Clinical and Morphological Conditions in Capsular Contracture Formed around Silicone Breast Implants

The cellular and molecular properties of capsule surrounding silicone implants in humans vary uniquely according to the tissue type adjacent to the implant

The foreign body reaction (FBR) to biomaterials results in fibrous encapsulation. Excessive capsule fibrosis (capsular contracture) is a major challenge to the long-term stability of implants. Clinical data suggests that the tissue type in contact with silicone breast implants alters susceptibility to developing capsular contracture; however, the tissue-specific inflammatory and fibrotic characteristics of capsule have not been well characterized at the cellular and molecular level. In this study, 60 breast implant capsule samples are collected from patients and stratified by the adjacent tissue type including subcutaneous tissue, glandular breast tissue, or muscle tissue. Capsule thickness, collagen organization, immune and fibrotic cellular populations, and expression of inflammatory and fibrotic markers is quantified with histological staining, immunohistochemistry, and real-time PCR. The findings suggest there are significant differences in M1-like macrophages, CD4+ T cells, CD26+ fibroblasts, and expression of IL-1β, IL-6, TGF-β, and collagen type 1 depending on the tissue type abutting the implant. Subglandular breast implant capsule displays a significant increase in inflammatory and fibrotic markers. These findings suggest that the tissue microenvironment contributes uniquely to the FBR. This data could provide new avenues for research and clinical applications to improve the site-specific biocompatibility and longevity of implantable devices.

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 .

Impact of Tissue Expander Surface Texture on Two-Stage Breast Reconstruction Outcomes: A Combined Analysis

BACKGROUND

With ongoing investigations of the impact of device texturing on breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL), studies have begun comparing complication profiles of tissue expanders. However, there is a paucity of timing and severity data of complications. The aim of this study was to provide a comparative survival analysis of postoperative complications between smooth (STEs) and textured tissue expanders (TTEs) in breast reconstruction.

METHODS

A single-institution experience with tissue expander breast reconstruction was reviewed for complications up to 1 year after second-stage reconstruction from 2014 to 2020. Demographics, comorbidities, operation-related variables, and complications were evaluated. Kaplan-Meier curves, Cox proportional hazard models, and a consensus-based ordinal logistic regression model were used to compare complication profiles.

RESULTS

Of 919 total patients, 600 (65.3%) received TTEs and 319 (34.7%) received STEs. There was increased risk of infection ( P < 0.0001), seroma ( P = 0.046), expander malposition ( P < 0.0001), and wound dehiscence ( P = 0.019) in STEs compared with TTEs. However, there was also a decreased risk of capsular contracture ( P = 0.005) in STEs compared with TTEs. Failure of breast reconstruction ( P < 0.001) and wound dehiscence ( P = 0.018) occurred significantly earlier in STEs compared with TTEs. Predictors for significantly higher severity complications included the following: smooth tissue expander use ( P = 0.007), shorter time to complication ( P < 0.0001), higher body mass index ( P = 0.005), smoking history ( P = 0.025), and nipple-sparing mastectomy ( P = 0.012).

CONCLUSIONS

Differences in the timing and severity of complications contribute to the safety profiles of tissue expanders. STEs are associated with increased odds of higher severity and earlier complications. Therefore, tissue expander selection may depend on underlying risk factors and severity predictors.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

The Spectrum of Non-neoplastic Changes Associated With Breast Implants: Histopathology, Imaging, and Clinical Significance

Breast implant-associated anaplastic large cell lymphoma has been recognized as a distinct entity in the World Health Organization classification of hematolymphoid neoplasms. These neoplasms are causally related to textured implants that were used worldwide until recently. Consequently, there is an increased demand for processing periprosthetic capsules, adding new challenges for surgeons, clinicians, and pathologists. In the literature, the focus has been on breast implant-associated anaplastic large cell lymphoma; however, benign complications related to the placement of breast implants occur in up to 20% to 30% of patients. Imaging studies are helpful in assessing patients with breast implants for evidence of implant rupture, changes in tissues surrounding the implants, or regional lymphadenopathy related to breast implants, but pathologic examination is often required. In this review, we couple our experience with a review of the literature to describe a range of benign lesions associated with breast implants that can be associated with different clinical presentations or pathogenesis and that may require different diagnostic approaches. We illustrate the spectrum of the most common of these benign disorders, highlighting their clinical, imaging, gross, and microscopic features. Finally, we propose a systematic approach for the diagnosis and handling of breast implant specimens in general.

Impact of post-operative infection on revision procedures in breast reconstruction: A marketscan database analysis

BACKGROUND

Esthetic complications, such as capsular contracture and soft-tissue contour defects, hinder the desired outcomes of breast reconstruction. As subclinical infection is a prevailing theory behind capsular contracture, we investigated the effects of post-operative infections on these issues and revision procedures.

METHODS

We conducted a retrospective database study (2007-2021) on breast reconstruction patients from the MarketScan® Databases. Esthetic complications were defined by their associated revision procedures and queried via CPT codes. Severe capsular contracture (Grade 3-4) was defined as requiring capsulotomy or capsulectomy with implant removal or replacement. Moderate and severe soft-tissue defects were determined by the need for fat grafting or breast revision, respectively. Generalized linear models were used, adjusting for comorbidities and surgical factors (p < 0.05).

RESULTS

We analyzed the data on 62,510 eligible patients. Post-operative infections increased the odds of capsulotomy (OR 1.59, p < 0.001) and capsulectomy (OR 2.30, p < 0.001). They also raised the odds of breast revision for severe soft-tissue defects (OR 1.21, p < 0.001). There was no significant association between infections and fat grafting for moderate defects. Patients who had post-operative infections were also more likely to experience another infection after fat grafting (OR 3.39, p = 0.0018). In two-stage reconstruction, infection after tissue expander placement was associated with greater odds of infection after implant placement.

CONCLUSION

Post-operative infections increase the likelihood of developing severe soft-tissue defects and capsular contracture requiring surgical revision. Our data reinforce the role of infections in the pathophysiology of capsular contracture. Additionally, infections elevate the risk of subsequent infections after fat grafting for moderate defects, further increasing patient morbidity.

Development and Validation of a Diagnostic Histopathological Scoring System for Capsular Contracture Based on 720 Breast Implant Capsules

BACKGROUND

Capsular contracture is traditionally evaluated with the Baker classification, but this has notable limitations regarding reproducibility and objectivity.

OBJECTIVES

The aim of this study was to develop and validate procedure-specific histopathological scoring systems to assess capsular contracture severity.

