Functional biocompatibility testing of silicone breast implants and a novel classification system based on surface roughness

Breast implant surface topography triggers a chronic-like inflammatory response

Breast implants are extensively employed for both reconstructive and esthetic purposes. However, the safety of breast implants with textured surfaces has been questioned, owing to a potential correlation with anaplastic large-cell lymphoma and the recurrence of breast cancer. This study investigates the immune response elicited by different prosthetic surfaces, focusing on the comparison between macrotextured and microtextured breast implants. Through the analysis of intraoperatively harvested periprosthetic fluids and cell culture experiments on surface replicas, we demonstrate that macrotextured surfaces elicit a more pronounced chronic-like activation of leucocytes and an increased release of inflammatory cytokines, in contrast to microtextured surfaces. In addition, in vitro fluorescent imaging of leucocytes revealed an accumulation of lymphocytes within the cavities of the macrotextured surfaces, indicating that the physical entrapment of these cells may contribute to their activation. These findings suggest that the topography of implant surfaces plays a significant role in promoting a chronic-like inflammatory environment, which could be a contributing factor in the development of lymphomas associated with a wide range of implantable devices.

An Update on Implant-Associated Malignancies and Their Biocompatibility

Implanted medical devices are widely used across various medical specialties for numerous applications, ranging from cardiovascular supports to orthopedic prostheses and cosmetic enhancements. However, recent observations have raised concerns about the potential of these implants to induce malignancies in the tissues surrounding them. There have been several case reports documenting the occurrence of cancers adjacent to these devices, prompting a closer examination of their safety. This review delves into the epidemiology, clinical presentations, pathological findings, and hypothesized mechanisms of carcinogenesis related to implanted devices. It also explores how the surgical domain and the intrinsic properties and biocompatibility of the implants might influence the development of these rare but serious malignancies. Understanding these associations is crucial for assessing the risks associated with the use of medical implants, and for developing strategies to mitigate potential adverse outcomes.

Periprosthetic effusions surrounding breast expander: a flow cytometric, immunohistochemical and molecular characterization

INTRODUCTION

The synthesis of the periprosthetic capsule during implant-based breast reconstruction is the result of a coordinate cascade of inflammatory events ending in a fibrous tissue deposition around the expander or implant. Although the development of small volumes of fluid is one of the complications of prosthetic-based breast reconstruction, the characterization of the periprosthetic effusions coupled with the micro-textured devices, that have been recently introduced after the recall of macro-textured ones, is still lacking. The investigation of these periprosthetic effusions and paired capsules in terms of immunological content were the primary and secondary aims of the present study, respectively.

METHODS

For this, 68 women, 41 of whom had periprosthetic effusions at the time of expander replacement with implant, were recruited. For each case, capsule and healthy dermal tissues were taken and for women with periprosthetic effusion, peripheral blood was also collected. Periprosthetic effusions and peripheral blood were characterized by cytometry while capsules and dermal tissues by immunohistochemistry and Nanostring analysis.

RESULTS

The results showed an increase of Th1, Th2 lymphocytes and a HLA-DR+bright CD16+ cells (likely representing monocytes-derived macrophages) in periprosthetic effusions in respect to peripheral blood. These pro-inflammatory cells were counterbalanced by the gain of suppressive CD4 Treg cells. In the corresponding capsules, immunohistochemistry revealed the absence of Th1 cells and the presence of tissutal FOXP3 Treg. No significant difference in expression of inflammatory-related genes between capsules and dermal tissues was present.

CONCLUSIONS

These results suggest the presence of a Treg-controlled inflammation in both periprosthetic effusions and capsules.

Identification of Drug Compounds for Capsular Contracture Based on Text Mining and Deep Learning

BACKGROUND

Capsular contracture is a common and unpredictable complication after breast implant placement. Currently, the pathogenesis of capsular contracture is unclear, and the effectiveness of nonsurgical treatment is still doubtful. The authors' study aimed to investigate new drug therapies for capsular contracture by using computational methods.

METHODS

Genes related to capsular contracture were identified by text mining and GeneCodis. Then, the candidate key genes were selected through protein-protein interaction analysis in Search Tool for the Retrieval of Interacting Genes/Proteins and Cytoscape. Drugs targeting the candidate genes with relation to capsular contracture were screened out in Pharmaprojects. Based on the drug-target interaction analysis by DeepPurpose, candidate drugs with highest predicted binding affinity were obtained eventually.

RESULTS

The authors' study identified 55 genes related to capsular contracture. Gene set enrichment analysis and protein-protein interaction analysis generated eight candidate genes. One hundred drugs targeting the candidate genes were selected. The seven candidate drugs with the highest predicted binding affinity were determined by DeepPurpose, including tumor necrosis factor alpha antagonist, estrogen receptor agonist, insulin-like growth factor 1 receptor, tyrosine kinase inhibitor, and matrix metallopeptidase 1 inhibitor.

CONCLUSION

Text mining and DeepPurpose can be used as a promising tool for drug discovery in exploring nonsurgical treatment to capsular contracture.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Management of Biofilm with Breast Implant Surgery

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand how bacteria negatively impact aesthetic and reconstructive breast implants. 2. Understand how bacteria infect breast implants. 3. Understand the evidence associated with common implant infection-prevention strategies, and their limitations. 4. Understand why implementation of bacteria-mitigation strategies such as antibiotic administration or "no-touch" techniques may not indefinitely prevent breast implant infection.

SUMMARY

Bacterial infection of aesthetic and reconstructive breast implants is a common and expensive problem. Subacute infections or chronic capsular contractures leading to device explantation are the most commonly documented sequelae. Although bench and translational research underscores the complexities of implant-associated infection, high-quality studies with adequate power, control groups, and duration of follow-up are lacking. Common strategies to minimize infections use antibiotics-administered systemically, in the breast implant pocket, or by directly bathing the implant before insertion-to limit bacterial contamination. Limiting contact between the implant and skin or breast parenchyma represents an additional common strategy. The clinical prevention of breast implant infection is challenged by the clean-contaminated nature of breast parenchyma, and the variable behavior of not only specific bacterial species but also their strains. These factors impact bacterial virulence and antibiotic resistance.

The Double Capsule Phenomenon in a Case Series and its Relationship with the Macro-Textured Breast Implant

BACKGROUND

Silicone breast augmentation remains one of the most common aesthetic surgery procedures, and 2022 marks the 60th anniversary of the first case. Recent studies suggest a link between double capsule (DC) formation and macro-textured devices.

METHODS

Between 2010 and 2015, 268 aesthetic patients underwent bilateral mammary prosthesis exchange for indications including PIP exchange, adverse capsular contracture and ultrasonographic evidence of rupture. All surgery, in the form of implant exchange and capsulectomy, was undertaken by the senior author using standard techniques. A retrospective review was undertaken, and data analysed with descriptive statistics and Fisher's exact and Mann-Whitney U tests.

