Comparison of the postoperative incidence rate of capsular contracture among different breast implants: a cumulative meta-analysis

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

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

Management of complications following implant-based breast reconstruction: a narrative review

Background and Objective

Complications associated with implant-based reconstruction have a spectrum of severity with sequelae ranging from mild aesthetic deformities to additional surgery, reconstructive failure and systemic illness. The purpose of this narrative review of the literature is to provide updated evidence-based information on the management of complications in implant-based reconstruction.

Methods

A systematic search of PubMed, OVID MEDLINE and the Cochrane Library databases was performed to identify common complications associated with implant-based breast reconstruction, incidences of occurrence as well as preventative and management strategies.

Key Content and Findings

Pertinent short and long-term complications of implant-based breast reconstruction include hematoma, implant infection, seroma, skin envelope necrosis, capsular contracture, rupture, malposition, animation and contour deformities, implant-associated anaplastic large cell lymphoma, and breast implant illness. Important preventative measures for short term complications include meticulous sterile technique and antibiotic irrigation, adequate drainage and critical evaluation of mastectomy flaps. Management of short-term complications requires early recognition and aggressive treatment to prevent reconstructive failure as well as long-term complications such as capsular contracture. Important technological advances include dual-port expanders for seroma drainage, indocyanine green angiography for mastectomy flap perfusion evaluation, cohesive form-stable implants for treatment of rippling, and various biologic and synthetic mesh products for pocket control and correction.

Conclusions

Important principles in management of short-term complications in implant-based reconstruction include aggressive and early intervention to maximize the chance of reconstructive salvage. Contemporary technological advances have played an important role in both prevention and treatment of complications. Over-arching principles in management of implant-based reconstruction complications focus on preventative techniques and preoperative patient counseling on potential risks, their likelihood, and necessary treatments to allow for informed and shared decision-making.

A Systematic Review of Outcomes and Complications of Tuberous Breast Surgery

BACKGROUND

Tuberous breast is a complex congenital breast anomaly that can be challenging to correct surgically.

OBJECTIVES

The authors conducted a systematic review with pooled analysis of data, with the aim of determining the effectiveness and complications related to operative management of the deformity.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were adopted in performing this systematic review. A simplified classification system for tuberous breast deformity was developed to accurately compare data and guide analysis.

RESULTS

The review identified 38 studies, reporting a total of 897 patients undergoing tuberous breast surgery. The mean age of patients was 24 years (range 13-53 years). Mean follow-up was 39 months. A combination of tissue rearrangement and implant augmentation was the most common technique (73% of patients) followed by fat transfer alone (9%). Breast implants were employed in 83% of patients. The mean implanted volume per breast was 263 cc. Fat grafting was performed in 13% of patients and mean volume of fat grafted per breast was 185 cc. An overall complication rate of 20% was reported. Subjective assessment of patient satisfaction was 99%, and the mean score on BREAST-Q for satisfaction with clinical outcome was 86.7. Future studies should focus on robust study designs including randomized and cohort studies, use of patient-reported outcome measures, and long-term follow-up.

CONCLUSIONS

The surgical techniques to correct tuberous breast deformity are safe, effective, and have a high satisfaction rate. Fat transfer has the capacity to provide promising results in treating tuberous breast deformity.

LEVEL OF EVIDENCE: 4

What Can We Learn from Breast Implant Explantation: a 28-Year, Multicenter Retrospective Study of 1004 Explantation Cases

BACKGROUND

Implant-based breast augmentation remains popular, but the controversy over the safety and longevity of implants has continued. An event-based analysis of reasons for implant explantation may provide us with some insight into the controversy.

METHODS

Data from May 1994 to October 2022 of explantation cases from aesthetic breast augmentation in three medical centers were retrospectively reviewed. Patient characteristics, time to explantation, reasons for visit, the major reason for explantation and intraoperative findings were analyzed.

RESULTS

A total of 522 patients with 1004 breasts were included in our study. Objective explantation reasons accounted for 34.0% in primary augmentation breasts and 47.6% in revision augmentation breasts, which were significantly different (p = 0.006). The most common complaint was dissatisfaction with breast appearance, followed by concerns about implant safety, poor hand feeling and pain. 43.5% of the implants worn for more than 10 years were removed for objective reasons, which was found significantly different with the proportion of objective reasons in implants removed within 1 year and 1-5 years postoperatively (p < 0.008).

CONCLUSION

The proportion of different reasons for implant explantation varies across the times of surgeries and the years that the implant had been worn. As the years of implant wearing increase, the proportion of subjective reasons decreases in implant removal cases and objective reasons increase among them.

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 .

Repeated Lipoteichoic Acid Injection at Low Concentration Induces Capsular Contracture by Activating Adaptive Immune Response through the IL-6/STAT3 Signaling Pathway

BACKGROUND

Capsular contracture is the most common complication of breast implantation surgery. Bacterial contamination was considered to play an important role in the occurrence of capsular contracture, and Gram-positive bacteria such as Staphylococcus epidermidis were discovered in the clinical specimens. Lipoteichoic acid (LTA) was a component of the cell wall of Gram-positive bacteria and was sufficient in the pathogenicity of the bacteria. The authors assumed that LTA could trigger the immunologic response against the implant and cause capsular contracture.

METHODS

The authors developed a rat model of capsular contracture by repeated injection of 10 μg/mL LTA. The histologic changes of the capsule tissue were measured by hematoxylin and eosin, sirius red, Masson, and immunohistochemical staining. The expression of related cytokines was measured by quantitative real-time polymerase chain reaction. The downstream pathway activation was shown by Western blot. The authors also applied tocilizumab, an interleukin (IL)-6 receptor antagonist, to verify the role of IL-6 in this pathologic process.

RESULTS

The authors discovered that repeated LTA injection, at a low concentration, could induce the thickening of capsule tissue, the deposition of collagen fiber, and the activation of myofibroblasts. The IL-6/signal transducer and activator of transcription 3 signaling pathway was activated in this process, and the inhibition of IL-6 receptor could relieve the symptoms. B cells and T-helper cells, especially T-helper type 1, could be related to this phenomenon.

CONCLUSIONS

The authors' research corroborated that subclinical infection could trigger capsular contracture, and the immune system played an important role in this process. The authors' results provided a possible research direction for the mechanism of bacterial infection-induced immune response against breast implants.

CLINICAL RELEVANCE STATEMENT

The authors' research provides a possible research direction for the mechanism of bacterial infection-induced immune response against breast implants, and a potential target for predicting the prognosis of capsular contracture.