METHODS

Biopsies of breast implant capsules were used to develop histopathological scoring systems for patients following breast augmentation and breast reconstruction. Ten histological parameters were evaluated by multivariable logistic regression to identify those most associated with capsular contracture. Significant parameters (P < .05) were selected for the scoring systems and assigned weighted scores (1-10). Validation was assessed from the area under the curve (AUC) and the mean absolute error (MAE).

RESULTS

A total of 720 biopsies from 542 patients were included. Four parameters were selected for the augmentation scoring system, namely, collagen layer thickness, fiber organization, inflammatory infiltration, and calcification, providing a combined maximum score of 26. The AUC and MAE for the augmentation scoring system were 81% and 0.8%, which is considered strong. Three parameters were selected for the reconstruction scoring system, namely, fiber organization, collagen layer cellularity, and inflammatory infiltration, providing a combined maximum score of 19. The AUC and MAE of the reconstruction scoring system were 72% and 7.1%, which is considered good.

CONCLUSIONS

The new histopathological scoring systems provide an objective, reproducible, and accurate assessment of capsular contracture severity. We propose these novel scoring systems as a valuable tool for confirming capsular contracture diagnosis in the clinical setting, for research, and for implant manufacturers and insurance providers in need of a confirmed capsular contracture diagnosis.

LEVEL OF EVIDENCE: 3

Implant-Based Breast Reconstruction with Bovine Pericardium: Our Approach Using Tutopatch® and Review of Literature

OBJECTIVES

To describe the usage and advantages of bovine pericardium mesh (Tutopatch®) in breast reconstruction and to compare different mesh materials used in immediate breast reconstruction.

METHODS

Our study involved a single-center, retrospective analysis of 103 patients (comprising 114 breasts) who underwent immediate implant-based breast reconstruction using bovine pericardium bovine matrix. The procedures were performed by the same surgical team between April 2018 and May 2023.

RESULTS

The rates of early and late complications were examined after a median follow-up period of 30.2 ± 5.5 months. The results revealed that the rates of early complications stood at 9.7%, while late complications were observed in 14.5% of the cases. The most common late complication was seroma formation (7.7%) which six were resolved without any surgical intervention.

CONCLUSION

Tutopatch® can be used as an extension of the muscle to cover the prosthesis. It forms an extra layer over the silicone implant that helps to decrease the complications as capsular contracture and implant exposure. It also represents a significant 85 % reduction in cost when compared to a similar-sized mesh materials.

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 .

Incidence and Risk Assessment of Capsular Contracture in Breast Cancer Patients following Post-Mastectomy Radiotherapy and Implant-Based Reconstruction

Our study aims to identify the risk factors and dosimetry characteristics associated with capsular contracture.

METHODS

We retrospectively analyzed 118 women with breast cancer who underwent PMRT following an IBR between 2010 and 2022. Patients were treated with PMRT of 50.0-50.4 Gy in 25-28 fractions. Capsular contracture was categorized according to the Baker Classification for Reconstructed Breasts.

RESULTS

After a median follow-up of 22 months, the incidence of clinically relevant capsular contracture (Baker III-IV) was 22.9%. Overall, capsular contracture (Baker I-IV) occurred in 56 patients (47.5%) after a median of 9 months after PMRT. The rate of reconstruction failure/implant loss was 25.4%. In the univariate analysis, postoperative complications (prolonged pain, prolonged wound healing, seroma and swelling) and regional nodal involvement were associated with higher rates of capsular contracture (p = 0.017, OR: 2.5, 95% CI: 1.2-5.3 and p = 0.031, respectively). None of the analyzed dosimetric factors or the implant position were associated with a higher risk for capsular contracture.

CONCLUSION

Postoperative complications and regional nodal involvement were associated with an increased risk of capsular contracture following breast reconstruction and PMRT, while none of the analyzed dosimetric factors were linked to a higher incidence. Additional studies are needed to identify further potential risk factors.

Biocompatibility of polyurethane-coated breast implants: A histological comparison of implant capsules

BACKGROUND

Biocompatibility describes the influence of materials on their biological environment. Implant material in the human body can cause a foreign body reaction and the formation of a capsule around the foreign material. Since capsular formation is the most frequent issue after breast-implant insertion, knowledge and awareness of biocompatibility is crucial, especially since worldwide, breast augmentation continues to be the most popular plastic surgery, with over 1.6 million procedures performed in 2020, according to surveys by the International Society of Aesthetic Plastic Surgery (ISAPS).

MATERIAL AND METHODS

This study includes 80 capsular samples of female patients who underwent revision surgery after breast-implant insertion at the University Hospital Regensburg. Capsules of breast implants with different surface structures (smooth, textured and polyurethane-coated) and shapes (round-shaped, anatomically-shaped) were analyzed histologically after hematoxylin-eosin-staining in respect to capsular thickness and layer formation.

RESULTS

Capsular thickness and layering showed a statistically significant difference between polyurethane-coated and smooth as well as polyurethane-coated and textured implants. Capsules around polyurethane-coated implants presented greater thickness. However, the difference between smooth and textured implants was not statistically significant. Furthermore, the shape of the implants also indicated a statistically significant difference in capsular thickness. Implants of anatomical shape resulted in a thinner capsule than round-shaped breast-implants.

CONCLUSION

In conclusion, this study demonstrated a thicker capsule around polyurethane-coated breast implants and no difference in capsular thickness between smooth and textured breast implants. Anatomically shaped breast-implants presented a thinner capsule than round shaped breast-implants.

Machine-Learning Prediction of Capsular Contraction after Two-Stage Breast Reconstruction

Background

Two-stage breast reconstruction is a common technique used to restore preoperative appearance in patients undergoing mastectomy. However, capsular contracture may develop and lead to implant failure and significant morbidity. The objective of this study is to build a machine-learning model that can determine the risk of developing contracture formation after two-stage breast reconstruction.

Methods

A total of 209 women (406 samples) were included in the study cohort. Patient characteristics that were readily accessible at the preoperative visit and details pertaining to the surgical approach were used as input data for the machine-learning model. Supervised learning models were assessed using 5-fold cross validation. A neural network model is also evaluated using a 0.8/0.1/0.1 train/validate/test split.

Results

Among the subjects, 144 (35.47%) developed capsular contracture. Older age, smaller nipple-inframammary fold distance, retropectoral implant placement, synthetic mesh usage, and postoperative radiation increased the odds of capsular contracture (p < 0.05). The neural network achieved the best performance metrics among the models tested, with a test accuracy of 0.82 and area under receiver operative curve of 0.79.

