Comparison of the capsular response to the Biocell RTV and Mentor 1600 Siltex breast implant surface texturing: a scanning electron microscopic study

Anatomical Breast Implant Assessment Using Ultrasound: A Case Series from the International Breast Implant Check Clinic

Background

Breast augmentation with anatomic implants can achieve a natural look, but over time, implant-related complications can occur. This includes a risk of potential rotation, which can cause a change in breast shape. Reported rates of rotation vary widely (0%-42%). Implant rotation is often detected by physical examination only or as a perioperative finding. Change in breast shape after augmentation requires clinical evaluation. In-office ultrasound allows for detailed assessment of implants for rotation and other complications.

Methods

Women with anatomical breast implants seeking follow-up at the International Breast Implant Check Clinic in Stockholm, Sweden, from April 2020 to July 2022 were included in the study. Using a standardized protocol, subjective symptoms were recorded, and a physical examination followed by an ultrasound assessment was performed by a single board-certified plastic surgeon (M.J.) trained in implant assessment via ultrasound. Rotation was defined as an implant rotated past 30 degrees off the breast midline at 6 o'clock.

Results

The study included 308 women (mean age 40.1, range 20-78) with bilateral anatomical implants. Overall, 40 women (13.0%) reported a change in breast shape; 35 had one or more implant-related complications, including five with rotation on ultrasound. Of the 308 women, 11 (3.6%) had rotations upon physical examination, and an additional 10 cases were identified using ultrasound.

Conclusions

Rotation is a potential complication of anatomical breast implants. However, in this study, change in breast shape was more commonly caused by other implant-related complications. Ultrasound is a valuable tool in evaluating causes of change in breast shape.

Breast Implant Capsule: A Murine Model Comparing Capsular Contracture Susceptibility Among Six Breast Implants Available in the Market

BACKGROUND

Breast implant capsule development and behavior are mainly determined by implant surface combined with other external factors such as intraoperative contamination, radiation or concomitant pharmacologic treatment. Thus, there are several diseases: capsular contracture, breast implant illness or Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL), that have been correlated with the specific type of implant placed. This is the first study to compare all major implant and texture models available in the market on the development and behave of the capsules. Through a histopathological analysis, we compared the behavior of different implant surfaces and how different cellular and histological properties give rise to different susceptibilities to develop capsular contracture among these devices.

METHODS

A total of 48 Wistar female rats were used to implant 6 different types of breast implants. Mentor®, McGhan®, Polytech polyurethane®, Xtralane®, Motiva® and Natrelle Smooth® implants were employed; 20 rats received Motiva®, Xtralane® and Polytech polyurethane®, and 28 rats received Mentor®, McGhan® and Natrelle Smooth® implants. The capsules were removed five weeks after the implants placement. Further histological analysis compared capsule composition, collagen density and cellularity.

RESULTS

High texturization implants showed the highest levels of collagen and cellularity along the capsule. However, polyurethane implants capsules behaved differently regarding capsule composition, with the thickest capsules but fewer collagen and myofibroblasts than expected, despite being generally considered as a macrotexturized implant. Nanotextured implants and microtextured implants histological findings showed similar characteristics and less susceptibility to develop a capsular contracture compared with smooth implants.

CONCLUSIONS

This study shows the relevance of the breast implant surface on the definitive capsules' development, since this is one of the most differentiated factors that determine the incidence of capsular contracture and probably other diseases like BIA-ALCL. A correlation of these findings with clinical cases will help to unify implant classification criteria based on their shell and their estimated incidence of capsule-associated pathologies. Up to this point, the establishment of additional groups is recommended as nanotexturized implants seem to behave differently to pure smooth surfaces and polyurethane implants present diverse features from macro- or microtextured implants.

NO LEVEL ASSIGNED

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

Feasibility of Imaging Modalities Combined with a Silicone Gel-Filled Breast Implant in Korean Women

With the occurrence of breast implant crises in Korea, it has become increasingly important to detect complications earlier in patients receiving a device. We have therefore combined imaging modalities with an implant-based augmentation mammaplasty. In this study, we assessed the short-term treatment outcomes and safety of the Motiva Ergonomix™ RoundSilkSurface (Establishment Labs Holdings Inc., Alajuela, Costa Rica) in Korean women. A total of 87 women (n = 87) were included in the current study. We compared preoperative anthropometric measurements between the right side and the left side of the breast. Moreover, we also compared the thickness of the skin, subcutaneous tissue and the pectoralis major measured on a breast ultrasound preoperatively and 3 months postoperatively. Furthermore, we analyzed the incidences of postoperative complications and the cumulative complication-free survival. Preoperatively, there was a significant difference in the distance from the nipple to the midline between the left and right side of the breast (p = 0.000). Both sides of the breast showed significant differences in the thickness of the pectoralis major preoperatively and 3 months postoperatively (p = 0.000). A total of 11 cases (12.6%) of postoperative complications occurred; these included five cases (5.7%) of early seroma, two cases (2.3%) of infection, two cases (2.3%) of rippling, one case (1.1%) of hematoma and one case (1.1%) of capsular contracture. Time-to-events were estimated at 386.68 ± 27.79 days (95% CI 334.11–439.27). Here, we describe our experience with imaging modalities in combination with the Motiva ErgonomixTM Round SilkSurface in Korean women.

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.

A non-manufacturer-sponsored, retrospective study to assess 2-year safety outcomes of the BellaGel® SmoothFine as compared with its competitors in the context of the first Korean case of a medical device fraud

BACKGROUND

We conducted this study to assess preliminary 2-year safety outcomes of an implant-based augmentation mammaplasty using the BellaGel® SmoothFine in the context of the first Korean case of a medical device fraud.

