DermACELL: a novel and biocompatible acellular dermal matrix in tissue expander and implant-based breast reconstruction

Immediate Prepectoral Tissue Expander Breast Reconstruction Without Acellular Dermal Matrix Is Equally Safe Following Skin-Sparing and Nipple-Sparing Mastectomy

BACKGROUND

Prepectoral breast reconstruction has become increasingly popular over the last decade. There is a paucity of data surrounding the impact of mastectomy type on clinical outcomes when comparing prepectoral immediate breast reconstruction without acellular dermal matrix (ADM) using tissue expansion. The purpose of this study was to compare 90-day reconstructive surgical outcomes in immediate prepectoral tissue expander reconstruction between patients with nipple-sparing mastectomy (NSM) and skin-sparing mastectomy (SSM).

METHODS

A retrospective review of patient records was carried out on all patients undergoing NSM or SSM with immediate prepectoral tissue expander reconstruction without ADM, in a single institution, from June 2020 to December 2021. All complications were recorded, categorized, and statistically analyzed for significance.

RESULTS

Seventy-nine patients (97 breasts) were studied. The mean age was 51 years old (range, 31-77). Twenty-two patients suffered complications recorded in 22 breasts (22.7%). There was no statistically significant difference in the total complications between the NSM (25.7%) and SSM (21.0%) groups or in the incidence of all major and minor complications.

CONCLUSIONS

Breast reconstruction using tissue expanders without ADM has similar reconstructive outcomes in both NSM and SSM. There were no significant differences in complication rates between either groups. Breast reconstruction without ADM can confer institutional cost savings without compromising safety.

Comparison of Different Acellular Dermal Matrix in Breast Reconstruction: A Skin-to-Skin Study

BACKGROUND

Since the early 2000s, acellular dermal matrix has been a popular adjunct to prepectoral breast reconstruction to enhance outcomes.

OBJECTIVES

The aim of this study was to investigate the differences in the postoperative course of 2 standard acellular dermal matrix products, AlloDerm SELECT Ready To Use and DermACELL.

METHODS

A prospective, patient-blind study of patients undergoing bilateral nipple and/or skin-sparing mastectomies with either tissue expander or silicone implant insertion between 2019 and 2022 were selected for this study. The study design used patients as their own controls between 2 products randomly assigned to the left or right breast. Outcomes between the products included average time for drain removal, infection rate, seroma rate, and incorporation rates.

RESULTS

The prospective clinical data of 55 patients (110 breasts) were recorded for 90 days. There were no significant differences between drain removal time, average drain output, or seroma aspiration amount. A higher percentage of seromas was recorded in the breasts with AlloDerm (30.91%) compared with breasts containing DermACELL (14.55%, P < .05), and a statistically significant difference between the incorporation rates of AlloDerm (93.4%) and DermACELL (99.8%, P < .05) was observed.

CONCLUSIONS

Irrespective of patient demographic disparities, both products had a 94.55% success rate for reconstruction outcomes. AlloDerm was determined to have a higher incidence of seromas as a postoperative complication and a trend to lower incorporation.

LEVEL OF EVIDENCE: 3

Extracellular Matrices as Bioactive Materials for In Situ Tissue Regeneration

Bioactive materials based on a nature-derived extracellular matrix (NECM) represent a category of biomedical devices with versatile therapeutic applications in the realms of tissue repair and engineering. With advancements in decellularization technique, the inherent bioactive molecules and the innate nano-structural and mechanical properties are preserved in three-dimensional scaffolds mainly composed of collagens. Techniques such as electrospinning, three-dimensional printing, and the intricate fabrication of hydrogels are developed to mimic the physical structures, biosignalling and mechanical cues of ECM. Until now, there has been no approach that can fully account for the multifaceted properties and diverse applications of NECM. In this review, we introduce the main proteins composing NECMs and explicate the importance of them when used as therapeutic devices in tissue repair. Nano-structural features of NECM and their applications regarding tissue repair are summarized. The origins, degradability, and mechanical property of and immune responses to NECM are also introduced. Furthermore, we review their applications, and clinical features thereof, in the repair of acute and chronic wounds, abdominal hernia, breast deformity, etc. Some typical marketed devices based on NECM, their indications, and clinical relevance are summarized.

Biological Cover Mitigates Disruption of the Dermal Structure in Mechanically Expanded Skin in a Porcine Model

Tissue expansion is an integral procedure of the vast majority of breast reconstruction and has a significant impact on the final clinical outcomes. Therefore, technological advances leading to a fewer number of unfavorable outcomes and a decrease in complication rates are imperative. In this study, using a porcine model, we investigated an effect of acellular dermal matrix (ADM) used as a tissue expander cover on the dermal changes induced by mechanical forces during tissue expansion. After 14 days of expansion, skin samples were collected from one animal, while the second animal underwent radiation, and tissue was collected 8 weeks later. Tissue expanded without the use of ADM and unexpanded skin served as the controls. Collected skin biopsies were used for histological and immunohistochemical evaluation, and for gene expression analysis. We revealed that the biological cover incorporation into host tissue is facilitated by macrophages without inducing a broad inflammatory response. The utilization of ADM mitigated disruption in the dermal structure, excessive collagen deposition, and capsule formation in non-irradiated expanded skin. The protective effect was not fully maintained in irradiated skin. These results demonstrate that tissue expansion might be improved by using the tissue expander cover.

