The role of the contractile fibroblast in the capsules around tissue expanders and implants

The Immediate Contraction of the Expanded Forehead Flap

INTRODUCTION

Flaps contract immediately after harvest, which added difficulty to flap design. This study aims to investigate the immediate contraction rate of the expanded forehead flap used in nasal reconstruction.

METHODS

Patients undergoing nasal reconstruction with expanded forehead flaps from September 2021 to January 2023 were included. Objective measurements of the pedicle width, maximum width, maximum length, and flap size of the expanded forehead flap before and after harvest were conducted.

RESULTS

Fourteen patients, including 9 males and 5 females, were included. The average expansion period was 4.6 months, and the mean injection volume was 658.6 ml. The average retraction rate of pedicle width, maximum width, maximum length, and size of the flap after harvest were 16.15%, 30.26%, 26.86%, and 50.89%, respectively.

CONCLUSION

This study presents the contraction rate of the expanded forehead flap used for nasal reconstruction. The data from the measurement will help surgeons to design the expanded forehead flap.

LEVEL OF EVIDENCE

Level-Level IV.

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.

Exploring the Overlooked Roles and Mechanisms of Fibroblasts in the Foreign Body Response

Significance: Foreign body response (FBR), wherein a fibrotic capsule forms around an implanted structure, is a common surgical complication that often leads to pain, discomfort, and eventual revision surgeries. Although believed to have some mechanistic overlap with normal wound healing, much remains to be discovered about the specific mechanism by which this occurs. Recent Advances: Current understanding of FBR has focused on the roles of the immune system and the biomaterial, both major contributors to FBR. However, another key player, the fibroblast, is often overlooked. This review summarizes key contributors of FBR, focusing on the roles of fibroblasts. As much remains to be discovered about fibroblasts' specific roles in FBR, we draw on current knowledge of fibroblast subpopulations and functions during wound healing. We also provide an overview on candidate biomaterials and signaling pathways involved in FBR. Critical Issues and Future Directions: While the global implantable medical devices market is considerable and continues to appreciate in value, FBR remains one of the most common surgical implant complications. In parallel with the continued development of candidate biomaterials, further exploration of potential fibroblast subpopulations at a transcriptional level would provide key insights into further understanding the underlying mechanisms by which fibrous encapsulation occurs, and unveil novel directions for antifibrotic and regenerative therapies in the future.

The activation of FPR3/PKA/Rap1/ERK1/2 and FPR3/p-IκB/NF-κB axis in fibroblasts promote capsular contracture after rhinoplasty

BACKGROUND

Capsular contracture may occur after rhinoplasty due to rejection of silicone implants by the immune system. Our previous high-throughput sequencing of RNA in nasal capsular contracture tissue revealed that FPR3 was significantly increased in grade IV capsular contracture tissue, compared with grade II.

OBJECTIVE

This study aimed to elucidate the effect and specific mechanism of FPR3 on capsular formation and contracture following rhinoplasty.

METHODS

Using the GeneMANIA Database, the genes involved with FPR3 expression were searched, and the Gene Ontology analysis was performed to annotate the biological functions of the aforementioned genes. The mRNA and protein expressions of related genes in fibroblasts and capsular contracture tissues were analyzed using quantitative real-time PCR, western blot, and immunohistochemical staining. CCK-8 was used to determine the viability of cells. The migration capacity of fibroblasts was assessed using a wound healing assay. ELISA was used to detect levels of IL-1β, TNF-α, and IL-6.

RESULTS

After rhinoplasty, the expression of FPR3 in the capsular tissue increased in proportion to the degree of contracture. By activating the PKA/Rap1/ERK1/2 axis, overexpression of FPR3 can significantly increase the cell viability of fibroblasts and promote their transformation into myofibroblasts. Moreover, FPR3 phosphorylates IκB to decrease NF-κB inhibition, thereby promoting the synthesis and release of the inflammatory cytokines IL-1β, TNF-α, and IL-6.

CONCLUSION

FPR3 is a crucial molecule that causes capsular development and contracture following rhinoplasty. In the future, local suppression of FPR3 may be an effective treatment for relieving capsular contracture.

Evolving Trends in Breast-Implant-Based Procedures in Israel: A National Survey

Rare reports linking textured breast implants to anaplastic large-cell lymphoma have generated controversies regarding their relative advantage over smooth implants. To evaluate trends in implant use in Israel, we sent a seven-item questionnaire to all active board-certified breast plastic surgeons in the country. About half responded. Approximately 60% of responders reported a moderate-to-considerable decrease in both the relative number of augmentation mammoplasty procedures and the use of implants during mastopexies in the last year. Nearly 40% had switched from textured to smooth implants to some extent. More than 40% still used textured implants for aesthetic procedures, and reconstructive procedures. Surgeons with more experience demonstrated a greater preference for smooth implants. The uncertainty regarding the safety of textured breast implants has led to a partial transition to the use of smoother implants and, importantly, to a general reduction in all breast-implant-based procedures.