The Role of Microorganisms in the Development of Breast Implant-Associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a variant of anaplastic large cell lymphoma (ALCL) associated with textured-surface silicone breast implants. Since first being described in 1997, over 1100 cases have been currently reported worldwide. A causal relationship between BIA-ALCL and textured implants has been established in epidemiological studies, but a multifactorial process is likely to be involved in the pathogenesis of BIA-ALCL. However, pathophysiologic mechanisms remain unclear. One of the hypotheses that could explain the link between textured implants and BIA-ALCL consists in the greater tendency of bacterial biofilm in colonizing the surface of textured implants compared to smooth implants, and the resulting chronic inflammation which, in predisposed individuals, may lead to tumorigenesis. This review summarizes the existing evidence on the role of micro-organisms and rough surface implants in the development of BIA-ALCL. It also provides insights into the most updated clinical practice knowledge about BIA-ALCL, from clinical presentation and investigation to treatment and outcomes.

Silicone Breast Implant Surface Texture Impacts Gene Expression in Periprosthetic Fibrous Capsules

BACKGROUND

Silicone breast implants with smooth outer shells are associated with higher rates of capsular contracture, whereas textured implants have been linked to the development of breast implant-associated anaplastic large cell lymphoma. By assessing the gene expression profile of fibrous capsules formed in response to smooth and textured implants, insight into the development of breast implant-associated abnormalities can be gained.

METHODS

Miniature smooth or textured silicone implants were surgically inserted into female rats ( n = 10) and harvested for the surrounding capsules at postoperative week 6. RNA sequencing and quantitative polymerase chain reaction were performed to identify genes differentially expressed between smooth and textured capsules. For clinical correlation, the expression of candidate genes was assayed in implant capsules harvested from human patients with and without capsular contracture.

RESULTS

Of 18,555 differentially expressed transcripts identified, three candidate genes were selected: matrix metalloproteinase-3 ( MMP3 ), troponin-T3 ( TNNT3 ), and neuregulin-1 ( NRG1 ). In textured capsules, relative gene expression and immunostaining of MMP3 and TNNT3 was up-regulated, whereas NRG1 was down-regulated compared to smooth capsules [mean relative fold change, 8.79 ( P = 0.0059), 4.81 ( P = 0.0056), and 0.40 ( P < 0.0001), respectively]. Immunostaining of human specimens with capsular contracture revealed similar gene expression patterns to those of animal-derived smooth capsules.

CONCLUSIONS

An expression pattern of low MMP3 /low TNNT3 /high NRG1 is specifically associated with smooth implant capsules and human implant capsules with capsular contracture. The authors' clinically relevant breast implant rat model provides a strong foundation to further explore the molecular genetics of implant texture and its effect on breast implant-associated abnormalities.

CLINICAL RELEVANCE STATEMENT

The authors have demonstrated that there are distinct gene expression profiles in response to smooth versus textured breast implants. Since surface texture may be linked to implant-related pathology, further molecular analysis of periprosthetic capsules may yield strategies to mitigate implant-related complications.

Conservative axillary surgery is emerging in the surgical management of breast cancer

Axillary lymph node dissection (ALND) has been the standard axillary treatment for breast cancer for a long time. However, ALND is associated with postoperative morbidities, including local sensory dysfunction, reduced shoulder mobility and most notably arm lymphedema. Recently, ALND can be avoided not only in clinically node-negative (cN0) patients with negative sentinel lymph nodes (SLNs), but also in patients with less than 3 positive SLNs receiving breast radiation, axillary radiation, or a combination of the two. Moreover, SLN biopsy has been adopted for use in clinically node-positive (cN +) patients presenting as cN0 after neoadjuvant chemotherapy (NAC); ALND may be avoided in cN + patients who convert to SLN-negative following NAC. Patients who undergo SLN biopsy alone have less postsurgical morbidities than those who undergo ALND. Nevertheless, ALND is still required in a select group of patients. A variety of conservative approaches to ALND have been developed to spare arm lymphatics to minimize arm lymphedema. These conservative procedures seem to decrease the incidence of lymphedema without increasing axillary recurrence. In the era of effective multimodality therapy, full conventional ALND removing all microscopic axillary disease may now be unnecessary in both cN0 patients and cN + patients. Regardless, emerging procedures for ALND should still be considered as investigational approaches, as further studies with longer follow-up are necessary to determine the safety of conservative ALND to spare arm lymphatics.

AGO Recommendations for the Surgical Therapy of Breast Cancer: Update 2022

The recommendations of the AGO Breast Committee on the surgical therapy of breast cancer were last updated in March 2022 (www.ago-online.de). Since surgical therapy is one of several partial steps in the treatment of breast cancer, extensive diagnostic and oncological expertise of a breast surgeon and good interdisciplinary cooperation with diagnostic radiologists is of great importance. The most important changes concern localization techniques, resection margins, axillary management in the neoadjuvant setting and the evaluation of the meshes in reconstructive surgery. Based on meta-analyses of randomized studies, the level of recommendation of an intraoperative breast ultrasound for the localization of non-palpable lesions was elevated to "++". Thus, the technique is considered to be equivalent to wire localization, provided that it is a lesion which can be well represented by sonography, the surgeon has extensive experience in breast ultrasound and has access to a suitable ultrasound device during the operation. In invasive breast cancer, the aim is to reach negative resection margins ("no tumor on ink"), regardless of whether an extensive intraductal component is present or not. Oncoplastic operations can also replace a mastectomy in selected cases due to the large number of existing techniques, and are equivalent to segmental resection in terms of oncological safety at comparable rates of complications. Sentinel node excision is recommended for patients with cN0 status receiving neoadjuvant chemotherapy after completion of chemotherapy. Minimally invasive biopsy is recommended for initially suspect lymph nodes. After neoadjuvant chemotherapy, patients with initially 1 - 3 suspicious lymph nodes and a good response (ycN0) can receive the targeted axillary dissection and the axillary dissection as equivalent options.

Oral doxycycline prevents skin-associated adverse effects induced by injectable collagenase in a rodent model of capsular contracture around silicone implants

Background

The collagenase of the bacterium Clostridium histolyticum (CCH) is already an established treatment for fibroproliferative diseases like M. Dupuytren and M. Peyronie Although results are comparable to surgical intervention, skin laceration is a severe and relevant side effect. Doxycycline (DOX) recently rose interest as an inhibitor of matrix-metalloproteinases alongside its capabilities of skin accumulation. It therefore might be a potential skin protective agent in the use of CCH.

