The peri-implant breast capsule: an immunophenotypic study of capsules taken at explantation surgery

A Histological Assessment Tool for Breast Implant Capsules Validated in 480 Patients with and Without Capsular Contracture

BACKGROUND

Understanding the impact of breast implants on the histological response in the surrounding fibrous capsule is important; however, consensus is lacking on how to analyze implant capsules histologically. We aimed to develop a standardized histological assessment tool to be used in research potentially improving diagnostic accuracy and treatment strategies for capsular contracture.

METHODS

Biopsies of breast implant capsules from 480 patients who had undergone breast augmentation or reconstruction were collected and stained with hematoxylin and eosin. Initially, biopsies from 100 patients were analyzed to select histological parameters demonstrating the highest relevance and reproducibility. Then, biopsies from the remaining 380 patients were used to determine intra- and interobserver agreements of two blinded observers and agreement with a pathologist. Finally, we tested the association between the parameters and capsular contracture.

RESULTS

The histological assessment tool included ten parameters assessing the inflammatory, fibrotic, and foreign-body reaction to breast implants, each graded on two-, three-, or four-point scales. Intra- and interobserver agreements were almost perfect (0.83 and 0.80), and agreement with the pathologist was substantial (0.67). Four parameters were significantly correlated with capsular contracture, namely chronic inflammation with lymphocyte infiltration (p < 0.01), thickness of the collagen layer (p < 0.0001), fiber organization (p < 0.01), and calcification (p < 0.001).

CONCLUSIONS

This is the first validated histological assessment tool for breast implant capsules. The validated tool not only advances our understanding of capsular contracture but also sets a new standard for histological evaluation in breast implant research and clinical diagnostics.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Histomorphological evaluation of acellularized bovine pericardium in breast implant coverage

Bovine pericardium (BP) has been used as a biomaterial for several decades in many medical applications particularly due to its mechanical properties and the high collagen content. In the acellular form it favors faster tissue repair, providing a three-dimensional support for cellular and vascular events observed during tissue repair and due, to a low elastin content, may favor its use as a breast implant cover, resulting in a low possibility of contracture of the biomaterial, preventing the appearance of irregularities during the reconstruction process. Thus, the aim of this study was to evaluate, histomorphologically, the behavior of acellularized bovine pericardium (ABP) as a mammary implant cover in rats. For this purpose, 16 animals were divided into two groups, with eight animals at each biological point: 7 and 15 days after surgery. Of the 16 animals, 32 specimens were obtained: 16 in the experimental group (EG) and 16 in the control group (CG). Throughout this study, none of the studied groups had postoperative complications. Results: The histomorphological results showed, in the two biological points, both in the EG and in the CG, chronic inflammatory infiltrate, leukocyte fibrin exudate, formation of granulation tissue and deposition of collagen fibers, more evident in the EG, regressive along the biological points. At 15 days, the implanted ABP showed initial biointegration with the fibrous capsule and surrounding tissues of the recipient bed. Conclusion: These results indicate that the due to the observed favorable tissue response ABP may be of potential use as a breast implant cover.

Breast Implant Capsule: A Murine Model Comparing Capsular Contracture Susceptibility Among Six Breast Implants Available in the Market

BACKGROUND

Breast implant capsule development and behavior are mainly determined by implant surface combined with other external factors such as intraoperative contamination, radiation or concomitant pharmacologic treatment. Thus, there are several diseases: capsular contracture, breast implant illness or Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL), that have been correlated with the specific type of implant placed. This is the first study to compare all major implant and texture models available in the market on the development and behave of the capsules. Through a histopathological analysis, we compared the behavior of different implant surfaces and how different cellular and histological properties give rise to different susceptibilities to develop capsular contracture among these devices.

METHODS

A total of 48 Wistar female rats were used to implant 6 different types of breast implants. Mentor®, McGhan®, Polytech polyurethane®, Xtralane®, Motiva® and Natrelle Smooth® implants were employed; 20 rats received Motiva®, Xtralane® and Polytech polyurethane®, and 28 rats received Mentor®, McGhan® and Natrelle Smooth® implants. The capsules were removed five weeks after the implants placement. Further histological analysis compared capsule composition, collagen density and cellularity.

RESULTS

High texturization implants showed the highest levels of collagen and cellularity along the capsule. However, polyurethane implants capsules behaved differently regarding capsule composition, with the thickest capsules but fewer collagen and myofibroblasts than expected, despite being generally considered as a macrotexturized implant. Nanotextured implants and microtextured implants histological findings showed similar characteristics and less susceptibility to develop a capsular contracture compared with smooth implants.

CONCLUSIONS

This study shows the relevance of the breast implant surface on the definitive capsules' development, since this is one of the most differentiated factors that determine the incidence of capsular contracture and probably other diseases like BIA-ALCL. A correlation of these findings with clinical cases will help to unify implant classification criteria based on their shell and their estimated incidence of capsule-associated pathologies. Up to this point, the establishment of additional groups is recommended as nanotexturized implants seem to behave differently to pure smooth surfaces and polyurethane implants present diverse features from macro- or microtextured implants.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. 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 .

Histologic and Immunohistochemical Evaluation of Human Breast Capsules Formed around Five Different Expander Surfaces

BACKGROUND

Polyurethane (PU) coating and implant texturization were designed to reduce the incidence of capsular contracture (CC), even if the link between surface type and CC remains unclear. To date, the etiopathogenetic aspects have not been fully clarified. The aim of this study was to evaluate capsules formed around five different breast expanders.

METHODS

Thirty patients were divided into randomized groups implanted with five different expanders: smooth, coated with PU foam (poly), with a low-microtextured, high-microtextured, and macrotextured surface (L-micro, H-micro, macro). Specimens of the capsules were removed at implant reconstruction and evaluated for morphology and immunohistochemistry expression of α-smooth muscle actin (α-SMA), collagen type I and III, CD68, CD34, and CD3. Remodeling Combined Index was also evaluated.

RESULTS

Expression of α-SMA was significantly increased in smooth capsules versus poly, low-microtextured, and high-microtextured groups ( P = 0.007; P = 0.010; P = 0.028), whereas the prevalence of collagen type I in smooth capsules and collagen type III in poly capsules identified a stable versus an unstable tissue. Remodeling Combined Index and α-SMA showed an inverted correlation. CD68 and CD34 cellular expression increased significantly in poly capsules with respect to smooth ( P < 0.001; P < 0.001) and macrotextured groups ( P < 0.001; P < 0.001). CD3 showed no significant difference among the groups.