RESULTS

Of 268 patients identified, 40 (14.9%) showed some degree of capsular duplication and bilateral involvement was marginally more common (52.5%). Two macroscopic patterns of duplication were observed: complete and subtotal. Complete DCs correlated with a clinical triad of extreme firmness, mobility and minimal-to-no pain. Whilst a wide range of manufacturers was represented, macro-textured devices were associated with the highest DC prevalence (58.3% vs. 5.6%) (Fisher's exact test p < 0.00001). Patients with DC had been implanted for less than half the time, median 52 versus. 120 months (p = 0.0003) of those without.

DISCUSSION

An elevated prevalence of duplicate capsules in macro-textured prostheses is reconfirmed in addition to a novel symptom constellation that may assist with clinical diagnosis. Our study reinforces the aetiopathogenic influence of the elastomer in DC formation and reports DC for the first time in non-macrotextured implants. Single-surgeon cohort of 268 consecutive patients with 532 implants Statistically significant association of macro-textured devices with DC Statistically significant reduced duration of implantation of macro-textured devices First report of DC in non-macro-textured devices 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 .

Monitoring the macrophage response towards biomaterial implants using label-free imaging

Understanding the immune system's foreign body response (FBR) is essential when developing and validating a biomaterial. Macrophage activation and proliferation are critical events in FBR that can determine the material's biocompatibility and fate in vivo. In this study, two different macro-encapsulation pouches intended for pancreatic islet transplantation were implanted into streptozotocin-induced diabetes rat models for 15 days. Post-explantation, the fibrotic capsules were analyzed by standard immunohistochemistry as well as non-invasive Raman microspectroscopy to determine the degree of FBR induced by both materials. The potential of Raman microspectroscopy to discern different processes of FBR was investigated and it was shown that Raman microspectroscopy is capable of targeting ECM components of the fibrotic capsule as well as pro and anti-inflammatory macrophage activation states, in a molecular-sensitive and marker-independent manner. In combination with multivariate analysis, spectral shifts reflecting conformational differences in Col I were identified and allowed to discriminate fibrotic and native interstitial connective tissue fibers. Moreover, spectral signatures retrieved from nuclei demonstrated changes in methylation states of nucleic acids in M1 and M2 phenotypes, relevant as indicator for fibrosis progression. This study could successfully implement Raman microspectroscopy as complementary tool to study in vivo immune-compatibility providing insightful information of FBR of biomaterials and medical devices, post-implantation.

The Influence of BIA-ALCL on the Use of Textured Breast Implant and its Placement: A Survey of Dutch Plastic Surgeons

BACKGROUND

Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) and its association with macrotextured breast implants may have induced plastic surgeons to change their breast augmentation and breast reconstruction practice.

OBJECTIVES

The aim of this study was to survey Dutch plastic surgeons about the effects of BIA-ALCL on their choice of breast implant texture and placement technique.

METHODS

An online questionnaire was distributed to all members of the Dutch Association of Plastic Surgeons. Descriptive data were presented as frequencies and percentages. Technique alterations were analyzed by the marginal homogeneity test for paired nominal data.

RESULTS

A total of 63 plastic surgeons completed the questionnaire. The majority of respondents altered their use of textured implants due to BIA-ALCL concerns for both breast augmentation and reconstruction (75.4% and 69.8%, respectively; both being statistically significant, P < .001). Microtextured and smooth/nanotextured breast implants are now most frequently used. BIA-ALCL did not influence the placement technique in breast augmentation and reconstruction (87.7% and 94.3%, respectively). Dual-plane breast implant placement is still the most favored technique for breast augmentation, and submuscular placement is still most favored for breast reconstruction.

CONCLUSIONS

BIA-ALCL has had a significant impact on the use of macrotextured breast implants by Dutch plastic surgeons in both aesthetic and reconstructive breast surgery. Breast implant placement technique has not been affected.

LEVEL OF EVIDENCE: 4

Use of High-Resolution Ultrasound in Characterizing the Surface Topography of a Breast Implant

Background and Objectives: With the emergence of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), it has become necessary to identify the implant shell type patients have received. Therefore, an immediate, reliable method for identifying a breast implant shell type is essential. Evidence-based research and applying a real-world technique that identifies the surface topographic information of the inserted breast implants, without surgery, has become of paramount importance for breast implant physicians. Methods and Materials: A review of the medical records of 1901 patients who received 3802 breast implants and subsequently received an ultrasound-assisted examination was performed. All patients received not only a breast cancer examination but also a high-resolution ultrasonography (HRUS) assisted examination of the device at a single center between 31 August 2017 and 31 December 2022. Results: Most patients had breast implants within 10 years (77.7%) of the examination. Of the 3802 implants screened, 2034 (53.5%) were identified with macro-textured shell topography in ultrasonography. A macrotextured shell type implant was used in 53.5% of cases and a smooth type in 42.7% of cases. Seventy-three (1.9%) breast implant shell types could not be identified due to ruptures. However, 250 breast implant shell types could be identified despite rupture cases (6.5%). Conclusions: HRUS was found to be a useful and reliable image modality for identifying various surface shell types of breast implants. The shell type information would be helpful to patients who lack information about their breast implants and are concerned about BIA-ALCL.

A Comparison of Smooth and Microtextured Breast Implants in Breast Augmentation: A Retrospective Study

Background  The number of cosmetic and reconstructive surgeries that use breast implants is increasing in Korea. Recently, it has been reported that breast implant-associated anaplastic large-cell lymphoma is related to textured breast implants, and interest in classification according to the texture of breast implants is increasing. However, there is currently no clear and unified classification. In particular, the definition of “microtextured” is highly varied. In this study, we retrospectively investigated and analyzed the clinical outcomes of smooth and microtextured breast implants.

Methods  A retrospective chart review of all patients who underwent breast augmentation surgery with smooth and microtextured silicone gel implants between January 2016 and July 2020 was performed. We retrospectively analyzed implant manufacturer, age, body mass index (BMI), smoking status, incision location, implant size, follow-up period, complications, and reoperation rate.

Results  A total of 266 patients underwent breast augmentation surgery, of which 181 used smooth silicone gel implants and 85 used microtextured silicone gel implants. Age, BMI, smoking status, implant size, and follow-up period were not significantly different between the two groups. Similarly, complications and reoperation rates were not significantly different between the two groups.

Conclusion  It is important to provide information regarding the clinical risks and benefits of breast implants to surgeons and patients through a clear and unified classification according to the texture of the breast implant.

Study of the Effect of Different Breast Implant Surfaces on Capsule Formation and Host Inflammatory Response in an Animal Model

BACKGROUND

Breast implants are biomaterials eliciting a physiological and mandatory foreign body response.

OBJECTIVES

The authors designed an animal study to investigate the impact of different implant surfaces on the formation of the periprosthetic capsule, the inflammatory response, and the cellular composition.

METHODS

The authors implanted 1 scaled-down version of breast implants by different manufactures on 70 female Sprague Dawley rats. Animals were divided into 5 groups of 14 animals. Group A received a smooth implant (Ra ≈ 0.5 µm) according to the ISO 14607-2018 classification, Group B a smooth implant (Ra ≈ 3.2 µm), Group C a smooth implant (Ra ≈ 5 µm), Group D a macrotextured implant (Ra ≈ 62 µm), and Group E a macrotextured implant (Ra ≈ 75 µm). At 60 days, all animals received a magnetic resonance imaging (MRI), and 35 animals were killed and their capsules sent for histology (capsule thickness, inflammatory infiltrate) and immunohistochemistry analysis (cellular characterization). The remaining animals repeated the MRI at 120 days and were killed following the same protocol.