DermACELL Acellular Dermal Matrix in Oncologic Breast Reconstruction: A Cohort Study and Systematic Review

Acellular dermal matrices (ADMs) are commonly used in tissue expander and direct-to-implant reconstruction following mastectomy. Few studies have reported outcomes of DermACELL use or compared DermACELL with AlloDerm ADM. This study sought to compare outcomes of DermACELL and AlloDerm in oncologic breast reconstruction and to review the literature reporting outcomes of patients undergoing reconstruction using DermACELL.

Clinical applications of acellular dermal matrices: A review

INTRODUCTION

The 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.

METHODS

PubMed, 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.

RESULTS

A 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).

CONCLUSION

Our 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 SUMMARY

Large 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.

Comparison of Skin Substitutes for Acute and Chronic Wound Management

Chronic and acute wounds, such as diabetic foot ulcers and burns, respectively, can be difficult to treat, especially when autologous skin transplantations are unavailable. Skin substitutes can be used as a treatment alternative by providing the structural elements and growth factors necessary for reepithelialization and revascularization from a nonautologous source. As of 2020, there are 76 commercially available skin substitute products; this article provides a review of the relevant literature related to the major categories of skin substitutes available.

Direct comparison of CGCRYODERM and DermACELL in the same patient for outcomes in bilateral implant-based breast reconstruction: a retrospective case series

Background

The use of acellular dermal matrix (ADM) has been popularized in implant-based breast reconstruction (IBR). However, it is still controversial if ADM-associated complication rates differ with varying types of ADM products. The aim of this study was to compare postoperative complications between CGCRYODERM and DermACELL.

Methods

A retrospective chart review was performed on 32 patients (64 breasts) who underwent bilateral prosthetic breast reconstruction between June 2015 and December 2019. All patients received two different ADMs in each breast during the surgery. Demographic variables, operative characteristics, and postoperative outcomes were compared between the cryopreserved and pre-hydrated ADM.

Results

The overall major and minor postoperative complications developed in 7 and 1 out of 32 patients, respectively. Seroma and infection were the most common complications. There were no cases that infection and/or seroma involved both breasts in one individual. No significant differences were observed in terms of seroma, infection, hematoma, mastectomy flap necrosis, or drainage period between the CGCRYODERM and DermACELL groups (P=0.5637, 0.1797, 1.0000, 0.3173, and 0.2925, respectively). There was no case of reconstruction failure leading to explantation.

Conclusions

There were no statistically significant differences in postoperative complications between the two breasts reconstructed with CGCRYODERM and DermACELL in the same patient who underwent bilateral IBR. This is the first study to compare cryopreserved and pre-hydrated ADMs. We suggest that CGCRYODERM is a suitable option with a comparable safety profile for IBR.

Fast protocol for the processing of split-thickness skin into decellularized human dermal matrix

BACKGROUND

Dermal scaffolds for tissue regeneration are nowadays an effective alternative in not only wound healing surgeries but also breast reconstruction, abdominal wall reconstruction and tendon reinforcement. The present study describes the development of a decellularization protocol applied to human split-thickness skin from cadaveric donors to obtain dermal matrix using an easy and quick procedure.

METHODS

Complete split-thickness donor was decellularized through the combination of hypertonic and enzymatic methods. To evaluate the absence of epidermis and dermal cells, and ensure the integrity of the extracellular matrix (ECM) structure, histological analysis was performed. Residual genetic content and ECM biomolecules (collagen, elastin, and glycosaminoglycan) were quantified and tensile strength was tested to measure the effect of the decellularization technique on the mechanical properties of the tissue.

RESULTS

Biomolecules quantification, residual genetic content (below 50 ng/mg dry tissue) and histological structure assessment showed the efficacy of the decellularization process and the preservation of the ECM. The biomechanical tests confirmed the preservation of native properties in the acellular tissue.

CONCLUSIONS

The acellular dermal matrix obtained from whole split-thickness skin donor with the newly developed decellualrization protocol, maintains the desired biomechanical and structural properties and represents a viable treatment option for patients.