CONCLUSION

In this human study, the authors observed that increased tissue remodeling and reduced myofibroblast activation, along with the inflammatory infiltration and neoangiogenesis, especially in the poly and low-microtextured groups, might promote the formation of an unstable and less fibrotic capsule, lowering the risk of CC.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Advances on Capsular Contracture-Prevention and Management Strategies: A Narrative Review of the Literature

Capsular contracture (CC) is the most relevant complication of both aesthetic and reconstructive breast implant surgery. For many years, experimental and clinical trials have attempted to analyze CC risk factors, clinical features, and appropriate management strategies. It is commonly accepted that a multifactorial etiology promotes CC development. However, the heterogeneity in patients, implants and surgical techniques make it difficult to suitably compare or analyze specific factors. As a consequence, discordant data are present in literature, and a true systematic review is often limited in its conclusions. Hence, we decided to present a comprehensive review of current theories on prevention and management strategies, rather than a specific "solution" to this complication.

Methods

The PubMed database was searched for literature regarding CC prevention and management strategies. Pertinent articles in English, published before December 1, 2022, were compared with selection criteria and eventually included in this review.

Results

Through the initial search, 97 articles were identified, of which 38 were included in the final study. Several articles explored different medical and surgical preventive and therapeutic strategies, showing numerous controversies on appropriate CC management.

Conclusions

This review provides a clear overview of the complexity of CC. The wide variety of clinical situations in term of patients, implants, and surgical techniques prevent the standardization of CC management strategies. By contrast, a patient-customized approach should be preferred, and different strategies should be considered depending on the specific case. Further research is desirable to better ascertain evidence-based protocols with regard to CC prevention and treatment.

The Value of Capsule Thickness on Breast Ultrasound as an Indicator of the Severity of Capsular Contracture and Its Correlation with the Baker Classification

BACKGROUND

We conducted this study to explore the value of the capsule thickness as an indicator of the severity of capsular contracture (CC) alternatively to the Baker classification system in patients who were treated with an implant-based augmentation mammaplasty.

METHODS

A total of 117 eligible patients (202 breasts) were included in the current study. We measured the capsule thickness using ultrasound and histologic examination in association with the Baker grades I, II, III and IV. Then, we analysed agreement of the capsule thickness between the two methods using an intra-correlation coefficient (ICC 2,1) with 95% confidence intervals (CIs). The CC of Baker grades II, III and IV (105 breasts), for which the capsule thickness could be measured using US, served as Model 1. Moreover, Model 1 including the CC of Baker grades I (97 breasts) served as Model 2.

RESULTS

The capsule thickness was measured as 0.58 ± 0.11 (0.4-0.8) mm, 1.07 ± 0.16 (0.8-1.31) mm and 1.89 ± 0.55 (1-4.1) mm on ultrasound in association with Baker grades II, III and IV, respectively. In addition, it was also measured as 0.28 ± 0.07 (0.09-0.41) mm, 0.58 ± 0.08 (0.42-0.75) mm, 1.06 ± 0.14 (0.79-1.34) mm and 2.13 ± 1.14 (1.38-6.98) mm on histologic examination in association with Baker grades I, II, III and IV, respectively. In Model 1 and 2, the ICC was calculated as 0.942 (95%CI 0.914-0.961) and 0.955 (95%CI 0.940-0.966), respectively. The cut-off values between the Baker grades I-II, II-III and III-IV were calculated as 0. mm, 0.8 mm and 1.2 mm, respectively.

CONCLUSIONS

In conclusion, the capsule thickness might be used as an indicator of the severity of CC alternatively to the Baker classification system. But further studies are warranted to establish our results.

LEVEL OF EVIDENCE IV

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 .

Histological Analyses of Capsular Contracture and Associated Risk Factors: A Systematic Review

BACKGROUND

Capsular contracture is a severe complication to breast surgery with implants. Previous studies suggest multiple risk factors are associated with capsular contracture, but the etiology is still unknown. We performed a literature review to investigate existing studies on histological analyses of breast implant capsules and how clinical risk factors impact the capsule morphology.

METHODS

The literature search was conducted in PubMed. Studies that performed histological analyses of breast implant capsules were included. Animal studies or studies with a study population of less than five patients were excluded.

RESULTS

Fifty-two studies were included. The histological analyses showed that the breast implant capsules were organized in multiple layers with an inner layer of synovial-like metaplasia which was reported to diminish in capsules with capsular contracture. The remaining layers of the capsule mostly consisted of collagen. The alignment of the collagen fibers differed between contracted and non-contracted capsules, and capsules with higher Baker grade were generally thickest and contained more tissue inflammation. Studies investigating capsules affected by radiotherapy found a more pronounced inflammatory response and the capsules were generally thicker and fibrotic compared with nonirradiated capsules.

CONCLUSIONS

The included studies offer valuable insights into the histological changes caused by capsular contracture and their relation to clinical risk factors. Further studies with larger sample sizes and more strict inclusion criteria are needed to further investigate implant capsules and the role of the synovial-like metaplasia for the development of 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 https://www.springer.com/00266 .

Capsular Contracture in Breast Implant Surgery: Where Are We Now and Where Are We Going?

Capsular contracture is the leading complication after surgery with breast implants. A lot of progress has been made investigating this complication over the years, and knowledge has been gained on this complication. Currently, the exact cause for capsular contracture is still unclear. It has been hypothesized that immunobiological factors (i.e., immunological and bacterial factors) and several risk factors play a central role in its development. In this paper, we give an overview of the known immunological factors that have been investigated in contracted and non-contracted capsules, as well as the role of bacterial formation around breast implants. We also report on risk factors that might increase the risk of capsular development. Lastly, it provides the latest research on this matter and discusses future perspectives as follow-up research is needed to unravel the pathogenic process leading to capsular contracture. This knowledge is of interest to establish medical therapies in order to prevent such side effects. Overall, capsular contracture seems to be a multifactorial condition consisting of several risk factors. LEVEL OF EVIDENCE V: 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 .

Reduced Remodeling Biomarkers Tissue Expression in Nanotextured Compared With Polyurethane Implants Capsules: A Study in Rats

BACKGROUND

In the biological response to biomaterials, the implant shell plays a key role in immune and inflammatory reactions. We hypothesized that the capsules formed around nanotextured implants exhibit an immunohistochemical behavior different to those formed around polyurethane implants.