RESULTS

MRI showed a thinner capsule in the smooth implants (Groups A-C) at 60 days (P < .001) but not at 120 days (P = .039), confirmed with histology both at 60 days (P = .005) and 120 days (P < .001). Smooth implants (Groups A-C) presented a mild inflammatory response at 60 days that was maintained at 120 days and a high M2-Macrophage concentration (anti-inflammatory).

CONCLUSIONS

Our study confirms that smooth implants form a thinner capsule, inferior inflammatory infiltrate, and a cellular composition that indicates a mild host inflammatory response. A new host inflammatory response classification is elaborated classifying breast implants into mild, moderate, and high.

Immune-responsive biodegradable scaffolds for enhancing neutrophil regeneration

Neutrophils are essential effector cells for mediating rapid host defense and their insufficiency arising from therapy-induced side-effects, termed neutropenia, can lead to immunodeficiency-associated complications. In autologous hematopoietic stem cell transplantation (HSCT), neutropenia is a complication that limits therapeutic efficacy. Here, we report the development and in vivo evaluation of an injectable, biodegradable hyaluronic acid (HA)-based scaffold, termed HA cryogel, with myeloid responsive degradation behavior. In mouse models of immune deficiency, we show that the infiltration of functional myeloid-lineage cells, specifically neutrophils, is essential to mediate HA cryogel degradation. Post-HSCT neutropenia in recipient mice delayed degradation of HA cryogels by up to 3 weeks. We harnessed the neutrophil-responsive degradation to sustain the release of granulocyte colony stimulating factor (G-CSF) from HA cryogels. Sustained release of G-CSF from HA cryogels enhanced post-HSCT neutrophil recovery, comparable to pegylated G-CSF, which, in turn, accelerated cryogel degradation. HA cryogels are a potential approach for enhancing neutrophils and concurrently assessing immune recovery in neutropenic hosts.

Advances in surface modifications of the silicone breast implant and impact on its biocompatibility and biointegration

Silicone breast implants are commonly used for cosmetic and oncologic surgical indications owing to their inertness and being nontoxic. However, complications including capsular contracture and anaplastic large cell lymphoma have been associated with certain breast implant surfaces over time. Novel implant surfaces and modifications of existing ones can directly impact cell-surface interactions and enhance biocompatibility and integration. The extent of foreign body response induced by breast implants influence implant success and integration into the body. This review highlights recent advances in breast implant surface technologies including modifications of implant surface topography and chemistry and effects on protein adsorption, and cell adhesion. A comprehensive online literature search was performed for relevant articles using the following keywords silicone breast implants, foreign body response, cell adhesion, protein adsorption, and cell-surface interaction. Properties of silicone breast implants impacting cell-material interactions including surface roughness, wettability, and stiffness, are discussed. Recent studies highlighting both silicone implant surface activation strategies and modifications to enhance biocompatibility in order to prevent capsular contracture formation and development of anaplastic large cell lymphoma are presented. Overall, breast implant surface modifications are being extensively investigated in order to improve implant biocompatibility to cater for increased demand for both cosmetic and oncologic surgeries.

Impact on capsule formation for three different types of implant surface tomography

Although capsular contracture remains one of the major problems following silicone breast implantation, the associated mechanism has yet to be determined. This study thus aimed to investigate capsule formation and capsular contracture using three types of implants with different surface topographies in vivo. Three types of implants (i.e., smooth, macrotexture, and nanotexture) with different surface topographies were inserted in a total of 48 Wistar rats. After 4 and 12 weeks, the samples were analyzed via histological, immunohistochemical, and Western blot examination. To identify implant movement, the degree to which implant position changed was measured. And the surface topography was characterized using scanning electron microscopy. Hematoxylin–eosin staining showed that the nanotexture type implant promoted significant decreases in capsule thickness at 12 weeks (P < 0.05), while Masson trichrome staining showed decreased collagen fiber density with the same implant type. Immunohistochemical and Western blot examination revealed reduced fibrosis markers (myofibroblast, and transforming growth factor beta-1) in the nanotexture surface implant. Meanwhile, implant location evaluation found that the nanotexture and smooth surface implants had significantly increased movement (P < 0.05). The nanotexture surface implant had been found to reduce capsule formation given that it minimizes the effects of factors related to foreign body reaction.

2022 Practice Recommendation Updates From the World Consensus Conference on BIA-ALCL

BACKGROUND

Laboratory and clinical research on breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is rapidly evolving. Changes in standard of care and insights into best practice were recently presented at the 3rd World Consensus Conference on BIA-ALCL.

OBJECTIVES

The authors sought to provide practice recommendations from a consensus of experts, supplemented with a literature review regarding epidemiology, etiology, pathogenesis, diagnosis, treatment, socio-psychological aspects, and international authority guidance.

METHODS

A literature search of all manuscripts between 1997 and August 2021 for the above areas of BIA-ALCL was conducted with the PubMed database. Manuscripts in different languages, on non-human subjects, and/or discussing conditions separate from BIA-ALCL were excluded. The study was conducted employing the Delphi process, gathering 18 experts panelists and utilizing email-based questionnaires to record the level of agreement with each statement by applying a 5-point Likert Scale. Median response, interquartile range, and comments were employed to accept, reject, or revise each statement.

RESULTS

The literature search initially yielded 764 manuscripts, of which 405 were discarded. From the remaining 359, only 218 were included in the review and utilized to prepare 36 statements subdivided into 5 sections. After 1 round, panelists agreed on all criteria.

CONCLUSIONS

BIA-ALCL is uncommon and still largely underreported. Mandatory implant registries and actions by regulatory authorities are needed to better understand disease epidemiology and address initial lymphomagenesis and progression. Deviation from current diagnosis and treatment protocols can lead to disease recurrence, and research on breast implant risk factors provide insight to etiology.

LEVEL OF EVIDENCE: 4

Using a Digital Implant Catalog Improves Data Quality and Reduces Administrative Burden in the Dutch Breast Implant Registry

BACKGROUND

Correct registration of implant characteristics is essential to monitor implant safety within implant registries. Currently, in the nationwide Dutch Breast Implant Registry (DBIR), these characteristics are being registered manually by plastic surgeons, resulting in administrative burden and potentially incorrect data entry.

OBJECTIVES

This study evaluated the accuracy of manually registered implant data, possible consequences of incorrect data, and the potential of a Digital Implant Catalog (DIC) on increasing data quality and reducing the administrative burden.

METHODS

Manually entered implant characteristics (fill, shape, coating, texture) of newly inserted breast implants in the DBIR, from 2015 to 2019, were compared with the corresponding implant characteristics in the DIC. Reference numbers were employed to match characteristics between the 2 databases. The DIC was based on manufacturers' product catalogs and set as the gold standard.