METHODS

Our clinical series of the patients (n = 579; 1,158 breasts) received augmentation using the BellaGel® SmoothFine, Naturgel™, Motiva Ergonomix™, Eurosilicone Round Collection™, Natrelle® INSPIRA™, Natrelle® 410, Mentor® MemoryGel Xtra or Microthane®. The patients were evaluated for incidences of postoperative complications and Kaplan-Meier survival and hazards.

RESULTS

Overall, there were a total of 101 cases (17.4%) of postoperative complications; these include 31 cases (5.4%) of shape deformity, 21 cases (3.6%) of CC, 18 cases (3.1%) of early seroma, 8 cases (1.4%) of infection, 5 cases (0.9%) of early hematoma, 1 case (0.2%) of delayed hematoma, 1 case (0.2%) of rupture and 1 case (0.2%) of ripping. Moreover, there were also 15 cases (2.6%) of other complications. There were significant differences in incidences of postoperative complications between the breast implants from different manufacturers (P = 0.034). The Natrelle® 410 showed the longest survival (333.3±268.2 [141.5-525.1] days). A subgroup analysis showed that there were no significant differences in incidences of postoperative complications between the breast implants (P = 0.831). Moreover, the Natrelle® INSPIRA™ showed the longest survival (223.7±107.1 [-42.3-489.6] days).

CONCLUSIONS

Here, we describe preliminary 2-year safety outcomes of an implant-based augmentation mammaplasty using the BellaGel® SmoothFine in the context of the first Korean case of a medical device fraud.

Pharmacological Approaches for the Prevention of Breast Implant Capsular Contracture

Capsular contracture is a common complication associated with breast implants following reconstructive or aesthetic surgery in which a tight or constricting scar tissue capsule forms around the implant, often distorting the breast shape and resulting in chronic pain. Capsulectomy (involving full removal of the capsule surrounding the implant) and capsulotomy (where the capsule is released and/or partly removed to create more space for the implant) are the most common surgical procedures used to treat capsular contracture. Various structural modifications of the implant device (including use of textured implants, submuscular placement of the implant, and the use of polyurethane-coated implants) and surgical strategies (including pre-operative skin washing and irrigation of the implant pocket with antibiotics) have been and/or are currently used to help reduce the incidence of capsular contracture. In this article, we review the pharmacological approaches-both commonly practiced in the clinic and experimental-reported in the scientific and clinical literature aimed at either preventing or treating capsular contracture, including (i) pre- and post-operative intravenous administration of drug substances, (ii) systemic (usually oral) administration of drugs before and after surgery, (iii) modification of the implant surface with grafted drug substances, (iv) irrigation of the implant or peri-implant tissue with drugs prior to implantation, and (v) incorporation of drugs into the implant shell or filler prior to surgery followed by drug release in situ after implantation.

Tissue Expander-associated T Cells: Relevance to Breast Implant-associated Anaplastic Large-cell Lymphoma

The generation of breast implant–associated anaplastic large-cell lymphoma (BIA-ALCL) is closely associated with textured implants. The phenotype of BIA-ALCL cells is well examined, but its cell of origin remains unknown. Here we investigate what types of T cells are recruited and differentiated in the surrounding capsules and tissues as a consequence of continuous contact with a textured surface.

Reoperative Augmentation Mammoplasty: An Algorithm to Optimize Soft-Tissue Support, Pocket Control, and Smooth Implant Stability with Composite Reverse Inferior Muscle Sling (CRIMS) and its Technical Variations

BACKGROUND

Reoperative augmentation mammoplasty (RAM) is a challenging procedure, with the highest rates of complications and revision. Complications include implant malposition, lateral displacement, bottoming out, and rotation. These deformities can be addressed with various procedures, but the pocket control and stability of the new smooth implant surface may present limitations.

OBJECTIVES

This study revisits a previously described predictable approach in primary breast augmentation and defines a surgical treatment algorithm for RAM technique selection.

METHODS

Between 2017 and 2021, 72 patients (144 breasts) underwent RAM with composite reverse inferior muscle sling (CRIMS) technique and its technical variations (types I-IV). CRIMS technique involves placing a silicone gel implant into the submuscular (SM) pocket with an inferior sling of the pectoralis major muscle based on the dimensions of the implant, in combination with support points/dermal bridge sutures to stabilize the implant and glandular tissue at the lower breast pole (LBP). Reasons for surgery were ptosis (92%), implant and malposition (59.6%). Patients were followed for at least 6 months in 5 cases (6.9%), at least 12 months in 50 cases (69.4%), for at least 36 months in 10 cases (13.8%), and more than 36 months in 7 cases (9.7%) (mean 34 months; range 6-48 months). Patients were evaluated in terms of resolution of symptoms, satisfaction, and complications. Three-dimensional imaging (3DI) obtained from the Divina scanner system was used and followed up for 1 year to evaluate breast position, lower pole stretch (LPS), and intermammary distance (IMD).

RESULTS

Eleven cases of minor complications were observed in 9 patients (12.5%): hypertrophic scarring in 4 (5.5%), wound dehiscence in 4 (5.5%), Baker II/III capsular contracture in 1 (1.3%). SmoothSilk surface silicone implants were used in all cases, with an average volume decrease of 120 cc. Sixty-eight patients (94.4%) were either very satisfied/satisfied with their aesthetic result. Breast images were performed in a group of 65 patients (90.2%), and in 7 breasts (10.7%), localized oil cysts were observed. The value for LPS was 7.87% (p <0.0001) between 10 days and 1 year, with the majority occurring early in the first 3 months, indicating that the LBP/implant remains steady during the last months of follow-up. No cases of fat necrosis/seroma were observed. There were no signs of intra/extracapsular ruptures, capsular contracture. There were 2 cases (3%) of minimal implant displacement and no cases of rotation.