OBJECTIVES

The aim of this study was to evaluate through immunohistochemistry markers the capsules formed around nanotextured and polyurethane implants.

METHODS

Sixty albino female Wistar rats were divided into 2 groups (nanotextured and polyurethane), with 30 animals in each group. A mini silicone implant was inserted on the back of the animals. After a predetermined period, the animals were killed, and the capsules formed around the implants were studied. The capsules in the 30-, 60-, and 90-day subgroups were analyzed via immunohistochemistry to detect markers for fibroblast α smooth muscle actin (α-SMA), transforming growth factor β (TGF-β), cluster of differentiation 34 (CD34), and CD68, via picrosirius staining to determine the density of type I and III collagen fibers and via hematoxylin and eosin staining to assess capsule thickness. A Wilcoxon-Mann-Whitney test was used to compare the groups, and a Kruskal-Wallis test was used to compare the subgroups.

RESULTS

Lower α-SMA, TGF-β, CD34 and CD68 immunoexpression was observed in the nanotextured 30- and 60-day subgroups than in the corresponding polyurethane subgroups. In the 90-day subgroup, more pronounced α-SMA and CD34 immunoexpression was observed in the nanotextured group; however, TGF-β and CD68 immunoexpression remained lower. The nanotextured implants showed reduced capsular thickness and greater formation of type I collagen in all the analyzed subgroups.

CONCLUSIONS

Nanotextured implants led to reduced immune and inflammatory reactions compared with polyurethane implants according to all analyzed variables.

The State of the Art about Etiopathogenetic Models on Breast Implant Associated-Anaplastic Large Cell Lymphoma (BIA-ALCL): A Narrative Review

Background: Breast-implant-associated anaplastic large cell lymphoma is a rare malignancy linked to texturized breast implants. Although many researchers focus on its etiopathogenesis, this topic is affected by a lack of evidence. Materials and Methods: A literature review about BIA-ALCL was made. Results and conclusions: Although the incidence is reported between 1:355–1:30,000, there is great attention to BIA-ALCL. The incidence is uncertain due to many reasons. It may well be lower, due to inclusion in multiple databases as pointed out by the FDA and undiagnosed cases. The role of chronic inflammation, bacterial contamination, and mechanical forces was discussed. Clarification is needed to understand the mechanisms underlying the progression of alterations and mutations for BIA-ALCL; new molecular analysis and pathogenetic models should be investigated.

The Capsule Question: How Much Should Be Removed with Explantation of a Textured Device?

SUMMARY

Current controversies surrounding breast implants are focused not only on the implant but also on the capsule. There has been tremendous discussion regarding how much of the capsule, if any, should be removed during explantation for benign conditions. The appearance of benign capsules is highly variable ranging from a thin membrane to densely fibrotic with calcifications. The options for capsulectomy include none, partial, complete, complete-intact, and en bloc. Some patients are requesting en bloc capsulectomy even in the absence of anaplastic large cell lymphoma; however, the scientific evidence only supports this for patients with capsular malignancies. The purpose of this article is to review the old and new evidence to answer the question regarding how much capsule should be removed during explantation for benign conditions.

Histopathological evaluation of the effect of hyperbaric oxygen therapy on capsule occurrence around silicone breast prosthesis: an experimental study

BACKGROUND

In general, capsular contracture is the underlying cause of complications such as pain, stiffening, breast asymmetry, and animation deformity that are seen in the late postoperative period due to the use of silicone breast prostheses. Considering the positive effects of HBO therapy on wound healing, the objective of this study was to investigate the effect of HBO therapy on capsule reaction occurring due to silicone implants.

MATERIAL AND METHODS

Rats were divided into four groups. 1 cm × 1 cm silicone implants with rough surface were inserted in subcutaneous plane on the m spinotrapezius muscle fascia at just right of the dorsal region midline in rats in Group 1, while implants with same properties were inserted beneath m spinotrapezius muscle in rats in Group 2.Implants with the same properties were inserted in the subcutaneous area on the m spinotrapezius muscle in rats in Group 3 and into the area under the muscle in rats in Group 4. Beginning from the first postoperative day, rats in Groups 3 and 4 received HBO therapy for 90 min under 2.5 ATM pressure as one session a day over 15 days.

RESULTS

The mean capsule thickness was statistically significantly lower in the groups treated with HBO compared to the control groups. Fibroblast, neutrophil and macrophage counts were statistically significantly lower in the groups treated with HBO compared to the control groups.

CONCLUSION

We believe that HBO therapy can be used as an adjuvant treatment options to decrease capsule contraction occurring after silicone implant application.

The Baker Classification for Capsular Contracture in Breast Implant Surgery Is Unreliable as a Diagnostic Tool

BACKGROUND

Breast implants are frequently used in cosmetic and reconstructive breast surgery. Capsular contracture, the most common long-term complication, is usually graded using the Baker classification. Despite its widespread use, the reliability of the Baker classification has never been established. The aim of this study was to determine the interobserver reliability and agreement of the Baker classification.

METHODS

Sixty women who had undergone cosmetic breast augmentation were included. They were examined independently by two plastic surgeons from an observer pool. The Baker score was determined, along with firmness, dislocation, symmetry, and pain using four-point scales. Patients were asked to complete the BREAST-Q postaugmentation module. The interobserver reliability and agreement were calculated for all variables with a quadratic weighted kappa.

RESULTS

The interobserver reliability of the Baker classification was poor (kappa, 0.55; 95 percent CI, 0.37 to 0.72). Interobserver reliability of the clinical parameters firmness (0.64; 95 percent CI, 0.49 to 0.79), dislocation (0.49; 95 percent CI, 0.26 to 0.73), and symmetry (0.61; 95 percent CI, 0.34 to 0.88) was also poor. Pain scores seemed more reliable (0.72; 95 percent CI, 0.56 to 0.89); however, most patients had no pain. The interobserver agreement for the Baker score was 48 percent; in 43 percent, the observers differed one category; and in 12 percent, the difference was more than one category.

CONCLUSIONS

Interobserver reliability and observer agreement of the Baker classification for capsular contracture were poor. Consensus about how to adequately rate the symptoms of capsular complaints is lacking. A more reliable method of measurement or description is needed, especially for scientific research purposes, to assess the long-term problems associated with breast implants.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, IV.