RESULTS

A total of 57,361 DBIR records could be matched with the DIC. Accuracy of implant characteristics varied from 70.6% to 98.0%, depending on the implant characteristic. The largest discrepancy was observed for "texture" and the smallest for "coating." All manually registered implant characteristics resulted in different conclusions about implant performance compared with the DIC (P < 0.01). Implementation of the DIC reduced the administrative burden from 14 to 7 variables (50%).

CONCLUSIONS

Implementation of a DIC increases data quality in the DBIR and reduces the administrative burden. However, correct registration of reference numbers in the registry by plastic surgeons remains key for adequate matching. Furthermore, all implant manufacturers should be involved, and regular updates of the DIC are required.

A Rationale for Micro-textured Breast Implant Augmentation

Background

Textured breast implants have been used in aesthetic breast surgery to decrease rates of malposition and capsular contracture. Recent concerns regarding breast implant-associated anaplastic large cell lymphoma (BIA-ALCL)’s link to textured devices have prompted many physicians to re-evaluate their use.

Objectives

The authors aimed to create an algorithm for when to use smooth versus micro-textured breast implants and provide their rationale for when micro-textured implants may be more beneficial.

Methods

133 patients received primary augmentations performed by a single surgeon from January 2018–December 2020. 84 patients received smooth implants and 49 patients received micro-textured implants. All surgeries were performed in the dual-plane using an inframammary incision. Implant-related complications and scar malposition were recorded and compared between groups.

Results

No significant difference in the prevalence of implant-related complications was found (3.57% for smooth devices and 2.04% for micro-textured devices [P-value 0.621257, 95% CI -0.06100–0.007467]). There were no cases of BIA-ALCL. Comparison of scar malposition rates between the smooth and micro-textured groups also revealed no statistically significant difference (15.4% for smooth devices and 8.16% for micro-textured devices [P-value 0.226156, 95% CI -0.1200–0.007467]). Patients in the micro-textured group proportionately had more anatomical risk factors for malposition.

Conclusions

Micro-textured breast implants continue to be a safe and effective choice for patients. Micro-textured implants show a trend towards decreased scar malposition, although not statistically significant. Patients at high risk for malposition with micro-textured breast implants give similar results to patients at average risk for malposition with smooth implants.

HISTORY OF BREAST IMPLANTS: BACK TO THE FUTURE

Modern breast implants are a staple of plastic surgery, finding uses in esthetic and reconstructive procedures. Their history began in the 1960s, with the first generation of smooth devices with thick silicone elastomer, thick silicone gel, and Dacron patches on the back. They presented hard consistency, high capsular contracture rates and the patches increased the risk of rupture. In the same decade, polyurethane coating of implants was implemented. A second generation was introduced in the 1970s with a thinner shell, less viscous gel filler and no patches, but increased silicone bleed-through and rupture rates. The third generation, in the early 1980s, featured implants with a thicker multilayered elastomer shell reinforced with silica to reduce rupture risk and prevent silicone bleed-through. A fourth generation from the late 1980s combined thick outer elastomer shells, more cohesive gel filler, and implemented for the first-time outer shell texturing. In the early 1990s, the fifth generation of devices pioneered an anatomical shape with highly cohesive form-stable gel filler and a rough outer shell surface. Surface texturing was hampered by the discovery of Breast Implant Associated-Anaplastic Large Cell Lymphoma and its link with textured devices. From the 2010s, we have the era of the sixth generation of implants, featuring innovations regarding the surface, with biomimetic surfaces, more resistant shells and variations in gel consistency. The road to innovation comprises setbacks such as the FDA moratorium in 1992, the PIP scandal, the Silimed CE mark temporary suspension and the FDA-requested voluntary recall of the Allergan BIOCELL implants.

Safety and Performance of POLYTECH Mesmo Breast Implants: A 5-Year Post-market Surveillance Study on 919 Patients

Background

In 2007, POLYTECH Health & Aesthetics (POLYTECH, Dieburg, Germany) established an ongoing patient survey to improve the post-market surveillance of silicone gel-filled breast implants based on patient-reported outcomes in the context of the pioneering "Implants of Excellence" (IoE) program.

Objectives

To disclose an update on safety and performance outcomes at 5 years for Mesmo breast implants.

Methods

Between January 2014 and October 2019, 919 patients (for a total of 1816 implants) who underwent breast augmentation and reconstruction with Mesmo implants were asked to participate in the IoE program. Data were collected by mean of 1320 questionnaires received. A survival analysis assessed the onset of different complications.

Results

Eight patients (0.9%) experienced capsular contracture Baker grade III or IV with a cumulative rate at 5 years of 1.2% (95% CI = 0.6-2.4). The proportion of revisional surgery was 0.5% with a 5-year rate of 0.6% (95% CI = 0.2-1.5). Additional adverse events such as hematoma, seroma, malposition, open wounds, and other complications were carefully monitored. Questionnaires showed that 93.9% (95% CI = 92.2-95.4) of the patients were satisfied or very satisfied with their aesthetic results with Mesmo implants.

Conclusions

Post-market clinical follow-up revealed that the overall complications rate reported was low. Data demonstrated an excellent safety property on a large cohort of patients. This result allows the rating of Mesmo breast implants as highly competitive and a very safe choice for both surgeons and patients.

Level of Evidence 3

Effects of Silicone Breast Implants on Human Cell Types In Vitro: A Closer Look on Host and Implant

BACKGROUND

Silicone (gel) breast implants (SBI) are used world-wide for breast augmentation, and reconstruction or to correct breast deformities. They consist of two compounds: an elastomer silicone shell (envelope) and a silicone gel filler (core). Breast Implant Illness (BII) is a term used for women with SBI, who suffer from various of symptoms including myalgia, arthralgia, fatigue, fever, dry eyes and/or dry mouth (sicca), as well as cognitive disturbances, which are rated by these woman as response to SBI. The pathogenesis of these adverse effects as well as the histocompatibility and the SBI-cell interaction of silicone and its surrounding tissue (implant-host tissue interface) is a subject of current research. The main purpose of this review is to provide an overview of the current knowledge regarding the effects of silicone (gel and elastomer surfaces) of a SBI on different human cell types from experimental - in vitro - models.

METHODS

A comprehensive research was conducted by two independent reviewers in March and July of 2020 in the PubMed, MEDLINE, and Cochrane databases.

RESULTS

A number of 1328 articles on this topic were initially identified, of which 62 could be finally included an analysed in this review.

CONCLUSION

SBI may lead to a physiologic pro-inflammatory and foreign body host response with fibrous encapsulation accompanied by a disturbed Th17/Treg balance and IL-17 production. No causal relationship is known for systemic symptoms and/or autoimmune outcomes in the context of BII.

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 .