CONCLUSIONS

CRIMS and its variations can be performed successfully in RAM. An algorithmic approach can facilitate the pre- and intraoperative decision-making process and provide the new pocket control and implant stability with acceptable complication rates. Further accurate evaluation is recommended to understand the benefits or disadvantages of CRIMS compared to other RAM techniques.

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 .

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

BACKGROUND

Capsular contracture is a severe complication to breast surgery with implants. Previous studies suggest multiple risk factors are associated with capsular contracture, but the etiology is still unknown. We performed a literature review to investigate existing studies on histological analyses of breast implant capsules and how clinical risk factors impact the capsule morphology.

METHODS

The literature search was conducted in PubMed. Studies that performed histological analyses of breast implant capsules were included. Animal studies or studies with a study population of less than five patients were excluded.

RESULTS

Fifty-two studies were included. The histological analyses showed that the breast implant capsules were organized in multiple layers with an inner layer of synovial-like metaplasia which was reported to diminish in capsules with capsular contracture. The remaining layers of the capsule mostly consisted of collagen. The alignment of the collagen fibers differed between contracted and non-contracted capsules, and capsules with higher Baker grade were generally thickest and contained more tissue inflammation. Studies investigating capsules affected by radiotherapy found a more pronounced inflammatory response and the capsules were generally thicker and fibrotic compared with nonirradiated capsules.

CONCLUSIONS

The included studies offer valuable insights into the histological changes caused by capsular contracture and their relation to clinical risk factors. Further studies with larger sample sizes and more strict inclusion criteria are needed to further investigate implant capsules and the role of the synovial-like metaplasia for the development of capsular contracture.

LEVEL OF EVIDENCE III

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

Defining Double Capsules: A Clinical and Histological Study

BACKGROUND

Macrotextured breast implants are associated with double capsules. There is little agreement as to what defines double capsules, how they present, and whether different degrees of double capsule exist.

OBJECTIVES

This study aimed to define double capsules and report an association between double-capsule type and degree of tissue adherence.

METHODS

Consecutive aesthetic patients undergoing explantation of Biocell (Allergan, Inc., Irvine, CA) implants between May 2018 and November 2018 were included if they were found to have double capsules intraoperatively. Patient demographics, implant characteristics, explantation reason, implant adherence, and intraoperative findings were recorded. Both adherent and double capsules were histologically examined. Data were analyzed by descriptive statistics.

RESULTS

Eleven patients had 22 Biocell implants explanted during the study period. The average explantation time was 8.0 years. Sixteen implants were found to have some degree of nonadherence, and all areas of nonadherence were associated with double-capsule formation. Double capsules were either partial or complete. The architecture of the inner layer of double capsules varied between an organized capsular layer and a thin area of nascent capsule. Histologically, all capsular specimens demonstrated an overall hypocellular fibrous capsule with scattered chronic inflammatory infiltrates. Synovial metaplasia was present in all capsule types and spaces/cracks in the capsule were disproportionately represented in partially adherent capsules.

CONCLUSIONS

This is the first study to identify a clinical and pathological correlation between double capsules and failed tissue adherence. Double capsules represent a spectrum of inner capsule formation ranging between nascent capsular tissue to a mature inner capsular layer.

LEVEL OF EVIDENCE: 4

Does the Textured-Type Tissue Expander Affect the Outcomes of Two-Stage Prosthetic Breast Reconstruction? A Propensity Score Matching Analysis between Macrotextured and Microtextured Expanders

BACKGROUND

In two-stage prosthetic breast reconstruction, two types of tissue expanders are used for the first stage: microtextured Siltex and macrotextured Biocell. Despite emerging concerns regarding the safety of macrotextured prostheses, the association between the use of macrotextured expanders and adverse outcomes remains unknown clinically. This study aimed to evaluate potential impacts of the type of tissue expander on the long-term outcomes of implant-based breast reconstruction.

METHODS

Patients who underwent immediate two-stage tissue expander/implant breast reconstruction between 2014 and 2018 were evaluated and categorized into two groups according to the expander type. Those two were propensity score matched for baseline characteristics and compared for complication rates after the first- and second-stage operations. The impacts of several variables, including type of tissue expander used, on outcomes were assessed using multivariable logistic regression analyses.

RESULTS

Of the 1391 cases in 1294 patients, 276 pairs (552 cases) were successfully propensity score matched. In the first-stage operation, the macrotextured group showed a significantly shorter drain indwelling period and lower rate of seroma than the microtextured group. These differences retained influences after adjusting for other variables. Incidence rates of other complications were similar between the groups. Regarding the second-stage operation, the use of macrotextured expanders showed a significant association, with an increased rate of severe capsular contracture on the multivariable analyses in cases using textured implants. Development of other complications was not affected by the expander type.

CONCLUSION

The type of tissue expander might influence the outcomes of two-stage implant-based breast reconstruction, and generally acceptable safety of both microtextured and macrotextured expanders was shown.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Additive Manufacturing of Multi-Scale Porous Soft Tissue Implants That Encourage Vascularization and Tissue Ingrowth

Medical devices, such as silicone-based prostheses designed for soft tissue implantation, often induce a suboptimal foreign-body response which results in a hardened avascular fibrotic capsule around the device, often leading to patient discomfort or implant failure. Here, it is proposed that additive manufacturing techniques can be used to deposit durable coatings with multiscale porosity on soft tissue implant surfaces to promote optimal tissue integration. Specifically, the "liquid rope coil effect", is exploited via direct ink writing, to create a controlled macro open-pore architecture, including over highly curved surfaces, while adapting atomizing spray deposition of a silicone ink to create a microporous texture. The potential to tailor the degree of tissue integration and vascularization using these fabrication techniques is demonstrated through subdermal and submuscular implantation studies in rodent and porcine models respectively, illustrating the implant coating's potential applications in both traditional soft tissue prosthetics and active drug-eluting devices.