A Randomized Controlled Trial Comparing Alloderm-RTU with DermACELL in Immediate Subpectoral Implant-Based Breast Reconstruction

Background: The effectiveness of different acellular dermal matrices (ADM) used for implant-based reconstruction immediately following mastectomy is an important clinical question. A prospective randomized clinical trial was performed to evaluate the superiority of DermACELL over Alloderm-RTU in reducing drain duration. Methods: Patients undergoing mastectomy with subpectoral immediate and permanent implant-based breast reconstruction were randomized to Alloderm-RTU or DermACELL. The primary outcome was seroma formation, measured by the duration of postoperative drain placement. Secondary outcomes included: post drain removal seroma aspiration, infection, redbreast syndrome, wound dehiscence, loss of the implant, and unplanned return to the operating room. Results: 62 patients were randomized for 81 mastectomies (41 Alloderm-RTU, 40 DermACELL). Baseline characteristics were similar. There was no statistically significant difference in mean drain duration (p = 0.16), with a trend towards longer duration in the Alloderm-RTU group (1.6 days; 95%CI, 0.7 to 3.9). The overall rate of minor and major complications were statistically similar between the two groups; although patients with Alloderm-RTU had 3 times as many infections requiring antibiotics (7.9% vs. 2.5%) with a risk difference of 5.4 (95%CI −4.5 to 15.2), and twice as many unplanned returns to the operating room (15.8% vs. 7.5%) with a risk difference of 8.3 (95% CI −5.9 to 22.5) as DermACELL. Conclusion: This is the first prospective randomized clinical trial comparing the two most commonly used human-derived ADMs. There was no statistically significant difference in drain duration, minor, or major complications between DermACELL over Alloderm-RTU in immediate subpectoral permanent implant-based breast reconstruction post-mastectomy.

A comparison of patient-reported outcomes between Alloderm and Dermacell in immediate alloplastic breast reconstruction: A randomized control trial

BACKGROUND

Alloderm and Dermacell are the two leading human acellular dermal matrices (ADM) in immediate breast reconstruction (IBR). Despite differences in sterility, consistency, thickness and cost, there are no comparative trials to date to compare patient-reported outcome measures (PROM) between the two products. The purpose of this study was to determine if there was a difference in patient-reported outcomes (as measured by the BREAST-Q) between patients reconstructed with Alloderm and Dermacell.

METHODS

A single center, open-label, randomized control trial of patients undergoing IBR with an implant for breast cancer or breast cancer prophylaxis was performed. Patients were randomized to either Alloderm or Dermacell. Baseline demographic data were compared, and linear mixed models were used to identify associations with BREAST-Q over time.

RESULTS

Between June 2016 and October 2018, 62 patients were randomized into two groups, 31(50%) Alloderm and 31(50%) Dermacell. Of these, 23(74%) patients in the Alloderm group and 27(87%) patients of the Dermacell group filled out BREAST-Q questionnaires. Baseline BREAST-Q scores with respect to satisfaction with breasts, psychosocial well-being, sexual well-being, and physical well-being were similar between groups (p>0.05). At 3 months postoperatively, the Alloderm group had a statistically significant improvement with respect to satisfaction with breasts (67 vs 53, p = 0.03), satisfaction with overall results (85 vs 61, p = 0.003), satisfaction with the surgeon (89 vs 67, p = 0.01), and satisfaction with information provided (74 vs 59, p = 0.02). At 12 months postoperatively, there were no statistically significant differences in PROM between groups (p>0.05).

CONCLUSION

We report the first randomized controlled trial to date comparing patient-reported outcomes of the two most commonly used ADMs in IBR in Canada. Although a short-term analysis favors the use of Alloderm, there does not appear to be any difference in outcomes between the two products in the longer term.

Invited Discussion on: Skin Reducing Mastectomy and Prepectoral Breast Reconstruction in Large Ptotic Breasts

The applicability of acellular dermal matrix (ADM) for breast reconstruction is a consolidated reality, as skin and nipple sparing techniques became standard mastectomy approaches. ADM is a soft connective tissue graft generated via a decellularization process that preserves intact the extracellular skin matrix. ADM not only provides tissue reinforcement, but also better pocket control, and shape without the compressive effects of total sub-muscular coverage. Our preference is using one "Strattice®" ADM in pocket's format to cover the implant's inferior pole, protecting the totality of the implant in its inferior pole by the ADM. This technique besides its versatility is cheaper than other techniques presented. The success of ADM prepectoral breast reconstruction depends on three pillars: careful patient selection, flap perfusion and postoperative management. The challenge in large and/or ptotic breasts under the risk of large badly perfused flaps as well as of nipple, due to the nipple-furcules distance which can be handled with well-selected criteria as mentioned and safe management of nipple ascension as well as the nipple graft. Traditionally, they need to be associated with reducing mammoplasty techniques to achieve the expected aesthetic results in a single stage. Therefore, the plastic surgeon must be prepared for new reconstructive approaches postmastectomy, having the ADM as an excellent option for that.