Conclusion

To our knowledge, this is the first study that uses a neural network to predict the development of capsular contraction after two-stage implant-based reconstruction. At the preoperative visit, surgeons may counsel high-risk patients on the potential need for further revisions or guide them toward autologous reconstruction.

Activin A and Follistatin Serum Concentrations in Breast Augmentation Patients

Background: Capsular contracture is caused by an excessive fibrotic reaction similar as observed in other progressive fibrotic disorders. For their pathogenesis, several studies confirmed the importance of activins and follistatin. The aim of this study was to determine and analyze serum levels of Activin A and follistatin in patients with capsular contracture after aesthetic breast augmentation. Methods: The study included 361 female patients who underwent primary aesthetic breast augmentation, came for control examination after breast augmentation or for revision operation because of capsular contracture. Blood samples were taken and using a specific ELISA to determine the serum concentration levels of Activin A and Follistatin. Results: Ninety-six patients (n = 96), who developed a capsular contracture Baker ≥°III and underwent revision surgery were collected (capsular fibrosis group). One-hundred and fourteen patients (n = 114) were asymptomatic for capsular fibrosis Baker ≥°III after primary breast augmentation and 33 (n = 33) of them had developed no capsular fibrosis after more than 10 years (long-term group). For control group, blood samples were taken from 167 patients (n = 167) before primary aesthetic breast augmentation. Serum Activin A levels were significantly higher in the long-term Group compared with those in the capsular fibrosis- and the control groups. Follistatin levels were significantly lower in the capsular fibrosis group compared to the control- and the long-term groups. A small amount of control group patients (n = 16) developed a capsular fibrosis within 2 years after primary breast augmentation with significant lower follistatin levels. Retrospectively, they showed significantly lower serum follistatin levels than the control group even before the onset of capsular contracture. Conclusions: Capsular fibrosis has no effect on Activin A serum levels. In contrast, follistatin serum levels are lower in patients with capsular fibrosis. These results show that besides many other factors, a dysregulation of the Activin-follistatin axis may have importance on the pathogenesis of capsular contracture.

Matrix Metalloproteinase-9 as a Potential Biomarker in 631 Human Implant-Induced Fibrotic Capsules: Analysis and Biomarker Study

BACKGROUND

Capsular fibrosis (CF) often occurs around biomedical devices following implantation causing pain, discomfort, and device failure. Breast implantation remains among the most common medical procedures worldwide. Revealing specific genes that drive fibrotic deposition will help us to garner a better understanding of the pathophysiology of this disease and develop different strategies to combat it.

METHODS

The authors collected 631 capsules around breast implants and were able to connect clinical baseline characteristics with histopathologic findings. In addition, the authors were able to conduct the first large systematic analysis to identify differentially expressed genes in fibrotic human tissue samples, comparing the lowest form of fibrosis with the most aggravated one.

RESULTS

The authors identified 2559 differentially expressed genes on which they performed a knowledge-based network generation and pathway association study to identify putative novel biomarkers for CF. The authors were able to show changes of cellular influx during progression of CF and distinguish several genes as potential clinical biomarkers and drug targets. Among these, matrix metalloproteinase-9 was one of the most up-regulated ( P = 0.006) and is attractive because of its wide detectability.

CONCLUSIONS

Matrix metalloproteinase-9 seems to be a potential biomarker to detect capsular fibrosis. It is a measurable indicator that can easily be detected in blood, sputum, and urine. For the diagnosis of fibrosis, this biomarker might be exceedingly beneficial to developing novel screening methods and prophylaxes.

CLINICAL RELEVANCE STATEMENT

Discovering biomarkers at the earliest and mildest stages for the diagnosis of fibrosis is clinically important. These results bring new hope for biomarker-based diagnosis for capsular fibrosis.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, V.

An Antifibrotic Breast Implant Surface Coating Significantly Reduces Periprosthetic Capsule Formation

BACKGROUND

The body responds to prosthetic materials with an inflammatory foreign body response and deposition of a fibrous capsule, which may be deleterious to the function of the device and cause significant discomfort for the patient. Capsular contracture (CC) is the most common complication of aesthetic and reconstructive breast surgery. The source of significant patient morbidity, it can result in pain, suboptimal aesthetic outcomes, implant failure, and increased costs. The underlying mechanism remains unknown. Treatment is limited to reoperation and capsule excision, but recurrence rates remain high. In this study, the authors altered the surface chemistry of silicone implants with a proprietary anti-inflammatory coating to reduce capsule formation.

METHODS

Silicone implants were coated with Met-Z2-Y12, a biocompatible, anti-inflammatory surface modification. Uncoated and Met-Z2-Y12-coated implants were implanted in C57BL/6 mice. After 21, 90, or 180 days, periprosthetic tissue was removed for histologic analysis.

RESULTS

The authors compared mean capsule thickness at three time points. At 21, 90, and 180 days, there was a statistically significant reduction in capsule thickness of Met-Z2-Y12-coated implants compared with uncoated implants ( P < 0.05).

CONCLUSIONS

Coating the surface of silicone implants with Met-Z2-Y12 significantly reduced acute and chronic capsule formation in a mouse model for implant-based breast augmentation and reconstruction. As capsule formation obligatorily precedes CC, these results suggest contracture itself may be significantly attenuated. Furthermore, as periprosthetic capsule formation is a complication without anatomical boundaries, this chemistry may have additional applications beyond breast implants, to a myriad of other implantable medical devices.

CLINICAL RELEVANCE STATEMENT

Coating of the silicone implant surface with Met-Z2-Y12 alters the periprosthetic capsule architecture and significantly reduces capsule thickness for at least 6 months postoperatively in a murine model. This is a promising step forward in the development of a therapy to prevent capsular contracture.

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.

An Evaluation of Native Breast Dimension and Tissue Expander Inflation Rate on the Risk of Capsular Contracture Development in Postmastectomy Reconstruction

INTRODUCTION

Capsular contracture is a common complication after 2-stage breast reconstruction. The relationships between native breast size, the rate of tissue expander expansion, and capsule formation have not been elucidated. This study aims to evaluate how these factors contribute to capsular contracture and establish cutoff values for increased risk.

METHODS

A data set consisting of 229 patients who underwent 2-stage breast reconstruction between 2012 and 2021 was included in the study. The rate of expansion is estimated as the final expanded volume subtracted by the initial filling volume of the tissue expander over time elapsed. The native breast size was estimated using various preoperative breast measurements and the weight of mastectomy specimen (grams). Further stratified analysis evaluated patients separately based on postoperative radiation status.