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 .

Reduced capsular contracture with smooth and textured breast implants following submuscular mammoplasty: systematic literature review

Background: Capsular contracture is common in breast augmentation and reconstruction surgery. The present systematic review discusses the safety of textured and smooth implants in the submuscular position. Methods: A literature search was conducted on PubMed and EMBASE from inception until June 2020. The primary outcome was reduction of capsular contracture (Baker grade); others included time of capsular contracture onset, implant position/rupture rate/surface, hematoma/seroma risk, surgeon assessment and patient satisfaction. A total of 7731 patients were included from six publications. Results: The overall risk rate for capsular contracture increased from 7.6 to 25% in 10 years. The capsular contracture rates in textured and smooth implants were 3-14% and 6-20%, respectively, and no significant difference between implants was observed when the implants were placed submuscularly. Submuscular placement and textured implants also reduced the incidence of other complications. Conclusion: This systematic review suggests that appropriate placement reduces capsular contracture rate, irrespective of implant surface.

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.

Repair Exposure of the Postauricular Tissue Expander Using the Modified Brent Method: A 7-Year Experience

OBJECTIVES

Ear reconstruction is a challenging surgery for the complicated conditions in patients with microtia. The tissue expansion techniques were necessary and relatively safe for patients with insufficient soft tissue. However, complications such as necrosis of expanded flap and exposure of tissue expander limited the popularization of this method. This study described the use of modified Brent method to handle the exposure of the postauricular tissue expander.

METHODS

From January 2013 to December 2019, 27 ear reconstruction patients with trauma or necrosis on an expanded skin flap and subsequent exposure of tissue expander were treated with modified Brent method, which consisted of 3 stages: removal of the expander, tension-free closure of wound, and framework fabrication; elevation of reconstructed ear; lobule rotation; and minor modification.

RESULTS

Fifty-six percent of exposures occurred in the lower pole of the tissue expander. Exposure usually occurred 54.5 days after implantation. The majority of reconstructed ears had a satisfactory appearance and showed relatively stable outcomes. Only one case of cartilage exposure required revision surgery and was repaired by the temporoparietal fascia.

CONCLUSION

With reasonable distribution of expanded flap, prolonged interval, and sutures under tension-free conditions, complications like the occurrence of trauma or necrosis-induced exposure of tissue expander can be repaired efficiently by a staging modified Brent method.

Smooth Prosthesis: Our Experience and Current State of Art in the Use of Smooth Sub-muscular Silicone Gel Breast Implants

BACKGROUND

The objective of this clinical review is to provide an overview of the use of silicone gel-filled breast implants placed in the sub-muscular position, with a focus on complication rates reported for both smooth and textured implants. Furthermore, our experience in this field is also reviewed.

METHODS

MEDLINE, EMBASE, Web of Science, Scopus, the Cochrane Central and Google Scholar databases were reviewed to identify the literature related to smooth breast implants. Each article was reviewed by two independent reviewers to ensure all relevant publications were identified. The literature search identified 98 applicable articles. Of these, just a few articles were found to have a therapeutic level of evidence. The reference lists in each relevant paper were screened manually to include relevant papers not found through the initial search.

RESULTS

Eight articles report the risk of capsular contracture when the breast implants were placed in the sub-muscular position. Six of these articles report a similar rate of capsular contracture in smooth and textured implants. Local complications such as wrinkling, late seroma and double capsules were found to be associated with the use of textured breast implants (4 articles). All articles concerning BIA-ALCL reported a total absence occurring in smooth breast implants. All cases have been associated with textured mammary prostheses.

CONCLUSION

With our expertise in the field and the results of this up-to-date literature review, it can be concluded that there are no significant advantages of using one type of implant surface over the other when placed in the sub-pectoral position.

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.

Redefinition of tumor capsule: Rho-dependent clustering of cancer-associated fibroblasts in favor of tensional homeostasis

Fibroblasts are the most frequent cells of the connective tissues. Having the ability to sense and respond to mechanical stimuli in addition to the biochemical ones makes them crucial for such a composite-like and tension-preserving tissue. Over the last decade, the investigation of the role of these cells in tumor progression was a hot topic of research in tumor biology. Literatures almost unanimously describe the re-education of stromal fibroblasts by tumor cells in favor of tumor progression, which resulted in the birth of a new nomenclature, the cancer-associated fibroblasts. On the other hand, some studies reported anti-tumor roles for these cells. Herein, author suggests that the previously described pro-migratory and pro-contractile contexts, which respectively results in divergent and convergent distribution of fibroblasts by changing Rho-Rac1 balance, could be applied for cancer-associated fibroblasts as well. Based on this proposed concept, stromal fibroblasts could represent different roles, either pro-tumor or anti-tumor, during the course of tumor progression. In the earlier phases, they tend to assemble along tumor-stroma interface in the form of tumor capsules in order to resist tumor growth and to maintain tensional homeostasis in stroma. But in later phases, after being chronically subjected to tumor-induced chemical and mechanical stimuli, they will gradually lose their substantial abilities to oppose tumor expansion and, in contrary, will promote tumorigenesis. In summary, this paper redefines tumor capsule from chemical and mechanical standpoints as Rho-dependent clustering of cancer-associated fibroblasts in favor of tensional homeostasis. Furthermore, it proposes that stromal fibroblasts will undergo some irreversible epigenetic changes in Rac1- and Rho-related proteins through tumor-stroma crosstalk, which irreversibly diminish their ability of capsule formation. Finally, the author discusses the possible researches helping us to assess the proposed concept and its clinical implications.

