A comparison of the capsules around smooth and textured silicone prostheses used for breast reconstruction. A light and electron microscopic study

Advances on Capsular Contracture-Prevention and Management Strategies: A Narrative Review of the Literature

Capsular contracture (CC) is the most relevant complication of both aesthetic and reconstructive breast implant surgery. For many years, experimental and clinical trials have attempted to analyze CC risk factors, clinical features, and appropriate management strategies. It is commonly accepted that a multifactorial etiology promotes CC development. However, the heterogeneity in patients, implants and surgical techniques make it difficult to suitably compare or analyze specific factors. As a consequence, discordant data are present in literature, and a true systematic review is often limited in its conclusions. Hence, we decided to present a comprehensive review of current theories on prevention and management strategies, rather than a specific "solution" to this complication.

Methods

The PubMed database was searched for literature regarding CC prevention and management strategies. Pertinent articles in English, published before December 1, 2022, were compared with selection criteria and eventually included in this review.

Results

Through the initial search, 97 articles were identified, of which 38 were included in the final study. Several articles explored different medical and surgical preventive and therapeutic strategies, showing numerous controversies on appropriate CC management.

Conclusions

This review provides a clear overview of the complexity of CC. The wide variety of clinical situations in term of patients, implants, and surgical techniques prevent the standardization of CC management strategies. By contrast, a patient-customized approach should be preferred, and different strategies should be considered depending on the specific case. Further research is desirable to better ascertain evidence-based protocols with regard to CC prevention and treatment.

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 .

Tissue Expansion Using Hyaluronic Acid Filler for Single-Stage Ear Reconstruction: A Novel Concept for Difficult Areas

BACKGROUND

Auricular reconstruction is one of the most challenging procedures in plastic surgery. An adequate skin envelope is essential for cartilage framework coverage, yet few good options exist without additional surgery. We propose a novel method for minimally invasive tissue expansion, using hyaluronic acid (HA) filler to allow for single-stage ear reconstruction.

OBJECTIVES

To introduce the novel concept of HA filler for tissue expansion in ear reconstruction, and as an alternative to traditional expansion techniques.

METHODS

Macrolane is a large particle HA gel developed for large volume restoration. Expansion of the non-hair-bearing mastoid skin was performed in our clinic weekly or every other week. Final expansion was completed one week prior to reconstructive surgery. Tissue from one patient's expanded pocket was sent for histological analysis.

RESULTS

Ten patients underwent single-stage auricular reconstruction with preoperative expansion. Injection sessions ranged from 7 to 13 (mean, 9.7). Mean injected volume per session was 2.03 mL per patient, for an average total of 19.8 mL (range, 14.5-30 mL). There were no major complications. One minor complication required removal of exposed wire from the antihelix in the office. Hematoxylin and eosin stain revealed similar histology to that seen with traditional expanders.

CONCLUSIONS

This novel expansion technique using serial HA injections allowed for optimized skin coverage in single-stage ear reconstruction. The concept of tissue expansion using HA filler is a new frontier for research that may be applicable to other arenas of reconstruction.

LEVEL OF EVIDENCE

4.

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.

Pseudoepithelialization of Breast Implant Capsules

A review of 11 breast implant capsules revealed that 5 (45%) possessed a pseudoepithe lial lining virtually indistinguishable morphologically from true synovium. These cap sules showed a spectrum of connective tissue metaplasia that culminated in an ex tremely well-ordered double layer of columnar-appearing cells marking only for vimentin intermediate filaments and failing to stain for various cytokeratins and human factor VIII. Neither trichrome stains nor electron microscopy showed evidence of a basement membrane. The cases indicate that under appropriate conditions breast tissues can undergo mesenchymal metaplasia as well as the much more common epithelial metaplasia. Furthermore, a process morphologically identical to that previ ously described as "synovial metaplasia" in other locations also occurs in some breast capsules where, as in the dermis and in periarticular sites, its development may be dependent upon local factors such as friction and micromotion. Int J Surg Pathol 1 (3): 151-154, 1994

The influence of external ultrasound on the histologic architecture of the organic capsule around smooth silicone implants: experimental study in rats

BACKGROUND

Capsular contracture is the main complication related to breast silicone implants, and its prevention remains a medical challenge. The authors present experimental research examining the effect of external ultrasound on the formation and contracture of peri-implant capsules.

METHODS

In this study, 42 male Wistar rats had a 2-mm smooth surface implant placed in a dorsal submuscular pocket. They then were separated into "ultrasound" and "control" groups that received repeated external applications either with or without the ultrasound power on. Ultrasound applications were given three times a week for a period of 90 days. After that, both groups were housed under the same conditions with no application scheduled. Five animals of each group, killed at 30, 60, 90, and 180 days, had their implants removed along with the capsule, which received a special histologic preparation via annular sectioning that provided wide circumferential observation of the capsular tissue. Sections were stained with hematoxylin/eosin stain, Masson's trichrome stain, and Pricrosirius Red stain for regular microscopic evaluation under normal and polarized light.