Biocell-Initial patents versus user instructions guide: A discrepancy at the core of a crisis

PURPOSE

Our aim is to do a comparative qualitative analysis of patents and "User Manuals" of the Biocell textured implants in order to determine if red flags were omitted when marketing and using Biocell textured implants.

MATERIALS AND METHODS

We performed a systematic qualitative analysis using the NVivo software version 11 of the patents describing the Biocell textured implants prior to their approval by the FDA and of user guides published by the 3 companies owning the patents (McGhan, Inamed, Allergan). To guide our thematic analysis, we used a form of systems theory known as the complexity theory.

RESULTS

Four patents related to Biocell and 2 user manuals (McGhan- Inamed and Allergan) were analyzed. Four themes emerged from the patents: invention description, mechanism of action (Tissue ingrowth), the timing of the mechanism of action and hypothetical actions on capsular contractures prevention. Of all patent's content, 34% described the invention, 29% the mechanism of action (tissue ingrowth), 1% the timing of this mechanism of action and 34% a hypothetical action against capsular contracture. Solid evidence was found on the concept of anchoring and very little on capsular contracture. On the user guide side, the main themes were indications and contraindications, surgical techniques and long-term effects. The "directed" content analysis approach of the user guides regarding the patent's themes reflected that 94% of the user guides content related to the patent thematics was about the hypothetical role on capsular contracture while only 4% was about invention description and 1.5% about tissue ingrowth.

CONCLUSIONS

This analysis highlights the discrepancies between patents of Biocell textured implants and user guides for these implants. The indications of use of a treatment or device can evolve quicker than the study of its potential complications and side effects. The BIA-ALCL crisis should serve as a cautionary tale to the plastic surgery community which embraces new technologies eagerly, and sometimes precariously, in a mission to advance patient care.

The State of the Art about Etiopathogenetic Models on Breast Implant Associated-Anaplastic Large Cell Lymphoma (BIA-ALCL): A Narrative Review

Background: Breast-implant-associated anaplastic large cell lymphoma is a rare malignancy linked to texturized breast implants. Although many researchers focus on its etiopathogenesis, this topic is affected by a lack of evidence. Materials and Methods: A literature review about BIA-ALCL was made. Results and conclusions: Although the incidence is reported between 1:355–1:30,000, there is great attention to BIA-ALCL. The incidence is uncertain due to many reasons. It may well be lower, due to inclusion in multiple databases as pointed out by the FDA and undiagnosed cases. The role of chronic inflammation, bacterial contamination, and mechanical forces was discussed. Clarification is needed to understand the mechanisms underlying the progression of alterations and mutations for BIA-ALCL; new molecular analysis and pathogenetic models should be investigated.

Three-Year Intermediate Results of a Prospective Multicenter Study Investigating the use of Smooth, Semi-Smooth, Microtextured and Macrotextured Implants from a Single Manufacturer in Breast Augmentation and Reconstruction Procedures

Silicone gel-filled implants exist in a wide range of shapes and textures, and yet there are relatively few long-term large-scale studies, particularly on recently developed "semi-smooth" implants. The present study fills this gap by presenting the 3-year findings from an ongoing 10-year multicenter prospective study on breast implants with four different surface types: smooth, semi-smooth, microtextured, and macrotextured. A total of 908 patients were recruited in 15 investigational sites across Europe and divided into three groups: 653 primary augmentations in Group 1, 144 revision augmentations in Group 2, and 111 reconstructions in Group 3. All 4 types of implant shells were manufactured by the same company using the same silicone material. Surgeons were free to choose their preferred technique and implant surface, but data were collected using a standardized software and included all complications, and satisfaction levels reported by the patients at each visit. The incidence of post-operative complications was estimated based on Kaplan-Meier risk rates, on a per patient basis. At 3 years post implantation, capsular contracture (Baker grade III/IV) was the most common complication, with a per-patient risk rate of 1.5% in Group 1. Interestingly, there was no capsular contracture in this group when semi-smooth implants were used. The risk of implant rupture in Group 1 was 0.2%. The preliminary findings of this 10-year prospective study indicate that, 3 years after the operation, the four types of silicone gel-filled implants investigated were safe, with a low complication rate in comparison with the most favorable results published in other similar studies.

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.

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.

Ultrastructural features of the double capsulated connective tissue around silicone prostheses

The implantation of breast prostheses for both aesthetic and reconstructive purposes has been growing exponentially in the last 20 years. Safety and prosthesis lifespan are majorly debated issues in relation to the correlated long-term complications. Mainly the periprosthetic capsule that develops around the implant is often the cause of complications and particularly for macrotextured silicone breast implants. Some reports have tried to elucidate the mechanism by which macrotextured silicone implants undergo damage and cause double capsule formation. In this study, we investigated the morphological characteristics of double capsule of macrotextured implants surgically removed from patients. With the use of microscopy techniques, this work analyzed the newly formed tissue observed in the interaction between synthetic and biological surfaces.