The Role of Periostin in Capsule Formation on Silicone Implants

Although silicone implants are widely used in breast and other reconstructive surgeries, the limited biocompatibility of these materials leads to severe complications, including capsular contracture. Here, we aimed to clarify the relationship between periostin and the process of capsule formation after in vivo implantation. Seven-week-old wild-type (WT) C57BL/6 mice and periostin-deficient mice were used. Round silicone implants were inserted into a subcutaneous pocket on the dorsum of the mice. After 8 weeks, the fibrous capsule around the implant was harvested and histologically examined to estimate capsular thickness and the number of inflammatory cells. Additionally, immunohistochemical analysis (periostin, α-SMA, and collagen type I) and western blotting (CTGF, TGF-β, VEGF, and MPO) were performed for a more detailed analysis of capsule formation. The capsules in periostin-knockout mice (PN-KO) were significantly thinner than those in WT mice. PN-KO mice showed significantly lower numbers of inflammatory cells than WT mice. Fibrous tissue formation markers (α-SMA, periostin, collagen type I, and CTGF) were significantly reduced in PN-KO mice. We also confirmed that inflammatory reaction and angiogenesis indicators (TGF-β, MPO, and VEGF) had lower expression in PN-KO mice. Inhibition of periostin could be important for suppressing capsule formation on silicone implants after in vivo implantation.

The role of angiogenesis, inflammation and estrogen receptors in breast implant capsules development and remodeling

BACKGROUND

Capsular contracture is the most common complication following breast implant placement. The multiple factors unbalancing the physiological response to the foreign body have not been fully elucidated. The aim of this study was to investigate the role of neo-angiogenesis, inflammation and estrogen receptors in peri-prosthetic tissue development and remodeling.

METHODS

The study enrolled 31 women who underwent expander substitution with definitive implant. Specimens were stained with hematoxylin/eosin, Masson trichrome, immunohistochemistry and immunofluorescence for alpha-smooth muscle actin, estrogen receptor-α (ER-α), estrogen receptor-β (ER-β), Collagen type I and III, CD31 (as a marker of neo-angiogenesis) and vascular endothelial growth factor (VEGF). Inflammatory infiltration was quantified and analyzed. Transmission electron microscopy was performed for ultrastructural evaluation.

RESULTS

Myofibroblasts, mainly localized in the middle layer of capsular tissue, expressed VEGF, ER-α and ER-β. ER-β expression positively correlated with Collagen type I deposition (p= 0.025). Neo-angiogenesis was predominant in the middle layer. CD31 expression positively correlated with Collagen type I expression (p=0.009) and inflammatory infiltration grade (p= 0.004). The degree of inflammatory infiltration negatively correlated with the time from implantation (p = 0.022).

DISCUSSION

The middle layer is key in the development and remodeling of capsular tissue. Myofibroblasts produce VEGF, that induces neo-angiogenesis. New vessels formation is also correlated to the inflammatory response. Collagen deposition is associated with ER-β expression and neo-angiogenesis. These findings may prelude to targeted pharmacologic therapies able to control such interactions, thus hampering the self-sustaining loop promoting the progression of physiologic fibrosis toward pathologic contracture.

Follistatin and the Breast Implant Capsule

Supplemental Digital Content is available in the text.

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Morphologic Features of Magnetic Resonance Imaging as a Surrogate of Capsular Contracture in Breast Cancer Patients With Implant-based Reconstructions

PURPOSE

Capsular contracture (CC) is a serious complication in patients receiving implant-based reconstruction for breast cancer. Currently, no objective methods are available for assessing CC. The goal of the present study was to identify image-based surrogates of CC using magnetic resonance imaging (MRI).

METHODS AND MATERIALS

We analyzed a retrospective data set of 50 patients who had undergone both a diagnostic MRI scan and a plastic surgeon's evaluation of the CC score (Baker's score) within a 6-month period after mastectomy and reconstructive surgery. The MRI scans were assessed for morphologic shape features of the implant and histogram features of the pectoralis muscle. The shape features, such as roundness, eccentricity, solidity, extent, and ratio length for the implant, were compared with the Baker score. For the pectoralis muscle, the muscle width and median, skewness, and kurtosis of the intensity were compared with the Baker score. Univariate analysis (UVA) using a Wilcoxon rank-sum test and multivariate analysis with the least absolute shrinkage and selection operator logistic regression was performed to determine significant differences in these features between the patient groups categorized according to their Baker's scores.