RESULTS

Greater nipple-inframammary fold distance and faster tissue expander enlargement rate conferred decreased odds of developing capsular contracture ( P < 0.05). On stratified analysis, faster tissue expansion rate was not significant in the nonradiated cohort but remained a significant negative predictor in the radiation group (odds ratio, 0.996; P < 0.05). Cut-point analysis showed an expansion rate of <240 mL/mo and a nipple-inframammary fold value of <10.5 cm as conferring a greater risk of capsular contracture.

CONCLUSION

Smaller inframammary fold distance may be associated with a higher risk of capsular contracture. Slower expansion rates correlate with increased odds of contracture in patients undergoing adjuvant radiation. Breast geometry should be considered when risk stratifying various reconstruction approaches (implant vs autologous). In addition, longer delays between implant exchange and initial tissue expansion should be avoided if clinically feasible.

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.

Polyacrylamide-based hydrogel coatings improve biocompatibility of implanted pump devices

The introduction of transcutaneous and subcutaneous implants and devices into the human body instigates fouling and foreign body responses (FBRs) that limit their functional lifetimes. Polymer coatings are a promising solution to improve the biocompatibility of such implants, with potential to enhance in vivo device performance and prolong device lifetime. Here we sought to develop novel materials for use as coatings on subcutaneously implanted devices to reduce the FBR and local tissue inflammation in comparison to gold standard materials such as poly(ethylene glycol) and polyzwitterions. We prepared a library of polyacrylamide-based copolymer hydrogels, which were selected from materials previously shown to exhibit remarkable antifouling properties with blood and plasma, and implanted them into the subcutaneous space of mice to evaluate their biocompatibility over the course of 1 month. The top performing polyacrylamide-based copolymer hydrogel material, comprising a 50:50 mixture of N-(2-hydroxyethyl)acrylamide (HEAm) and N-(3-methoxypropyl)acrylamide (MPAm), exhibited significantly better biocompatibility and lower tissue inflammation than gold standard materials. Moreover, when applied to polydimethylsiloxane disks or silicon catheters as a thin coating (45 ± 1 μm), this leading copolymer hydrogel coating significantly improved implant biocompatibility. Using a rat model of insulin-deficient diabetes, we showed that insulin pumps fitted with HEAm-co-MPAm hydrogel-coated insulin infusion catheters exhibited improved biocompatibility and extended functional lifetime over pumps fitted with industry standard catheters. These polyacrylamide-based copolymer hydrogel coatings have the potential to improve device function and lifetime, thereby reducing the burden of disease management for people regularly using implanted devices.

Is It All about Surface Topography? An Intra-Individual Clinical Outcome Analysis of Two Different Implant Surfaces in Breast Reconstruction

The most common long-term complication of silicone breast implants (SMI) remains capsular fibrosis. The etiology of this exaggerated implant encapsulation is multifactorial but primarily induced by the host response towards the foreign material silicone. Identified risk factors include specific implant topographies. Of note, breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) has only been observed in response to textured surface implants. We hypothesize that reduction of SMI surface roughness causes less host response and, hence, better cosmetic outcomes with fewer complications for the patient. A total of 7 patients received the routinely used CPX^®4 breast expander (~60 µM Ra) and the novel SmoothSilk^® (~4 µM Ra), fixed prepectoral with a titanized mesh pocket and randomized to the left or right breast after bilateral prophylactic NSME (nipple-sparing mastectomy). We aimed to compare the postoperative outcome regarding capsule thickness, seroma formation, rippling, implant dislocation as well as comfortability and practicability. Our analysis shows that surface roughness is an influential parameter in controlling fibrotic implant encapsulation. Compared intra-individually for the first time in patients, our data confirm an improved biocompatibility with minor capsule formation around SmoothSilk^® implants with an average shell roughness of 4 µM and in addition an amplification of host response by titanized implant pockets.

Quantitative Proteomic Characterization of Foreign Body Response towards Silicone Breast Implants Identifies Chronological Disease-Relevant Biomarker Dynamics

The etiology of exaggerated fibrous capsule formation around silicone mammary implants (SMI) is multifactorial but primarily induced by immune mechanisms towards the foreign material silicone. The aim of this work was to understand the disease progression from implant insertion and immediate tissue damage response reflected in (a) the acute wound proteome and (b) the adsorption of chronic inflammatory wound proteins at implant surfaces. An intraindividual relative quantitation TMT-liquid chromatography-tandem mass spectrometry approach was applied to the profile wound proteome formed around SMI in the first five days post-implantation. Compared to plasma, the acute wound profile resembled a more complex composition comprising plasma-derived and locally differentially expressed proteins (DEPs). DEPs were subjected to a functional enrichment analysis, which revealed the dysregulation of signaling pathways mainly involved in immediate inflammation response and ECM turnover. Moreover, we found time-course variations in protein enrichment immediately post-implantation, which were adsorbed to SMI surfaces after 6-8 months. Characterization of the expander-adhesive proteome by a label-free approach uncovered a long-term adsorbed acute wound and the fibrosis-associated proteome. Our findings propose a wound biomarker panel for the early detection and diagnosis of excessive fibrosis that could potentially broaden insights into the characteristics of fibrotic implant encapsulation.

Effect of Carboxymethyl Chitin on Capsule Formation around Silicone Implants: An In Vivo and In Vitro Study

BACKGROUND

Capsular contracture is a serious complication that occurs after augmentation mammaplasty. The authors previously identified that carboxymethyl chitin had an inhibitory effect on capsule formation. This study was performed to elucidate the possible molecular mechanisms through which carboxymethyl chitin inhibits the formation of a capsule around silicone implants.

METHODS

In this study, the authors cultured human dermal fibroblasts and treated them with carboxymethyl chitin in vitro. The difference in proliferation between treated and untreated cells was analyzed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Protein levels of transforming growth factor beta-1 and alpha smooth muscle actin (α-SMA) were examined by Western blot analysis. Expression levels of type I and type III collagen were checked by enzyme-linked immunosorbent assay. In vivo, silicone implants were placed under the pectoralis muscle in 12 female rabbits. The thickness of the capsule was measured by histologic analysis, and the effect of carboxymethyl chitin on α-SMA, collagen type I and III expression levels was evaluated by real-time polymerase chain reaction analysis, enzyme-linked immunosorbent assay, Western blot, and immunofluorescence analysis.

