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

Protective role of transforming growth factor-Β3 (TGF-Β3) in the formation of radiation-induced capsular contracture around a breast implant: In vivo experimental study

Postmastectomy radiotherapy causes capsular contracture due to fibroproliferation of the capsular tissue around the implant. In fibrosis, unlike normal wound healing, structural and functional disorders are observed in the tissues caused by excessive/irregular accumulation of extracellular matrix proteins. It has been reported that transforming growth factor-β3 (TGF-β3) prevents and reverses fibrosis in various tissues or provides scarless healing with its antifibrotic effect. Additionally, TGF-β3 has been shown to reduce fibrosis in radiotherapy-induced fibrosis syndrome. However, no study in the literature investigates the effects of exogenously applied TGF-β3 on capsular contracture in aesthetic or reconstructive breast implant application. TGF-β3, which has a very short half-life, has low bioavailability with parenteral administration. Within the scope of this study, free TGF-β3 was loaded into the nanoparticles to increase its low bioavailability and extend its duration of action by providing controlled release. The aim of this study is to investigate the preventive/improving effects of radiation induced capsular contracture using chitosan film formulations containing TGF-β3 loaded poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles in implant-based breast reconstruction. In the characterization studies of nanoparticles, the particle size and zeta potential of the TGF-β3-loaded PLGA-b-PEG nanoparticle formulation selected to be used in the treatment group were found to be 123.60 ± 2.09 nm and -34.87 ± 1.42 mV, respectively. The encapsulation efficiency of the formulation was calculated as 99.91 %. A controlled release profile was obtained in in vitro release studies. Chitosan film formulations containing free TGF-β3 or TGF-β3-loaded PLGA-b-PEG nanoparticles were used in in vivo studies. In animal studies, rats were randomly distributed into 6 groups (n = 8) as sham, implant, implant + radiotherapy, implant + radiotherapy + chitosan film containing unloaded nanoparticles, implant + radiotherapy + chitosan film containing free TGF-β3, implant + radiotherapy + chitosan film containing TGF-β3 loaded nanoparticle. In all study groups, a 2 cm incision was made along the posterior axillary line at the thoracic vertebral level in rats to reach the lateral edge of the latissimus dorsi. The fascial attachment to the chest wall was then bluntly dissected to create a pocket for the implants. In the treatment groups, the wound was closed after films were placed on the outer surface of the implants. After administering prophylactic antibiotics, rats were subjected to irradiation with 10 Gy photon beams targeted to each implant site. Each implant and the surrounding excised tissue were subjected to the necessary procedures for histological (capsule thickness, cell density), immunohistochemical, and biochemical (α-SMA, vimentin, collagen type I and type III, TGF-β1 and TGF-β3: expression level/protein level) examinations. It was determined that the levels of TGF-β1 and TGF-β3 collagen type III, which decreased as a result of radiotherapy, were brought to the control level with free TGF-β3 film and TGF-β3 nanoparticle film formulations. Histological analyses, consistent with biochemical analyses, showed that thick collagen and fibrosis, which increased with radiotherapy, were brought to the control level with free TGF-β3 film and TGF-β3 nanoparticle film treatments. In biochemical analyses, the decrease in thick collagen was compatible with the decrease in the collagen type I/type III ratio in the free TGF-β3 film and TGF-β3 nanoparticle film groups. Changes in protein expression show that TGF-β3 loaded nanoparticles are more successful than free TGF-β3 in wound healing. In line with these results and the literature, it is thought that the balance of TGF-β1 and TGF-β3 should be maintained to ensure scarless wound healing with no capsule contracture.

The Prevalence and Histological Characteristics of the Double Capsule Phenomenon in Breast Augmentation With Implants

BACKGROUND

Double capsule formation around breast implants is associated with implant rotation and seroma. However, the prevalence and histological characteristics remain unclear.

OBJECTIVES

To quantify the prevalence of double capsule formation between different implant surface textures and to explore the histological differences between the inner- and outer capsules from breast implant capsule biopsies.