RESULTS

UVA showed statistically significant differences between grade 1 and grade ≥2 for morphologic shape features and histogram features, except for volume and skewness. Only eccentricity, ratio length, and volume were borderline significant in differentiating grade ≤2 and grade ≥3. Features with P<.1 on UVA were used in the multivariate least absolute shrinkage and selection operator logistic regression analysis. Multivariate analysis showed a good level of predictive power for grade 1 versus grade ≥2 CC (area under the receiver operating characteristic curve 0.78, sensitivity 0.78, and specificity 0.82) and for grade ≤2 versus grade ≥3 CC (area under the receiver operating characteristic curve 0.75, sensitivity 0.75, and specificity 0.79).

CONCLUSIONS

The morphologic shape features described on MR images were associated with the severity of CC. MRI has the potential to further improve the diagnostic ability of the Baker score in breast cancer patients who undergo implant reconstruction.

Histological characterization of human breast implant capsules

Background

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

Methods

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

Results

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

Conclusion

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

Level of Evidence III

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.

Myofibroblast differentiation: main features, biomedical relevance, and the role of reactive oxygen species

SIGNIFICANCE

Myofibroblasts are prototypical fibrotic cells, which are involved in a number of more or less pathological conditions, from foreign body reactions to scarring, from liver, kidney, or lung fibrosis to neoplastic phenomena. The differentiation of precursor cells (not only of fibroblastic nature) is characterized by a complex interplay between soluble factors (growth factors such as transforming growth factor β1, reactive oxygen species [ROS]) and material properties (matrix stiffness).

RECENT ADVANCES

The last 15 years have seen very significant advances in the identification of appropriate differentiation markers, in the understanding of the differentiation mechanism, and above all, the involvement of ROS as causative and persistence factors.

CRITICAL ISSUES

The specific mechanisms of action of ROS remain largely unknown, although evidence suggests that both intracellular and extracellular phenomena play a role.

FUTURE DIRECTIONS

Approaches based on antioxidant (ROS-scavenging) principles and on the potentiation of nitric oxide signaling hold much promise in view of a pharmacological therapy of fibrotic phenomena. However, how to make the active principles available at the target sites is yet a largely neglected issue.

Breast implant capsule flaps and grafts: a review of the literature

BACKGROUND

A breast implant capsule forms as a physiological response to the foreign material. Over the past decades, authors started to consider the breast implant capsule as a new source of tissue, thus describing several capsular flaps and grafts. The aim of this article is to provide an overview of the applications and indications for the use of capsular tissue flaps and grafts in reconstructive and aesthetic surgery.

METHODS

A review of the literature on breast implant capsule grafts and flaps was conducted. The reported surgical techniques were described and compared for indications and complications. The studies were evaluated and compared for number of patients and follow-up.

RESULTS

The search yielded a total of 21 citations. Patient population was reported in 11 studies for capsular flaps and 2 articles for capsular grafts. Between 1997 and 2012, a total of 74 patients underwent surgery with the use of capsular tissue. Among these, 60 patients had a capsular flap (81 %) and 14 (19 %) had a capsular graft. Complications were experienced in 5 patients (6.7 %).

CONCLUSIONS

Capsular flaps and grafts are indicated mainly to address breast implant-related problems. The breast implant capsule represents a versatile and reliable source of tissue for both aesthetic and reconstructive surgery.

NO LEVEL ASSIGNED

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

The effect of montelukast and antiadhesion barrier solution on the capsule formation after insertion of silicone implants in a white rat model

BACKGROUND AND PURPOSES

Capsular contracture is one of the most severe complications that can occur in breast surgery following silicone implant insertion. The purpose of this study was to investigate the effect of montelukast and antiadhesion barrier solution (AABS) on reducing capsular formation and their possible synergism.

MATERIALS AND METHODS

This study was approved by the Animal Ethics Committee (Reference No. KNU 2012-33) and was conducted in accordance with the Kyungpook National University - Institutional Animal Care and Use Committee, Animal Ethics Committee. The experiments in this study were conducted in vivo in 4 groups of 24 rats. Following silicone implant insertion, the pocket was injected with different agents. Group I (control group) was given normal saline injections into the pocket and fed with pure water. Group II was given injections of AABS and fed with pure water. Group III was given injections of normal saline and the medication montelukast during the experimental period. Group IV was given injections of AABS and montelukast as postoperative medication. Peri-implant capsules were excised after 8 weeks and were evaluated for transparency, inflammatory cell content, capsule thickness, collagen pattern and TGF-β expression.