Comparison of inflammatory response and synovial metaplasia in immediate breast reconstruction with a synthetic and a biological mesh: a randomized controlled clinical trial

The aim of this study was to compare inflammatory response and synovial metaplasia in implant-based immediate breast reconstruction with a biological mesh (Veritas^®) with that of a synthetic mesh (TIGR^® Matrix Surgical Mesh). We hypothesize that the inflammatory response and formation of synovial metaplasia might be different and the rate of capsular contracture therefore different. The patients were recruited from the Gothenburg TIGR^®/Veritas^® Study (ClinicalTrials.Gov identifier NCT02985073). All referrals for bilateral immediate breast reconstruction were assessed for inclusions. During the operation, the patients were randomized to which sides the biological and the synthetic mesh were going to be applied. During the implant exchange biopsies were taken. Biopsies were taken from 30 breasts in 15 patients. There seem to be more myofibroblast and neovascularization in the biological meshes than in the synthetic and the collagen fibers seem to be aligned in an irregular pattern with both parallel and vertical fibers. In the synthetic meshes, there were more giant cells and foreign body reaction and the collagen fibers were loosely and well aligned, oriented parallel to the surface of the implant. Synovial metaplasia was seen in the majority of both the biological and the synthetic meshes. The histological patterns in early capsules from biological and synthetic meshes vary considerably. Nonetheless, it is unknown what role different cell types have in capsular formation in the long run and there was no difference in clinical capsular contracture at the clinical follow-up in this study.

PCR Characterization of Microbiota on Contracted and Non-Contracted Breast Capsules

BACKGROUND

The aetiology of capsular contracture around breast implants remains unclear. The leading theory is that a subclinical infection around the implant plays a role in the development of capsular contractions. Several studies found associations between the presence of bacteria and the occurrence of capsular contraction. However, it is unclear whether detected bacteria originate from the breast capsule, breast glandular tissue or skin contamination. Moreover, this has never been investigated with molecular techniques. The aim of this study was to assess the bacterial microbiota on breast capsules, glandular tissue and skin using a highly sensitive PCR assay.

MATERIALS AND METHODS

Fifty breast capsules were collected during implant removal or replacement. Ten specimens of glandular breast tissue and breast skin were collected in females who were undergoing reduction mammoplasty. A sample specimen (4 mm) was sterilely obtained from all tissues. All specimens were analysed by IS-pro, a 16S-23S interspace region-based PCR assay.

RESULTS

Low numbers of Staphylococcus spp. (four species in four capsules) were found on breast capsules. There was no difference in bacterial presence between normal and contracted capsules. The skin of the breast-harboured Streptococcus spp. and Staphylococcus spp. while the glandular tissue was sterile.

CONCLUSION

The low numbers of bacteria found on the capsules are most likely caused by contamination during capsule removal. More and larger studies are needed to investigate the bacterial presence on breast capsules using a PCR assay. This is the first study in which breast capsules have been studied using a highly sensitive PCR assay.

LEVEL OF EVIDENCE IV

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Toll-Like Receptors (TLRs) Expression in Contracted Capsules Compared to Uncontracted Capsules

INTRODUCTION

The etiology of capsular contracture after surgical implantation of breast implants remains unclear, but an important role is seen for the immune system. Toll-like receptors are immune receptors recognizing both pathogen-associated molecular patterns and damage-associated molecular patterns. The former are present on bacteria such as Staphylococcus epidermidis (bacteria earlier associated with capsular contracture), and the latter are released after (mechanical) stress. The aim of this study was to investigate the expression of TLRs 1-10 in relation to capsular contracture.

MATERIALS AND METHODS

Fifty consecutive breast capsules were collected during implant removal or replacement. The extent of capsular contracture was scored according to the Baker score. A sample specimen (0.5 cm3) was obtained from all tissues. cDNA was synthesized from isolated mRNA from the collected specimens. PCR analyses were conducted to test for cDNA presence and to quantify concentration. TLR1-10 expression was measured for each of the Baker scores separately and compared to all Baker scores.

RESULTS

Expression of all TLRs in all Baker scores was seen. TLR2 and TLR6 were more often present in contracted samples (Baker 3 or 4) compared to uncontracted samples (Baker 1 or 2) [Baker 2 vs. 3 (p = 0.034) and Baker 2 vs. 3 (p = 0.003), respectively]. None of the TLRs displayed a significantly higher expression in contracted capsules compared to uncontracted capsules.

CONCLUSION

This study shows that TLR2 and TLR6 are more often expressed in contracted capsules compared to non-contracted capsules however not in higher concentrations.

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 .

Evaluation of Antibiotic-Impregnated Mesh in Preventing the Recurrence of Capsular Contracture

BACKGROUND

Capsular contracture (CC) is the most frequently reported complication following breast augmentation. A growing body of evidence implicates subclinical (biofilm) infection around breast implants as an important cause of CC; however, effective prophylactic and treatment modalities remain controversial.

OBJECTIVES

This article aims to review a single surgeon's experience using an antibiotic-impregnated mesh as a prophylactic measure against biofilm formation and recurrent CC.

METHODS

This study retrospectively reviewed 5 consecutive patients presenting with CC (Baker grades III and IV) who were managed by capsulectomy with implant replacement and simultaneous insertion of an antibiotic-impregnated mesh. Patient demographics and major complications were recorded, including CC recurrence, reoperation, and infection.

RESULTS

Complete correction of the contracture with no recurrence was achieved in all patients at a median followup of 25 months.

CONCLUSIONS

This study demonstrates a novel technique using an antibiotic mesh to reduce bacterial access to breast implants at the time of insertion. Further investigation is warranted with more clinical cases in order to recommend this technique for the management of subclinical infection and CC.

LEVEL OF EVIDENCE: 4

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.

