Acellular Dermal Matrices (ADM) and Meshes

Capsular contracture is a known complication of breast augmentation and is among the top reasons for revisional breast augmentation procedures. The use of acellular dermal matrix (ADM) has been shown to reduce the rate of capsular contracture in breast reconstruction and augmentation, theorizing that it acts as a protective barrier between the implant capsule and inflammatory process responsible for capsular contracture. The role of ADM in treatment of capsular contracture has been investigated in numerous studies, with a variety of ADMs. The aim of this study was to perform a systematic review of existing literature on the use of ADM for treatment of capsular contracture in aesthetic breast augmentation patients to investigate differences in efficacy of ADM types. The PubMed, Embase, and CINAHL databases were systematically reviewed for articles pertaining to capsular contracture, acellular dermal matrices, and breast augmentation. Number of patients, type of ADM, Baker grade, follow-up time, complication rate, and capsular contracture rate were recorded from identified articles. Data was pooled from studies to calculate a capsular contracture rate for each ADM type, with a chi-squared test performed for analysis. Identified studies with a comparative group were included in a meta-analysis utilizing risk ratio (RR) to assess the efficacy of ADM. Nine articles including ADM for treatment of capsular contracture in breast augmentation met criteria for inclusion, with a total of 481 breasts. Strattice was the most commonly utilized ADM (n = 391), followed by AlloDerm (n = 57). There was a statistically significant difference in efficacy of ADM among the studied ADM types (P < .001). AlloDerm, FlexHD, and DermaMatrix had the lowest capsular contracture rates (0%). NeoForm and SurgiMend had the highest capsular contracture rates (each 25%, but with n = 4 and n = 8, respectively). Strattice had a capsular contracture rate of 1.53% in the pooled data, and meta-analysis showed that Strattice reduced the risk of capsular contracture (RR 0.14 [95% CI 0.06, 0.31]) compared with conventional treatment. Acellular dermal matrices appear to be effective at treating capsular contracture after breast augmentation while maintaining a low complication rate. Overall capsular contracture rates are low with the use of ADM. There is a statistically significant difference in efficacy among ADM types. Meta-analysis shows that Strattice is effective at reducing the risk of capsular contracture in breast augmentation patients when compared to conventional treatment. Future research, especially in the form of randomized controlled trials, is needed to further investigate the efficacy of various ADMs in the treatment of capsular contracture.

BACKGROUND: Acellular dermal matrices (ADMs) are used for soft tissue augmentation across surgical specialties. The increased use of ADMs has been particularly apparent in the setting of implant-based breast reconstruction, where matrices are used to supplement the thickness of the mastectomy skin flaps and ensure adequate soft tissue coverage of implants. However, long-term review of these devices has indicated that there is a strong correlation between seroma formation and the use of ADM. Since allograft integration and neovascularization is dependent having on direct opposition between the ADM and a vascular bed, the presence of seromas can inhibit the area of the graft which is in contact with the native tissue. As a result, most ADM products are available in a variety of meshed or perforated forms. Because of the lack of consistency between manufacture designs, we set out to determine the fluid egress properties and the increase in surface area resulting from common cut patterns. METHODS: The fluid egress properties were analyzed for three different commonly encountered commercially available ADM cut patterns: 1 meshed design and 2 distinct perforation designs. Mesh Pattern #1 was designed with 1:1 meshed cuts each measuring 1.5 mm in length. Perforation Pattern #1 was designed with 3 mm diameter perforations at a density of 0.128 perforations per cm2. Perforated Pattern #2 was designed with 3 mm diameter perforations at a density of 0.25 perforations per cm2. The surface area of these modified ADM samples was also calculated, accounting for the mesh length or the perforation diameter and frequency. Fluid egress was calculated by passing fluid through each ADM and measuring the amount of time required for complete passage. An analysis of variance was used to determine if there was a significant difference in egress properties across the three patterns. A P value of <0.05 was used to determine statistical significance. RESULTS: Meshing in a 1:1 pattern resulted in a 97.50% increase in surface area compared to the uncut product. In comparison, only a 0.30% increase resulted from Perforation Pattern #1 and a 0.59% increase resulted from Perforation Pattern #2. There was a significant difference in egress properties across the 3 cut patterns (P = 0.000). The average egress time of Mesh Pattern #1 was 1.974 seconds. The average egress time of Perforation Pattern #2 was 6.504 seconds and of Perforation Pattern #1 was 10.369 seconds. Neither donor (P = 0.249) nor graft thickness (P = 0.914) had a significant impact on the results. CONCLUSION: To our knowledge, this study is the first to directly compare clinically applicable properties between different ADM cut patterns. By comparing a variety of common manufacturer designs, ranging from simple punch-shape perforations to a full 1:1 mesh pattern, we were able to demonstrate that meshing ADM tissue significantly improves fluid egress properties and substantially increases the surface area compared to ADM tissue perforated at levels typically available on the market. Therefore, the use of meshed ADM tissue could improve the ability of the product to incorporate with the recipient, resulting in decreased complications and improved patient outcomes.