RESULTS

In the in vitro study, we confirmed that carboxymethyl chitin inhibited the proliferation of fibroblasts. The protein expression levels of collagen type I, transforming growth factor beta-1, and α-SMA were inhibited by carboxymethyl chitin treatment. In vivo, carboxymethyl chitin treatment reduced capsular thickness and the expression of α-SMA and collagen types I and III in capsules around silicone implants.

CONCLUSION

The authors' results showed that carboxymethyl chitin could influence capsule formation around silicone implants by inhibiting the fibroblast activity, interrupting fibroblast-to-myofibroblast differentiation, and decreasing collagen synthesis.

CLINICAL RELEVANCE STATEMENT

Carboxymethyl chitin influence capsule formation around silicone implants. Although more clinical studies are needed to verify the effect of carboxymethyl chitin on capsular contracture, the authors believe that it will play an effective role in the clinical application of reducing the occurrence of capsular contracture.

Progranulin Promotes the Formation and Development of Capsules Caused by Silicone in Sprague-Dawley Rats

Background

Silicone implants are currently the most widely used artificial materials in plastic surgery. Capsule formation following implant application is unavoidable. When the capsule is excessively thick and strongly contracted, it can lead to obvious symptoms, clinically known as capsular contracture. Biological factors have always been the focus of research on the capsule formation. As a growth factor, progranulin (PGRN) plays an important regulatory role in wound healing, tissue fibrosis, tumor proliferation and invasion, and inflammation regulation. At present, the research on the capsule mainly involves the regulation of tissue healing and fibrosis under the influence of inflammation. Because PGRN has a regulatory role in these processes, we believe that the study of both can provide a new theoretical basis and intervention sites for monitoring and inhibiting the development of the capsule.

Methods

In this experiment, the effects of different surgical operations on the content of PGRN in the surgical site and plasma of rats were detected. Sprague-Dawley (SD) rat dermal fibroblasts were co-cultured by recombinant PGRN. The effects of r-PGRN on fibroblasts were detected by 5-ethynyl-2’-deoxyuridine (EdU) assay, wound healing assay and Western blot assay. Finally, the effect of PGRN on capsule formation and contracture was studied by changing the content of PGRN in the prosthesis in rats after operation.

Results

Surgical trauma and silicone implant increased plasma and local PGRN levels in SD rats. PGRN can activate the TGF-β/SMAD signaling pathway in a dose-dependent manner, thereby promoting fibroblast proliferation, differentiation and migration and inhibiting apoptosis and enhancing cell function, thereby promoting capsule formation and contracture.

Conclusion

PGRN promotes the formation and contracture of the silicone implant capsule in SD rats by activating the TGF-β/SMAD signaling pathway. This discovery may provide new therapeutic targets and detection indicators.

Defining the Relationship Between Pocket and Breast Implant Surface Area as the Basis for a New Classification System for Capsular Contracture

BACKGROUND

The precise etiology and treatment for capsular contracture remains uncertain at least partially due to the fact that there is no reliable quantitative measurement tool. To address this, it is postulated that the surface area of an implant as defined by the surrounding pocket may provide a quantifiable variable that can be measured to evaluate the degree of capsular contracture.

METHODS

A bench model for capsular contracture was developed. The surface area of a series of spherical test objects and non-contracted and contracted breast implants was measured using a wax coating technique as well as three-dimensional reconstructions created from CT scan images.

RESULTS

Comparison of the mathematically calculated surface areas to the wax and CT results for spheres of known dimension provided nearly identical values documenting the accuracy of the two experimental methods. Comparison of the surface area measurements between the test groups showed that the average decrease in surface area for all implants was 20%, ranging from a high of 30.9% for a low profile implant to a low of 14.1 % for a high profile implant. The anatomically shaped devices demonstrated nearly uniform degrees of surface area change over three different heights with volume and projection held relatively constant.

CONCLUSIONS

The described bench model provides a useful tool for the study of capsular contracture. Surface area is a descriptive variable that can assess the degree of capsular contracture that is present. A classification system based on surface area is presented.

Evaluation of Chlorhexidine Concentration on the Skin After Preoperative Surgical Site Preparation in Breast Surgery-A Randomized Controlled Trial

BACKGROUND

Although there is a rationale supporting that preoperative showering with 2% or 4% chlorhexidine gluconate (CHG) would decrease skin bacterial colonization, there is no consensus that this practice reduces the risk of surgical site infection (SSI).

OBJECTIVES

Analyze the skin concentration of CHG after preoperative showering associated with the traditional skin preparation with CHG 4% for breast surgery.

METHODS

Randomized controlled trial that included 45 patients, all candidates for augmentation mammaplasty, allocated into three groups (A: no preoperative showering; B: one preoperative showering; C: two preoperative showering with CHG 4%) in a 1:1:1 ratio. Skin swabs collection was performed right before the surgical incision. The samples were, then, sent to spectrophotometry in order to determine the skin concentration of CHG at the beginning of surgery.

RESULTS

The age ranged from 18 to 61 years, with a mean of 37 years old. Group C had the lowest median concentration (0.057) followed by group B (0.060) and group A (0.072), however, with no statistical significance. The areola was the place with the lowest median concentration level (0.045), followed by the axilla (0.061) and the inframammary fold (IMF) (0.069). Still, when comparing the distribution of the sites, a statistically significant difference was found only between the axilla and the areola (p = 0.022).

CONCLUSION

Preoperative showering with CHG 4% did not increase the concentration of this agent on the skin surface right before the surgical incision.

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 .

Capsule formation around breast implants

All implants are rapidly coated by the host with glycoproteins forming a thin capsule, and this is a normal response. Where an inflammatory stimulus such as infection is present, the capsule can thicken and become microvascularised and sometimes calcified. This inflammatory stimulus can take the form of leachable chemicals from the implant, or bacteria live or dead. The presence of live bacteria can lead to biofilm development, which is part of the chronic infective, inflammatory process. Staphylococcus epidermidis and Cutibacterium acnes have been implicated in chronic infection around breast implants, and some animal models suggest their involvement in capsule contracture. Molecular methods have revealed an array of microorganisms from samples of removed capsular material, though they are extremely sensitive to contamination. The relevance of the results to capsular contracture remains poorly understood. Bacteria of low virulence are shown associated with capsular contracture and calcification, and measures beyond those conventionally applied need to be investigated to limit perioperative contamination.

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 .