Thermogel Loaded with Low-Dose Paclitaxel as a Facile Coating to Alleviate Periprosthetic Fibrous Capsule Formation

Medical-grade silicones as implants have been utilized for decades. However, the postoperative complications, such as capsular formation and contracture, have not yet been fully controlled and resolved. The aim of the present study is to elucidate whether the capsular formation can be alleviated by local and sustained delivery of low-dose paclitaxel (PTX) during the critical phase after the insertion of silicone implants. A biocompatible and thermogelling poly(lactic acid- co-glycolic acid)- b-poly(ethylene glycol)- b-poly(lactic acid- co-glycolic acid) triblock copolymer was synthesized by us. The micelles formed by the amphiphilic polymers in water could act as a reservoir for the solubilization of PTX, a very hydrophobic drug. The concentrated polymer aqueous solution containing PTX exhibited a sol-gel transition upon heating and formed a thermogel depot at body temperature. In vitro release tests demonstrated that the entrapped microgram-level PTX displayed a sustained release manner up to 57 days without a significant initial burst effect. Customized silicone implants coated with the PTX-loaded thermogels at various drug concentrations were inserted into the pockets of the subpanniculus carnosus plane of rats. The histological observations performed 1 month postoperation showed that the sustained release of PTX with an appropriate dose significantly reduced the peri-implant capsule thickness, production and deposition of collagen, and expression of contracture-mediating factors compared with bare silicone implants. More importantly, such an optimum dose had an excellent repeatability for the suppression of the capsular formation. Therefore, this study provides a strategic foothold regarding the sustained release of low-dose PTX to alleviate fibrotic capsule formation after implantation, and the microgram-level PTX-loaded thermogel holds great potential as an "all-purpose antifibrosis coating" for veiling the surfaces of various implantable medical devices.

Current Approaches Including Novel Nano/Microtechniques to Reduce Silicone Implant-Induced Contracture with Adverse Immune Responses

Capsular contracture, which is the pathologic development of fibrous capsules around implants, is a major complication of reconstructive and aesthetic breast surgeries. Capsular contracture can cause implant failure with breast hardening, deformity, and severe pain. The exact mechanisms underlying this complication remain unclear. In addition, anaplastic large cell lymphoma is now widely recognized as a very rare disease associated with breast implants. Foreign body reactions are an inevitable common denominator of capsular contracture. A number of studies have focused on the associated immune responses and their regulation. The present article provides an overview of the currently available techniques, including novel nano/microtechniques, to reduce silicone implant-induced contracture and associated foreign body responses.

The aetiopathogenesis of capsular contracture: A systematic review of the literature

BACKGROUND

Capsular contracture is the most frequent complication after breast augmentation or reconstruction with breast implants. The immune system plays a prominent role in capsular contracture formation, albeit to an unknown extent. Bacterial contamination in situ has been hypothesized to be causative for capsular contracture. How this relates to the immunological processes involved is unknown. This article aims to provide an overview of immunological and bacterial factors involved in development of capsular contracture.

MATERIALS AND METHODS

We undertook a systematic literature review focused on immunological factors and microbiota in relation to capsular contraction around implants. This systematic review was performed in accordance with the PRISMA guidelines. PubMed, EMBASE, and the Cochrane databases were searched from inception up to October 2016. Included studies were assessed for the following variables: subject characteristics, number of capsules, primary indication for surgery, surgical procedure, follow-up or implant duration, study methods, type of antibiotics or medical therapies and outcomes related to microbiota and immunological factors.

RESULTS

Data on immunological factors and bacterial contamination were retrieved from 64 included studies. Notably the presence of macrophages and Staphylococcus epidermidis within capsules was often associated with capsular contracture.

CONCLUSION

This review provides a clear overview of the immunological factors associated with capsular contracture and provides a hypothetical immunological model for development of the disease. Furthermore, an overview of bacterial contamination and associations with capsular contracture has been provided. Follow-up research may result in clinical recommendations to prevent capsular contracture.

Role of Mitomycin C in Preventing Capsular Contracture in Implant-Based Reconstructive Breast Surgery: A Randomized Controlled Trial

BACKGROUND

Capsular contracture represents the most frequent complication after implant-based breast reconstruction. An experimental study on mice demonstrated that capsule formation around breast implants is considerably diminished after topical application of mitomycin C. The authors conducted a randomized controlled clinical trial investigating the efficacy of mitomycin C in reducing capsular contracture rates following implant-based breast reconstruction after mastectomy for breast cancer.

METHODS

The authors randomized all women older than 18 years scheduled for the second stage of an implant-based breast reconstruction after mastectomy for breast cancer at the National Cancer Institute in Milan from October of 2005 to February of 2010 to receive or not receive the topical application of mitomycin C during surgery. The authors assessed capsular contracture, major postoperative complications, and aesthetic outcome.

RESULTS

The authors randomized 322 patients to receive mitomycin C or not at the second stage of implant-based breast reconstruction. One hundred sixty-two patients were allocated to the mitomycin C group and 160 patients were allocated to the control group. The relative risk of capsular contracture in the mitomycin C group was 0.92 (95 percent CI, 0.60 to 1.41). Major complications leading to reintervention, oncologic outcomes, and aesthetic outcomes were comparable between the two groups.

CONCLUSIONS

This is the first trial reporting data about the use of mitomycin C in breast reconstructive surgery in a clinical setting. Mitomycin C seems not to significantly affect capsular contracture rate and severity following implant-based reconstructive breast surgery at the tested doses.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

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.

Impedance Changes and Fibrous Tissue Growth after Cochlear Implantation Are Correlated and Can Be Reduced Using a Dexamethasone Eluting Electrode

BACKGROUND

The efficiency of cochlear implants (CIs) is affected by postoperative connective tissue growth around the electrode array. This tissue formation is thought to be the cause behind post-operative increases in impedance. Dexamethasone (DEX) eluting CIs may reduce fibrous tissue growth around the electrode array subsequently moderating elevations in impedance of the electrode contacts.

METHODS

For this study, DEX was incorporated into the silicone of the CI electrode arrays at 1% and 10% (w/w) concentration. Electrodes prepared by the same process but without dexamethasone served as controls. All electrodes were implanted into guinea pig cochleae though the round window membrane approach. Potential additive or synergistic effects of electrical stimulation (60 minutes) were investigated by measuring impedances before and after stimulation (days 0, 7, 28, 56 and 91). Acoustically evoked auditory brainstem responses were recorded before and after CI insertion as well as on experimental days 7, 28, 56, and 91. Additionally, histology performed on epoxy embedded samples enabled measurement of the area of scala tympani occupied with fibrous tissue.

RESULTS

In all experimental groups, the highest levels of fibrous tissue were detected in the basal region of the cochlea in vicinity to the round window niche. Both DEX concentrations, 10% and 1% (w/w), significantly reduced fibrosis around the electrode array of the CI. Following 3 months of implantation impedance levels in both DEX-eluting groups were significantly lower compared to the control group, the 10% group producing a greater effect. The same effects were observed before and after electrical stimulation.