Effect of Microgroove Structure in PDMS-Based Silicone Implants on Biocompatibility

Capsule and capsule contracture around implants are important concerns in a clinic. The physical topology of the material surface regulates the formation of the capsule, but the specific regulatory mechanism is unclear. In this study, four types of silicone implant materials with different microgroove structures (groove depths of 10 and 50 μm and widths of 50 and 200 μm) were constructed using lithography to form different gradient surface topologies. Mass spectrometry, Cell Counting Kit-8, 5-ethynyl-2′-deoxycytidine (EdU), enzyme-linked immunosorbent assay, western blot, immunofluorescence, and immunohistochemistry were used to explore the changes in protein adsorption, cell adhesion, cell proliferation, and collagen deposition on the surface of the materials. At the same time, RNA-seq was used to detect transcriptome differences caused by different structures. Furthermore, collagen deposition and capsule formation were observed in the rats. The groove structure was observed to significantly increase the surface roughness of the material. The deeper groove and the narrower width of the polydimethylsiloxane would increase the surface roughness of the material and the surface water contact angle but reduce the total amount of adsorbed protein in the first two hours. In vitro cell experiments revealed that microtopology affected cell proliferation and adhesion and regulated collagen secretion. Further analysis indicated the deeper and narrower groove (group 50–50) on the surface of the material caused more evident collagen deposition around the material, forming a thicker envelope. Surface roughness of the material was thus related to collagen deposition and envelope thickness. The thickness of the envelope tissue around smooth materials does not exceed that of the materials with surface roughness. In conclusion, the narrower and deeper grooves in the micron range exhibited poor histocompatibility and led to formation of thicker envelopes around the materials. The appropriate grooves can reduce envelope thickness.

Silicon breast implants’ texture affecting bacterial biofilm formation

Introduction/Objective. The most important etiologic factors for both, capsular contracture (CC) and breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is subclinical infection, defined as a response of an organism on presence of biofilm on the implant surface. The aim of this research was to examine the possibility of biofilm formation of four different bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Ralstonia picketti) on three differently textured silicone breast implants (Siltex, Mentor, pore size 70?150 ?m; MESMORsensitive, Polytech, pore size 50?900 ?m; and SilkSurface, Motiva pores 13 ?m) in vitro. Methods. Samples of silicone breast implant capsules (sized 1 ? 1 cm) were divided into three groups according to texture. After sterilization, 30 samples in every group were contaminated with 100 ?l of examined bacterial broth, followed by incubation which led to biofilm formation. For testing the capability of biofilm formation, modified technique with microtitar plates described by Stepanovic? was used. Results. All four examined bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Ralstonia picketti) form more biofilm on implants with pore sizes 50?900 ?m compared to implants with pore size 70?150 ?m and those with 13 ?m. Statistical significance was found in biofilm formation on implants with pores 70?150 ?m compared to implants with pores 13 ?m. The only exception was P. aeuruginosa which did not show significant difference in biofilm formation on implants 70?150 ?m and 13 ?m. Conclusion. Silicone breast implants with micro and nanotexture should be chosen in order to prevent biofilm formation and possible consequent complications.

Clinical and MRI Evaluation of Silicone Gel Implants with RFID-M Traceability System: A Prospective Controlled Cohort Study Related to Safety and Image Quality in MRI Follow-Up

BACKGROUND

SmoothSilk implants (SSI) are the first generation of implants to incorporate a radio-frequency identification device (RFID-M), a non-invasive traceability system. Although the RFID-M is considered compatible with magnetic resonance imaging (MRI), the size of the artifact and its influence on breast tissue vary. This prospective study assessed safety and MRI issues in a cohort of breast reconstruction patients.

METHODS

Forty-four SSI were used for breast reconstruction in patients undergoing treatment for breast cancer. All patients were evaluated for magnetic field interactions, MRI-related heating and artifacts in a 1.5-T MRI unit using standard T1/T2-weighted sequences utilized in clinical assessment of breast tissue/implants.

RESULTS

Mean patient age was 41.5 years (27-53ys) and body mass index was 28+-6.44 kg/m². In 18/22 patients (81.8%), mastectomies were unilateral. No patients reported local heat/discomfort. All implants showed RFID-M-related artifacts with an estimated mean volume in T1 of 42.9cm³ (26.2-63.6cm³; SD±8.6 and 95% CI, 40.37-45.45) and in T2 of 60.5cm³ (35.4-97.2cm³; SD±14.7 and 95% CI, 56.29-65.01). Artifact volume was smaller in T1 than in T2, to a statistically significant degree (p <0.001). There were no statistically significant differences in artifact volume according to surgical indication, breast side or implant volume. There were 4/44 (9%) cases of minor rotation (<45°). In all cases, adequate analysis of the breast tissue was performed.

CONCLUSIONS

The results demonstrate that SSI with RFID-M technology presented an artifact volume of 42.9cm³ and 60.5cm³ in T1 and T2 images, respectively. Our findings provide detailed information on the quality and location of MRI artifacts in a reconstructed cohort which can help guide clinical decision-making for patients. To our knowledge, this is the first time RFID-M breast implants have been prospectively evaluated for clinical and MRI issues in a cohort of reconstructive patients.

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 .

Suppression of the fibrotic encapsulation of silicone implants by inhibiting the mechanical activation of pro-fibrotic TGF-β

The fibrotic encapsulation of implants involves the mechanical activation of myofibroblasts and of pro-fibrotic transforming growth factor beta 1 (TGF-β1). Here, we show that both softening of the implant surfaces and inhibition of the activation of TGF-β1 reduce the fibrotic encapsulation of subcutaneous silicone implants in mice. Conventionally stiff silicones (elastic modulus, ~2 MPa) coated with a soft silicone layer (elastic modulus, ~2 kPa) reduced collagen deposition as well as myofibroblast activation without affecting the numbers of macrophages and their polarization states. Instead, fibroblasts around stiff implants exhibited enhanced intracellular stress, increased the recruitment of α_v and β₁ integrins, and activated TGF-β1 signalling. In vitro, the recruitment of α_v integrin to focal adhesions and the activation of β₁ integrin and of TGF-β were higher in myofibroblasts grown on latency-associated peptide (LAP)-coated stiff silicones than on soft silicones. Antagonizing α_v integrin binding to LAP through the small-molecule inhibitor CWHM-12 suppressed active TGF-β signalling, myofibroblast activation and the fibrotic encapsulation of stiff subcutaneous implants in mice.

Surgical Treatment of Capsular Contracture (CC): Literature Review and Outcomes Utilizing Implants in Revisionary Surgery

BACKGROUND

The objective of this clinical review is to provide an overview of the use of breast implants after capsular contracture (CC) surgical treatment, with a focus on type of implants used. 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 literature related to surgical treatment of capsular contracture and implant replacement. Each article was reviewed by two independent reviewers to ensure all relevant publications were identified. The literature search identified 54 applicable articles. Of these, 26 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

Only four articles report the replacement of implants after surgical treatment of capsular contracture. Six articles reported an implant exchange with only smooth silicone gel filled implants. Two reviews advice to use smooth implants in implant replacement.

CONCLUSION

With our expertise in the field and the results of this up-to-date literature review, it can be concluded that implant exchange is recommended in case of breast revision for capsular contracture, and the use of subpectoral smooth silicone gel breast implants is a good option after surgical treatment in patients with primary or recurrence Baker III-IV.

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 .