Methods

For simulation of a fibroproliferative disease adjacent to the skin, we utilized a rodent model of capsular fibrosis involving silicone implants and subsequent fibrotic capsule formation. For in-vitro studies, fibrotic capsules were excised and incubated with 0.9 mg/ml CCH and four different doses of DOX. For in-vivo experiments, animals received 0.0, 0.3 or 0.9 mg/ml CCH injections into the fibrotic capsules with or without prior oral DOX administration. Outcome analysis included histology, immunohistochemistry, gene expression analysis, chemical collagen and DOX concentration measurements as well as μCT imaging.

Results

In-vitro, DOX showed a dose-dependent inhibition of CCH activity associated with increasing capsule thickness and collagen density and content. In-vivo, oral DOX administration did neither interfere with capsule formation nor in effectiveness of CCH dissolving fibrotic capsule tissue. However, skin thickness and especially collagen density was significantly higher compared to control groups. This led to a reduced rate of clinical skin lacerations after DOX administration.

Conclusion

DOX inhibits CCH and accumulates in the skin. Thereby, DOX can effectively reduce skin laceration after CCH treatment.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Asiaticoside Combined With Carbon Ion Implantation to Improve the Biocompatibility of Silicone Rubber and to Reduce the Risk of Capsule Contracture

Capsular contracture caused by silicone rubber is a critical issue in plastic surgery that urgently needs to be solved. Studies have shown that carbon ion implant in silicone rubber (carbon silicone rubber, C-SR) can significantly improve the capsular structure, but the effect of this improvement only appear 2months or later. In this study, asiaticoside combined with carbon silicone rubber was used to explore the changes in the capsule to provide a reference for the treatment of capsule contracture. Human fibroblasts (HFF-1) were used for in vitro experiments. The combined effect of asiaticoside and carbon silicone rubber on cell proliferation was determined by the CCK8 method, cell migration changes were measured by Transwell assays, cell cycle changes were measured by flow cytometry, and the expression levels of fibroblast transformation markers (vimentin and α-SMA), collagen (Col-1A1) and TGF-β/Smad signaling pathway-related proteins (TGF-β1, TβRI, TβRII and Smad2/3) were detected by immunofluorescence. In vivo experiments were carried out by subcutaneous implantation of the material in SD rats, and asiaticoside was oral administered simultaneously. WB and ELISA were used to detect changes in the expression of TGF-β/Smad signaling pathway-related proteins. TGF-β/Smad signaling pathway proteins were then detected and confirmed by HE, Masson and immunohistochemical staining. The results shown that asiaticoside combined with carbon ion implantation inhibited the viability, proliferation and migration of fibroblasts on silicone rubber. In vitro immunofluorescence showed that the secretion levels of α-SMA and Col-1A1 were significantly decreased, the transformation of fibroblasts into myofibroblasts was weakened, and the TGF-β/Smad signaling pathway was inhibited. In vivo experimental results showed that asiaticoside combined with carbon silicone rubber inhibited TGF-β1 secretion and inhibited the TGF-β/Smad signaling pathway, reducing the thickness of the capsule and collagen deposition. These results imply that carbon silicone rubber combined with asiaticoside can regulate the viability, proliferation and migration of fibroblasts by inhibiting the TGF-β/Smad signaling pathway and reduce capsule thickness and collagen deposition, which greatly reduces the incidence of capsule contracture.

Environmental, Microbiological, and Immunological Features of Bacterial Biofilms Associated with Implanted Medical Devices

The spread of biofilms on medical implants represents one of the principal triggers of persistent and chronic infections in clinical settings, and it has been the subject of many studies in the past few years, with most of them focused on prosthetic joint infections. We review here recent works on biofilm formation and microbial colonization on a large variety of indwelling devices, ranging from heart valves and pacemakers to urological and breast implants and from biliary stents and endoscopic tubes to contact lenses and neurosurgical implants. We focus on bacterial abundance and distribution across different devices and body sites and on the role of environmental features, such as the presence of fluid flow and properties of the implant surface, as well as on the interplay between bacterial colonization and the response of the human immune system.

Advanced Strategies to Thwart Foreign Body Response to Implantable Devices

Mitigating the foreign body response (FBR) to implantable medical devices (IMDs) is critical for successful long‐term clinical deployment. The FBR is an inevitable immunological reaction to IMDs, resulting in inflammation and subsequent fibrotic encapsulation. Excessive fibrosis may impair IMDs function, eventually necessitating retrieval or replacement for continued therapy. Therefore, understanding the implant design parameters and their degree of influence on FBR is pivotal to effective and long lasting IMDs. This review gives an overview of FBR as well as anti‐FBR strategies. Furthermore, we highlight recent advances in biomimetic approaches to resist FBR, focusing on their characteristics and potential biomedical applications.

IQGAP1-mediated mechanical signaling promotes the foreign body response to biomedical implants

The aim of this study was to further elucidate the molecular mechanisms that mediate pathologic foreign body response (FBR) to biomedical implants. The longevity of biomedical implants is limited by the FBR, which leads to implant failure and patient morbidity. Since the specific molecular mechanisms underlying fibrotic responses to biomedical implants have yet to be fully described, there are currently no targeted approaches to reduce pathologic FBR. We utilized proteomics analysis of human FBR samples to identify potential molecular targets for therapeutic inhibition of FBR. We then employed a murine model of FBR to further evaluate the role of this potential target. We performed histological and immunohistochemical analysis on the murine FBR capsule tissue, as well as single-cell RNA sequencing (scRNA-seq) on cells isolated from the capsules. We identified IQ motif containing GTPase activating protein 1 (IQGAP1) as the most promising of several targets, serving as a central molecular mediator in human and murine FBR compared to control subcutaneous tissue. IQGAP1-deficient mice displayed a significantly reduced FBR compared to wild-type mice as evidenced by lower levels of collagen deposition and maturity. Our scRNA-seq analysis revealed that decreasing IQGAP1 resulted in diminished transcription of mechanotransduction, inflammation, and fibrosis-related genes, which was confirmed on the protein level with immunofluorescent staining. The deficiency of IQGAP1 significantly attenuates FBR by deactivating downstream mechanotransduction signaling, inflammation, and fibrotic pathways. IQGAP1 may be a promising target for rational therapeutic design to mitigate pathologic FBR around biomedical implants.

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.

