeks after surgery or as a treatment for capsular contracture, decreased applanation tonometry measurements and pain were observed. It was assumed that intraoperative application of triamcinolone was not effective because its effect does not last long enough. However, betadine, antibiotics, and fibrin were found to be effective in preventing capsular contracture with intraoperative applications and are more effective in the early phases of wound healing than in later stages. The role of triamcinolone acetonide in capsule formation is unknown. The purpose of this study was to determine if triamcinolone acetonide modulates breast capsule formation or capsular contracture in the early phases of wound healing in a rabbit model.

METHODS

Rabbits (n=19) were implanted with one tissue expander and two breast implants and were killed at 4 weeks. Implant pocket groups were (1) Control (n=10) and (2) Triamcinolone (n=9). Pressure/volume curves and histological, immunological, and microbiological evaluations were performed. Operating room air samples and contact skin samples were collected for microbiological evaluation.

RESULTS

In the triamcinolone group, a decreased capsular thickness, mild and mononuclear inflammation, and negative or mild angiogenesis were observed. There were no significant differences in intracapsular pressure, fusiform cell density, connective tissue, organization of collagen fibers, and microbiological results between the groups. There was no significant difference in the dialysate levels of IL-8 and TNF-α, but correlation between IL-8 and TNF-α was observed.

CONCLUSION

Triamcinolone acetonide during breast implantation influences early capsule formation and may reduce capsular contracture.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266.

Effects of coagulase-negative staphylococci and fibrin on breast capsule formation in a rabbit model

BACKGROUND

The etiology and ideal clinical treatment of capsular contracture (CC) remain unresolved. Bacteria, especially coagulase-negative staphylococci, have been previously shown to accelerate the onset of CC. The role of fibrin in capsule formation has also been controversial.

OBJECTIVE

The authors investigate whether fibrin and coagulase-negative staphylococci (CoNS) modulate the histological, microbiological, and clinical outcomes of breast implant capsule formation in a rabbit model and evaluate contamination during the surgical procedure.

METHODS

Thirty-one New Zealand white female rabbits were each implanted with one tissue expander and two breast implants. The rabbits received (1) untreated implants and expanders (control; n = 10), (2) two implants sprayed with 2 mL of fibrin and one expander sprayed with 0.5 mL of fibrin (fibrin; n = 11), or (3) two implants inoculated with 100 µL of a CoNS suspension (10(8)CFU/mL-0.5 density on the McFarland scale) and one expander inoculated with a CoNS suspension of 2.5 × 10(7) CFU/mL (CoNS; n = 10). Pressure/volume curves and histological and microbiological evaluations were performed. Operating room air samples and contact skin samples were collected for microbiological evaluation. The rabbits were euthanized at four weeks.

RESULTS

In the fibrin group, significantly decreased intracapsular pressures, thinner capsules, loose/dense (<25%) connective tissue, and negative/mild angiogenesis were observed. In the CoNS group, increased capsular thicknesses and polymorph-type inflammatory cells were the most common findings. Similar bacteria in capsules, implants, and skin were cultured from all the study groups. One Baker grade IV contracture was observed in an implant infected with Micrococcus spp.

CONCLUSIONS

Fibrin was associated with reduced capsule formation in this preclinical animal model, which makes fibrin an attractive potential therapeutic agent in women undergoing breast augmentation procedures. Clinical strategies for preventing bacterial contamination during surgery are crucial, as low pathogenic agents may promote CC.