CONCLUSION

To our knowledge, this is the first study to demonstrate a correlation between the extent of new tissue growth around the electrode and impedance changes after cochlear implantation. We conclude that DEX-eluting CIs are a means to reduce this tissue reaction and improve the functional benefits of the implant by attenuating electrode impedance.

Histological characterization of human breast implant capsules

Background

This study investigated the relationships between histomorphological aspects of breast capsules, including capsule thickness, collagen fiber alignment, the presence of α-smooth muscle actin (α-SMA)–positive myofibroblasts, and clinical observations of capsular contracture.

Methods

Breast capsule samples were collected at the time of implant removal in patients undergoing breast implant replacement or revision surgery. Capsular contracture was scored preoperatively using the Baker scale. Histological analysis included hematoxylin and eosin staining, quantitative analysis of capsule thickness, collagen fiber alignment, and immunohistochemical evaluation for α-SMA and CD68.

Results

Forty-nine samples were harvested from 41 patients. A large variation in histomorphology was observed between samples, including differences in cellularity, fiber density and organization, and overall structure. Baker I capsules were significantly thinner than Baker II, III, and IV capsules. Capsule thickness positively correlated with implantation time for all capsules and for contracted capsules (Baker III and IV). Contracted capsules had significantly greater collagen fiber alignment and α-SMA–positive immunoreactivity than uncontracted capsules (Baker I and II). Capsules from textured implants had significantly less α-SMA–positive immunoreactivity than capsules from smooth implants.

Conclusion

The histomorphological diversity observed between the breast capsules highlights the challenges of identifying mechanistic trends in capsular contracture. Our findings support the role of increasing capsule thickness and collagen fiber alignment, and the presence of contractile myofibroblasts in the development of contracture. These changes in capsule structure may be directly related to palpation stiffness considered in the Baker score. Approaches to disrupt these processes may aid in decreasing capsular contracture rates.

Level of Evidence III

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Multiple extracorporeal shock wave therapy degrades capsular fibrosis after insertion of silicone implants

Capsular fibrosis is the most frequent long-term complication after insertion of silicone devices. Today, mainly direct immunostimulation and subclinical infection are held responsible for inducing and maintaining inflammatory reactions, which lead to overwhelming extracellular matrix formation. Extracorporeal shock waves (ESWs) are capable of inhibiting inflammatory processes and revealing antibacterial capacity. In our previous study, we observed decelerated capsule development after application of a single shock wave immediately after surgery. The purpose of this study was to evaluate the effects of multiple ESWT after insertion of silicone implants in the same rodent model. Therefore, silicone prostheses were inserted into a submuscular pocket in 12 additional male Lewis rats, and shock waves were administered over a 14-d interval. At 35 d (n = 6) and 100 d (n = 6) after insertion, silicone implants and surrounding capsule tissue were removed and prepared for histologic and immunohistochemical analysis, as well as polymerase chain reaction (Ccl2, CD68, transforming growth factor β1, matrix metalloproteinase 2). Compared with the control group, multiple ESWT had no effect on day 35, but resulted in a significantly thinner capsule on day 100 (825.8 ± 313.2 vs. 813.3 ± 47.9, p = 0.759, and 1062.3 ± 151.9 vs. 495.4 ± 220.4, p < 0.001, respectively). The capsule was even thinner than after a single shock wave application, which had been found to result in thinner capsules at every time point in our previous study. This active degradation of the fibrous envelope caused by multiple ESWs was accompanied by synergistic alterations in pro- and anti-fibrotic proteins (transforming growth factor β1 and matrix metalloproteinase 2, respectively). In conclusion, after insertion of silicone devices, single ESWT is capable of decelerating capsule formation in contrast to multiple ESWT, which degrades fibrotic tissue. These findings seem to be associated with inhibition of inflammation and beneficial effects on pro- and anti-fibrotic proteins.

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.

Effect of propranolol on capsular reaction around silicone implants in guinea pigs

PURPOSE

To evaluate the effect of propranolol on capsular architecture around silicone implants by measuring the inflammation, capsular thickness, and collagen fiber density, using a guinea pig experimental model.

METHODS

Thirty six adult male guinea pigs randomly divided into two groups (n=18) were used. Each one received a silicone implant with textured-surface. The capsular tissue around implants from untreated or treated animals with the beta-adrenoceptor antagonist propranolol (10 mg/kg, dissolved in daily water) were analyzed for inflammation by histological scoring, capsular thickness by computerized histometry, and collagen fibers type I and Type III density by picrosirius polarization at different time points (7, 14 or 21 days after silicone implantation).

RESULTS

Propranolol treatment reduced inflammation and impaired capsular thickness and delayed collagen maturation around the textured implant.

CONCLUSION

Propranolol reduces the risk of developing capsular contracture around silicone implants with textured surface.

Further evidence that human acellular dermal matrix decreases inflammatory markers of capsule formation in implant-based breast reconstruction

BACKGROUND

Human acellular dermal matrix (HADM; previously termed "acellular cadaveric dermis") may limit inflammatory changes believed to play a role in capsular contracture, a common complication of implant-based breast reconstruction.

OBJECTIVES

Differences between HADM and native breast capsule specimens were evaluated by immunohistochemical analysis of key inflammatory markers involved in capsule formation.

METHODS

Twenty consecutive patients underwent immediate, 2-stage, implant-based breast reconstruction with dual-plane HADM. During tissue expander-implant exchange, full-thickness biopsies of biointegrated HADM and native breast capsule (internal control) from the tissue-expander envelope were obtained. Immunohistochemical analysis was performed for endothelial cells (CD31), B cells (CD20), T cells (CD3), macrophages (CD68), collagen I and III, and myofibroblasts (α-smooth muscle actin). Observed levels of marker labeling were semiquantitatively scored from 0 (none) to 3 (severe) by a blinded histopathologist and were statistically analyzed with the Wilcoxon rank sum test.

RESULTS

A bilateral sample was obtained from 1 patient; all other samples were unilateral. Compared with capsule samples from native breast tissue, HADM samples had significantly lower levels of all inflammatory markers (P < .001).

CONCLUSIONS

These lower levels of inflammatory markers support previous evidence that HADM may inhibit inflammatory and profibrotic signaling characteristics of breast capsule development and decrease the risk of capsular contracture. Further investigation is needed to determine the mechanism by which HADM inhibits these inflammatory cells, whether HADM reduces the incidence of breast capsular contracture, and if so, the longevity of this effect.