In modern implant-based immediate breast reconstruction, it has become common to use biological acellular dermal and synthetic matrices in combination with a tissue expander or an implant. The aim of this systematic review was to examine differences in recurrence of cancer, impact on oncological treatment, health related quality of life, complications and aesthetic outcome between matrix and no matrix in immediate breast reconstruction. Systematic searches, data extraction and assessment of methodological quality were performed according to predetermined criteria. Fifty-one studies were eligible and included in the review. The certainty of evidence for overall complication rate and implant loss is low (GRADE ⊕⊕□ □). The certainty of evidence for delay of adjuvant treatment, implant loss, infection, capsular contraction and aesthetic outcome is very low (GRADE ⊕□ □ □). No study reported data on recurrence of cancer or health related quality of life. In conclusion, there is a lack of high quality studies that compare the use of matrix with no matrix in immediate breast reconstruction. Specifically, there are no data on risk of recurrence of cancer, delay of adjuvant treatment and Health related quality of life (HRQoL). In addition, there is a risk of bias in many studies. It is often unclear what complications have been included and how they have been diagnosed, and how and when capsular contracture and aesthetic outcome have been evaluated. Controlled trials that further analyse the impact of radiotherapy, type of matrix and type of procedure (one or two stages) are necessary.

Sir: We read with interest the recent article by Yi and Kim (Plast Reconstr Surg. 2015;135:609e–616e). The authors compared the effect of simultaneous application of acellular dermal matrix with autologous split-thickness skin graft and that of split-thickness skin graft alone on traumatic full-thickness skin defects on the extremities, and concluded that the cograft of acellular dermal matrix with split-thickness skin graft produced better outcomes than split-thickness skin graft alone in terms of scar appearance, without increasing complications. The combination of acellular dermal matrix with epidermal coverage, usually an autologous split- thickness skin graft, has increasingly replaced the full-thickness skin graft to reconstruct full-thickness skin defects. However, the timing of split-thickness skin grafting remains controversial. For a split-thickness skin graft to attach promptly after transplantation, a well-vascularized wound bed is required. The thickness of a skin graft that can easily become vascularized is approximately 0.7 to 1.0 mm. Therefore, most acellular dermal matrices thicker than 1.0 mm are covered by a split-thickness skin graft 3 to 4 weeks later to allow sufficient vascularization and to avoid graft necrosis or loss.1 However, this two-step approach is lengthy, gives no guarantee of success, and is an additional stress factor for the patient. More recent approaches include use of thinner dermal layers, with the aim of transplanting acellular dermal matrix simultaneously with split-thickness skin graft.2 Several of the authors’ procedures might contribute to the success of their single-step technique: (1) the wound bed was completely débrided and prepared with well-vascularized granulation tissue before grafting, (2) negative-pressure therapy was applied throughout to stimulate angiogenesis and prevent complications, and (3) the application of meshed acellular dermal matrix and thin split-thickness skin graft improved the take rate and allowed better blood supply to the cograft. However, we still have great interest in the thickness of the acellular dermal matrix in this article. Does the meshed morphology of acellular dermal matrix compensate for the thickness of it? In addition, the split-thickness skin graft combined with acellular dermal matrix was meshed and expanded, whereas the split-thickness skin graft applied alone was neither meshed nor expanded and was 0.1 mm thicker than the cografted one. The difference interests and confuses us. Beyond this, the pigmentation merits specific attention. Melanocytes and fibroblasts are believed to contribute to the repigmentation process.3 Because acellular dermal matrix does not contain cellular components, it is acceptable in this article that the pigmentation subscore was not improved in the cograft group. In our experience, noncultured autologous cell suspensions, such as ReCell (Avita Medical, Northridge, Calif.), could commendably improve skin color, as it contains viable melanocytes and fibroblasts apart from abundant keratinocytes.4 As these authors move forward, it could be tentatively used to aid the cograft of acellular dermal matrix and split-thickness skin graft or even cografted directly with acellular dermal matrix to heal full- thickness skin defects. We agree with the authors that the one-step graft of acellular dermal matrix and split-thickness skin graft is more than welcome and encourage them and others to investigate this approach so that this very important technique can be more completely understood and taken advantage of. DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication. Panxi Yu, M.D.Zuoliang Qi, M.D., Ph.D.Plastic Surgery HospitalChinese Academy of Medical Sciences and Peking UnionMedical CollegeBeijing, People’s Republic of China