RESULTS

The capsules in the experimental groups (i.e., groups II-IV) were significantly more transparent than those in group I (controls; p < 0.05, Student's t test). The mean capsule thickness of the experimental groups II (296 ± 14.76 μm), III (280 ± 14.77 μm) and IV (276 ± 39.28 μm) was smaller than that of the control group I (361 ± 35.43 μm). Compared to the control group, the histologic findings in the experimental groups suggested a decreased inflammatory response occurring in the peri-implant capsules as they exhibited minor vascularization and a reduced number of mast cells and macrophages. The collagen patterns in the experimental groups were of a lower density than in the control group with the former showing a loose, tidy collagen pattern. The amounts of TGF-β and collagen I were higher in the control group than in the experimental groups. Group IV (the synergic effect group) had a more pronounced effect on all the parameters examined than that in groups II and III with separate drug administration.

CONCLUSIONS

Montelukast and AABS reduced the thickness, the inflammatory cell infiltrate and the myofibroblast content of the peri-implant capsules around silicone implants in this white rat model. They lowered the expression of the fibrotic mediator, TGF-β, and inhibited the peri-implant capsular fibrosis. Therefore, montelukast and AABS are effective in the reduction of silicone-induced peri-implant capsular formation.

Oestrogen receptor-alpha and -beta expression in breast implant capsules: experimental findings and clinical correlates

Myofibroblasts provide a force to decrease the surface area of breast implant capsules as the collagen matrix matures. 17-β-Oestradiol promotes myofibroblast differentiation and contraction. The aim of the study was to investigate the expression of oestrogen receptors α and β in capsular tissue. The study enrolled 70 women (80 capsules) who underwent expander or implant removal, following breast reconstruction. Specimens were stained with haematoxylin/eosin, Masson trichrome and immunohistochemistry and immunofluorescence stainings for alpha-smooth muscle actin (α-SMA), oestrogen receptor-alpha (ER-α) and oestrogen receptor-beta (ER-β). The relationship between anti-oestrogenic therapy and capsular severity was evaluated. A retrospective analysis of 233 cases of breast reconstruction was conducted. Myofibroblasts expressed ER-α, ER-β or both. In the whole sample, α-SMA score positively correlated with ER-α (p = 0.022) and ER-β expression (p < 0.004). ER-β expression negatively correlated with capsular thickness (p < 0.019). In capsules surrounding expanders α-SMA and ER-α, expressions negatively correlated with time from implantation (p = 0.002 and p = 0.016, respectively). The incidence of grade III-IV contracture was higher in patients who did not have anti-oestrogenic therapy (p < 0.036); retrospective analysis of 233 cases confirmed this finding (p < 0.0001). This study demonstrates the expression of oestrogen receptors in myofibroblasts of capsular tissue. A lower contracture severity was found in patients who underwent anti-oestrogenic therapy.

Capsular contracture by silicone breast implants: possible causes, biocompatibility, and prophylactic strategies

The most common implanted material in the human body consists of silicone. Breast augmentation and breast reconstruction using silicone-based implants are procedures frequently performed by reconstructive and aesthetic surgeons. A main complication of this procedure continues to be the development of capsular contracture (CC), displaying the result of a fibrotic foreign body reaction after the implantation of silicone. For many years, experimental and clinical trials have attempted to analyze the problem of its etiology, treatment, and prophylaxis. Different theories of CC formation are known; however, the reason why different individuals develop CC in days or a month, or only after years, is unknown. Therefore, we hypothesize that CC formation, might primarily be induced by immunological mechanisms along with other reasons. This article attempts to review CC formation, with special attention paid to immunological and inflammatory reasons, as well as actual prophylactic strategies. In this context, the word “biocompatibility” has been frequently used to describe the overall biological innocuousness of silicone in the respective studies, although without clear-cut definitions of this important feature. We have therefore developed a new five-point scale with distinct key points of biocompatibility. Hence, this article might provide the basis for ongoing discussion in this field to reduce single-publication definitions as well as increase the understanding of biocompatibility.

Identification of molecular phenotypic descriptors of breast capsular contracture formation using informatics analysis of the whole genome transcriptome

Breast capsular contracture formation following silicone implant augmentation/reconstruction is a common complication that remains poorly understood. The aim of this study was to identify potential biomarkers implicated in breast capsular contracture formation by using, for the first time, whole genome arrays. Biopsy samples were taken from 18 patients (23 breast capsules) with Baker Grade I-II (Control) and Baker Grade III-IV (Contracted). Whole genome microarrays were performed and six significantly dysregulated genes were selected for further validation with quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. Hematoxylin and eosin was also carried out to compare the histological characteristics of control and contracted samples. Microarray results showed that aggrecan, tissue inhibitor of metalloproteinase 4 (TIMP4), and tumor necrosis factor superfamily (ligand) member 11 were significantly down-regulated in contracted capsules; while matrix metallopeptidase 12, serum amyloid A 1, and interleukin 8 (IL8) were significantly up-regulated. The dysregulation of aggrecan, tumor necrosis factor superfamily (ligand) member 11, TIMP4, and IL8 was validated by quantitative reverse transcriptase polymerase chain reaction (p < 0.05). Immunohistochemistry confirmed an increased protein expression for IL8 and matrix metallopeptidase 12 in contracted capsules (p < 0.05), and decreased protein expression of TIMP4 (p < 0.05). This study has shown, for the first time, a number of unique biomarkers of significance in capsular contracture formation. IL8 and TIMP4 may serve as potential key diagnostic, therapeutic, and prognostic biomarkers in capsular contracture formation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Tissue regeneration during tissue expansion and choosing an expander