Implants and Breast Pocket Irrigation: Outcomes of Antibiotic, Antiseptic, and Saline Irrigation

BACKGROUND

Breast implant-associated infection and capsular contracture are challenging complications that can result in poor outcomes following implant-based breast surgery. Antimicrobial irrigation of the breast pocket or implant is a widely accepted strategy to prevent these complications, but the literature lacks an evidence-based consensus on the optimal irrigation solution.

OBJECTIVES

The objective of this systematic review was to compare clinical outcomes, specifically capsular contracture, infection, and reoperation rates, associated with the use of antibiotic, antiseptic, and saline irrigation.

METHODS

A systematic review was performed in March 2020 based on the following search terms: "breast implant," "irrigation," "antibiotic," "bacitracin," "antiseptic," "povidone iodine," "betadine," "low concentration chlorhexidine," and "hypochlorous acid." Capsular contracture, infection, and reoperation rates were compared by analysis of forest plots.

RESULTS

Out of the 104 articles screened, 14 met the inclusion criteria. There was no significant difference in capsular contracture rates between antibiotic and povidone-iodine irrigation, although the data comparing these 2 groups were limited and confounded by the concurrent use of steroids. Antibiotic irrigation showed a significantly lower rate of capsular contracture compared with saline irrigation and a lower rate of capsular contracture and reoperation compared with no irrigation at all. Povidone-iodine was associated with lower rates of capsular contracture and reoperation compared with saline irrigation but there were no data on infection rates specific to povidone-iodine irrigation.

CONCLUSIONS

Our study supports the use of antibiotics or povidone-iodine for breast implant irrigation. Further research is required to better determine which of these 2 irrigation types is superior.

LEVEL OF EVIDENCE: 4

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.

Comparison Of Endoscopic Transaxillary And Peri-areolar Approaches In Breast Augmentation With Smooth Implants

INTRODUCTION

The most common surgical approaches for breast augmentation in Asia have traditionally been peri-areolar and transaxillary. In recent years, transaxillary approach has become increasingly popular with the use of endoscopic methods, which result in safer and better outcomes. In the literature, there are no comparison studies of endoscopic transaxillary and peri-areolar approaches.

METHODS

This prospective study compared the outcomes of 275 women undergoing primary breast augmentation (endoscopic transaxillary n=205, peri-areolar n=70). All procedures were performed by a single surgeon using smooth round silicone implants and dual-plane pockets from April 2013 to March 2016. Every patient was monitored for a minimum of 4 years for minor and major complications.

RESULTS

Types and percentage of patients experiencing minor complications among transaxillary and peri-areolar patients were localized fluid collection in the wound (1% transaxillary, 7.1% peri-areolar), hypertrophic scarring or keloids (1% transaxillary, 8.6% peri-areolar), and areolar and nipple deformity (0% transaxillary, 8.6% peri-areolar). Major complications were postoperative bleeding (0% transaxillary, 2.9% peri-areolar) and capsular contracture, Baker Group III or IV (1% transaxillary, 5.7% peri-areolar).

CONCLUSIONS

Endoscopic transaxillary breast augmentation had better outcomes, with lower rates of complications than the peri-areolar approach. Reviewing the literature, our study is the first direct comparison of peri-areolar and endoscopic transaxillary incisions using smooth implants. With the risk of anaplastic large cell lymphoma associated with certain macrotexture implants, endoscopic transaxillary approach using smooth implants is the safer technique and very good alternative choice for Asian women who do not want any scarring on their breasts.

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.

Physics and Physiology of Cell Spreading in Two and Three Dimensions

Cells spread on surfaces and within three-dimensional (3-D) matrixes as they grow, divide, and move. Both chemical and physical signals orchestrate spreading during normal development, wound healing, and pathological states such as fibrosis and tumor growth. Diverse molecular mechanisms drive different forms of cell spreading. This article discusses mechanisms by which cells spread in 2-D and 3-D and illustrates new directions in studies of this aspect of cell function.

Implant Fibrosis and the Underappreciated Role of Myofibroblasts in the Foreign Body Reaction

Body implants and implantable medical devices have dramatically improved and prolonged the life of countless patients. However, our body repair mechanisms have evolved to isolate, reject, or destroy any object that is recognized as foreign to the organism and inevitably mounts a foreign body reaction (FBR). Depending on its severity and chronicity, the FBR can impair implant performance or create severe clinical complications that will require surgical removal and/or replacement of the faulty device. The number of review articles discussing the FBR seems to be proportional to the number of different implant materials and clinical applications and one wonders, what else is there to tell? We will here take the position of a fibrosis researcher (which, coincidentally, we are) to elaborate similarities and differences between the FBR, normal wound healing, and chronic healing conditions that result in the development of peri-implant fibrosis. After giving credit to macrophages in the inflammatory phase of the FBR, we will mainly focus on the activation of fibroblastic cells into matrix-producing and highly contractile myofibroblasts. While fibrosis has been discussed to be a consequence of the disturbed and chronic inflammatory milieu in the FBR, direct activation of myofibroblasts at the implant surface is less commonly considered. Thus, we will provide a perspective how physical properties of the implant surface control myofibroblast actions and accumulation of stiff scar tissue. Because formation of scar tissue at the surface and around implant materials is a major reason for device failure and extraction surgeries, providing implant surfaces with myofibroblast-suppressing features is a first step to enhance implant acceptance and functional lifetime. Alternative therapeutic targets are elements of the myofibroblast mechanotransduction and contractile machinery and we will end with a brief overview on such targets that are considered for the treatment of other organ fibroses.

Applying Principles of Breast Revision to Managing Aesthetic Patients with Textured Implants

SUMMARY

Textured breast implants have garnered increased attention recently because of their risk of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), an uncommon and treatable type of T-cell lymphoma. Treatment involves bilateral en bloc capsulectomy, which is curative in the majority of cases. At present, there is no defined management approach for aesthetic patients asymptomatic for BIA-ALCL requesting the removal of their textured implants, particularly as it relates to the management of the capsule. It is unclear if en bloc capsulectomy is necessary in these patients as it is in patients with BIA-ALCL. In the absence of clear guidance on the management of the capsule in asymptomatic patients, the basic principles of breast revision surgery can be applied to these patients.

[Impact of breast dimension in one-stage augmentation mastopexies on implant selection: review of 103 consecutive breast augmentations with nanotextured silicone implants]

INTRODUCTION

According to current studies, one-stage augmentation mastopexy (AM) is associated with only minor complications and a lower reoperation rate compared with a staged procedure. In AM, breast dimension can differ notably compared with those cases without simultaneous mastopexy. However, these differences have only been insufficiently investigated. This study aims to quantify the differences and then evaluate the effect of breast dimension on implant selection. In addition, it evaluates the influence of mastopexy on the outcome of augmentation mammoplasties with round nanotextured silicone gel implants.