RESULTS

Histologic data showed that capsules from the ultrasound and control groups had statistically significant differences. Ultrasound application developed a capsular architecture similar to that shown within textured silicone implants, and its effect had an early definition with subsequent stabilization.

CONCLUSION

The authors conclude that early and repeated external ultrasound application enhances the thickness, cellular count, and vascularity of smooth silicone capsular tissue, whereas it diminishes the pattern of parallel orientation of collagen fibers.

Ultrastructural anatomy of contracted capsules around textured implants in augmented breasts

The development of a capsule around an implant is part of the physiological response to a foreign body. Capsular contracture is the most specific and frustrating complication of augmentation mammaplasty, and a lot of studies have been devoted to it. The aim of the current study is to examine the fine architecture of the contracted capsule around textured implants in humans. Eight capsules from augmented and contracted breasts with gel-filled, textured-surface silicone implants were studied after standard preparation for light and scanning electron microscopy, and after partial digestion in sodium hydroxide. Two capsules from contracted breasts around smooth implants and two noncontracted capsules around textured implants were prepared and studied in the same fashion as controls. A multilayer structure of the contracted capsule was seen, and the architecture of the various layers is described. The inner surface presents irregular craterlike depressions. The arrangement of collagen fibers varies in capsule layers. The effect of a textured-surface implant on the mechanism of capsule contraction based on the observed capsular architecture is that only part of the capsule is effective mechanically in producing a contracting force. A thin vascular layer was identified near the inner surface in contracted capsules around textured implants, and the authors' think that this layer is probably the key structure in the histological development and growth of the capsule.

Alloplastic implantation

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Define an alloplastic material and know the differences between an alloplast and other types of implants available for surgical use. 2. Determine the biologic response to alloplastic implantation and the material and host characteristics that contribute to long-term reconstruction success with their use. 3. Review the criteria for choosing a specific alloplastic material for a reconstruction site and the principles of surgical technique for its proper placement. 4. Evaluate the various alloplastic material types that are currently available for surgical use and be able to discuss several physical properties of each as they relate to handling and clinical implantation. 5. Discuss the complication of alloplastic infection, its pathogenesis, preoperative and intraoperative measures for its avoidance, and the postoperative management of its occurrence.

The influence of time on human breast capsule histology: smooth and textured silicone-surfaced implants

Although the histology of capsular tissue is well described in the literature, most studies in humans do not correlate histologic findings with implant age (number of years an implant was in place before sampling). As such, questions regarding the long-term histology in humans remain. The microanatomy of 93 human periprosthetic capsular tissues surrounding 22 textured and 71 smooth silicone-surfaced prostheses was studied. The implants were divided into two groups according to the time between implantation and capsulectomy: between 0 and 5 years or more than 5 years. Hematoxylin and eosin and Masson trichrome-stained sections were analyzed by light microscopy, with and without polarization. Eighteen of the textured implants contained silicone gel and four contained saline. Sixty of the smooth implants contained silicone gel, eight contained saline, and in three, the filler type was not known. For the majority of patients, surgery was performed for augmentation mammaplasty, and the implants were removed because of capsular contracture. The following histologic features were assessed: synovial-like metaplasia, villous hyperplasia, density of the collagenous capsule, alignment of collagen fibers within the capsule, and the presence of foreign material and of a foreign body reaction. The following trends were observed. In smooth implants, increasing implant duration was associated with a decrease in the presence of synovial-like metaplasia (p = 0.003) and villous hyperplasia; there was no significant difference in the presence of a dense collagenous capsule, the orientation of collagen fibers, or the presence of a foreign body reaction. An increase was observed in the presence of foreign material (p = 0.01). In textured implants, increasing implant duration was associated with a decrease in the presence of synovial-like metaplasia, villous hyperplasia (p = 0.003), dense collagenous architecture, and parallel orientation of collagen fibers (p = 0.017). An increase in the presence of a foreign body type reaction and foreign material (p = 0.024) was observed. In comparing textured and smooth-surfaced implants, synovial-like metaplasia was observed more often in the textured group, both at 0 to 5 years (p = 0.01) and at greater than 5 years (p < 0.01). Textured implants more often had villous hyperplasia at 0 to 5 years (p = 0.03) but not beyond 5 years. Smooth implants more often had a dense collagenous capsule than textured implants after 5 years. No significant difference was seen in the orientation of collagen fibers in capsules around smooth and textured implants at 0 to 5 years. After 5 years, the incidence of capsules with collagen fibers arranged parallel to the implant surface was significantly greater in the smooth group than in the textured group (p = 0.01). The presence of a foreign body type reaction was seen more often in the textured group between 0 and 5 years (p = 0.01) and at greater than 5 years (p < 0.01), and the presence of foreign material was more often seen in the textured group between 0 and 5 years (p = 0.06) and at greater than 5 years (p < 0.01). In summary, the cytologic changes around implants seem to be dynamic in nature, and implantation duration and shell type play a significant role. Synovial-like metaplasia, villous hyperplasia, and foreign material were more often observed in the textured group within the 0 to 5 year interval. Beyond 5 years, synovial-like metaplasia, a foreign body type reaction, and foreign material were more often observed in the textured group. Differences in the density of collagenous capsules were not significant at any time point, and collagen fibers oriented parallel to the implant surface were more often observed in the smooth group after 5 years. The significance of these findings awaits further investigation.