Povidone-iodine Does Not Affect Acellular Dermal Matrix Integration in Patients Undergoing 2-staged, Prepectoral, Breast Reconstructive Surgery

Background:

Povidone-iodine has been traditionally used as an antimicrobial agent to irrigate the breast pocket and rinse the prosthesis before placement in the pocket. Use of povidone-iodine with breast implants was banned from 2000 to 2017. During this period, acellular dermal matrix (ADM) was introduced to breast surgery. In nonclinical studies, povidone-iodine can impair collagen synthesis and kill fibroblasts. Cellular repopulation was critical for ADM integration. Whether povidone-iodine impacts ADM integration was unknown.

Methods:

Patients who underwent immediate, prepectoral, 2-staged breast reconstruction were included in this retrospective study. Study population was divided into povidone-iodine–treated patients and triple-antibiotic–treated patients. The breast pockets were rinsed with the antimicrobial agent, and the prostheses and ADMs were presoaked in the agent perioperatively. At implant exchange, the extent of ADM integration was clinically assessed. ADM integration was defined as >25% of matrix vascularization. ADM integration and postoperative complications were compared between the groups.

Results:

A total of 111 patients (257 reconstructions) were included—58 patients (111 reconstructions) were exposed to povidone-iodine and 53 patients (97 reconstructions) to triple-antibiotic solution. ADM integration was noted in 97% of breasts in each group. Integrated matrices appeared healthy, had no signs of foreign body reaction, and demonstrated punctate bleeding. Complications did not differ between the groups, including the rate of infections, seroma, and expander loss.

Conclusion:

Irrigation of the breast pocket and presoaking of the prosthesis and ADM with povidone-iodine appear to have no adverse consequences on clinical outcomes and did not impede matrix integration.

In Vitro Characterization of a Novel Human Acellular Dermal Matrix (BellaCell HD) for Breast Reconstruction

In the past, acellular dermal matrices (ADMs) have been used in implant-based breast reconstruction. Various factors affect the clinical performance of ADMs since there is a lack of systematic characterization of ADM tissues. This study used BellaCell HD and compared it to two commercially available ADMs—AlloDerm Ready to Use (RTU) and DermACELL—under in vitro settings. Every ADM was characterized to examine compatibility through cell cytotoxicity, proliferation, and physical features like tensile strength, stiffness, and the suture tensile strength. The BellaCell HD displayed complete decellularization in comparison with the other two ADMs. Several fibroblasts grew in the BellaCell HD with no cytotoxicity. The proliferation level of fibroblasts in the BellaCell HD was higher, compared to the AlloDerm RTU and DermACELL, after 7 and 14 days. The BellaCell HD had a load value of 444.94 N, 22.44 tensile strength, and 118.41% elongation ratio, and they were higher than in the other two ADMs. There was no significant discrepancy in the findings of stiffness evaluation and suture retention strength test. The study had some limitations because there were many other more factors useful in ADM’s testing. In the study, BellaCell HD showed complete decellularization, high biocompatibility, low cytotoxicity, high tensile strength, high elongation, and high suture retention strengths. These characteristics make BellaCell HD a suitable tissue for adequate and safe use in implant-based breast reconstruction in humans.

A retrospective review of breast reconstruction outcomes comparing AlloDerm and DermaCELL

Acellular dermal matrix (ADM) has become an accepted and advantageous adjunct to alloplastic breast reconstruction. The increase in demand has led to an upsurge of dermal-based products, both human and animal derived. There are few direct ADM comparative studies, but it is unclear whether there are any differences in complication rates. Our primary objective was to determine whether there is a difference in outcomes between AlloDerm and DermACELL in immediate alloplastic breast reconstruction.

A retrospective chart review of those who underwent immediate alloplastic breast reconstruction from January to December 2016 was performed. This encompassed 64 consecutive patients (95 breasts) with tissue expander or direct-to-implant reconstruction and either AlloDerm or DermACELL ADM. Demographics, particulars of the surgery, additional treatments and complications were all recorded. Differences in seroma, haematoma and infection rates, as well as more serious complications including implant replacement, capsular contracture and failure, were all reviewed.

The groups were comparable in terms of age, BMI and relevant comorbidities. Mastectomy weight and resulting implant volume were higher in the DermACELL group, with volume reaching statistical significance (p = 0.001). With an average follow-up of 18 months, there was no difference in capsular contraction or implant replacement. However, in those who developed capsular contracture in the DermACELL group, more breasts had no history of radiation, which was significant (p = 0.042). Overall, there were no significant differences in complication rates of seroma, haematoma, mastectomy flap necrosis and infection.