PATIENTS AND METHODS

Over a two-year period, all patients with primary augmentation mammoplasties using nanotextured implants were included in the study. Patients' demographic data, breast measurements, specifications of the implants placed, and complications in the breast augmentation group without mastopexy were compared with those of the group with AM. The satisfaction of patients and surgeons was documented using Likert scales.

RESULTS

A total of 206 breast augmentations were performed in n = 103 patients. The mean follow-up was 24.0 ± 4.3 months. Compared with augmentations without an indication for simultaneous mastopexy, the AM group had wider breast bases and larger preoperative cup sizes; p < 0.001. As a result, implants selected for AM had greater diameters and lower volumes (p < 0.05) and were associated with smaller projections; p < 0.001. The total revision rates after augmentations without (n = 51) and with combined mastopexy (n = 52) were 5.9 % and 19.2 % (p < 0.05), respectively. AM increased tissue-related revisions from 2.0 % to 13.4 % (p < 0.05) without having an impact on implant-related revisions (3.9 % vs. 5.8 %, p = 0.663). The overall incidence of capsular contracture was 1.9 %. Satisfaction levels were approximately equal in both groups.

CONCLUSION

In comparison to augmentations without mastopexy, wider breast bases and larger breast volumes before surgery lead to the selection of significantly different implant dimensions in AM. Nanotextured silicone implants are associated with low complication rates, while an increased risk for tissue-related revisions of the combined procedure remains. Further studies are necessary in order to evaluate possible advantages and disadvantages over established implants.

Not All Breast Explants Are Equal: Contemporary Strategies in Breast Explantation Surgery

SUMMARY

Breast implant removal and replacement has been a common secondary breast procedure in the long-term maintenance of breast augmentation, but more recently growing concerns about silicone-related systemic illness, breast implant-associated anaplastic large cell lymphoma (BIA-ALCL), and changing perceptions of aesthetic beauty have seen breast implant removal without replacement become increasingly requested by patients. Explantation can be challenging, especially when performed with a total capsulectomy. Currently, there is no evidence regarding whether a partial or total capsulectomy has any effect on BIA-ALCL risk mitigation in patients that have textured implants without disease. Total capsulectomy with incomplete resection of a mass can contribute to hyperprogression of BIA-ALCL and death. There have also been cases of BIA-ALCL diagnosed years after removal of the textured device and "total capsulectomy." Therefore, the common practice of simple prophylactic capsulectomy in a textured implant to mitigate future disease has not been established and at the current time should be discouraged. In addition, aesthetic outcomes can be quite variable, and patients should have appropriate preoperative counseling regarding the indications and contraindications for explantation, associated risks, financial implications, and postoperative appearance. The authors review salient aspects related to the planning and management of breast implant removal.

Breast Implants for Mammaplasty: An Umbrella Review of Meta-analyses of Multiple Complications

BACKGROUND

The association of breast implants and complications after mammaplasty has been extensively researched. The aim of this study is to summarize all available results in meta-analysis investigating the association between implants and the incidence of various complications.

METHODS

An umbrella review for breast implants and associated complications was performed by searching related reviews from electronic databases including Pubmed, Ovid and CINAHL. We collected and reviewed evidence across meta-analyses of observational and interventional studies of implants and any health outcome. The quality of the reviews was assessed using the AMSTAR tool (A measurement tool to assess systematic reviews).

RESULTS

The research included 92 meta-analyses of 609 studies concerning various areas. Capsular contracture was the most investigated outcome. Radiotherapy, human acellular dermal matrix application, direct-to-implant reconstruction, smooth implant, silicone-filled implant and periareolar incision were significantly associated with higher rates of some of the complications.

CONCLUSIONS

This umbrella review provides surgeons with summarized evidence of the association between the complications and implant-related factors in mammaplasty surgery to help surgeons make informed choices in the future.

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 .

Co-effects of C/Ag dual ion implantation on enhancing antibacterial ability and biocompatibility of silicone rubber

Although silicone implants are the most popular choice around the world for breast augmentation, reconstruction, and revision, due to the poor antibacterial properties and limited biocompatibility of silicone rubber (SR), one of the major complications, capsule contracture, is a lingering problem. To overcome the two main shortcomings, a dual ion implantation technique was applied to modify the surface of SR with the basic skeleton element of organic matter, carbon (C) and the broad-spectrum bactericide, silver (Ag). We present surface characterization, toxicological effects, and evaluation of the mechanical, antibacterial and biocompatible properties of C and Ag co-implanted SR (C/Ag-SRs). After ion implantation, surface roughness and tensile strength of these new materials increased. Biotoxicity was fully assessed by in vitro experiments on human fibroblasts and in vivo experiments on rats, showing that the low-Ag groups met safety standards. Both the anti-bacterial adhesion and bactericidal abilities of C/Ag-SRs were superior to those of SR, which had few antibacterial activities, especially against Staphylococcus epidermidis. With respect to biocompatibility, the adhesion of fibroblasts was promoted, while their proliferation was moderately inhibited on ion-implanted surfaces. After subcutaneous implantation in rats for 7, 30, 90 and 180 d, the capsular thickness around C/Ag-SRs was significantly lower than that around the SR. Additionally, there was no difference in the inflammatory reaction after 7 d of retention in vivo between C/Ag-SRs and SR. The results demonstrate that C/Ag-SRs are desirable shell materials for breast implants.

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.

Is Banning Texturized Implants to Prevent Breast Implant-Associated Anaplastic Large Cell Lymphoma a Rational Decision? A Meta-Analysis and Cost-Effectiveness Study

BACKGROUND

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an emergent disease that threatens patients with texturized breast implants. Major concerns about the safety of these implants are leading to global changes to restrict the utilization of this product. The principal alternative is to perform breast augmentation utilizing smooth implants, given the lack of association with BIA-ALCL. The implications and costs of this intervention are unknown.

OBJECTIVES

The authors of this study determined the cost-effectiveness of smooth implants compared with texturized implants for breast augmentation surgery.

METHODS

A tree decision model was utilized to analyze the cost-effectiveness. Model input parameters were derived from published sources. The capsular contracture (CC) rate was calculated from a meta-analysis. Effectiveness measures were life years, avoided BIA-ALCL, avoided deaths, and avoided reoperations. A sensitivity analysis was performed to test the robustness of the model.