METHODS

The study was performed on data from the Copenhagen Breast Implant (COBI) Biobank comparing the prevalence of double capsule formation around Allergan Biocell implants (Allergan, Dublin, Ireland), Eurosilicone Cristalline implants (GC Aesthetics, Dublin, Ireland), and Mentor Siltex implants (Mentor, Irvine, CA). The histological characteristics of the inner and outer capsules was analyzed using a validated assessment tool.

RESULTS

The study included data from 588 patients and 1128 implants. Double capsule formation was found around 25 implants resulting in an overall prevalence of 2.5% for textured implants. Mentor implants with a Siltex surface had a double capsule prevalence of 0.72%, which was significantly lower than the prevalence for Allergan implants with a Biocell surface (7.8%), (P<.001), and Eurosilicone implants with a Cristalline surface (3.4%), (P=.03). Histological analysis showed that inner capsules had lower cellular density (P=.04) and were more calcified (P=.03) compared with outer capsules.

CONCLUSIONS

The risk of double capsule formation was highly correlated with the roughness of the breast implant texture, with the risk of double capsule formation around Mentor Siltex implants being significantly lower than that of macrotextured implants. The histological analysis implies that loss of vascularization to the inner capsule results in a lower cellular density and more frequently calcification.

A new type of dual-plane breast augmentation: Redefining parenchyma-muscle interface in high mobile glandular ptotic breast

BACKGROUND

High mobile glandular ptotic breasts present the greatest challenge for implant breast augmentation with suboptimal outcomes occurring frequently. Here, we describe and evaluate an innovative approach for breast augmentation in this breast type. By widely disrupting and redefining the parenchyma-muscle interface, this technique offers opportunities to restore the takeoff point of the breast and improve the fullness of the upper pole, thus producing a "perkier" breast appearance.

METHODS

A retrospective review was performed, and 68 patients who underwent breast augmentation with either type III dual-plane or the new approach between January 2015 and January 2021 were included. The patients were divided into two groups. The aesthetic outcome and patient satisfaction were evaluated using different 10-point rating forms. Data on demographic information, surgical details, and relative complication rates were recorded and compared.

RESULTS

Upon comparing the aesthetic outcomes and satisfaction, the test group demonstrated better breast shape, nipple-areola position, upper pole contour outcome, and upper pole satisfaction. No post-operative hematoma, seroma, or infection occurred in either groups. No double-bubble deformity occurred in the test group, whereas it occurred in two patients in the control group. The rates of capsular contracture were 1.4% and 1.6%, in the test and control groups, respectively.

CONCLUSIONS

The new approach is a safe surgical method with good aesthetic outcome, high patient satisfaction, and long-lasting result. This approach is a supplement to the dual-plane techniques, to realize the benefits of mastopexy and type III dual-plane breast augmentation.

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 .

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

Transcriptomic and machine learning analyses identify hub genes of metabolism and host immune response that are associated with the progression of breast capsular contracture

Capsular contracture is a prevalent and severe complication that affects the postoperative outcomes of patients who receive silicone breast implants. At present, prosthesis replacement is the major treatment for capsular contracture after both breast augmentation procedures and breast reconstruction following breast cancer surgery. However, the mechanism(s) underlying breast capsular contracture remains unclear. This study aimed to identify the biological features of breast capsular contracture and reveal the potential underlying mechanism using RNA sequencing. Sample tissues from 12 female patients (15 breast capsules) were divided into low capsular contracture (LCC) and high capsular contracture (HCC) groups based on the Baker grades. Subsequently, 41 lipid metabolism-related genes were identified through enrichment analysis, and three of these genes were identified as candidate genes by SVM-RFE and LASSO algorithms. We then compared the proportions of the 22 types of immune cells between the LCC and HCC groups using a CIBERSORT analysis and explored the correlation between the candidate hub features and immune cells. Notably, PRKAR2B was positively correlated with the differentially clustered immune cells, which were M1 macrophages and follicular helper T cells (area under the ROC = 0.786). In addition, the expression of PRKAR2B at the mRNA or protein level was lower in the HCC group than in the LCC group. Potential molecular mechanisms were identified based on the expression levels in the high and low PRKAR2B groups. Our findings indicate that PRKAR2B is a novel diagnostic biomarker for breast capsular contracture and might also influence the grade and progression of capsular contracture.