IntroductionThe extracellular matrix (ECM) plays an integral role in wound healing. It provides both structure and growth factors that allow for the organised cell proliferation. Large or complex tissue defects may compromise host ECM, creating an environment that is unfavourable for the recovery of anatomical function and appearance. Acellular dermal matrices (ADMs) have been developed from a variety of sources, including human (HADM), porcine (PADM) and bovine (BADM), with multiple different processing protocols. The objective of this report is to provide an overview of current literature assessing the clinical utility of ADMs across a broad spectrum of applications.MethodsPubMed, MEDLINE, EMBASE, Scopus, Cochrane and Web of Science were searched using keywords ‘acellular dermal matrix’, ‘acellular dermal matrices’ and brand names for commercially available ADMs. Our search was limited to English language articles published from 1999 to 2020 and focused on clinical data.ResultsA total of 2443 records underwent screening. After removing non-clinical studies and correspondence, 222 were assessed for eligibility. Of these, 170 were included in our synthesis of the literature. While the earliest ADMs were used in severe burn injuries, usage has expanded to a number of surgical subspecialties and procedures, including orthopaedic surgery (e.g. tendon and ligament reconstructions), otolaryngology, oral surgery (e.g. treating gingival recession), abdominal wall surgery (e.g. hernia repair), plastic surgery (e.g. breast reconstruction and penile augmentation), and chronic wounds (e.g. diabetic ulcers).ConclusionOur understanding of ADM’s clinical utility continues to evolve. More research is needed to determine which ADM has the best outcomes for each clinical scenario.Lay SummaryLarge or complex wounds present unique reconstructive and healing challenges. In normal healing, the extracellular matrix (ECM) provides both structural and growth factors that allow tissue to regenerate in an organised fashion to close the wound. In difficult or large soft-tissue defects, however, the ECM is often compromised. Acellular dermal matrix (ADM) products have been developed to mimic the benefits of host ECM, allowing for improved outcomes in a variety of clinical scenarios. This review summarises the current clinical evidence regarding commercially available ADMs in a wide variety of clinical contexts.

Do we need acellular dermal matrix in prepectoral breast reconstruction? A systematic review and meta-analysis

Characterization of acellular dermal matrices (ADMs) prepared by two different methods

The management of hard-to-heal wounds is a significant clinical challenge. Acellular dermal matrices (ADMs) have been successfully introduced to enhance the healing process. Here, we aimed to develop protocol for the preparation of novel ADMs from abdominoplasty skin. We used three different decellularization protocols for skin processing, namely, 1M NaCl and sodium dodecyl sulfate (SDS, in ADM1); 2M NaCl and sodium dodecyl sulfate (SDS, in ADM1); and a combination of recombinant trypsin and Triton X-100 (in hADM 3). We assessed the effectiveness of decellularization and ADM’s structure by using histochemical and immunochemical staining. In addition, we evaluated the therapeutic potential of novel ADMs in a murine model of wound healing. Furthermore, targeted transcriptomic profiling of genes associated with wound healing was performed. First, we found that all three proposed methods of decellularization effectively removed cellular components from abdominoplasty skin. We showed, however, significant differences in the presence of class I human leukocyte antigen (HLA class I ABC), Talin 1/2, and chondroitin sulfate proteoglycan (NG2). In addition, we found that protocols, when utilized differentially, influenced the preservation of types I, III, IV, and VII collagens. Finally, we showed that abdominoplasty skin-derived ADMs might serve as an effective and safe option for deep wound treatment. More importantly, our novel dressing (ADM1) improves the kinetics of wound closure and scar maturation in the proliferative and remodeling phases of wound healing. In conclusion, we developed a protocol for abdominoplasty skin decellularization suitable for the preparation of biological dressings. We showed that different decellularization methods affect the purity, structure, and therapeutic properties of ADMs.