Mast cells in the periprosthetic breast capsule

BACKGROUND

Symptomatic capsular contracture occurs in about 10 % of primary breast augmentations and in more than double that rate in reconstruction after mastectomy, especially in the setting of radiation. Mast cells, traditionally associated with immune response and inflammation, secrete profibrotic mediators and may play a role in capsule formation and contracture. We analyzed the mast cell and fibroblast populations in breast capsule tissue from patients who underwent capsular excision.

METHODS

Capsule tissue was collected from patients who underwent exchange of tissue expanders for permanent implants, revision of reconstruction, or revision augmentation. Breast capsule tissues were prepared for histological analyses of mast cells, fibroblasts, and collagen. Mast cells and fibroblasts were isolated from capsule tissue and screened for mediators and receptor expression.

RESULTS

In breast capsule tissue, the average numbers of mast cells and fibroblasts were 9 ± 1/mm(2) and 33 ± 10/mm(2), respectively. There were significantly more mast cells on the posterior side than on the anterior side of the capsule tissue (12 ± 2 vs. 6 ± 1/mm(2), p < 0.01). Baker grade IV capsules had an increased number of fibroblasts compared to Baker grade I capsules (93 ± 9 vs. 40 ± 19/mm(2), p < 0.001). In breast capsule tissue, mast cells contained renin, histamine, and TGF-β, and their respective receptors, AT1R, H1R, and TGF-βRI were expressed by fibroblasts.

CONCLUSION

These data indicate that within breast capsule tissue mast cells contain mediators that may activate neighboring fibroblasts. Understanding the role of mast cells in pathologic periprosthetic breast capsule formation may lead to novel therapies to prevent and treat capsular contracture.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266.

Experimental total wrapping of breast implants with acellular dermal matrix: a preventive tool against capsular contracture in breast surgery?

BACKGROUND

Capsular contracture remains a hitherto unsolved complication after implantation of silicone gel-filled breast prostheses. Based on clinical and experimental data, the use of an acellular dermal matrix as a sheath around implants may lead to lesser capsular contracture acting as a proposed biological environment mimicking wound bed tissue. The aim of our study was to analyse the tissue reaction after implantation of silicone prosthesis with and without an envelope of acellular dermal matrix.

METHODS

Implantation of 60 silicone prostheses in the back of Lewis rats were carried out, randomly paired taking one rat from group A and one from group B. Group A included implants completely enveloped with xenogenic acellular dermis and group B undraped silicone implants. At 3, 6 and 12 weeks postoperatively, the samples were explanted and subjected to histological and immunohistochemical evaluation.

RESULTS

A new myofibroblast tissue layer was identified in proximity to the implant in both groups. The thickness of the layer in group A was continuously thinner than in group B regarding the different explantation time points. Implants completely wrapped with acellular dermal matrix showed significantly lesser inflammatory signs at 3 and 12 weeks after implantation compared to controls. Cell proliferation after 12 weeks was significantly decreased in group A.

CONCLUSION

The slight myofibroblast layer and reduced rate of inflammation and proliferation in the treatment group show a positive effect of total acellular dermal matrix envelope and hypothesise the decrease of capsular contracture in long-term periods.

Influence of curing agent on fibrosis around silicone implants

Severe capsular contracture around silicone expander breast implants leading to pain and failure is a major clinical problem. Even though earlier studies have implicated the immunogenicity of silicone, the role of physical and chemical properties of the silicone material in excessive collagen deposition and fibrosis has been less addressed. The present study investigates whether there is any correlation between the type of curing systems i.e. addition and free radical curing and the fibrosis around silicone elastomer. The experiment carried out uses commercially available silicone ventriculo-peritoneal shunt material elastomer cured by platinum and the results are compared with results obtained in a similar study carried out by the authors using commercially available silicone tissue expander material cured by peroxide. Ultra-high molecular weight poly-ethylene (UHMWPE), the standard reference for biocompatibility evaluation, was used as the control material. The materials were implanted in rat skeletal muscle for 30 and 90 days. Inflammatory cells, myofibroblasts, cytokines, and collagen deposition at the material-tissue interface were identified by haematoxylin-eosin and Masson's Trichrome stains and semi-quantitated based on immunohistochemical studies. Results indicate that even though the cellular response in the initial phase of wound healing was similar in both platinum and peroxide-cured materials, the collagen deposition in the proliferative phase was more around peroxide-cured material in comparison to the platinum-cured silicone elastomer. There is a need to look into the molecular mechanisms of this interaction and the possibility of using curing systems other than free radical peroxide in the manufacture of silicone elastomer expanders for breast prosthesis.

The periprosthetic capsule and connective tissue diseases: a piece in the puzzle of autoimmune/autoinflammatory syndrome induced by adjuvants

Breast prostheses have been criticized for being responsible for triggering systemic autoimmune disease. The presence of breast implants causes a natural foreign body reaction characterized by the infiltration of macrophages and T-cells. Using PubMed, Medline and eMedicine, we performed a systematic literature review on the stages of periprosthetic capsule formation and cells involved in order to understand which immunological pathways could be responsible for giving rise to, and the development of, connective tissue disease such as systemic sclerosis. We focused on the relationship between tissue growth factor- β, interleukin (IL)-1, IL-6 and T helper 17 or T regulatory cells, as well as on their effects on the different steps of capsular tissue formation. A disturbance in the modulation of these key cytokines may be responsible, in susceptible individuals, for a perpetuation of the inflammatory reaction which can locally lead to capsular contracture and at the systemic level may contribute to triggering autoimmune diseases.

Capsular contracture - What are the risk factors? A 14 year series of 1400 consecutive augmentations

The modern era of breast augmentation and reconstruction began in 1963, with the introduction of silicone implants by Cronin and Gerow. To date, the demand for cosmetic augmentation continues to increase exponentially. However, whilst the surgical techniques and quality of mammary prosthesis have improved dramatically in recent years, patients are still confronted with significant potential complications. We performed a retrospective study of 1400 consecutive primary breast augmentations performed between March 1995 and March 2009 by a single surgeon. We specifically examined the incidence of capsular contracture and the possible causative factors. Follow up ranged from 1 to 16 years. The mean age at the time of surgery was 32.8 years and fill volume was between 195 ml and 800 ml. Our capsular contracture rate was in the order of 26.9%. BMI >30, fill volumes >350 ml, smoking and alcohol consumption did not significantly increase capsular contracture rate. Implant type, pregnancy, infection and delayed haematoma significantly increased the risk of capsular contracture. Our series has given us a unique insight into the frequency of capsular contracture and identified several risk factors. To our knowledge, this is the first report of pregnancy having a significant effect on capsular contracture. We now counsel patients thoroughly into the detrimental effects of pregnancy on the implant.