This paper reviews the various aspects of tissue regeneration during the process of tissue expansion. “Creep” and mechanical and biological “stretch” are responsible for expansion. During expansion, the epidermis thickens, the dermis thins out, vascularity improves, significant angiogenesis occurs, hair telogen phase becomes shorter and the peripheral nerves, vessels and muscle fibres lengthen. Expansion is associated with molecular changes in the tissue. Almost all these biological changes are reversible after the removal of the expander.This study is also aimed at reviewing the difficulty in deciding the volume and dimension of the expander for a defect. Basic mathematical formulae and the computer programmes for calculating the dimension of tissue expanders, although available in the literature, are not popular. A user-friendly computer programme based on the easily available Microsoft Excel spread sheet has been introduced. When we feed the area of defect and base dimension of the donor area or tissue expander, this programme calculates the volume and height of the expander. The shape of the expander is decided clinically based on the availability of the donor area and the designing of the future tissue movement. Today, tissue expansion is better understood biologically and mechanically. Clinical judgement remains indispensable in choosing the size and shape of the tissue expander.

Lubricin in human breast tissue expander capsules

Capsular contraction is the most common complication of breast reconstruction surgery. While presence of the contractile protein alpha smooth muscle actin (α-SMA) is considered among the causes of capsular contraction, the exact etiology and pathophysiology is not fully understood. The objective of this study was to investigate the possible role of lubricin in capsular formation and contraction by determining the presence and distribution of the lubricating protein lubricin in human breast tissue expander capsules. Related aims were to evaluate select histopathologic features of the capsules, and the percentage of cells expressing α-SMA, which reflects the myofibroblast phenotype. Capsules from tissue expanders were obtained from eight patients. Lubricin, at the tissue-implant interface, in the extracellular matrix, and in cells, and α-SMA-containing cells were evaluated immunohistochemically. The notable finding was that lubricin was identified in all tissue expander capsules: as a discrete layer at the tissue-implant interface, extracellular, and intracellular. There was a greater amount of lubricin in the extracellular matrix in the intimal-subintimal zone when compared with the tissue away from the implant. Varying degrees of synovial metaplasia were seen at the tissue-implant interface. α-SMA-containing cells were also seen in all but one patient. The findings might help us better understand factors involved in capsule formation.

Prefabricated tracheal prosthesis with partial biodegradable materials: a surgical and tissue engineering evaluation in vivo

Large and circumferential tracheal defects remain at this time an unsolved problem for reconstructive surgery. Many types of prosthetic and tissue grafts have been used but with limited comfortable results. Major complications are anastomotic dehiscence, graft ischemia and stenosis due to the poor vascularization of the prosthetic complex. We studied the in vivo behaviour of a prefabricated flap composed of a partially bioresorbable tracheal prosthesis and an arterio-venous vascular carrier. The prosthesis was made of a tubular skeleton of knitted Dacron (20 microm porosity) embedded within a bioresorbable poly-lactic-co-glycolic acid polymer (PLA(75)GA(25)) covering both sides. Fifteen New Zealand White rabbits were divided in three groups, depending on the time of examination (30, 90 and 180 days post-implantation). The prosthesis was implanted in the visceral space of the neck using the common carotid trunk and the internal jugular vein as vascular pedicle. The histological, immunohistochemical, and ESEM analyses of collected samples, showed a time-dependent process of tissue neoformation and neovascularization on the prosthetic material with a significant increase from 30 to 90 days post-implantation. In contrast, there was no statistically significant difference in the fibrovascular connective deposition from 90 to 180 days. This finding indicated the three months time as the best period for the tissue deposition and consequent hypothetical orthotopic transplantation of the prosthesis. Further in vivo studies are intended to confirm the results.

Hyaluronan, TSG-6, and inter-α-inhibitor in periprosthetic breast capsules: reduced levels of free hyaluronan and TSG-6 expression in contracted capsules

BACKGROUND

The exact mechanism of capsular contracture (CC) is still unknown. The covalent modification of hyaluronan (HA) with the heavy chains (HC) of inter-α-inhibitor (IαI) has been identified as an important pathway in inflammation and tissue remodeling, where HC·HA formation is catalyzed by TSG-6 (the protein product of tumor necrosis factor stimulated gene-6).

OBJECTIVE

The authors quantitatively assess the correlation between severity of CC (measured by Baker grade) and expression of HA, TSG-6, and IαI (ie, the polypeptides HC1, HC2, and bikunin) in periprosthetic breast capsules.