ALK-Negative Anaplastic Large Cell Lymphoma: Current Concepts and Molecular Pathogenesis of a Heterogeneous Group of Large T-Cell Lymphomas

Simple Summary

ALK- anaplastic large cell lymphoma (ALK- ALCL) is a rare subtype of CD30+ large T-cell lymphoma that typically affects older adults and has a poor prognosis. Recognition of its histopathologic spectrum, subtypes, and of other tumors that can resemble ALK- ALCL is crucial to avoid making a wrong diagnosis that could result in inappropriate treatment for a patient. In recent years, several important studies have identified recurrent molecular alterations that have shed light on the pathogenesis of this lymphoma. However, on the other hand, putting all this vast information together into a concise form has become challenging. In this review, we present not only a more detailed view of the histopathologic findings of ALK- ALCL but also, we attempt to provide a more simplified perspective of the relevant genetic and molecular alterations of this type of lymphoma, that in our opinion, is not available to date.

Abstract

Anaplastic large cell lymphoma (ALCL) is a subtype of CD30+ large T-cell lymphoma (TCL) that comprises ~2% of all adult non-Hodgkin lymphomas. Based on the presence/absence of the rearrangement and expression of anaplastic lymphoma kinase (ALK), ALCL is divided into ALK+ and ALK-, and both differ clinically and prognostically. This review focuses on the historical points, clinical features, histopathology, differential diagnosis, and relevant cytogenetic and molecular alterations of ALK- ALCL and its subtypes: systemic, primary cutaneous (pc-ALCL), and breast implant-associated (BIA-ALCL). Recent studies have identified recurrent genetic alterations in this TCL. In systemic ALK- ALCL, rearrangements in DUSP22 and TP63 are detected in 30% and 8% of cases, respectively, while the remaining cases are negative for these rearrangements. A similar distribution of these rearrangements is seen in pc-ALCL, whereas none have been detected in BIA-ALCL. Additionally, systemic ALK- ALCL—apart from DUSP22-rearranged cases—harbors JAK1 and/or STAT3 mutations that result in the activation of the JAK/STAT signaling pathway. The JAK1/3 and STAT3 mutations have also been identified in BIA-ALCL but not in pc-ALCL. Although the pathogenesis of these alterations is not fully understood, most of them have prognostic value and open the door to the use of potential targeted therapies for this subtype of TCL.

In Vitro Effect of Replicated Porous Polymeric Nano-MicroStructured Biointerfaces Characteristics on Macrophages Behavior

In the last decades, optimizing implant properties in terms of materials and biointerface characteristics represents one of the main quests in biomedical research. Modifying and engineering polyvinylidene fluoride (PVDF) as scaffolds becomes more and more attractive to multiples areas of bio-applications (e.g., bone or cochlear implants). Nevertheless, the acceptance of an implant is affected by its inflammatory potency caused by surface-induced modification. Therefore, in this work, three types of nano-micro squared wells like PVDF structures (i.e., reversed pyramidal shape with depths from 0.8 to 2.5 microns) were obtained by replication, and the influence of their characteristics on the inflammatory response of human macrophages was investigated in vitro. FTIR and X-ray photoelectron spectroscopy analysis confirmed the maintaining chemical structures of the replicated surfaces, while the topographical surface characteristics were evaluated by AFM and SEM analysis. Contact angle and surface energy analysis indicated a modification from superhydrophobicity of casted materials to moderate hydrophobicity based on the structure’s depth change. The effects induced by PVDF casted and micron-sized reversed pyramidal replicas on macrophages behavior were evaluated in normal and inflammatory conditions (lipopolysaccharide treatment) using colorimetric, microscopy, and ELISA methods. Our results demonstrate that the depth of the microstructured surface affects the activity of macrophages and that the modification of topography could influence both the hydrophobicity of the surface and the inflammatory response.

Implant Shell Characteristics: The Science Behind the Surface

Modern breast implant design emphasizes the host response at the surface. Implant surfaces are characterized by their roughness, surface area, and potential for bacterial attachment. The future of implant design may lie in the ability of bioengineers to transform both the structure and chemical properties of the device surface and therefore affect potential long-term outcomes.

Management of Symptomatic Patients with Textured Implants

SUMMARY

Proper management of symptomatic textured implant patients is critical to identify and treat associated oncologic disease. Textured surface breast implants were first introduced more than 50 years ago in an effort to decrease high rates of capsular contracture and implant malposition observed with first-generation smooth surface breast implants. Textured implants were dominant over smooth devices in the United States in the late 1990s, but they fell out of favor for newer-generation smooth implants, while texture remained the dominant selling implants worldwide until recently. A class I device recall by the US Food and Drug Administration in 2019 precipitated a removal of the highest selling implant worldwide, Allergan Biocell, due to a disproportionately increased risk of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). Operative strategies, such as bacterial control at the time of textured implant insertion, have not been credibly shown to affect or prevent the future development of BIA-ALCL. BIA-ALCL patients require complete surgical excision of their disease, whereas textured implant patients who are otherwise asymptomatic do not require surgical removal. For suspicious cases, diagnostic testing with CD30 immunohistochemistry should be performed before any surgical intervention. Capsules are evaluated with 12 strategic regional biopsies in a standardized approach. If surgeons are revising or exchanging textured implants, they may reasonably consider a total capsulectomy, though this is not advocated by the Food and Drug Administration or national societies, and has not been shown to mitigate future risk of BIA-ALCL. The purpose of this article is to review data on and outcomes for textured surface implants, disease-associated risk, and the management strategy for revisionary surgery and device surveillance.

In search for the 'perfect' breast implant: are textured implants still indicated in today's breast augmentation practice?

The popularity of breast augmentation procedure has driven research and debate as to whether any given implant characteristic offers a functional advantage. One such debate exists about the role of surface texturing. In the aftermath of the recent withdrawal of aggressively textured surfaces we would like to summarize the first author's experience of nearly 1500 primary aesthetic breast augmentations with different surfaces and offer our thoughts on this topic. All consecutive primary breast augmentations operated by the first author from January 2010 to June 2019 were included. All patients had silicone implants inserted via inframammary incision. Of all the operated cases, 1029 consecutive female patients had at least 6 months' follow-up (mean 15.1 months). Their mean age was 31.2 years, mean BMI 20.8 kg/m² and mean implant volume was 311 cc. 997(96.9%) patients had dual plane and 32(3.1%) had sub-glandular implant placement. In total 113 patients (11.0%) developed a complication. This represented 15.1% of those with round and 10.0% of anatomical shape (or 10.6% of textured and 14.5% of smooth surface implants). As clinicians, we like patients to receive all the advantages of an implant but not be exposed to any risks. However, in reality, such a 'perfect implant' still does not exist. New literature continues to shed light on this trade-off between an implant's perceived utility and its complications profile. We hope that the search for an alternative technology, with more beneficial surface characteristics and less drawbacks, continues.

Review of silicone surface modification techniques and coatings for antibacterial/antimicrobial applications to improve breast implant surfaces

Silicone implants are widely used in the medical field for plastic or reconstructive surgeries for the purpose of soft tissue issues. However, as with any implanted object, healthcare-associated infections are not completely avoidable. The material suffers from a lack of biocompatibility and is often subject to bacterial/microbial infections characterized by biofilm growth. Numerous strategies have been developed to either prevent, reduce, or fight bacterial adhesion by providing an antibacterial property. The present review summarizes the diverse approaches to deal with bacterial infections on silicone surfaces along with the different methods to activate/oxidize the surface before any surface modifications. It includes antibacterial coatings with antibiotics or nanoparticles, covalent attachment of active bacterial molecules like peptides or polymers. Regarding silicone surfaces, the activation step is essential to render the surface reactive for any further modifications using energy sources (plasma, UV, ozone) or chemicals (acid solutions, sol-gel strategies, chemical vapor deposition). Meanwhile, corresponding work on breast silicone prosthesis is discussed. The latter is currently in the line of sight for causing severe capsular contractures. Specifically, to that end, besides chemical modifications, the antibacterial effect can also be achieved by physical surface modifications by adjusting the surface roughness and topography for instance.