Acellular Dermal Matrix Reconstruction of the Head and Neck: A Versatile Reconstructive Option

Acellular dermal matrices (ADMs) have been commonly used in expander-based breast reconstruction to provide inferolateral prosthesis coverage. Although the clinical performance of these biologic scaffold materials varies depending on a number of factors, an in-depth systematic characterization of the host response is yet to be performed. The present study evaluates the biochemical composition and structure of two ADMs, AlloDerm(®) Regenerative Tissue Matrix and AlloMax™ Surgical Graft, and provides a comprehensive spatiotemporal characterization in a porcine model of tissue expander breast reconstruction. Each ADM was characterized with regard to thickness, permeability, donor nucleic acid content, (residual double-stranded DNA [dsDNA]), and growth factors (basic fibroblast growth factor [bFGF], vascular endothelial growth factor [VEGF], and transforming growth factor-beta 1 [TGF-β1]). Cytocompatibility was evaluated by in vitro cell culture on the ADMs. The host response was evaluated at 4 and 12 weeks at various locations within the ADMs using established metrics of the inflammatory and tissue remodeling response: cell infiltration, multinucleate giant cell formation, extent of ADM remodeling, and neovascularization. AlloMax incorporated more readily with surrounding host tissue as measured by earlier and greater cell infiltration, fewer foreign body giant cells, and faster remodeling of ADM. These findings correlated with the in vitro composition and cytocompatibility analysis, which showed AlloMax to more readily support in vitro cell growth. AlloMax and AlloDerm demonstrated distinct remodeling characteristics in a porcine model of tissue expander breast reconstruction.

Acellular dermal matrices (ADMs) are gaining popularity as surgical materials for operations on the pelvic organs, as well as in burn therapy and plastic surgery. Evaluation of the biocompatibility of surgical materials is an important and necessary step in the development of new ADMs.The aim of the study was to compare the results of subcutaneous implantation of ADM and native porcine skin in rats.Materials and methods. To obtain ADMs, detergent – enzymatic decellularization was used. On days 7, 14, 21, and 60 after the implantation of ADMs (the experimental group) and native porcine skin (the control group), the animals were removed from the experiment. The histologic sections were stained with hematoxylin – eosin and Masson’s trichrome stain, then an immunohistochemical reaction with antibodies to CD3 and CD68 was performed. Computer morphometry was carried out using the ImageJ software.Results. On day 7 after the implantation, moderate sterile inflammation in the experimental group and pronounced sterile inflammation with eosinophil infiltration in the control group were observed. On day 14 of the experiment, the samples from the experimental group were characterized by a relatively low content of macrophages and T-lymphocytes with insignificant edema and no signs of ADM biodegradation. The control group showed pronounced inflammation, a large number of infiltrating macrophages and T lymphocytes, as well as fragmentation of collagen fibers. On day 21 of the experiment, a thin capsule was formed around ADM, there was a small number of infiltrating T lymphocytes and macrophages, the collagen fibers of the implant were intact. In the samples of the control group, there was pronounced inflammation with the presence of a significant number of lymphocytes and macrophages, as well as fragmentation and vascularization of the implant. On day 60 of the experiment, no inflammatory response was observed around ADM, biodegradation was minimal, and a dense fibrous capsule was formed around the fragment of the native porcine skin.Conclusion. The experimental ADM has low immunogenicity and a low degree of biodegradation, which makes it possible to use it for further research to create efficient surgical material that is safe for use in clinical practice.