The Evolution of Breast Implants

The present review traces the evolution of breast implants over the past 50 years. During the early years (from 1951 to 1962), a number of different sponges were used for breast augmentation. The first of these was Ivalon, a polyvinyl alcohol sponge. Other sponges were introduced subsequently, including Etheron (a poly-ether sponge popularized by Dr Paule Regnault in Montreal) and Polystan (fabric tapes that were wound into a ball). Subsequently, polyethylene strips enclosed in a fabric or polyethylene casing were also used for breast augmentation. All of these materials had similar outcomes. Although the initial results were encouraging, within one year of augmentation, breasts became very firm and lost over 25% of their volume. This was due to capsular contracture, a process that would lead to the collapse of the sponge and would continue to plague plastic surgeons and their patients for the next 50 years. In 1963, Cronin and Gerow introduced the silicone gel ‘natural feel’ implant, which revolutionized breast augmentation surgery. Approximately 10 companies have manufactured many types of silicone gel breast implants over the years. They obtained their raw materials for gels and shells from a similar number of other companies that entered and left the market at intervals. Many of the suppliers and manufactures changed their names and ownership over the years, and most of the companies no longer exist. No formal process of United States Food and Drug Administration premarket testing was in effect until 1988. There have been three generations of gel implants and a number of other lesser variations. First-generation implants (1963 to 1972) had a thick gel and a thick wall. They have generally remained intact over the years. Second-generation implants (1973 to the mid-1980s) had a thin gel and a thin wall. They have tended to disrupt over time. Third-generation implants (mid-1980s to 1992) had a thick wall and a thick gel. Except for those made by Surgitek, these implants remain intact. The breast implant business was competitive and companies introduced changes such as softer gels; barrier low-bleed shells; greater or lesser shell thickness; surface texturing; different sizes, contours and shapes; and multiple lumens in search of better aesthetics. Ultimately, more than 240 styles and 8300 models of silicone gel breast implants were manufactured in the United States alone. Inflatable breast implants were introduced in Toulons, France in 1965 (the Simaplast implant). There have been three main eras of inflatable implants: seamed, high-temperature vulcanized and room temperature vulcanized implants. In 1973, spontaneous deflation rates of 76% to 88% over three years were reported for many types of inflatable implants. Because of this, most plastic surgeons abandoned their use. From 1963 until the moratorium on gel implants (January 6, 1992), about 95% of all breast implants inserted were silicone gel filled. Only 5% were saline filled. Since the moratorium, this ratio has been reversed and 95% of all implants have been saline-filled, with only 5% being gel filled. Polyurethane-coated (PU) silicone gel implants were introduced in 1968. Over the next 20 years, they were shown to reduce the prevalence of capsular contracture to 2% to 3%. Other forms of surface texturing (Biocell, Siltex, multistructured implant) also appear to reduce capsular contracture with gel implants, but the reduction has been much less dramatic than that seen with PU implants. Contoured (anatomical) shaping appears to have advantages in some patients with gel implants. No such advantage has been seen for texturing or shaping with saline-filled implants. The story of gel implants has culminated in the largest class action lawsuit in medical history, with US$4.2 billion being awarded to women with silicone gel implants. During the past decade, there has been a tremendous amount of research on the reaction of a woman's body to gel implants. A plethora of studies have demonstrated that silicone gel implants are not associated with the development of any medical diseases. Silicone gel-filled implants have therefore been approved for use under Health Canada's Special Access Program. Silicone gel-filled implants may now be used in certain patients in whom they would provide advantages over saline implants. Silicone gel implants have not been approved for unrestricted general use. The evolution of breast implants occupies the past half century. It has been a stormy course, with many exciting advances and many bitter disappointments. The universe of breast implants is large and the variation among the implants is substantial. The purpose of the present review is to trace the evolution of breast implants over the past 50 years.

BellaGel breast implant: 6-Year results of a prospective cohort study

Background

This is the first clinical study conducted among Asian women using breast implants manufactured by an Asian company. Four-year data regarding the safety and efficacy of BellaGel breast implants have already been published, and we now report 6-year data.

Methods

This study was designed to take place over 10 years. It included 103 patients who underwent breast reconstruction or augmentation using BellaGel breast implants. The rates of implant rupture and capsular contracture were measured and analyzed to evaluate the effectiveness of the breast implant.

Results

At patients’ 6-year postoperative visits, the implant rupture and capsular contracture rates were 1.15% and 2.30%, respectively. The implant rupture rate was 3.77% among reconstruction cases and 0% among augmentation cases. The capsular contracture rate was 5.66% among reconstruction cases and 0.83% among augmentation cases.

Conclusions

The 6-year data from this planned 10-year study suggest that the BellaGel cohesive silicone gel-filled breast implant is an effective and safe medical device that can be used in breast reconstruction and augmentation.

The Evolution of Breast Implants

Breast augmentation remains one of the most commonly performed aesthetic procedures in the United States and worldwide. Throughout the last few decades, the implants used for this procedure have undergone significant advancements, which has allowed surgeons to provide safer and more aesthetically pleasing outcomes. This article discusses the history of breast implants since their invention in 1962. Particular emphasis is given to the evolution of silicone implants with its many challenges, which has resulted in the development of the currently used fourth- and fifth-generation devices. Knowledge of these advances will allow physicians to more critically evaluate their results, and also will encourage them to provide more up-to-date scientific data on these devices to further improve the clinical outcomes of their patients.

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.

Characteristics of adhesion areas between the tissue expander and capsule in implant-based breast reconstruction

Background

The use of anatomic implants has improved the aesthetic results of breast surgery; however, implant malrotation is an uncommon, but serious complication of these procedures. Nevertheless, little research has explored implant adhesion. In this study, we investigated adhesion between the expander and the capsule.

Methods

Seventy-nine cases of immediate breast reconstruction via two-stage implantbased reconstruction performed between September 2016 and November 2017 were evaluated. Mentor CPX4 expanders were used in 14 breasts, and Natrelle expanders in 65. We analyzed areas of adhesion on the surfaces of the tissue expanders when they were exchanged with permanent implants. We investigated whether adhesions occurred on the cephalic, caudal, anterior, and/or posterior surfaces of the expanders.

Results

Total adhesion occurred in 18 cases, non-adhesion in 15 cases, and partial adhesion in 46 cases. Of the non-adhesion cases, 80% (n=12) were with Mentor CPX4 expanders, while 94.4% (n=17) of the total adhesion cases were with Natrelle expanders. Of the partial adhesion cases, 90.7% involved the anterior-cephalic surface. The type of tissue expander showed a statistically significant relationship with the number of attachments in both univariate and multivariate logistic regression analyses (P<0.001) and with total drainage only in the univariate analysis (P=0.015).