Textured or smooth implants for breast augmentation? Three year follow-up of a prospective randomised controlled trial

Silicone breast implant surface texturing has been shown to reduce the short-term incidence of adverse (Baker III/IV) capsular contracture in augmentation mammaplasty in double-blind randomised controlled trials. It is, however, undetermined whether the textured surface merely delays the onset of severe contracture or its effect on capsular contraction is persistent. The current study reviewed, after three years, 49 of the 53 patients who had undergone subglandular breast augmentation mammaplasty in a randomised double-blind study with textured or smooth silicone gel-filled implants in 1989. The incidence of adverse capsular contracture was 59% for smooth implants and 11% for textured ones (P = 0.001; chi 2 = 10.60). Eight patients (31%) with smooth prostheses underwent breast implant exchange for severe capsular contracture between the one and three year assessments, compared with a revisional surgery rate of only 7.4% (2/27 patients) for the textured group (P < 0.04). These adverse capsular contracture and revisional breast implant surgery rates clearly demonstrate that the effect of textured implants in reducing capsular contracture in augmentation mammaplasty found at one year is maintained at three years, and suggest that it may be long lasting.

Immunolocalization of keratan sulfate, chondroitin-4-sulfate, and chondroitin-6-sulfate in periprosthetic breast capsules exhibiting synovial metaplasia

The distribution of various proteoglycans and basement membrane components within 10 breast capsules with synovial metaplasia was assessed immunohistochemically. Immunoreactive keratan sulfate and chondroitin-4-sulfate were present in many of the synovial metaplasia lining cells, suggesting active secretion of these proteoglycans into the intraprosthetic space. In contrast, chondroitin-6-sulfate was confined to the extracellular matrix of the underlying supporting fibrous capsule. Type IV collagen and laminin were not associated with the synovial metaplasia lining, thus confirming the absence of a basement membrane, as previously indicated by morphologic analysis. As with tendon reconstruction, the development and maintenance of a synovial metaplasia lining that secretes lubricating factors such as proteoglycans may be beneficial for decreased capsular contracture.

Quality of the capsule in reconstructions with textured or smooth silicone implants after mastectomy

Many women desire some kind of reconstruction after mastectomy for breast cancer to improve the cosmetic result. Since the introduction of silicone breast implants, capsular contracture has been the most common complication of breast augmentation or reconstruction. The aim of the present study was to evaluate the capsule quality in patients with breast cancer who had undergone reconstructions with either textured (rough) or smooth silicone implants after simple or modified radical mastectomy. Forty-three consecutive patients had reconstructions with textured silicone implants (49 implants) and were evaluated 32 months post-operatively in a prospective clinical trial. The last 43 consecutive patients who had reconstructions with bilumen smooth silicone implants (49 implants) acted as controls. The results were graded by Baker's classification. Among the patients with textured implants only 9% (4/47) was graded as having moderate or severe capsular contracture in contrast to 24% (11/46) in patients with bilumen smooth-surface implants (p < 0.05). These results confirm previous reports that favour textured silicone implants in breast augmentation and reconstruction.

True synovial metaplasia of breast implant capsules: a light and electron microscopic study

The formation of true synovial-lined membranes at tissue sites not intimately related to an articulation or a tendon sheath has been described in a variety of pathologic and postsurgical conditions, but until recently has not been well recognized to occur in association with tissue surrounding silicone breast implants. Of 15 cases with resected periprosthetic breast capsules, 7 (47%) demonstrated true synovial metaplasia with capsule-implant interfaces lined by typical synovial cells. Histochemical and immunohistochemical staining reactions were essentially identical to those observed in synovial control cases and featured positive reactions to Alcian blue-periodic acid-Schiff, reticulin, and vimentin. Focal positive immunoreactivity was observed with alpha 1-antitrypsin, alpha 1-antichromotrypsin, lysozyme, and CD68. No immunoreactivity was observed with cytokeratin AE1/AE3, S-100 protein, carcinoembryonic antigen, or basement membrane antigens. Transmission electron microscopy of the lining cells confirmed their true synovial nature with the type A (macrophage-like) cells, type B (fibroblast-like) cells, and intermediate forms or type AB cells identified. We conclude that the cellular lining surrounding silicone breast implants is a true synovial membrane, that synovial metaplasia may occur in nearly one half of all resected periprosthetic capsules, and that awareness of this entity will enable the surgical pathologist to render an accurate histopathologic diagnosis.