RESULTS

For avoided BIA-ALCL, the incremental cost was $18,562,003 for smooth implants over texturized implants. The incremental cost-effectiveness ratio was negative for life years, and avoided death and avoided reoperations were negative. The sensitivity analysis revealed that to avoid 1 case of BIA-ALCL, the utilization of smooth implants would be cost-effective for a risk of developing BIA-ALCL equal to or greater than 1:196, and there is a probability of CC with smooth implants equal to or less than 0.096.

CONCLUSIONS

The utilization of smooth implants to prevent BIA-ALCL is not cost-effective. Banning texturized implants to prevent BIA-ALCL may involve additional consequences, which should be considered in light of higher CC rates and more reoperations associated with smooth implants than with texturized implants.

Does Implant Surface Texture Affect the Risk of Capsular Contracture in Subglandular Breast Augmentation and Breast Augmentation-Mastopexy?

BACKGROUND

Previous studies have reported decreased rates of capsular contracture associated with the use of textured surface breast implants placed in the subglandular plane during breast augmentation. However, since the publication of these studies, our understanding of the pathophysiology of capsular contracture, as well as the surgical techniques utilized to minimize bacterial contamination of the implant, have advanced considerably.

OBJECTIVES

The purpose of this study was to re-evaluate the relation between implant surface texturization and capsular contracture rates for breast implants placed in the subglandular plane during primary breast augmentation.

METHODS

Retrospective chart review was performed of all primary subglandular breast augmentation procedures involving the use of either smooth or textured round silicone gel implants, with or without simultaneous mastopexy. The primary outcome measures included clinically significant capsular contracture (Baker grade III/IV) and revision surgery for capsular contracture.

RESULTS

Between 2010 and 2017, 526 patients underwent primary subglandular breast augmentation with either smooth (n = 212) or textured (n = 314) round silicone gel implants; 248 patients underwent breast augmentation, whereas 278 underwent breast augmentation-mastopexy. Average follow-up was 756 days in the textured group and 461 days in the smooth group. Five cases of capsular contracture were observed in the textured group, and 7 cases of capsular contracture were observed in the smooth group (P = 0.20).

CONCLUSIONS

Smooth surface implants placed in the subglandular plane were not at a significantly increased risk of capsular contracture compared with textured surface implants. We suggest that adherence to a surgical technique focused on minimizing bacterial contamination of the implant is of greater clinical significance than implant surface characteristics when discussing capsular contracture.

LEVEL OF EVIDENCE: 4

Size matters-in vitro behaviour of human fibroblasts on textured silicone surfaces with different pore sizes

Capsular contracture remains a challenge in plastic surgery and represents one of the most common postoperative complications following alloplastic breast reconstruction. The impact of the surface structure of silicone implants on the foreign body reaction and the behaviour of connective tissue-producing cells has already been discussed. The aim of this study was to investigate different pore sizes of silicone surfaces and their influence on human fibroblasts in an in vitro model. Four different textures (no, fine, medium and coarse texture) produced with the salt-loss technique, have been assessed in an in vitro model. Human fibroblasts were seeded onto silicone sheets and evaluated after 1, 4 and 7 days microscopically, with viability assay and gene expression analysis. Comparing the growth behaviour and adhesion of the fibroblasts on the four different textures, a dense cell layer, good adhesion and bridge-building ability of the cells could be observed for the fine and medium texture. Cell number and viability of the cells were increasing during the time course of experiments on every texture. TGFß1 was lowest expressed on the fine and medium texture indicating a trend for decreased fibrotic activity. For silicone surfaces produced with the salt-loss technique, we were able to show an antifibrotic effect of smaller sized pores. These findings underline the hypothesis of a key role of the implant surface and the pore size and pore structure in preventing capsular contracture.

Safety and Efficacy of Smooth Surface Tissue Expander Breast Reconstruction

BACKGROUND

Traditional 2-stage breast reconstruction involves placement of a textured-surface tissue expander (TTE). Recent studies have demonstrated textured surface devices have higher propensity for bacterial contamination and biofilm formation.

OBJECTIVES

The purpose of this study was to evaluate the safety and efficacy of smooth surface tissue expanders (STE) in immediate breast reconstruction.

METHODS

The authors retrospectively reviewed consecutive women who underwent STE breast reconstruction from 2016 to 2017 at 3 institutions. Indications and outcomes were evaluated.

RESULTS

A total 112 patients underwent STE reconstruction (75 subpectoral, 37 prepectoral placement), receiving 173 devices and monitored for a mean follow-up of 14.1 months. Demographics of patients included average age of 53 years and average BMI of 27.2 kg/m2, and 18.6% received postmastectomy radiation therapy. Overall complication rates were 15.6% and included mastectomy skin flap necrosis (10.4%), seroma (5.2%), expander malposition (2.9%), and infection requiring intravenous antibiotic therapy (3.5%). Six (3.5%) unplanned reoperations with explantation were reported for 3 infections and 3 patients requesting change of plan with no reconstruction.

CONCLUSIONS

STEs represent a safe and efficacious alternative to TTE breast reconstruction with at least equitable outcomes. Technique modification including tab fixation, strict pocket control, postoperative bra support, and suture choice may contribute to observed favorable outcomes and are reviewed. Early results for infection control and explantation rate are encouraging and warrant comparative evaluation for potential superiority over TTEs in a prospective randomized trial.

LEVEL OF EVIDENCE: 4

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.

US FDA Breast Implant Postapproval Studies: Long-term Outcomes in 99,993 Patients

OBJECTIVE

To analyze the long-term safety and efficacy outcomes of patients with breast implants.

SUMMARY BACKGROUND DATA

Research is ongoing regarding the safety of silicone breast implants. Despite the number of patients with breast implants followed by United States Food and Drug Administration large postapproval studies (LPAS), this database has not been thoroughly analyzed or reported.

METHODS

This is a multicentered, cohort study. LPAS prospectively monitor long-term implant-related outcomes and systemic harms for silicone/saline implants from 2 manufacturers (Allergan and Mentor) placed for primary/revision augmentation/reconstruction. Systemic harms, self-harm, and reproductive outcomes are compared with normative data. Implant-related complications are analyzed by implant composition and operative indication in the short and long terms.