Conclusions

We sought to identify the location(s) of adhesion after tissue expander insertion. The texture of the implant was a significant predictor of the success of adhesion, and partial adhesion was common. The anterior-cephalic surface showed the highest adhesion rate. Nevertheless, partial adhesion suffices to prevent unwanted rotation of the expander.

Implant selection in the setting of prepectoral breast reconstruction

Implants vary in width, height, projection, volume, fill consistency, shell surface, and shape. Given the wide variety of implants that are available, selecting an implant that best suits a patient can be challenging. This article reviews the principles governing implant selection. Based on the authors' clinical experience, an algorithm for implant selection is proposed.

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.

Dual surface modification of PDMS-based silicone implants to suppress capsular contracture

In this study, we report a new physicochemical surface on poly(dimethylsiloxane) (PDMS)-based silicone implants in an effort to minimize capsular contracture. Two different surface modification strategies, namely, microtexturing as a physical cue and multilayer coating as a chemical cue, were combined to achieve synergistic effects. The deposition of uniformly sized microparticles onto uncured PDMS surfaces and the subsequent removal after curing generated microtextured surfaces with concave hemisphere micropatterns. The size of the individual micropattern was controlled by the microparticle size. Micropatterns of three different sizes (37.16, 70.22, and 97.64 μm) smaller than 100 μm were produced for potential application to smooth and round-shaped breast implants. The PDMS surface was further chemically modified by layer-by-layer (LbL) deposition of poly-l-lysine and hyaluronic acid. Short-term in vitro experiments demonstrated that all the PDMS samples were cytocompatible. However, lower expression of TGF-β and α-SMA, the major profibrotic cytokine and myofibroblast marker, respectively, was observed in only multilayer-coated PDMS samples with larger size micropatterns (70.22 and 97.64 μm), thereby confirming the synergistic effects of physical and chemical cues. An in vivo study conducted for 8 weeks after implantation in rats also indicated that PDMS samples with larger size micropatterns and multilayer coating most effectively inhibited capsular contracture based on analyses of tissue inflammation, number of macrophage, fibroblast and myofibroblast, TGF-β expression, collagen density, and capsule thickness.

STATEMENT OF SIGNIFICANCE

Although poly(dimethylsiloxane) (PDMS)-based silicone implants have been widely used for various applications including breast implants, they usually cause typical side effects called as capsular contracture. Prior studies have shown that microtexturing and surface coating could reduce capsular contracture. However, previous methods are limited in their scope for application, and it is difficult to obtain FDA approval because of the large and nonuniform size of the microtexture as well as the use of toxic chemical components. Herein, those issues could be addressed by creating a microtexture of size less than 100 m, with a narrow size distribution and using layer-by-layer deposition of a biocompatible polymer without using any toxic compounds. Furthermore, this is the first attempt to combine microtexture with multilayer coating to obtain synergetic effects in minimizing the capsular contracture.

Nanotechnology, nanosurfaces and silicone gel breast implants: current aspects

Nanotechnology is defined as the design of products that interact with biological systems on the nanoscopic scale. Creating a controlled nanotexture and understanding the ways in which surface properties impact inflammatory response is of the utmost significance in designing implants that can provide satisfactory outcomes.

Do Bacteria and Biofilm Play a Role in Double-Capsule Formation around Macrotextured Implants?

BACKGROUND

The double capsule is a complication mostly described in aggressive macrotextured implants. Mechanical shear stress applied onto an immature periprosthetic capsule has been linked to their formation. The authors aim to demonstrate the role of bacterial phenotype and biofilm in the development of the double capsule.

METHODS

Seven double capsules formed at the interface of macrotextured breast expander implants were studied using scanning electron microscopy. Two samples for each surface of the inner capsule layer (the prosthesis interface and the intercapsular space) were analyzed for bacteria cell size, bacterial density, and biofilm deposition.

RESULTS

Although all routine bacterial cultures were negative, the prosthesis interface had both higher bacteria load and biofilm deposition compared with the intercapsular space (Mann-Whitney U test, p = 0.004 and p = 0.008, respectively). Moreover, bacteria cell sizes were significantly smaller at the prosthesis interface in six of seven samples. Comparison of bacteria density and biofilm dispersion showed an increase of biofilm extracellular matrix deposition over 2000 cells/mm (linear regression, p = 0.0025). These results indicate a common trend among bacteria species.

CONCLUSIONS

Bacterial expression between the different surfaces of the double capsule displays significant differences; bacteria at the prosthesis interface are mostly in a biofilm state, whereas they demonstrate a planktonic phenotype at the intercapsular space. When a sufficient amount of bacteria are present at a specific location, quorum sensing may trigger a biofilm phenotypic switch in planktonic bacteria cells. Biofilm formation may alter capsule formation through immune response, thereby weakening capsule strength and facilitating extracellular matrix delamination and double-capsule formation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Is Rotation a Concern with Anatomical Breast Implants? A Statistical Analysis of Factors Predisposing to Rotation

BACKGROUND

Since their introduction in 1993, anatomical implants have provided a more natural appearance in breast augmentation, and many surgeons advocate their use and promote the good aesthetic results. However, the risk of implant rotation makes some of them reluctant to use these devices. The rotation rate varies among authors.

METHODS

The authors present a 6.5-year series of 531 patients who underwent primary breast augmentation with macrotextured anatomical implants in a Swedish facility performed by one consultant surgeon (P.M.). The authors examined the rotation rate and the correlation with possible predisposing factors such as preoperative breast cup size, childbirth, and body mass index.