Cosmetic reconstruction in breast cancer patients: Opportunities for nanocomposite materials

The most common malignancy in women, breast cancer remains a major medical challenge that affects the life of thousands of patients every year. With recognized benefits to body image and self-esteem, the use of synthetic mammary implants for elective cosmetic augmentation and post-mastectomy reconstruction continues to increase. Higher breast implant use leads to an increased occurrence of implant-related complications associated with implant leakage and rupture, capsular contracture, necrosis and infections, which include delayed healing, pain, poor aesthetic outcomes and the need for revision surgeries. Along with the health status of the implant recipient and the skill of the surgeon, the properties of the implant determine the likelihood of implant-related complications and, in doing so, specific patient outcomes. This paper will review the challenges associated with the use of silicone, saline and "gummy bear" implants in view of their application in patients recovering from breast cancer-related mastectomy, and investigate the opportunities presented by advanced functional nanomaterials in meeting these challenges and potentially opening new dimensions for breast reconstruction. STATEMENT OF SIGNIFICANCE: Breast cancer is a significant cause of morbidity and mortality in women worldwide, which is difficult to prevent or predict, and its treatment carries long-term physiological and psychological consequences. Post-mastectomy breast reconstruction addresses the cosmetic aspect of cancer treatment. Yet, drawbacks of current implants contribute to the development of implant-associated complications, which may lead to prolonged patient care, pain and loss of function. Nanomaterials can help resolve the intrinsic biomechanical mismatch between implant and tissues, enhance mechanical properties of soft implantable materials, and provide an alternative avenue for controlled drug delivery. Here, we explore advances in the use of functionalized nanomaterials to enhance the properties of breast implants, with representative examples that highlight the utility of nanomaterials in addressing key challenges associated with breast reconstruction.

Breast reconstruction with Alloderm Ready to Use: A meta-analysis of nine observational cohorts

BACKGROUND

AlloDerm-RTU is a new member of human acellular dermal matrix (HADM) which was launched in 2012. The present meta-analysis aimed to investigate whether AlloDerm-RTU was superior compared with previous HADMs.

METHODS

All available databases were searched for retrospective or prospective studies regarding breast reconstruction with AlloDerm-RTU compared with other HADMs. The primary outcome was the incidence of complications among different HADMs.

RESULTS

Two prospective and seven retrospective studies with a total of 1406 patients were enrolled. There was no significant difference in any of the complications, including the incidence of hematoma (RR 0.78, 95%CI 0.19 to 3.19; P = 0.73), seroma (RR 0.98, 95%CI 0.43 to 2.26; P = 0.97), cellulitis (RR 0.82, 95%CI 0.32 to 2.11; P = 0.68), necrosis (RR 0.69, 95%CI 0.44 to 1.10; P = 0.12), infection (RR 0.68, 95%CI 0.37 to 1.25; P = 0.22), explantation (RR 0.61, 95%CI 0.35 to 1.06; P = 0.08), and total complications (RR 0.91, 95%CI 0.55 to 1.52; P = 0.73). Subgroup analysis showed that AlloDerm-RTU demonstrated no superiority compared with FD AlloDerm, AlloMax, or DermACELL. Sensitivity analysis indicated that the outcomes were stabilized. No publication bias existed in the present meta-analysis.

CONCLUSION

Four HADM products, AlloDerm-RTU, FD AlloDerm, AlloMax, and DermACELL, showed similar risks of complications. However since most of the included studies had a low level of evidence, further random trials with large numbers of patients are needed.

Decellularized materials derived from TSP2-KO mice promote enhanced neovascularization and integration in diabetic wounds

Decellularized biologic scaffolds are gaining popularity over synthetic biomaterials as naturally derived materials capable of promoting improved healing. Nevertheless, the most widely used biologic material - acellular dermal matrix (ADM) - exhibits slow repopulation and remodeling, which prevents integration. Additionally, engineering control of these materials is limited because they require a natural source for their production. In the current report, we demonstrate the feasibility of using genetically engineered animals to create decellularized biologic scaffolds with favorable extracellular matrix (ECM) properties. Specifically, we utilized skin from thrombospondin (TSP)-2 KO mice to derive various decellularized products. Scanning electron microscopy and mechanical testing showed that TSP-2 KO ADM exhibited an altered structure and a reduction in elastic modulus and ultimate tensile strength, respectively. When a powdered form of KO ADM was implanted subcutaneously, it was able to promote enhanced vascularization over WT. Additionally, when implanted subcutaneously, intact slabs of KO ADM were populated by higher number of host cells when compared to WT. In vitro studies confirmed the promigratory properties of KO ADM. Specifically, degradation products released by pepsin digestion of KO ADM induced greater cell migration than WT. Moreover, cell-derived ECM from TSP-2 null fibroblasts was more permissive to fibroblast migration. Finally, ADMs were implanted in a diabetic wound model to examine their ability to accelerate wound healing. KO ADM exhibited enhanced remodeling and vascular maturation, indicative of efficient integration. Overall, we demonstrate that genetic manipulation enables engineered ECM-based materials with increased regenerative potential.