Hybrid Breast Augmentation: Double Benefit or Double Risk? A Comparative Study of 932 Cases

BACKGROUND

The authors propose a hybrid breast augmentation (HBA) method combining implants and fat grafting and explore the outcome and safety through a retrospective, single-center, propensity score-matched, comparative study.

METHODS

Outcome, satisfaction, and complications were compared between the HBA group (302 cases) and the implant-based breast augmentation (IBA) group (353 cases), and between the HBA group and the autologous fat grafting (AFG) group (277 cases).

RESULTS

The mean follow-up period was 31.7 months. After propensity score matching (PSM), 270 cases were matched between the HBA and IBA groups, and 156 cases were matched between the HBA and AFG groups. Compared with the IBA group, HBA achieved higher scores of implant visibility/palpability and upper pole contour with the specialists' evaluations (before and after PSM; P < 0.05). Regarding patient satisfaction, the scores of softness (before and after PSM), smoothness of the upper pole (before PSM), and overall satisfaction (after PSM) of the HBA group were better ( P < 0.05). Implant-related complications occurred at a similar rate. Compared with the AFG group, HBA achieved higher scores of shape (before and after PSM) and symmetry (after PSM) with evaluations by specialists ( P < 0.05). The scores of shape, symmetry, and overall satisfaction in the HBA group were better (before and after PSM; P < 0.05). The HBA group showed a lower incidence of palpable cysts, fat necrosis, oil cysts, and fat calcification (before PSM; P < 0.05).

CONCLUSION

When the three techniques were compared objectively, HBA presented better indices of aesthetic outcomes, satisfaction, and acceptable complications rates when compared with IBA and AFG.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

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.

Attenuating Chronic Fibrosis: Decreasing Foreign Body Response with Acellular Dermal Matrix

Surgical implants are increasingly used across multiple medical disciplines, with applications ranging from tissue reconstruction to improving compromised organ and limb function. Despite their significant potential for improving health and quality of life, biomaterial implant function is severely limited by the body's immune response to its presence: this is known as the foreign body response (FBR) and is characterized by chronic inflammation and fibrotic capsule formation. This response can result in life-threatening sequelae such as implant malfunction, superimposed infection, and associated vessel thrombosis, in addition to soft tissue disfigurement. Patients may require frequent medical visits, as well as repeated invasive procedures, increasing the burden on an already strained health care system. Currently, the FBR and the cells and molecular mechanisms that mediate it are poorly understood. With applications across a wide array of surgical specialties, acellular dermal matrix (ADM) has emerged as a potential solution to the fibrotic reaction seen with FBR. Although the mechanisms by which ADM decreases chronic fibrosis remain to be clearly characterized, animal studies across diverse surgical models point to its biomimetic properties that facilitate decreased periprosthetic inflammation and improved host cell incorporation. Impact Statement Foreign body response (FBR) is a significant limitation to the use of implantable biomaterials. Acellular dermal matrix (ADM) has been observed to decrease the fibrotic reaction seen with FBR, although its mechanistic details are poorly understood. This review is dedicated to summarizing the primary literature on the biology of FBR in the context of ADM use, using surgical models in breast reconstruction, abdominal and chest wall repair, and pelvic reconstruction. This article will provide readers with an overarching review of shared mechanisms for ADM across multiple surgical models and diverse anatomical applications.

Comparative clinical outcomes of using three-dimensional and TIGR mesh in immediate breast reconstruction surgery for breast cancer patients

INTRODUCTION

Breast reconstruction (BR) surgery is a widely utilized approach for women who have undergone mastectomy. Using synthetic mesh can offer advantages over other materials providing long-lasting support and natural-looking results. This study aims to compare the effectiveness of 3DMax™ mesh to TIGR mesh in BR surgery, providing clear information about the non-inferiority of 3DMax™ mesh to TIGR.

METHODS

This retrospective cohort study evaluates postoperative complications in breast cancer patients who underwent subcutaneous mastectomy with direct-to-implant immediate BR using silicone implants and either 3DMax™ mesh or TIGR® Matrix Surgical Mesh.