RESULTS

A total of 20 implants (1.88 percent; 95 percent CI, 1.15 to 2.89 percent) in 19 patients (3.58 percent; 95 percent CI, 2.17 to 5.53 percent) were rotated. In one patient (0.22 percent), both implants rotated, whereas in the remaining patients, the rotation was unilateral. The authors were unable to establish a statistically significant correlation between implant rotation and previous childbirth or increased body mass index. However, there was a relation between rotation rate and preoperative breast cup size that showed an upward trend as the cup size increased from A to C.

CONCLUSION

The authors believe that if the implant is correctly selected and the operation is performed meticulously with proper pocket dissection, the rotation rate is minimal and it should not be considered a disadvantage for the use of anatomical implants.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Textured Breast Implants: A Closer Look at the Surface Debris Under the Microscope

BACKGROUND

Texturing of breast implants is done to decrease the risk of associated complications. Each manufacturer utilizes unique and at times proprietary techniques to texture the surface of their implants. Little is known about the integrity of this surface structure texturing or the propensity for the surfaces to shed particulate matter. This study aimed to determine the extent of surface particulate shedding from 3 textured implants approved by the US Food and Drug Administration (FDA), which are manufactured by Allergan, Mentor, and Sientra.

METHODS

Control images of each of the 3 textured breast implants were obtained with scanning electron microscopy (SEM). A liquid adhesive, ethylene vinyl acetate (EVA) copolymer was then applied to the external shell of the implants, allowed to cool, and peeled from the surface. Images of the EVA copolymer were taken with SEM to qualitatively analyze displacement of surface particulate debris. Scanning electron microscopy imaging of the implants was repeated for qualitative comparisons with the control images.

RESULTS

The peeled copolymer of the 3 implants exhibited surface shedding. Comparison of the 3 breast implants showed the shedding to be greatest for the Allergan implant.

CONCLUSIONS

This study highlights the dynamic surface material properties of the 3 FDA-approved breast implants. Shedding of particulate matter from the implant surfaces can be precipitated by moderate adhesion. Our qualitative examination of SEM findings showed more debris shed from the Allergan breast implants than from the Mentor or Sientra implants.

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

PURPOSE

Increasing numbers of women undergo breast implantation for cosmetic and reconstructive purposes. Contracture of the fibrous capsule, which encases the implant leads to significant pain and reoperation. Texture, wettability and the cellular reaction to implant surfaces are poorly understood determinants of implant biocompatibility. The aim of this study was to evaluate the in-vitro characteristics of a range of commercial available implants using a macrophage based assay of implant biocompatibility and a quantitative assessment of wettability and texture.

METHODS

Thirteen commercially available surfaces were subjected to wettability and texture characterisation using scanning and laser confocal microscopy. THP-1 macrophages were cultured on their surfaces and assessed using Integrin αV immunocytochemistry, SEM and RT-PCR for the expression of TNF-Alpha, IL-6, IL-10 and a cytokine array for the production of TNF-alpha, IL-10, IL-1RA and IL1β; important indicators of inflammation and macrophage polarization.

RESULTS

Textured surfaces can be accurately sub-categorized dependent upon roughness and re-entrant features into four main types (macro, micro, meso and nano-textured surfaces). Significant (P < 0.0001) differences in implant hydrophobicity and texture exist. Certain surfaces promoted poor macrophage polarization and an innate potential to foster a proinflammatory response. A subgroup analysis showed that texture had a variable effect on markers of inflammation in these surfaces.

CONCLUSIONS

We propose a classification of implant surfaces based on roughness and present a macrophage based assay of breast implant biocompatibility with a quantitative assessment of implant wettability and texture. The breast implant surface-cell interaction is variable and sufficient to alter healing response and capsular contracture fate in-vivo.

Breast implant design

Breast Augmentation remains as one of the most common procedures performed in the United States. This article explores the evolution of breast implants with special emphasis on the advancement of the silicone implants.

Development, fabrication and evaluation of a novel biomimetic human breast tissue derived breast implant surface

Breast implant use has tripled in the last decade with over 320,000 breast implant based reconstructions and augmentations performed in the US per annum. Unfortunately a considerable number of women will experience capsular contracture, the irrepressible and disfiguring, tightening and hardening of the fibrous capsule that envelops the implant. Functionalising implant surfaces with biocompatible tissue-specific textures may improve in vivo performance. A novel biomimetic breast implant is presented here with anti-inflammatory in vitro abilities. Topographical assessment of native breast tissue facilitated the development of a statistical model of adipose tissue. 3D grayscale photolithography and ion etching were combined to successfully replicate a surface modelled upon the statistics of breast tissue. Pro-inflammatory genes ILβ1, TNFα, and IL6 were downregulated (p<0.001) and anti-inflammatory gene IL-10 were upregulated on the novel surface. Pro-inflammatory cytokines Gro-Alpha, TNFα and neutrophil chemoattractant IL8 were produced in lower quantities and anti-inflammatory IL-10 in higher quantities in culture with the novel surface (p<0.01). Immunocytochemistry and SEM demonstrated favourable fibroblast and macrophage responses to these novel surfaces. This study describes the first biomimetic breast tissue derived breast implant surface. Our findings attest to its potential translational ability to reduce the inflammatory phase of the implant driven foreign body reaction.

STATEMENT OF SIGNIFICANCE

Breast implants are still manufactured using outdated techniques and have changed little since their inception in the 1960's. Breast implants can cause a medical condition, capsular contracture which often results in disfigurement, pain, implant removal and further surgery. This condition is due to the body's reaction to these breast implants. This article describes the successful development and testing of a novel breast implant surface inspired by the native shapes present in breast tissue. Results show that this novel implant surface is capable of reducing the negative reaction of human cells to these surfaces which may help reduce capsular contracture formation. This work represents the first steps in producing a biocompatible breast implant.