What happens to an acellular dermal matrix after implantation in the human body? A histological and electron microscopic study

Acellular matrices are used for various purposes and they have been studied extensively for their potential roles in regenerating tissues or organs. The acellular matrix generates physiological cues that mimic the native tissue microenvironment. Acellular dermal matrix (ADM) is a soft connective tissue graft generated by a decellularization process that preserves the intact extracellular skin matrix. Upon implantation, this structure serves as a scaffold for donor-side cells to facilitate subsequent incorporation and revascularization. In breast reconstruction, ADM is used mainly for lower pole coverage and the shaping of a new breast. It helps control the positioning of the implant in the inframammary fold, and prevents the formation of contractile pseudocapsule around the breast implant. In this study, we provide a comprehensive histological description of ADM used for human breast reconstruction over the course of several months following implementation. Using immunohistochemical methods (a panel of 12 antibodies) coupled with optical and transmission electron microscopy, we confirmed that the original acellular dermal matrix became recolonized by fibroblasts and myofibroblasts, and also by various other free cells of the connective tissue (lymphocytes, macrophages and multinucleated giant cells, granulocytes, mast cells) after implantation into the patient’s body. Within the implanted ADM, there was a relatively rapid ingrowth of blood vessels. Lymphatic vessels were only detected in one case 9 months after the implantation of the ADM. These results suggest that lymphangiogenesis is a longer process than angiogenesis.

Delayed post mastectomy breast reconstructions with allogeneic acellular dermal matrix prepared by a new decellularizationmethod

Acellular dermal matrix (ADM) is a tissue graft of allogeneic origin from post-mortem tissue donors prepared by an innovative decellularization process. The newly developed non-toxic and low cost decellularization process of cadaver origin dermis included ADM in breast reconstruction procedures proved to help coverage of the lower-pole of breast expanders or implants. As the results have shown, it did help to eliminate autologous dermis donor site morbidity along with shortening the operation time by avoiding elevation of additional muscle or fascia during the operation. Main aims of this article include histology evaluation of allogeneic acellular dermal matrix prepared by a new decellularization method and presentation of clinical results of its use. A total of 22 patients underwent 26 ADM based breast reconstructions. The mean patient's follow up was 12.6 months. Average total size of ADM used for one breast was 273 cm². Post-operative complications occurred in 3 patients including one expander infection, one expander extrusion and one expander pocket disfiguration. Microscopic analysis of tissue samples has confirmed incorporation of the acellular dermal matrices into the surrounding connective tissue without any noticeable immune reaction. In a majority of the ADM samples we found pseudocapsullar formation on implant side of samples without acute or chronic inflammatory cells. The use of ADM prepared by new preparation method in expansive post mastectomy breast reconstruction was associated by a relatively low complication rate resulting in good outcomes.

Clinical Outcomes in Breast Reconstruction Patients Using a Sterile Acellular Dermal Matrix Allograft

BACKGROUND

Human acellular dermal matrices (ADMs) have enabled successful breast reconstructions while decreasing muscle donor morbidity and pain for the patient. However, some literature reports indicate an increase in complications, especially infection. The decellularization and terminal sterilization properties of DermACELL (D-ADM), a human ADM, may reduce the rate of complications in augmented breast reconstruction while still maintaining successful outcomes. In the study presented here, we evaluate the quality and safety of outcomes with the use of D-ADM during tissue expander breast reconstruction.

METHODS

A retrospective chart review was conducted of patients who underwent breast reconstruction with the use of D-ADM, at a single-military hospital-based practice, resulting in a population of 38 subjects and 58 breasts who had breast reconstruction augmented with D-ADM.

RESULTS

Fifty-six breasts (96.6%) in thirty-six patients demonstrated successful outcomes with a median 27 weeks' time to complete healing. Post-reconstruction radiation and chemotherapy were applied to 24.1 and 25.9% of reconstructions, respectively. Complications rates were minimal with rates of 1.7% for surgical site infection and 1.7% for red breast syndrome.

CONCLUSION

The low complication rates combined with the high success and patient satisfaction rates observed for D-ADM support the use of this ADM in breast reconstruction.

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 .

Biological incorporation of human acellular dermal matrix used in Achilles tendon repair

Human acellular dermal matrices (ADMs) are used successfully in a variety of procedures, including sports medicine related, wound repair, and breast reconstructions, but the mechanism of repair is still not fully understood. An opportunity to explore this mechanism presented itself when a patient experienced a rerupture of the native tendon due to a fall that occurred 2 months after undergoing an Achilles tendon repair using Matracell treated ADM. The ADM was removed and an extensive histology analysis was performed on the tissue. Additionally, a literature review was conducted to determine the mechanism of ADM integration into the tendon structure and explore if differences in this mechanism exist for different types of human ADMS. The histology analysis demonstrated that the healing process during a tendon reconstruction procedure is similar to that of wound healing. Furthermore, the literature review showed that differences exist in the mechanism for integration among various human ADMs and that these differences may be due to variances in the methods and technologies that manufactures use to process human ADMs.