Current Challenges in Breast Implantation

Breast implantation (BI) is the most common plastic surgery worldwide performed among women. Generally, BI is performed both in aesthetic and oncoplastic procedures. Recently, the prevalence of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) or breast implant illness (BII) has aroused concerns. As a result, several countries, like Australia, Korea or the United Kingdom, introduced national registries dedicated to the safety and quality of BI surgeries. This narrative review aimed to focus on the clinical challenges, management and the current state of knowledge of BI. Both short and long-term outcomes of BI are determined by various alternatives and differences, which surgeons must consider during the planning and performing breast augmentation along with further complications or risk of reoperation. Proper preoperative decisions and aspects of surgical technique emerged to be equally important. The number of performed breast reconstructions is increasing, providing the finest aesthetic results and improving patient’s quality of life. Choice of prosthesis varies according to individual preferences and anatomical variables. A newly diagnosed cases of BIA-ALCL with lacking data on prevention, diagnosis, and treatment are placing it as a compelling medical challenge. Similarly, BII remains one of the most controversial subjects in reconstructive breast surgery due to unspecified diagnostic procedures, and recommendations.

Peri-prosthetic Fat Grafting Decreases Collagen Content, Density, and Fiber Alignment of Implant Capsules

Background:

Lower capsular contracture rates have been observed with peri-prosthetic fat grafting. We investigated the effect of fat grafting on capsular characteristics and peri-prosthetic collagen density, content, and fiber alignment.

Methods:

Forty miniature tissue expanders were placed on the backs of 20 rats. After four weeks, both inguinal fat pads were harvested, homogenized, and injected into peri-prosthetic tissue of the right tissue expander (fat graft) while the left served as control. The animals were killed at three (10 rats) and 12 weeks (10 rats), and full thickness peri-prosthetic samples were histologically processed for morphology (H&E) and collagen type and content (picrosirius red).

Results:

An 8.1% increase in adipose peri-prosthetic thickness was associated with a 10% decrease in collagen content at any time point (P = 0.004). Fat-grafted capsules displayed a 59% reduction in % total collagen when compared with controls (P < 0.001). There were no differences in capsular thickness. Fat-grafted samples were 54 times more likely to have a higher inflammation score and 69 times more likely to have a lower capsular density score than their nongrafted counterparts (P < 0.001 and P = 0.001, respectively). The extent of inflammation decreased over time in all samples (P = 0.002). Additionally, fat-grafted samples were 67 times more likely to have a lower fiber alignment score than the controls (P < 0.001).

Conclusions:

Enhancement of peri-prosthetic tissue with fat grafting decreases collagen content, density, and fiber alignment of implant capsules. These findings support clinical application of fat grafting in prosthetic breast surgery to potentially decrease capsular contracture.

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.

Immunomodulatory Biomaterials for Tissue Repair

All implanted biomaterials are targets of the host's immune system. While the host inflammatory response was once considered a detrimental force to be blunted or avoided, in recent years, it has become a powerful force to be leveraged to augment biomaterial-tissue integration and tissue repair. In this review, we will discuss the major immune cells that mediate the inflammatory response to biomaterials, with a focus on how biomaterials can be designed to modulate immune cell behavior to promote biomaterial-tissue integration. In particular, the intentional activation of monocytes and macrophages with controlled timing, and modulation of their interactions with other cell types involved in wound healing, have emerged as key strategies to improve biomaterial efficacy. To this end, careful design of biomaterial structure and controlled release of immunomodulators can be employed to manipulate macrophage phenotype for the maximization of the wound healing response with enhanced tissue integration and repair, as opposed to a typical foreign body response characterized by fibrous encapsulation and implant isolation. We discuss current challenges in the clinical translation of immunomodulatory biomaterials, such as limitations in the use of in vitro studies and animal models to model the human immune response. Finally, we describe future directions and opportunities for understanding and controlling the biomaterial-immune system interface, including the application of new imaging tools, new animal models, the discovery of new cellular targets, and novel techniques for in situ immune cell reprogramming.

Expression of NF-κB-p65 and α-SMA in the Study of Capsules formed by Surface Textured Implants Versus Foam Covered Silicone Implants in a Rat Model

BACKGROUND

We aimed to compare inflammatory and intercellular transcription responses induced by surface textured (ST) implants versus foam covered (FC) silicone implants placed on the dorsal aspect of rats.

METHODS

We utilized 80 female rats of the Wistar lineage. The rats were divided into four subgroups of 20 with one type of implant placed in the dorsum per rat. Analysis was carried out on peri-implant capsules at 90 d and at 180 d post-surgery with microscopic evaluation of inflammatory and immuno-histochemical response of NF-κB-p65 and α-SMA in fibroblasts. This study was carried out at the Evangelical Faculty of Parana and at the Ivo Pitanguy Institute, Brazil in 2015.

RESULTS

The FC exhibited higher levels of acute and chronic inflammation on evaluation in both time frames. The capsule surrounding the ST implants was significantly thicker with well-organized collagen fibres. NFκB-p65 expression in the capsule surrounding the FC implant was more pronounced. There was higher and more significant α-SMA expression in the capsules of the surface textured (ST) silicone implants compared to the foam-covered (FC) silicone implants.

CONCLUSION

Activation of NFκB-p65 plays a key role in the evolution of capsule formation and maintenance of inflammation by regulating the healing process. Similarly, higher and more prolonged levels of inflammation (increased NF-κB-p65 results in increased inflammation) and lower α-SMA (higher α-SMA is protective against capsular contracture) did not directly translate to a thicker capsule and ultimately, capsular contracture in foam covered silicone implants.

Histological evaluation of capsules formed by texturized silicone implants with and without polyester mesh coverage (Parietex®). A study on female rats

Purpose

To evaluate capsules formed by microtextured silicone implants with and without Parietex® mesh coverage histologically.

Methods

Sixty Wistar rats were divided in two groups (meshed and unmeshed). Each group was, then, divided into two subgroups for evaluation at 30 and 90 days. Capsules were analyzed based on hematoxylin and eosin (HE) and picrosirius staining.

Results

The number of fibroblasts, neutrophils and macrophages was similar among all subgroups. There was a higher lymphocyte reaction in the 30-day meshed group (p = 0.003). Giant cell reaction, granulation tissue and neoangiogenesis were similar among the subgroups. Synovial metaplasia was milder at 90-day in the unmeshed (p = 0.002) and meshed group (p < 0.001). Capsular thickness was significantly greater in the meshed samples (30-day p < 0.001 and 90-day p < 0.001). There was a similar amount of collagen types I and III in both groups.