Acellular dermal matrices can be combined with implant-based breast reconstruction to help optimize outcomes. SurgiMend PRS is a fetal bovine dermis-derived acellular dermal matrix composed of type I collagen and approximately 30 percent type III collagen, sharing many of the properties of human cadaveric acellular dermal matrix. This was a retrospective, single-center analysis of 111 adult patients (147 breasts) undergoing one-stage (83.7 percent) or two-stage (16.3 percent) immediate breast reconstruction after mastectomy. The aims were to characterize the safety profile of SurgiMend and investigate associations between risk factors and complications. The mean age of the patients was 47.9 years and the mean body mass index was 24.7 kg/m. After a median follow-up of 24.3 months, the overall rates of minor and major complications were 25.2 percent (n = 37 of 147) and 12.9 percent (n = 19 of 147), respectively. The most common major complications were seroma [n = 12 (8.2 percent)] and necrosis [n = 9 (6.1 percent)]. All occurred within 3 months after surgery. The rate of capsular contracture was 2.7 percent (n = 4). A total of 2.7 percent of implanted breasts (n = 4) required explantation. In a univariate analysis, smokers had a greater risk of major complications (p = 0.013), and postoperative radiation therapy and obesity were associated with an increased risk of capsular contracture (p = 0.006) and explantation (p = 0.006), respectively. In a multivariate analysis, several factors were associated with complications or explantation, including obesity (p < 0.05), preoperative chemotherapy (p < 0.001), and mastectomy weight (p < 0.05). These associations align with other studies of implant-based reconstruction and do not appear to be specific to this acellular dermal matrix. The results are consistent with previous analyses of SurgiMend, and support its value in implant-based breast reconstruction. Therapeutic, IV.

Acellular dermal matrices have been proposed to decrease the incidence of capsular contracture in implant-based breast reconstructions. The authors have modified acellular dermal matrices with fenestrations to facilitate greater lower pole expansion and improve contour. The effect of fenestrations on the ability of matrices to suppress capsule formation, however, has not been examined. A retrospective review of all fenestrated acellular dermal matrix-assisted, implant-based breast reconstructions performed by the two senior authors, with a minimum of 1-year follow-up after permanent implant placement, was completed. Patient demographics, details of extirpative and reconstructive procedures, and complications were examined. Capsular contractures were scored according to the Baker grading scale and compared to those reported in the literature. Thirty patients (50 breasts) underwent fenestrated acellular dermal matrix-assisted reconstruction, with mean follow-up times of 3.3 and 2.6 years after expander placement and implant exchange, respectively. Seven patients (23 percent) had a body mass index greater than 30 kg/m, three (10 percent) were active smokers, and six breasts (12 percent) were irradiated. Complications included one infection (2 percent), six cases (12 percent) of incisional superficial skin necrosis, and one (2 percent) tissue expander extrusion. Zero breasts had clinically significant Baker grade III/IV capsular contracture. The average Baker grade was 1.1. Fenestrated acellular dermal matrices decrease capsular contracture to rates similar to what is seen with nonfenestrated matrices. Further research is necessary to determine whether this observation is a result of decreased need for inferolateral acellular dermal matrix coverage to achieve these effects or modified physical interaction of acellular dermal matrices with surrounding soft tissues. Therapeutic, IV.

Acellular dermal matrices (ADM) are a novel graft. The goal of this systematic review is to evaluate the evidence behind differences in human and porcine ADM, irrelevant of manufacturing method, and to determine if there is enough of an evidence base to change clinical practice. An extensive literature search was performed through MEDLINE and Embase with search terms defining a population, intervention and outcome. Title and abstract exclusion were performed with other exclusion criteria. In 191 articles were found after exclusion of duplicates, with only 29 remaining following exclusions. Ten studies were found to have level I and II evidence (I=3, II=8), of which two were histopathological, one was an animal model, one was a systematic review, and six were clinical. The remaining studies were reviewed and considered for discussion, but did not hold high enough standards for medical evidence. Strong clinical evidence already exists for the use of human ADM, but questions of access, cost, and ethics require consideration of a xenograft. Histopathologically, evidence suggests minimal long-term differences between human and porcine ADM, although there is a short acute immune response with porcine ADM. Clinically, there is limited difference in outcomes, with a small range in effect of different ADM preparations. Considering the effectiveness of ADM in wound healing, more high-level research with appropriate statistical analysis to facilitate a future meta-analysis is recommended to justify a transition from human to porcine ADM.

We report a 7-year-old girl with xeroderma pigmentosum (XP), who presented in our clinic with a large melanoma (35 × 50 × 20 mm, Breslow depth 18 mm) in the zygomatic-malar area. Palliative surgery was performed to maintain her residual vision and to reduce the pain caused by the compression of local structures. Because of the limited access of autologous skin grafts in pediatric patients with XP who are severely affected, we opted to use an acellular dermal matrix. There was 100% graft uptake, and the pain due to compression by the tumor was alleviated. This case demonstrates that acellular dermal matrices can be safely and effectively used in oncological facial reconstruction, especially in patients with progressive conditions such as XP.