METHODS

Immunofluorescent staining for HA, TSG-6, HC1, HC2, and bikunin was carried out on periprosthetic breast capsules (n = 7) of each Baker grade from four anatomical locations. Quantitative analysis was performed to identify differences in staining intensity. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to determine differences in TSG-6 gene expression levels.

RESULTS

Severity of contracture was associated with reduced staining for both free HA (Pearson correlation coefficient, r = -0.645, P < .001) and TSG-6 (r = -0.642, P = .002). RT-qPCR showed a significant negative correlation between severity of contracture and TSG-6 gene expression levels (r = -0.750, P = .001).

CONCLUSIONS

The negative correlation between TSG-6 expression levels and severity of CC suggests a possible protective role for TSG-6 in the context of CC formation, and this may have a clinically relevant role in prevention of breast CC.

Flector tissugel used to treat capsular contracture after breast augmentation surgery

Capsular contracture constitutes the main postoperative complication after breast augmentation by implant placement. To date, no systemic treatment known allows for improvement that does not simultaneously put the patient at risk for secondary complications of a more general nature. Flector Tissugel is the sole locally active antiinflammatory patch. Its durable local antiinflammatory effect is associated only with a risk for rare and highly limited side effects. After approximately 3 weeks of treatment, a high frequency of change from capsular contracture Baker 2 or 3 to Baker 1 occurs, provided the application was started no later than 3 months after the onset of capsular contracture.

Breast Implant Capsules Are Partially Composed of Bone Marrow–Derived Cells

Capsular contracture is the most common complication following breast augmentation or reconstruction with implants. We recently demonstrated that bone marrow-derived cells provide fibroblasts to murine skin during wound healing. To determine if bone marrow-derived cells were the cellular source of periprosthetic capsules, we created chimeric C57BL mice containing bone marrow cells from isogeneic enhanced green fluorescent protein (EGFP) mice and implanted with a textured silicone shell implant. We found that none of the mice developed infection or capsular contracture, but day 30 capsules were composed of 26.4 +/- 6.1% EGFP cells, and day 60 capsules had 21.8 +/- 10.3% EGFP cells. Immunohistochemistry revealed a small population of EGFP cells in the capsules that were myofibroblasts. Thus, breast implant capsules are partially composed of bone marrow-derived cells and, given the potential of these cells to become myofibroblasts, may explain the cellular source of capsular contracture when it develops.

Capsular Contracture in Subglandular Breast Augmentation with Textured versus Smooth Breast Implants: A Systematic Review

BACKGROUND

There are conflicting recommendations in the literature regarding the use of textured implants to reduce capsular contracture in subglandular breast augmentation. The authors reviewed the literature to evaluate the effectiveness of surface texturization in reducing capsular contracture.

METHODS

The electronic databases MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials comparing textured with smooth implants for subglandular breast augmentation. Study quality was evaluated, and data were extracted from the relevant studies by two reviewers. Outcome measures were reduction in capsular contracture as defined by Baker grade, applanation tonometry, and patient self-assessment. Overall, the treatment effects were expressed as relative risk for dichotomous data and as weighted mean differences for continuous data.

RESULTS

Six randomized controlled trials were identified with a total of 235 patients (470 breasts). Textured implants were associated with less capsular contracture as evaluated by Baker grade at 1 year (relative risk, 4.16; 95% CI, 1.58 to 10.96), 3 years (relative risk, 7.25; 95% CI, 2.42 to 21.69), and 7 years (relative risk, 2.98; 95% CI, 0.86 to 10.37) of follow-up. Applanation tonometry used as an objective measure of firmness, however, was not sensitive enough to detect any significant difference in contractures in the two groups (weighted mean differences, -1.54; 95% CI, -6.83 to -3.75). Interestingly, the self-assessment questionnaire revealed that capsular contracture or firmness is one (albeit a very important factor) of many facets in patient overall satisfaction.

CONCLUSIONS

This systematic review suggests that implant texturization reduces the incidence of early capsular contracture in subglandular breast augmentation. However, further studies are needed to evaluate the long-term effect of texturization and confirm the long-term benefits noted in this study.