Preliminary outcomes and comparison of polytech POLYtxtⓇ and MESMOsensitiveⓇ breast implants with focus on late seroma: Single-surgeon, retrospective cohort study on 621 consecutive aesthetic breast surgery cases

BACKGROUND

Recent history shows incomplete understanding of the long-term interaction between breast implants and biological tissues. Although complications of silicone-textured implants have been previously reported, conclusive data are still controversial due to the lack of reduced bias, long-term, comparative studies. We present our preliminary outcomes of 3 years aesthetic use of POLYTECH silicone POLYtxt^Ⓡ and MESMO Sensitive^Ⓡ implants.

METHODS

This article is a retrospective analysis of 621 patients who have undergone primary aesthetic breast surgery (breast augmentation (BA) or augmentation mastopexy). The surgeries were performed by a single surgeon using Polytech microtextured silicone implants (POLYtxt and MESMO). Complications, with main focus on late seroma, were assessed and compared based on texturization type.

RESULTS

From January 2015 to September 2018, 358 patients were treated with POLYtxt and 263 with MESMO-textured implants. Incidence of complications, such as hematoma, infection, early seroma, capsular contraction and malposition/rotation was comparable between the two groups. Incidence of late seroma was, respectively, 6.4% (POLYtxt) and 0% (MESMO) resulting in a statistically significant difference between the two groups. Overall complications and reinterventions were 12.5%-9.2% (POLYtxt) and 4.5%-3.8% (MESMO), respectively, showing a significantly lower occurrence in the MESMO group.

CONCLUSIONS

This reduced bias study shows an increased risk in overall complications and reoperations with POLYtxt surface implants compared with MESMO. Furthermore, we registered an exceptionally high rate of late seroma when the more "aggressive" POLYtxt texturization was used. Conversely, a significantly low incidence of adverse events was registered with the MESMO surface, which has turned this device in our first choice in daily practice.

What is the Process for Breast Implant Manufacturing? Inside Eight Breast Implant Factories

BACKGROUND

With the recent association between breast implants and anaplastic large cell lymphoma, breast implants have become the focus of many warnings. Surgeons and health professionals are not involved in all the processes of the manufacturing and distribution of this product. Not all countries have breast implant factories that are easy for surgeons to visit and better understand the manufacturing process.

METHODS

A questionnaire about breast implant manufacturing and distribution was validated in consensus and form. Two plastic surgeons visited eight factories and administered the questionnaire in the presence of a photographer, who documented that the questionnaire was answered in the same way for all visits. Once the visitors finished obtaining the information (questionnaire responses and video recording), this information was validated by a different member of a safety committee in Mexico. For the observations to be considered valid, the information from the questionnaire and the video must be presented.

RESULTS

We visited eight factories: three in France (Sebbin, Arion and Eurosilicone), two in Costa Rica (Allergan and Motiva), one in Scotland (Nagor), one in Germany (Polytech) and one in Korea (Bellagel). In four factories (Eurosilicone, Motiva, Nagor and Sebbin), the information on the process for manufacturing an implant was observed and recorded (validated). The quality laboratory was visited, and video recording was performed in six factories (Bellagel, Eurosilicone, Motiva, Nagor, Polytech and Sebbin).

CONCLUSION

It was possible to observe and verify that most of the companies that distribute breast implants in Mexico perform their manufacturing processes according to ISO standards. A breast implant registry can help people further understand how BIA-ALCL will behave in the future and allow more tests to better understand this pathology.

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 .

Retrospective multicenter cohort analysis of 621 cases of BellaGel silicone breast implants with study of physicochemical properties and surface topography

This study aimed to assess the effectiveness and safety of BellaGel implants after implantation in Asian women and inform surgeons of another option for use in breast augmentation and reconstruction. This study was conducted in eight hospitals from November 27, 2015 to April 30, 2018. All patients underwent augmentation mammoplasty or implant-based breast reconstruction with BellaGel implants. Complication rates were compared between groups, and the cumulative hazard function was compared using the Kaplan-Meier survival analysis. Implants were grouped by surface type, and the cumulative hazard functions of total complication cases were compared. The biomechanical properties of the BellaGel implant and other company representative implants were tested using a mechanical testing machine, and surface topography was analyzed using a 3D laser scanning confocal microscope. There was a significant difference in the incidence of complications between the reconstruction (17.1%) and augmentation (4.7%) groups, but no significant difference in the complication rates of each group. There was no difference in the reoperation or revision rates between the groups. The log rank test showed a statistically significant difference in cumulative hazard function between the groups. Among the three types of implants (smooth, textured, and microtextured), the microtextured type had the lowest complication rate. The BellaGel microtexture implant had the highest maximal tensile load and displacement value. The BellaGel and Silksurface implants had the highest stored energy, although there was no significant difference. BellaGel implants can serve as a criterion for the selection of safe and effective implants among currently available implants.

Various Properties of Silicone Breast Implant Surfaces and Multimodal Techniques for the Functional Surface Modification

"Silicone breast implants are the most widely used medical devices for breast reconstruction and augmentation, and revision, but even after more than 60 years of use they are associated with multiple continued complications. Using advancement in current technologies, researchers are attempting to create an optimal implant surface for patients. Through these efforts, plastic surgeons and material researchers have made great progress in the field of implant research. Multimodal techniques for the functional modification of implant surfaces will contribute to further the development of ideal biomaterials useful in breast implants.

Biological responses to physicochemical properties of biomaterial surface

Biomedical scientists use chemistry-driven processes found in nature as an inspiration to design biomaterials as promising diagnostic tools, therapeutic solutions, or tissue substitutes. While substantial consideration is devoted to the design and validation of biomaterials, the nature of their interactions with the surrounding biological microenvironment is commonly neglected. This gap of knowledge could be owing to our poor understanding of biochemical signaling pathways, lack of reliable techniques for designing biomaterials with optimal physicochemical properties, and/or poor stability of biomaterial properties after implantation. The success of host responses to biomaterials, known as biocompatibility, depends on chemical principles as the root of both cell signaling pathways in the body and how the biomaterial surface is designed. Most of the current review papers have discussed chemical engineering and biological principles of designing biomaterials as separate topics, which has resulted in neglecting the main role of chemistry in this field. In this review, we discuss biocompatibility in the context of chemistry, what it is and how to assess it, while describing contributions from both biochemical cues and biomaterials as well as the means of harmonizing them. We address both biochemical signal-transduction pathways and engineering principles of designing a biomaterial with an emphasis on its surface physicochemistry. As we aim to show the role of chemistry in the crosstalk between the surface physicochemical properties and body responses, we concisely highlight the main biochemical signal-transduction pathways involved in the biocompatibility complex. Finally, we discuss the progress and challenges associated with the current strategies used for improving the chemical and physical interactions between cells and biomaterial surface.