Relevant In Vitro Predictors of Human Acellular Dermal Matrix-Associated Inflammation and Capsule Formation in a Nonhuman Primate Subcutaneous Tissue Expander Model

Objective: Benchtop methods were evaluated for preclinical inflammation/capsule formation correlation following implantation of human acellular dermal matrices. Methods: Dermal matrices were compared with native dermis for structure (histology, scanning electron microscopy), collagen solubility (hydroxyproline), enzymatic susceptibility (collagenase), and thermal stability (differential scanning calorimetry). Results were compared with implantation outcomes in a primate tissue expander model. Results: Native dermis, electron beam-sterilized, and freeze-dried human acellular dermal matrices had equivalent morphology, acid-soluble collagen (60.5% ± 6.3%, 65.3% ± 3.2%, and 63.3% ± 2.4%, respectively), and collagenase resistance. Implant results showed minimal inflammation/matrix degradation, lack of capsule formation, insignificant elastic modulus change (57.65 ± 20.24 MPa out-of-package/44.84 ± 23.87 MPa in vivo), and low antibody induction (2- to 8-fold increase) for electron beam-sterilized matrix. Similar results for freeze-dried dermal matrix were previously observed. γ-Irradiated, γ-irradiated/freeze-dried, and ethanol-stored dermal matrices were statistically different from native dermis for acid-soluble collagen (82.4% ± 5.8%, 72.2% ± 6.2%, and 76.8% ± 5.0%, respectively) and collagenase digestion rate, indicating matrix damage. γ-Irradiated matrix-implanted animals demonstrated elevated inflammatory response, foreign body giant cells, capsule formation at the tissue expander junction, and robust matrix metalloproteinase-1 staining with significant elastic modulus decrease (37.43 ± 7.52 MPa out-of-package/19.58 ± 1.16 MPa in vivo). Antibody increase (32- to 128-fold) was observed 6 to 10 weeks following γ-irradiated matrix implantation. Ethanol-stored dermal matrix elicited an acute antibody response (4- to 128-fold increase, 2-4 weeks) and macrophage-concentrated synovial-like hyperplasia at the tissue expander junction, moderate matrix metalloproteinase-1 staining, and significant elastic modulus decrease (61.15 ± 9.12 MPa out-of-package/17.92 ± 4.02 MPa in vivo) by 10 weeks implantation. Conclusion: Demonstrated loss of collagen integrity in vitro may be predictive of inflammation/capsule formation in primate tissue expander models. These results may be further predictive of clinical observations.

Complication Rates With Human Acellular Dermal Matrices: Retrospective Review of 211 Consecutive Breast Reconstructions

Background:

Human acellular dermal matrix (HADM) is commonly used to provide coverage and support for breast reconstruction. The primary purpose of this study was to evaluate the complication rates associated with breast reconstruction procedures when performed in conjunction with multiple types of HADM in a consecutive series.

Methods:

After receiving institutional review board approval, medical records from a single surgeon were retrospectively reviewed for 126 consecutive patients (170 breasts and 211 procedures) who received a breast reconstruction or revision with implantation of HADM between 2012 and 2014. Patient demographics, surgical technique, and the complication profile of 4 major types of HADM were evaluated by procedure. Complication data were primarily evaluated for infection, seroma formation, necrosis, and other complications requiring additional surgery.

Results:

The total complication rate was 19.4%. The complication rates were not statistically different between all 4 types of HADM: Alloderm (n = 143); Alloderm RTU (n = 19); FlexHD (n = 18); hMatrix (n = 32) (P > 0.05). Smokers and large-breasted women (≥500 g) had a significantly higher complication rate than the rest of the population (P < 0.01 and P < 0.03, respectively). The complication rates associated with all other patient cohorts analyzed (age, body mass index, comorbid conditions, cancer diagnosis, prepectoral technique) showed no influence on complication rates (P > 0.05).

Conclusions:

In characteristically similar cohorts, there was no statistically significant difference in complication rates based on type of HADM; however, certain risk factors and anatomy should be considered before HADM-assisted breast reconstruction.

Aseptic versus Sterile Acellular Dermal Matrices in Breast Reconstruction: An Updated Review

BACKGROUND

As the use of acellular dermal matrices in breast reconstruction has become more commonplace and efforts are made to improve on postoperative outcomes, the method of acellular dermal matrix (ADM) processing (aseptic versus sterile) has become a subject of interest. This article provides an updated overview of the critical aspects of ADM processing in addition to application of ADMs in single- and two-stage breast reconstruction, a review of the morbidity associated with ADM use, and alternatives.

METHODS

A literature review was performed in PubMed identifying recent systematic reviews, meta-analyses, and head-to-head comparisons on aseptically processed ADM and sterile-processed ADM in implant-based breast reconstruction.

RESULTS

Recent meta-analyses have shown a 2- to 3-fold increase in infections and tissue expander/implant explantation rates and a 3- to 4-fold increase in seroma formation compared with non-ADM reconstruction techniques. Comparisons of aseptic and sterile ADMs in multiple studies have shown no significant difference in infection rates and equivocal findings for other specific complications such as seroma formation.