RESULTS

This study involved BR surgeries in 82 patients, including 57 surgeries in the 3D mesh group and 49 in the TIGR mesh group. The two groups had no significant differences regarding age, body mass index (BMI), cancer stage, or surgical complications. However, patients with neoadjuvant chemotherapy or radiotherapy had higher incidence rates of long-term complications than other patients. Patients with infection or partial necrosis had a heightened risk of implant loss.

CONCLUSION

The clinical results obtained in this study suggest that among synthetic meshes used in immediate BR, 3DMax™ is not inferior to TIGR Matrix Surgical Mesh regarding complications.

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 .

COVID-19 Vaccination Status and Capsular Contracture Following Prosthetic Breast Reconstruction: A Retrospective, Multicenter Nested Case-Control Study

BACKGROUND

Capsular contracture (CC) is a common long-term complication following prosthetic-based breast reconstruction (PBBR). Seven cases of CC following mRNA vaccination for coronavirus 2019 (COVID-19) are reported in the literature.

OBJECTIVES

The aim of this study was to determine whether receiving the COVID-19 vaccine was associated with CC development following PBBR.

METHODS

A retrospective, multicenter nested case-control study was performed from January 2014 to July 2022 of adult female patients who underwent PBBR with acellular dermal matrix placement. Cases of CC were selected if no adjuvant radiation was received and they presented for follow-up between December 2020 and July 2022. Controls included patients who met inclusion criteria but who did not experience CC in either breast. Patient demographics, breast cancer characteristics, reconstructive surgery details, postoperative complications, and COVID-19 exposure details were analyzed and correlated with CC development.

RESULTS

Of a total of 230 patients (393 breasts) who received PBBR, 85 patients (135 breasts) met inclusion criteria, of whom 12 patients (19 breasts) developed CC and 73 patients (116 breasts) did not. At the time of median follow-up of 18.1 months (n = 85; interquartile range, 12.2-33.6 months), no statistically significant differences were observed between the short- or long-term complications in cases or controls. There were no significant differences in COVID-19 vaccination status, number of vaccine doses, or vaccination type between cases and controls. Vaccination status was not associated with greater odds of CC development (odds ratio, 1.44; 95% CI, 0.42-5.37; P > .05).

CONCLUSIONS

Direct association between CC and COVID-19 vaccination is difficult to prove. Given the known risk of severe COVID-19 infection among immunocompromised patients, those with breast cancer who undergo PBBR should be properly counseled on the benefits and risks of vaccination.

LEVEL OF EVIDENCE: 4

The Role of Verteporfin in Prevention of Periprosthetic Capsular Fibrosis: An Experimental Study

BACKGROUND

Capsular contracture (CC) characterized by excessive fibrosis is one of the most common complications after silicone implant surgery. Verteporfin (VP), an inhibitor of Yes-associated protein 1 (YAP1), has recently been found to reduce the fibrotic process.

OBJECTIVES

The aim of this study was to use an in vivo rabbit model to evaluate the efficacy of VP for the prevention of CC.

METHODS

Twenty-four New Zealand rabbits received 10-cc smooth saline silicone implants inserted in the dorsal skin and were randomly divided into 2 groups to receive 2 mL VP (1.5 mg/mL) or 2 mL phosphate-buffered saline solution instillation in the implant pocket. When the animals were killed on Day 60, capsule formation was observed both macroscopically and microscopically. Histologic evaluation included capsule thickness, fibrosis degree, and myofibroblast (α smooth muscle actin positive) content. In addition, the YAP1 expression level was examined by immunofluorescence staining. Transforming growth factor β1, collagen I, and connective tissue growth factor expression were measured by real-time quantitative polymerase chain reaction.

RESULTS

The VP-treated group exhibited thinner, more transparent capsules and less fibrosis than the control group at 60 days postsurgery (P < 0.05). Moreover, the VP treatment significantly reduced α smooth muscle actin, YAP1, transforming growth factor β1, collagen I, and connective tissue growth factor expression levels in the capsular tissues (P < 0.05).

CONCLUSIONS

VP reduced capsule formation after silicone implantation by inhibiting YAP1-mediated mechanical signaling, thereby attenuating excessive collagen deposition in the rabbit model. This preclinical study may provide a feasible strategy to prevent periprosthetic capsular fibrosis in clinical application.