Surface Texturization of Breast Implants Impacts Extracellular Matrix and Inflammatory Gene Expression in Asymptomatic Capsules

BACKGROUND

Texturing processes have been designed to improve biocompatibility and mechanical anchoring of breast implants. However, a high degree of texturing has been associated with severe abnormalities. In this study, the authors aimed to determine whether implant surface topography could also affect physiology of asymptomatic capsules.

METHODS

The authors collected topographic measurements from 17 different breast implant devices by interferometry and radiographic microtomography. Morphologic structures were analyzed statistically to obtain a robust breast implant surface classification. The authors obtained three topographic categories of textured implants (i.e., "peak and valleys," "open cavities," and "semiopened cavities") based on the cross-sectional aspects. The authors simultaneously collected 31 Baker grade I capsules, sorted them according to the new classification, established their molecular profile, and examined the tissue organization.

RESULTS

Each of the categories showed distinct expression patterns of genes associated with the extracellular matrix (Timp and Mmp members) and inflammatory response (Saa1, Tnsf11, and Il8), despite originating from healthy capsules. In addition, slight variations were observed in the organization of capsular tissues at the histologic level.

CONCLUSIONS

The authors combined a novel surface implant classification system and gene profiling analysis to show that implant surface topography is a bioactive cue that can trigger gene expression changes in surrounding tissue, even in Baker grade I capsules. The authors' new classification system avoids confusion regarding the word "texture," and could be transposed to implant ranges of every manufacturer. This new classification could prove useful in studies on potential links between specific texturizations and the incidence of certain breast-implant associated complications.

Short-term Safety of a Silicone Gel-filled Breast Implant: A Manufacturer-sponsored, Retrospective Study

Currently, 8 different brands of a silicone gel–filled breast implant are commercially available in Korea. But the superiority of short-term safety has not been established.

Device-Specific Findings of Imprinted-Texture Breast Implants: Characteristics, Risks, and Benefits

BACKGROUND

The relative risks and benefits of various textured breast implants are the focus of considerable discussion. Studies have suggested different risk-benefit profiles for different implant surface topographies.

OBJECTIVES

The study aim was to provide device-specific, quantitative information on Mentor's imprinted Siltex Textured breast implants with respect to textured surface characteristics and ISO 14607 classification, risk of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), and risk-reduction benefits relative to smooth implants.

METHODS

Surface metrology was performed. Data for smooth and Siltex implants from the prospective MemoryGel Core Study were evaluated by Kaplan-Meier analysis for the most frequently occurring postoperative complications in augmentation and reconstruction leading to subsequent reoperation.

RESULTS

The overall average surface roughness for Siltex MemoryGel and MemoryShape implants was 29.5 and 36.1 µm, respectively. A statistically significantly lower rate of reoperation in patients with Siltex compared with smooth devices over 10 years was observed for both capsular contracture in subglandular primary augmentation patients (4.21% vs 19.84%) and for asymmetry in primary reconstruction patients (3.88% vs 11.1%).

CONCLUSIONS

Surface analysis demonstrated that Siltex implants fall within the ISO 14607 category of "microtexture" breast implants. These devices exhibited a rare risk of BIA-ALCL (0.0012%) based on the most extensive data available. Relative to smooth implants, these Siltex devices provided risk-reduction benefits for the most common reason of reoperation in patients who underwent primary augmentation (capsular contracture) or primary reconstruction (asymmetry) in the Core Study. These findings provide valuable risk-benefit information for surgeons and their patients.

LEVEL OF EVIDENCE: 2

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.

Breast Implant Surfaces and Their Impact on Current Practices: Where We Are Now and Where Are We Going?

Most commercially available breast implants feature some degree of elastomer surface modifications to increase surface roughness, in part because several clinical series have demonstrated positive outcomes from texturizing. However, the literature shows that textured implants support higher rates of bacterial growth, and there is a clear association between increased bacterial contamination and host response in vivo, such as capsular contracture. Furthermore, the infectious theory related to bacterial contamination has recently been described as a potential cause in the etiology of anaplastic large-cell lymphoma. Recent research has focused on the physiology of breast implant surfaces advances and how they interact with the body, creating new surface technologies which have the potential to affect all aspects of breast surgery. Understanding how surface properties affect inflammatory cell response will be essential in designing implants that can provide an esthetic solution while also minimizing long-term clinical complications. This special topic highlights the current knowledge on silicone implant surfaces, as well as innovations that have shaped and will continue to change the silicone breast implant industry in the future. It also provides an overview of the principal surfaces that exist and may find clinical applications in esthetic and reconstructive breast surgery. As additional advances emerge, objective tools will be required to evaluate the different surfaces available on the market, along with the long-term efficacy of new technologies.

Periareolar Augmentation-Mastopexy

The authors describe their surgical technique for single-stage periareolar mastopexy with subglandular breast augmentation. They have performed this procedure in 85 patients since 2009 and found that this operative technique has allowed them to achieve reproducible outcomes in a single-stage procedure. Periareolar mastopexy with subglandular breast augmentation is an excellent procedure for patients who desire a larger breast size and who present with mild to moderate nipple ptosis with a paucity of excess skin in the lower pole of the breast. This article will review the perioperative management and detailed steps of the procedure and outline its indications for utilization and some of the common complications the authors have encountered.

Microtexture and the Cell/Biomaterial Interface: A Systematic Review and Meta-Analysis of Capsular Contracture and Prosthetic Breast Implants

BACKGROUND

The use of textured breast implants over smooth implants has been widely shown to have a lower incidence of capsular contracture. However, the impact of micropatterning techniques on the incidence of postoperative patient morbidity has not been comprehensively investigated.

OBJECTIVES

The authors sought to examine the incidence of capsular contracture, seroma, and implant rippling among the 3 major micropatterning techniques applied in the manufacturing of textured breast implants.

METHODS

Literature searches of PubMed/Medline and Embase between 1995 and 2017 were performed, and 19 studies were selected for analysis. Data from each study were extracted into a form including mean age, study design, population size, mean follow-up, number of capsular contracture cases, number of seroma cases, and number of rippling cases. Meta-analysis was performed separately for studies that included capsular contracture rates for foam textured implants, imprinted textured implants, and salt-loss textured implants.

RESULTS

The pooled rate of capsular contracture rates in primary augmentation patients was 3.80% (95% CI, 2.19-5.40) for imprinted textured implants, 4.90% (95% CI, 3.16-6.64) for foam textured implants, 5.27% (95% CI, 3.22-7.31) for salt-loss textured implants, and 15.56% (95% CI, 13.31-18.16) for smooth implants. The results of each meta-analysis were summarized on a forest plot depicting the distribution of capsular contracture rates from each study.

CONCLUSIONS

Micropatterning of prosthetic implants could drastically reduce postoperative patient morbidity given the advent of recent technologies that allow for more detailed texturing of implant surfaces.

LEVEL OF EVIDENCE: 4