The Pocket Protector: A New Breast Implant Device

Introduction:

Although strides have been made to improve breast augmentation surgery, they have focused on the use of single implant devices, necessitating adjustments to the type of operation performed and implants used. And although some breast types obtain excellent results, many others are less than optimal. By developing a thin synthetic expanded polytetrafluoroethylene device, the Pocket Protector, that lines the breast pocket by integrating with the body without a capsule formation, smooth-surfaced gel (or saline) implants can remain soft and provide improved augmentation mammoplasty results. Even patients with Baker class III and IV breasts refractory to all types of revisional surgery can achieve soft, natural breasts after revision with the Pocket Protector.

Materials and Methods:

Augmentation mammoplasty and revision mammoplasty, often with capsulectomy, with the Pocket Protector was performed on 38 patients with smooth gel or saline implants. Since the initial prototype in April 1995, data have been collected with each patient to evaluate the efficacy of this device.

Results:

Patients involved in the current study have yielded soft, natural-feeling breasts in the normal anatomic position. Two patients who experienced a flu syndrome in the immediate postoperative period developed refractory seromas necessitating removal of the expanded polytetrafluoroethylene. Both cases have subsequently been successfully revised with Pocket Protectors and smooth-gel implants. Three patients with very thin tissues experienced rippling in spite of using smooth-gel implants.

Discussion:

The net result yields a soft, ripple-free (or near ripple-free) breast. Additionally, gel implants inside the Pocket Protector are potentially shielded from the body, should the implants rupture. Implants are easily exchangeable if necessary without need for capsulectomy or capsulotomy. The Pocket Protector may also represent an implant device appropriate to treat breasts refractory to traditionally attempted augmentations, such as subcutaneous mastectomy. Although the first case performed in April 1995 has remained successful, most of the experience has been gathered over the past year. This preliminary paper presents the experience with the past 38 cases.

The Evolution of Breast Implants

Breast augmentation remains one of the most common procedures performed in the United States. However, shape, feel, safety, and longevity of the implants remain important areas of research. The data provided by manufacturers show the safety and efficacy of these medical devices. Clinicians should strive to provide ongoing data and sound science to continue to improve clinical outcomes in the future. This article explores the evolution of breast implants with special emphasis on the advancement of silicone implants.

Characterization of Breast Implant Surfaces, Shapes, and Biomechanics: A Comparison of High Cohesive Anatomically Shaped Textured Silicone, Breast Implants from Three Different Manufacturers

Several companies offer anatomically shaped breast implants but differences among manufacturers are often misunderstood. The shell texture is a crucial parameter for anatomically shaped implants to prevent rotation and to decrease the risk of capsular contracture, even though concerns have recently been raised concerning the complications associated with textured breast implants. The aim of this study was to characterize differences in terms of texture, cell adhesion, shape, and stiffness between some commonly used anatomically shaped implants from three different manufacturers.

METHODS

Five commercially available anatomically shaped breast implants from 3 different manufacturers (Allergan, Mentor, and Sebbin) were used. Scanning electron microscopy, X-ray microtomography, and scanning mechanical microscopy were used to characterize the shell texture. Human fibroblast adhesion onto the shells was evaluated. 3D models of the implants were obtained using CT-scan acquisitions to analyze their shape. Implant stiffness was evaluated using a tractiometer.

RESULTS

Major differences were observed in the topography of the textures of the shells, but this was not conveyed by a statistically significant fibroblast adhesion difference. However, fibroblasts adhered better on anatomically shaped textured implants than on smooth implants (p < 0.01). Our work pointed out differences in the Biocell® texture in comparison with older studies. The 3D analysis showed significant shape differences between the anatomically shaped implants of the 3 companies, despite similar dimensions. Implant stiffness was comparable among the 3 brands.

CONCLUSIONS

Each texture had its specific topography, and this work is the first description of Sebbin anatomic breast implant texturation. Moreover, major discrepancies were found in the analysis of the Biocell® texture when comparing our results with previous reports. These differences may have clinical implications and are discussed. This study also highlighted major shape differences among breast implants from different manufacturers, which is quite counterintuitive. The clinical impact of these differences however needs further investigation.

NO LEVEL ASSIGNED

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Negating Tissue Contracture Improves Volume Maintenance and Longevity of In Vivo Engineered Tissues

BACKGROUND

Engineering large, complex tissues in vivo requires robust vascularization to optimize survival, growth, and function. Previously, the authors used a "chamber" model that promotes intense angiogenesis in vivo as a platform for functional three-dimensional muscle and renal engineering. A silicone membrane used to define the structure and to contain the constructs is successful in the short term. However, over time, generated tissues contract and decrease in size in a manner similar to capsular contracture seen around many commonly used surgical implants. The authors hypothesized that modification of the chamber structure or internal surface would promote tissue adherence and maintain construct volume.

METHODS

Three chamber configurations were tested against volume maintenance. Previously studied, smooth silicone surfaces were compared to chambers modified for improved tissue adherence, with multiple transmembrane perforations or lined with a commercially available textured surface. Tissues were allowed to mature long term in a rat model, before analysis.

RESULTS

On explantation, average tissue masses were 49, 102, and 122 mg; average volumes were 74, 158 and 176 μl; and average cross-sectional areas were 1.6, 6.7, and 8.7 mm for the smooth, perforated, and textured groups, respectively. Both perforated and textured designs demonstrated significantly greater measures than the smooth-surfaced constructs in all respects.

CONCLUSIONS

By modifying the design of chambers supporting vascularized, three-dimensional, in vivo tissue engineering constructs, generated tissue mass, volume, and area can be maintained over a long time course. Successful progress in the scale-up of construct size should follow, leading to improved potential for development of increasingly complex engineered tissues.