CONCLUSIONS

Current evidence on the impact of processing techniques that improve ADM sterility on postoperative morbidity in implant breast reconstruction is unclear. Deficiencies of the available data highlight the need for well-designed, multicenter, randomized controlled studies that will aid in optimizing outcomes in implant-based breast reconstruction.

Recellularized human dermis for testing gene electrotransfer ex vivo

Gene electrotransfer (GET) is a proven and valuable tool for in vivo gene delivery to a variety of tissues such as skin, cardiac muscle, skeletal muscle, and tumors, with controllable gene delivery and expression levels. Optimizing gene expression is a challenging hurdle in preclinical studies, particularly for skin indications, due to differences in electrical conductivity of animal compared to human dermis. Therefore, the goal of this study was to develop an ex vivo model for GET using recellularized human dermis to more closely mimic human skin. Decellularized human dermis (DermACELL(®)) was cultured with human dermal fibroblasts and keratinocytes for 4 weeks. After one week of fibroblast culture, fibroblasts infiltrated and dispersed throughout the dermis. Air-liquid interface culture led to epithelial cell proliferation, stratification and terminal differentiation with distinct basal, spinous, granular and cornified strata. Firefly luciferase expression kinetics were evaluated after GET of recellularized constructs for testing gene delivery parameters to skin in vitro. Elevated luciferase expression persisted up to a week following GET compared to controls without electrotransfer. In summary, recellularized dermis structurally and functionally resembled native human skin in tissue histological organization and homeostasis, proving an effective 3D human skin model for preclinical gene delivery studies.

Alloplastic adjuncts in breast reconstruction

BACKGROUND

There has been an increasing role of acellular dermal matrices (ADMs) and synthetic meshes in both single- and two-stage implant/expander breast reconstruction. Numerous alloplastic adjuncts exist, and these vary in material type, processing, storage, surgical preparation, level of sterility, available sizes and cost. However, there is little published data on most, posing a significant challenge to the reconstructive surgeon trying to compare and select the most suitable product. The aims of this systematic review were to identify, summarize and evaluate the outcomes of studies describing the use of alloplastic adjuncts for post-mastectomy breast reconstruction. The secondary aims were to determine their cost-effectiveness and analyze outcomes in patients who also underwent radiotherapy.

METHODS

Using the PRSIMA 2009 statement, a systematic review was conducted to find articles reporting on the outcomes on the use of alloplastic adjuncts in post-mastectomy breast reconstruction. Multiple databases were searched independently by three authors (Cabalag MS, Miller GS and Chae MP), including: Ovid MEDLINE (1950 to present), Embase (1980 to 2015), PubMed and Cochrane Database of Systematic Reviews.

RESULTS

Current published literature on available alloplastic adjuncts are predominantly centered on ADMs, both allogeneic and xenogeneic, with few outcome studies available for synthetic meshes. Outcomes on the 89 articles, which met the inclusion criteria, were summarized and analyzed. The reported outcomes on alloplastic adjunct-assisted breast reconstruction were varied, with most data available on the use of ADMs, particularly AlloDerm(®) (LifeCell, Branchburg, New Jersey, USA). The use of ADMs in single-stage direct-to-implant breast reconstruction resulted in lower complication rates (infection, seroma, implant loss and late revision), and was more cost effective when compared to non-ADM, two-stage reconstruction. The majority of studies demonstrated inferior outcomes in ADM assisted, two-stage expander-to-implant reconstruction compared to non-ADM use. Multiple studies suggest that the use of ADMs results in a reduction of capsular contracture rates. Additionally, the reported beneficial effects of ADM use in irradiated tissue were varied.

CONCLUSIONS

ADM assisted two-stage breast reconstruction was associated with inferior outcomes when compared to non-ADM use. However, alloplastic adjuncts may have a role in single stage, direct-to-implant breast reconstruction. Published evidence comparing the long-term outcomes between the different types of adjuncts is lacking, and further level one studies are required to identify the ideal product.

DermACELL: Human Acellular Dermal Matrix Allograft A Case Report

Diabetes often causes ulcers on the feet of diabetic patients. A 56-year-old, insulin-dependent, diabetic woman presented to the wound care center with a Wagner grade 3 ulcer of the right heel. She reported a 3-week history of ulceration with moderate drainage and odor and had a history of ulceration and osteomyelitis in the contralateral limb. Rigorous wound care, including hospitalization; surgical incision and drainage; intravenous antibiotic drug therapy; vacuum-assisted therapy; and a new room temperature, sterile, human acellular dermal matrix graft were used to heal the wound, save her limb, and restore her activities of daily living. This case presentation involves alternative treatment of a diabetic foot ulcer with this new acellular dermal matrix, DermACELL.