Conclusions

The mesh-covered implants produced capsules similar to the microtextured ones when analyzing inflammatory variables. Synovial metaplasia was milder at 90 than at 30 days, and the capsular thickness was significantly greater in the meshed group. A similar amount of collagen types I and III was observed. Due to these characteristics, the mesh coverage did not seem to significantly affect the local inflammatory activity.

The Treatment of Capsular Contracture Around Breast Implants Induced by Fractionated Irradiation: The Collagenase of the Bacterium Clostridium Histolyticum as a Novel Therapeutic Approach

BACKGROUND

Irradiation therapy limits the utilization of silicone implants for breast reconstruction due to a significant risk for capsular contracture. The injection of the collagenase of the bacterium Clostridium histolyticum (CCH) might trivialize this risk by providing a minimal-invasive treatment option by capsular contracture degradation. However, efficacy in degrading breast implant capsules induced by fractionated irradiation remains unclear.

METHODS

Twenty-four rats in three groups received miniature silicone implants in a submuscular pocket. After 3D dose calculation and treatment field definition, rats of two groups underwent fractionated radiotherapy (6 × 8 Gy) using a linear accelerator. A third group served as control. On day 120, one irradiated group received injections of 0.3 mg/ml collagenase. Administration of plain solvent solution served as control in the two other groups. Outcome parameters included CT-imaging, histology, vessel wall analysis, immunohistochemistry, chemical collagen quantification and gene expression analysis.

RESULTS

Fractioned irradiation leads to a significant increase in collagen deposition around silicone implants with higher capsule thickness and collagen density when comparing all groups. Additionally, significant alterations of collagen fiber deposition were evident. Vessel wall thickness was significantly increased after radiotherapy. The injection of collagenase led to a significant reduction of capsule thickness, collagen density and content. However, the collagenase application induced a significant overexpression of TGFβ1. No side effects were monitored.

CONCLUSIONS

The CCH proved to be a safe and effective approach to degrade capsule tissue induced by fractionated irradiation in an animal model. This may pave its way for clinical application in implant-based breast reconstruction patients.

LEVEL OF EVIDENCE

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 .

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 .

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.

SEM and TEM for identification of capsular fibrosis and cellular behavior around breast implants - a descriptive analysis

BACKGROUND

Capsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM).

RESULTS

Miniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure. An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules.

CONCLUSIONS

This murine model accurately recapitulates CF found in humans and can be utilized for future research on cellular invasion in capsular fibrosis. This descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis.

Botulinum Toxin Type A as a Tool for Correcting Capsular Contracture after Reconstructive Breast Surgery

Capsular contracture is one of the most common complications after breast reconstruction. Surgical treatment is the main option for capsular contracture correction and includes capsulotomy, capsulectomy, and removal/replacement of the affected implant. However, the surgical trauma from reoperation, along with reduced quality of life, in patients with clinically significant capsular contracture has prompted a search for alternative treatment options. The use of the botulinum toxin type A in the treatment of neurological diseases and of keloid scars in aesthetic practice nudged the idea of using the same toxin for the correction of capsular contractures in breast cancer patients. Botulinum toxin type A injection is an easy procedure requiring no anesthesia or inpatient care. The treatment has few side effects. In addition, the injection does not cause sensory loss or dysesthesia. We described a clinical case of the capsular contracture correction using incobotulinumtoxin A. Capsular contracture IV developed 4 months post surgery after long-term lymphorrhea. Radiation therapy was not performed. According to the internal protocol, the patient was advised to undergo incobotulinumtoxin A treatment instead of surgery. Within 1 week after the second injection, all symptoms decreased—specifically, the general shape of the reconstructed breast. Also, the pain syndrome disappeared.

Immediate Breast Reconstruction after mastectomy with polyurethane implants versus textured implants: A retrospective study with focus on capsular contracture

BACKGROUND

Capsular contracture (CC) is the most common complication following Immediate Breast Reconstruction (IBR) with breast implants. Different implant surfaces were developed aiming to reduce the incidence of CC. We evaluated the incidence and degree of CC after Direct-to-Implant (DTI) IBR with insertion of textured (TE) or polyurethane (PU) covered implants.

METHODS

A retrospective review of consecutive patients treated at our Institution with mastectomy and one-stage IBR and implant reconstruction between 2013 and 2018, with or without post mastectomy radiation therapy (PMRT), was conducted. Immediate breast reconstruction was performed by implanting 186 PU covered implants and 172 TE implants.

RESULTS

Three-hundred-twelve women underwent 358 DTI IBR with PU or TE implants, were analyzed with a median follow-up time of 2.3 years (range 1.0-3.0). The overall rate of CC Baker grade III and IV was 11.8% (95%CI: 8.4-16.3), while, after PU and TE implant placement it was 8.1% (95% CI: 4.1-15.7) and 15.8% (95% CI: 4.1-15.7) [p = 0.009]), respectively. Irradiated breasts developed CC more frequently rather than non-irradiated breasts (HR = 12.5, p < 0.001), and the relative risk was higher in the TE group compared with the PU group (HR = 0.3, p = 0.003).

CONCLUSIONS

After mastectomy and one-stage IBR, the use of PU covered implants is associated with a lower incidence of CC compared to TE implants. This advantage is amplified several folds for patients who necessitate PMRT. Footnote: Capsular contracture (CC); Immediate Breast Reconstruction (IBR); Directto- Implant (DTI); Textured (TE); Polyurethane (PU); Post mastectomy radiation therapy (PMRT); Nipple Sparing mastectomy (NSM).

Risk Factors for Capsular Contracture: A Retrospective Study in Immediate Reconstruction versus Delayed Reconstruction

Capsular contracture is a common complication among breast implant reconstruction patients. The aim of this study was to assess the duration of and risk factors associated with capsular contracture by comparing 2 reconstruction methods.

Novel Histopathologic and Immunohistochemical Observations in Explanted Orbital Peri-implant Capsules

PURPOSE

To describe the histopathologic and immunohistochemical characteristics of peri-orbital implant capsule and correlate the observed changes with delayed implant extrusion.

MATERIALS AND METHODS

Prospective, ex-vivo, histopathologic, immunohistochemical study of peri-implant capsules excised from capsules surrounding a poly-methyl metha acrylate (PMMA) implant. Thirteen capsules were harvested and divided into two groups. Group 1 (implant extrusion group) consisted of capsules harvested from around exposed/extruded implants and Group 2 (implant non-extrusion group) from implants that were surgically exchanged for volume augmentation. Data collected included demography, clinical presentations, etiology of the explantation, age of the capsule in months, inflammatory cells noted/high power field (HPF), CD3, CD20, and CD68, percentage Masson's trichrome staining and mean capsular thickness.