RESULTS

LPAS data includes 99,993 patients, 56% of implants were silicone for primary augmentation. Long-term magnetic resonance imaging surveillance is under 5%. Compared with normative data, silicone implants are associated with higher rates of Sjogren syndrome (Standardized incidence ratio [SIR]8.14), scleroderma (SIR 7.00), rheumatoid arthritis (SIR5.96), stillbirth (SIR4.50), and melanoma (SIR3.71). One case of BI-ALCL is reported. There is no association with suicide. In the short term, rupture is higher for saline (2.5% vs. 0.5%, P < 0.001), and capsular contracture higher for silicone (5.0% vs. 2.8%, P < 0.001). At 7 years, reoperation rate is 11.7% for primary augmentation, and 25% for primary/revision reconstruction. Capsular contracture (III/IV) occurs in 7.2% of primary augmentations, 12.7% primary reconstructions, and is the most common reason for reoperation among augmentations.

CONCLUSIONS

This is the largest study of breast implant outcomes. Silicone implants are associated with an increased risk of certain rare harms; associations need to be further analyzed with patient-level data to provide conclusive evidence. Long-term safety and implant-related outcomes should inform patient and surgeon decision-making when selecting implants.

An actuatable soft reservoir modulates host foreign body response

The performance of indwelling medical devices that depend on an interface with soft tissue is plagued by complex, unpredictable foreign body responses. Such devices-including breast implants, biosensors, and drug delivery devices-are often subject to a collection of biological host responses, including fibrosis, which can impair device functionality. This work describes a milliscale dynamic soft reservoir (DSR) that actively modulates the biomechanics of the biotic-abiotic interface by altering strain, fluid flow, and cellular activity in the peri-implant tissue. We performed cyclical actuation of the DSR in a preclinical rodent model. Evaluation of the resulting host response showed a significant reduction in fibrous capsule thickness (P = 0.0005) in the actuated DSR compared with non-actuated controls, whereas the collagen density and orientation were not changed. We also show a significant reduction in myofibroblasts (P = 0.0036) in the actuated group and propose that actuation-mediated strain reduces differentiation and proliferation of myofibroblasts and therefore extracellular matrix production. Computational models quantified the effect of actuation on the reservoir and surrounding fluid. By adding a porous membrane and a therapy reservoir to the DSR, we demonstrate that, with actuation, we could (i) increase transport of a therapy analog and (ii) enhance pharmacokinetics and time to functional effect of an inotropic agent. The dynamic reservoirs presented here may act as a versatile tool to further understand, and ultimately to ameliorate, the host response to implantable biomaterials.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Ten-Year Safety Data for Eurosilicone's Round and Anatomical Silicone Gel Breast Implants

Background

Although silicone breast implants have been available for over 60 years, their safety and efficacy continue to be assessed via long-term clinical and vigilance studies. Complications often associated with breast implant surgery include but are not limited to capsular contracture and rupture.

Objective

The authors investigate and evaluate the safety and performance of Eurosilicone’s (Eurosilicone S.A.S, Apt Cedex, France) Cristalline Paragel breast implants at least 10 years postimplantation.

Methods

Nine hundred and ninety-five of Eurosilicone’s textured mammary implants were implanted in 526 women undergoing primary (423 patients) and revision surgery (103 patients) at 17 centers throughout France. Complications were recorded at 3 months and annually thereafter for 10 years. Descriptive statistics were used and the Kaplan-Meier method was utilized to analyze key complications.

Results

Seventy-four women (98 implants) experienced capsular contracture across all cohorts. The Kaplan-Meier 10-year cumulative risk of capsular contracture (Baker Grade III/IV) per implant was 11.5% in the primary augmentation cohort and 25.2% in the primary reconstruction cohort. Sixteen implant ruptures were observed by surgeon examination giving a Kaplan-Meier risk of 3.8% per patient and 3.5% per implant. Surgical re-intervention (explantation/exchange) was reported 80 times resulting in a Kaplan-Meier cumulative risk of 13.3% and 31.6% for primary augmentation and primary reconstruction, respectively, per patient. Local complication rates including infection and seroma were low with risk rates of 0.6% and 0.2% by subject.

Conclusions

This multicenter clinical study demonstrates the long-term safety and efficacy profile through 10 years for Eurosilicone round and anatomical silicone gel breast implants.

Level of Evidence: 3

The A, B and C's of Silicone Breast Implants: Anaplastic Large Cell Lymphoma, Biofilm and Capsular Contracture

Breast implantation either for cosmetic or reconstructive e purposes is one of the most common procedures performed in plastic surgery. Biofilm infection is hypothesised to be involved in the development of both capsular contracture and anaplastic large cell lymphoma (ALCL). Capsular contracture is one of the principal reasons for breast revision surgery and is characterised by the tightening and hardening of the capsule surrounding the implant, and ALCL is an indolent lymphoma found only in women with textured implants. We describe the types of breast implants available with regard to their surface characteristics of surface area and roughness and how this might contribute to capsular contracture and/or biofilm formation. The pathogenesis of capsular contracture is thought to be due to biofilm formation on the implant, which results in on-going inflammation. We describe the current research into breast implant associated ALCL and how implant properties may affect its pathogenesis, with ALCL only occurring in women with textured implants.

Breast Implant Texturization Does Not Affect the Crosstalk Between MSC and ALCL Cells

In the last decade, there has been a growing interest about the possible association between anaplastic large cell lymphoma (ALCL) and breast implants (BIA-ALCL). Many variables, such as breast implants texturization, have been investigated. Breast implants often lead to the formation of a periprosthetic capsule, characterized by inflammation. The presence of the inflamed capsule has been found in the majority of patients with BIA-ALCL. Inflammation may be sustained or counteracted by mesenchymal stem cells (MSCs) by the secretion of pro- or anti-inflammatory cytokines. MSCs were isolated from three capsules surrounding micro-textured (micro-MSCs) and from three capsules surrounding macro-textured (macro-MSCs) implants; after characterization, MSCs were co-cultured with KI-JK cells (a cell line derived from the cutaneous form of ALCL). The secretion of cytokines related to inflammation, the proliferation rate, and the expression of genes referred to pro-tumoral mechanisms were evaluated. Co-cultures of KI-JK cells with micro- or macro-MSCs gave the same results about the secretion of cytokines (increase of IL10, G-CSF, and TGF-β1 and decrease of IL4, IL5, IL12, IL13, IL17A, IFN-γ (p < 0.05) with respect to mock sample), expression of selected genes (increase for ACVR1, VEGF, TGF-βR2, CXCL12, and MKi67 (p < 0.05) with respect to control sample), and the proliferation rate (no variation between mock and co-cultured samples). Our results suggest that MSCs derived from capsules surrounding micro- and macro-textured implants display the same effects on the ALCL cells.