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

BACKGROUND

The root cause of capsular contracture (CC) associated with breast implants is unknown. Recent evidence points to the possible role of fibrin and bacteria in CC formation.

OBJECTIVES

The authors sought to determine whether fibrin, thrombin, and blood modulated the histological and microbiological outcomes of breast implant capsule formation in a rabbit model.

METHODS

The authors carried out a case-control study to assess the influence of fibrin, thrombin, and blood on capsule wound healing in a rabbit model. Eighteen New Zealand white rabbits received four tissue expanders. One expander acted as a control, whereas the other expander pockets received one of the following: fibrin glue, rabbit blood, or thrombin sealant. Intracapsular pressure/volume curves were compared among the groups, and histological and microbiological evaluations were performed (capsules, tissue expanders, rabbit skin, and air). The rabbits were euthanized at two or four weeks.

RESULTS

At four weeks, the fibrin and thrombin expanders demonstrated significantly decreased intracapsular pressure compared to the control group. In the control and fibrin groups, mixed inflammation correlated with decreased intracapsular pressure, whereas mononuclear inflammation correlated with increased intracapsular pressure. The predominant isolate in the capsules, tissue expanders, and rabbit skin was coagulase-negative staphylococci. For fibrin and thrombin, both cultures that showed an organism other than staphylococci and cultures that were negative were associated with decreased intracapsular pressure, whereas cultures positive for staphylococci were associated with increased intracapsular pressure.

CONCLUSIONS

Fibrin application during breast implantation may reduce rates of CC, but the presence of staphylococci is associated with increased capsule pressure even in the presence of fibrin, so care should be taken to avoid bacterial contamination.

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.

Smooth and textured silicone surfaces of modified gel mammary prostheses cause a different impact on fibroproliferative properties of dermal fibroblasts

Our study addressed the question of whether surface properties of modern standard gel prostheses may have a measurable impact on the fibrogenic properties of cultured human dermal fibroblasts. Fibroblasts were isolated from breast implants by using the explant culture technique and incubated either on smooth or on textured silicone elastomere surfaces. Fibroblast growth was observed 4 weeks following incubation. Expression of transforming growth factor (TGF)-β1 was measured after cell culture. Incubated fibroblasts on textured surfaces showed a fivefold lower growth rate during all experiments. TGF-β1 expression was lowered in smooth surface fibroblasts compared with textured surface cultures. Our results show that smooth and textured silicone surfaces of modified gel breast implants have a different impact on the fibroproliferative properties of dermal fibroblasts. These preliminary results seem promising and we aim to further perform qualitative and quantitative analyses of the inflammatory processes in the environment of the implant and their link to the TGF-β pathway.

Role of immune cells and inflammatory cytokines in regulation of fibrosis around silicone expander implants

This study aimed to investigate the progress of wound healing around silicone expander with particular emphasis on fibroblasts, myofibroblasts and collagen in the repair phase. Semi-quantitative evaluation of inflammatory cells and their cytokines, fibroblasts and myofibroblasts at the tissue-material interface was carried out. Commercially available silicone expander was implanted in gluteus muscle of young female Wistar rats for 3, 7, 14, 30, 90 and 180 days. Ultra high molecular weight polyethylene served as control. The cellular response was studied by immunohistochemistry and Transmission Electron Microscopy. A thick collagenous fibrous capsule was observed around the silicone expander at 180 days, with persistent myofibroblasts, lymphocytes and macrophages as compared to the thin fibrous encapsulation around the UHMWPE implants. The regulatory role of cytokines and immune cells in myofibroblast persistence in tissue-implant interface around silicone expander has been extensively studied. Results of this study indicate the need to elucidate the signaling molecules in the transition of fibroblast to myofibroblast around silicone expander implants.

The immunology of fibrosis: innate and adaptive responses

Fibrosis is an important health problem, and its pathogenetic principles are still largely unknown. It can develop either spontaneously, or, more frequently, as a consequence of various underlying diseases. Irrespective of the primary cause, however, fibrotic tissue is always infiltrated by mononuclear immune cells. In most instances the reason for the attraction of these cells to fibrotic tissue and their proliferation remains to be determined; however their cytokine profile shows clear-cut proinflammatory and profibrotic characteristics. In this review, we discuss the innate and adaptive immune reactions associated with the development of fibrosis and the molecular basis of the profibrotic mechanisms taking place in systemic sclerosis (scleroderma), arteriosclerosis and peri-silicone mammary implant fibrosis.

Altered systemic serologic parameters in patients with silicone mammary implants

BACKGROUND

The most common local complication in patients with silicone mammary implants (SMIs) is excessive peri-SMI connective tissue capsule formation and its subsequent contracture. However, considerable controversy remains as to whether these implants also cause systemic side effects. The present study was undertaken to identify possible alterations of serological markers in SMI patients that may herald systemic side effects.

METHODS

We investigated several systemic serological parameters in 143 individuals, 93 of whom had received SMIs and 50 were controls. The patients were grouped according to the severity of capsular contracture (Baker scores I-IV) and the duration of SMI implants (less than 1 year, between 1 and 5 years, more than 5 years). We also included control groups (female blood donors, nurses with possible professional silicone exposure). Patients with breast cancer and subsequent SMI-reconstruction were excluded from the study since they are generally considered immunocompromised. The following parameters were determined: anti-neutrophil cytoplasmatic autoantibodies (cANCA), anti-nuclear autoantibodies (ANA), anti-cardiolipin antibodies (CL-Ab), rheumatoid factor (RF), complement components (C3, C4), circulating immune complexes (CIC), procollagen III (a marker of active fibrosis), anti-polymer antibodies (APA) and soluble intercellular adhesion molecule-1 (sICAM-1).

RESULTS

The following parameters were increased in the sera of SMI patients: CIC, procollagen III, APA, sICAM-1.

CONCLUSIONS

We found a set of parameters in serum that correlate with fibrosis development and the duration of the implants in otherwise healthy SMI carriers. Future studies will clarify whether these serological abnormalities will be useful in predicting clinical disease, and also further assess the sensitivity and specificity of these parameters. Our present recommendation as a result of this study is that SMI patients with persistent abnormal serological parameters should be monitored closely by a clinical team that includes rheumatologists.