RESULTS

Mean patient age at presentation was 33 ± 13 years. Of the 13 capsules included, 7 belonged to group 1and 6 to group 2. Mean age of the fibro-collagenous membranes were 33 ± 57 months (median 13 months). Median CD3, CD20, and CD68 positivity was 80%, 9%, and 7% denoting a predominant T-lymphocytic response. Mean capsular thickness was 733 ± 422µ (median 678µ). Age of the harvested capsule showed a linear correlation with inflammatory cells/HPF (r = 0.93, p < .0001, 95% C.I. 0.73 to 0.98), with CD3 positivity (r = 0.6, p = .04, 95% C.I. 0.02 to 0.9), with capillary proliferation/HPF (r = 0.85, p = .003, 95% C.I. 0.43 to 0.96) and with percentage of cells showing Masson's trichrome stain positivity (r = 0.71, p = .03, 95% C.I. 0.08 to 0.93). In the extrusion group, the capsules demonstrated high inflammation and low fibrosis.

CONCLUSIONS

PMMA orbital spherical implant incites a predominantly T-cell mediated inflammatory response which clinically presents as a peri-implant capsule. Increasing inflammation in the absence of significant fibrosis may be responsible for delayed PMMA implant exposure and extrusion.

Efficient reduction of fibrous capsule formation around silicone breast implants densely grafted with 2-methacryloyloxyethyl phosphorylcholine (MPC) polymers by heat-induced polymerization

This article presents the efficacy of heat-induced MPC-grafting against excessive fibrous capsule formation and related inflammation in tissues surrounding silicone breast implants inserted in a pig model.

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.

Modulation of Foreign Body Reaction against PDMS Implant by Grafting Topographically Different Poly(acrylic acid) Micropatterns

The surface of poly(dimethylsiloxane) (PDMS) is grafted with poly(acrylic acid) (PAA) layers via surface-initiated photopolymerization to suppress the capsular contracture resulting from a foreign body reaction. Owing to the nature of photo-induced polymerization, various PAA micropatterns can be fabricated using photolithography. Hole and stripe micropatterns ≈100-µm wide and 3-µm thick are grafted onto the PDMS surface without delamination. The incorporation of PAA micropatterns provides not only chemical cues by hydrophilic PAA microdomains but also topographical cues by hole or stripe micropatterns. In vitro studies reveal that a PAA-grafted PDMS surface has a lower proliferation of both macrophages (Raw 264.7) and fibroblasts (NIH 3T3) regardless of the pattern presence. However, PDMS with PAA micropatterns, especially stripe micropatterns, minimizes the aggregation of fibroblasts and their subsequent differentiation into myofibroblasts. An in vivo study also shows that PDMS samples with stripe micropatterns polarized macrophages into anti-inflammatory M2 macrophages and most effectively inhibits capsular contracture, which is demonstrated by investigation of inflammation score, transforming-growth-factor-β expression, number of macrophages, and myofibroblasts as well as the collagen density and capsule thickness.

Management of Capsular Contracture in Cases of Silicone Gel Breast Implant Rupture with Use of Pulse Lavage and Open Capsulotomy

INTRODUCTION

Pulse lavage (PL) irrigation of prosthesis pockets has prior been described for breast implant salvages. However, PL for removal of leaked silicone from prosthesis pockets after implant ruptures has not been studied yet. Since open capsulotomies are regarded as equal treatment of capsular contracture (CC) than capsulectomies, this study analyzed the clinical outcome of PL for silicone removal and subsequent capsulotomy in cases of concurrent CC and breast implant rupture.

METHODS

Between 2012 and 2017, 55 patients (75 breasts) with suspected silicone implant rupture and CC (Baker grade III/IV), after primary breast augmentation or implant-based breast reconstruction, were included in a retrospective, observational study. Mean patient follow-up was 12.2 ± 3.6 months.

RESULTS

In all preoperatively suspected ruptured silicone breast implants, around a quarter were intact. In contrast to previously published data, implant exchanges in cases of implant ruptures did not lead to significantly higher CC recurrence rates (27.6% vs. 22.2% in cases of intact implants, p = 0.682), if the prosthesis pockets were treated with PL irrigation followed by open capsulotomy. PL reduced the amount of encapsulated silicone remnants histologically. The age of patients with CC after failed implant-based reconstruction was significant lower for salvage surgeries with flap reconstruction than for implant exchanges, p < 0.05.

CONCLUSIONS

PL irrigation of prosthesis pockets prior to open capsulotomy is a safe and effective treatment of CC with concurrent silicone leakage. Remaining silicone remnants in breast capsules may affect the development of a recurrent CC. To avoid CC recurrences, patients should consider conversion to autologous tissue.

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 .

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

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 .

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

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The Collagenase of the Bacterium Clostridium histolyticum in the Treatment of Irradiation-Induced Capsular Contracture

BACKGROUND

Irradiation therapy is an important pillar in the treatment of breast cancer. However, it can trigger capsular fibrosis, the most significant complication of implant-based breast reconstruction. As collagen is the main component of fibrotic capsules, the collagenase of the bacterium Clostridium histolyticum poses a potential treatment option for this pathological condition.

METHODS

Thirty-six rats received miniature silicone implants on their backs. On day 1, the implant sites of two groups were irradiated with 10 Gy. On day 120, one irradiated group received collagenase injections into the implant pockets (n = 12). Non-irradiated (n = 12) and irradiated capsules (n = 12) were injected with plain solvent solution serving as controls. Data were analyzed by means of in vivo imaging, histology, immunohistochemistry and gene expression analysis.

RESULTS

Compared with both controls, the injection of collagenase led to significantly thinner capsules. This was verified by in vivo imaging and histology. Although irradiation provoked alterations in capsule collagen structure and vessel wall thickness, the application of collagenase resulted in a significant reduction of collagen density. This was accompanied by an up-regulation of VEGF-A gene expression. Of note, hematoma formation inside the implant pocket occurred in two cases after collagenase injection.

CONCLUSIONS

The collagenase of the bacterium Clostridium histolyticum is effective in degrading irradiation-induced capsular fibrosis around silicone implants. Hematoma formation occurred most likely because of irradiation-induced alterations in vessel wall architecture and capsule vascularization. Further studies need to be performed to address the clinical safety of this novel treatment option.