Is short term intraoperative application of disinfectants harmful to breast implants in breast reconstruction? An experimental study and literature survey

OBJECTIVES

Bacterial contamination of breast implants and biofilm formation has been discussed as a major reason for implant loss and capsular contraction. Intra- and perioperative treatment of breast implants with disinfectants to prevent bacterial contamination has been frequently reported. Given the increasing awareness of concerns about product liability the question of whether short-time irrigation of implants with antimicrobial substances during the operative procedure would potentially alter the integrity of the implant shell has attracted legal and medical interest. In this study we therefore investigated whether irrigating breast implants with antimicrobials commonly used in clinical practice with a clinically relevant application time would affect the physical integrity of the implant shell.

MATERIALS AND METHODS

Samples, which were previously punched from the shell of explanted standard silicone gel filled breast implants in a defined way, were exposed to different disinfectant solutions for two minutes. Multiple defined specimens from 5 different explants from 4 different producers (including PIP) were tested. The testing included tensile strength and disruption tests.

RESULTS

In our prospective test series we could not find a significant influence of a single distinct disinfectant on silicone shell implant surfaces.

CONCLUSION

Despite the potential legal implications that might be considered when a surgeon manipulates an implant with disinfectants intraoperatively, we find it worthwhile to state that from a material and surgical standpoint there is no evidence that short-time treatment of alloplastic materials would be detrimental to the physical properties of the implant shell.

Polyurethane Microparticles for Stimuli Response and Reduced Oxidative Degradation in Highly Porous Shape Memory Polymers

Shape memory polymers (SMPs) have been found to be promising biomaterials for a variety of medical applications; however, the clinical translation of such technology is dependent on tailorable properties such as gravimetric changes in degradation environments. For SMPs synthesized from amino-alcohols, oxidation resulting in rapid mass loss may be problematic in terms of loss of material functionality as well as toxicity and cytocompatibility concerns. Control of gravimetric changes was achieved through the incorporation of small molecule antioxidants, either directly into the polymer matrix or included in microparticles to form a SMP composite material. With direct incorporation of small molecule phenolic antioxidant 2,2'-methylenebis(6- tert-butyl)-methylphenol (Methyl), SMPs displayed reduce strain recovery by more than 50% (Methyl) and increase elastic modulus from approximately 1.4 to 2.3 MPa, at the expense of the strain to failure being reduced from 45% to 32%. Importantly, such changes could not ensure retention of the antioxidants and therefore did not increase oxidative stability beyond 15 days in accelerated oxidative conditions (equivalent to approximately 800 days in porcine aneurysms) in all cases except for the inclusion of a hindered amine that capped network growth, which also resulted in shape memory reduction (only 80% recoverable strain achieved). However, the inclusion of antioxidants in microparticles was found to produce materials with similar thermomechanical ( T_g migration below 1.0 °C) and shape recovery of 100%, while increasing oxidative resistance compared to controls (oxidation onset was delayed by 3 days and material lifespan increased to approximately 20-22 days in accelerated oxidative solution or beyond 1000 days in the porcine aneurysm). The microparticle composite SMPs also act as a platform for environmental sensing, such as pH-dependent fluorescence shifts and payload release, as demonstrated by fluorescent dye studies using phloxine B and nile blue chloride and the release of antioxidants over a 3 week period. The use of polyurethane-urea microparticles in porous SMPs is demonstrated to increase biostability of the materials, by approximately 25%, and ultimately extend their lifespan for use in aneurysm occlusion as determined through calculated in vivo degradation rates corresponding to a porcine aneurysm environment.

The healthcare seeking rate of individuals with influenza like illness: a meta-analysis

BACKGROUND

Not all individuals with Influenza like illness (ILI) seek healthcare. Knowing the proportion that do is important to evaluate the actual burden and fatality rate of ILI-relevant diseases, such as seasonal influenza and human infection with avian influenza. A number of studies have investigated the healthcare seeking rate, but the results varied from 0.16 to 0.85. We conducted this analysis for better understanding the healthcare seeking rate for ILI, and providing fundamental data for researchers in relevant fields.

METHODS

In this meta-analysis, a total of 799 articles, published as of 13 December 2016, were retrieved from Pubmed, Embase, Web of Science and Cochrane, and 11 of them were included after screening. The pooled estimates and factors which influence healthcare seeking rates were analysed.

RESULTS

The overall pooled healthcare seeking rate was 0.52 (95% CI: 0.46-0.59). The rate was significantly higher during the H1N1 pandemic in 2009 (0.61, 95% CI: 0.51-0.74), in children (0.56, 95% CI: 0.55-0.57) and in patients with documented fever (0.62, 95% CI: 0.53-0.72) than during non-pandemic periods (0.39, 95% CI: 0.33-0.45), in adults (0.45, 95% CI: 0.42-0.48) and in patients without documented fever (0.44, 95% CI: 0.38-0.50). Meta-regression indicated that these three factors could jointly explain 70.1% of the total heterogeneity among published studies.

CONCLUSION

The healthcare seeking rate of ILI patients is needed for estimation of the burden of ILI in the general population based on data from routine ILI sentinel surveillance systems.

Effect of Keller Funnel on the Rate of Capsular Contracture in Periareolar Breast Augmentation

Background

Capsular contracture is 1 of the most common complications after breast implant surgery and is a major indication for reoperation. Capsular contracture is believed to be a multifactorial process that is affected by implant texture, incision type, and ultimately pocket contamination. This contamination causes a biofilm that leads to capsular contracture. The intraoperative use of a Keller funnel is a mechanical way to decrease the implant's contact with the skin and ducts, reducing bacterial contamination that can cause these biofilms. For this reason, periareolar breast augmentation has been less popular among surgeons. The purpose of this study was to examine if there was a significant difference between the rates of capsular contracture in patients having periareolar breast augmentations with the use of a Keller funnel for insertion and those having periareolar breast augmentations without Funnel use.

Methods

This level 3 retrospective study followed 2 groups of patients, the first having periareolar breast augmentations without the use of a funnel for insertion (group A; patients n = 15; implants n = 30) and the second having periareolar breast augmentations with the use of a funnel for insertion (group B; patients n = 151; implants n = 300).

Results

The rate of capsular contracture in group A was found to be 10% compared with a rate of capsular contracture of 1.3% for patients in group B, an 87% reduction (P = 0.0019).

Conclusions

According to the results found in this study, the rate of capsular contracture in patients having periareolar breast augmentations after insertion with a Keller funnel was statistically significantly lower than the rate in patients having implants inserted without the assistance of a funnel, making the device useful in reducing the occurrence of postoperative capsular contracture.