Capsular contracture around saline-filled and textured subcutaneously-placed implants in irradiated and non-irradiated breast cancer patients: Five years of monitoring of a prospective trial

One hundred and seven breast cancer patients underwent subcutaneous mastectomy and immediate reconstruction with a subcutaneously-placed, round, saline-filled prosthesis with a textured surface. The primary aim of this prospective study was to determine the frequency of capsular contracture in both irradiated and non-irradiated breasts after this operation. Two different types of round implants with different pore sizes on their textured surfaces, Siltex and Microcell, were randomly chosen. Twenty-four patients received radiotherapy within the first year following the operation. Capsular contracture was measured by the Baker/Palmer classification and by applanation tonometry at regular intervals for 5 years or as long as the patients lived (median 60 months). Twenty-two patients (20.6%) developed capsular contracture, defined as Baker three or four. Sixteen of those were reoperated, 15 with open capsulotomy with or without implant exchange, one with closed compression capsulotomy, and monitored thereafter for 5 years or until death (median 60 months). All 107 patients could be monitored for 2 years, while 87 reported for the 5-year follow-up. The rate of capsular contracture was significantly higher (p=0.01) for irradiated breasts than for non-irradiated ones, 41.7 and 14.5%, respectively. It was slightly higher (p<0.05) for large-pore implants than for those with smaller (and more numerous) pores. There was a good correlation between the two different methods for measuring capsular contracture. None of the 16 reoperated patients had a recurrence of capsular contracture within 5 years. The results indicate a high rate of capsular contracture after this operation, especially when followed by radiation. However, a fairly simple procedure to treat capsular contracture seems to give good long-term results.

Silicone rubber tubulization in peripheral sensory nerve reconstruction: an experimental study in rabbits

Silicone rubber (polydimethyl siloxane) tubes are used clinically in peripheral nerve reconstruction. A disadvantage of this procedure is that the material often has to be removed owing to its mechanical properties. The aim of our study was to investigate the healing of reconstructed sensory nerves tubulized by silicone rubber in an animal model. In our experiments, we reconstructed the saphenous nerves in 27 rabbits. In series 1 (n = 12), silicone rubber tubes were slid over a nerve suture without a gap. In series 2 (n = 12), silicone rubber tubes were slid over a 10-mm nerve gap. In series 3 (n = 12), conventional suturing was performed in the collateral saphenous nerves of the animals of the series 1. Epineurial suturing was performed. Three other collateral nonoperated saphenous nerves served as controls. The healing was studied after 3, 6, and 12 months. Morphometric analysis of the regenerating axons was performed by using our new method for quantification of nerve fibers in cross sections stained by immunohistochemistry and using confocal laser scanning microscopy. Data analysis was carried out using a software program especially developed for this purpose. Our results showed in the silicone procedures that at 12 months significantly fewer axons per fascicle area were present compared with conventional suturing. However, mean axon diameters in the distal nerve stump of the silicone procedures did not differ significantly compared with the conventional suturing procedure. The ratio of total axon area to total fascicle area in the distal nerve stumps of the silicone procedure without gap was significantly smaller compared with the conventionally sutured nerve. The percentage outgrowing axons from the proximal nerve stump into the distal one in the silicone rubber procedure without gap was 57%. This was significantly higher than in the silicone rubber procedure with 10-mm gap (48%). However, in conventional suturing, the percentage of outgrowing axons (99%) was significantly higher than in both tubulization procedures. It appeared that tubulization by silicone rubber of sutured nerves without gap did not enhance axon regeneration. Conventional suturing gave significantly better results. If a gap was present, the use of a silicone rubber tube was preferable to non-suturing.

Long-term advantages of permanent expandable implants in breast aesthetic surgery

Permanent expandable implants are widely used in breast reconstructive surgery, but their use in aesthetic surgery is still uncommon. Previous reports on breast expansion-augmentation using permanent expandable implants focused on immediate and early advantages but failed to evaluate long-term benefits, because the reservoir was removed a few months after implantation and the ability to adjust the implant size was lost. Since 1986, we have used permanent expandable implants in 129 women for unilateral or bilateral breast augmentation using the following approach: implants were positioned submuscularly through a transaxillary incision; the filling port was placed a few centimeters below the incision and permanently retained; the implants were positioned underinflated and then overexpanded starting 2 weeks after implantation; after a period of overinflation, deflation to the preoperatively planned volume was scheduled; patients' suggestions regarding final volume adjustments were followed; the effects of repeated overinflations and deflations were investigated in several different conditions. Permanent expandable implants offer unique long-term technical and psychological advantages in the management of highly demanding patients and in the following clinical situations: pregnancy, impending capsular contracture, contralateral progressive ptosis, tubular breasts(s), difficult mammographic examination, spontaneous deflation, and rippling. Disadvantages include economical cost, port-related problems, and repeated requests by patients for volume changes. Saline permanent expandable implants allowed less flexibility in adjusting the breast size and caused discomfort when overexpanded. Permanent expandable implants in breast aesthetic surgery offer several advantages, and because patients can play an active role in deciding volume adjustments, compliance is very high.

Silicone breast implants: complications

Silicone breast implants have been used for augmentation mammoplasty for cosmetic purposes as well as for breast reconstruction following mastectomy for more than three decades. Though the use of the silicone gel filled variety has been banned in the USA except for special cases, they continue to be available elsewhere in the world including the UK. Despite the immense benefit they provide, their usage is associated with some complications. Most of these are related to the surgery and can be reduced by good surgical management. The major complications associated with their use is adverse capsular contracture, an outcome which can be very frustrating to manage. This article reviews the commonly reported complications and suggested management alternatives.