Amniotic Suspension Allograft and Fetal Bovine Acellular Dermal Matrix to Treat Complex, Acute, Full-Thickness Wounds

A Retrospective Analysis of Safety and Treatment Efficacy

Steven Thomas, MD; Peter Yen, PA-C; Joseph Sclafani, MD; Joseph Connor, MD; John McQuilling, PhD; Katie Culpepper Mowry, PhD

Disclosures

Wounds. 2020;32(1):30-36. 

In This Article

Abstract and Introduction

Abstract

Introduction: Comorbidities; inadequate vascularity; exposure of bones, tendons, or other avascular structures; and loss or removal of significant tissue volume all complicate the clinical treatment of patients with large, acute wounds. A number of amniotic tissue products are currently available for wound healing and other applications; one of these is a human amniotic suspension allograft (ASA) consisting of particulated human amniotic membrane and cells from the amniotic fluid from the same human donor.

Objective: In this study, the use of ASA with a fetal-derived bovine acellular dermal matrix to promote the healing of large, acute, full-thickness wounds is evaluated. The authors herein hypothesize treatment with ASA may allow for the healing of these wounds.

Materials and Methods: This study consisted of a chart review of 33 patients, with an average age of 42.2 years, and large acute wounds that were treated with a fetal-derived bovine acellular dermal matrix adsorbed with ASA. To the best of the authors' knowledge, this is the first study to date to investigate the usefulness of ASA in wound healing for large, complex, acute wounds.

Results: In this study, 30 of 33 patients were confirmed as fully healed, and 3 patients were lost to follow-up. The average wound size was 537.4 cm2, and the average time to split-thickness skin grafting (STSG) was 30.5 days, with an average time of 6.8 days until at least 95% graft take was achieved. Of the patient population studied, 45.5% had 1 or more significant comorbidities, 30.3% had wounds larger than 500 cm2, and 39.4% had exposed bone or tendon.

Conclusions: In a small but challenging population including a high number of patients with comorbidities and exposed bone or tendon, it was found that ASA delivery, along with a dermal matrix, was successful in treating large, complex, acute wounds.

Introduction

Appropriate selection of the proper treatment modality can be confusing and challenging in the field of wound care. Current estimates for total Medicare spending for the management of all wound types range from $28.1 to $96.8 billion in annual health care-associated costs.[1] Despite a dearth of clinical trials to guide therapy, a lack of consensus on a treatment algorithm for complex, acute wounds remains. For example, a meta-review[2] found that after analyzing 99 systematic reviews regarding wound healing, there were multiple promising interventions but minimal consistency across wound types and throughout the literature.

For chronic wounds, some of the commonly employed techniques utilize hydrogels and foams to decrease moisture imbalance.[3] Based on a 2013 meta-analysis of 5 studies with 446 patients,[4] hydrogels demonstrated significantly greater healing in patients with diabetic foot ulcers when compared with standard dressings or no dressing at all. In addition, there are more advanced biological treatments, including topical treatments with enzymes, growth factors, and cell-based products, to modulate the wound environment to promote healing.[5] In a recent review and meta-analysis,[5] more than 40 trials with over 1700 patients presented evidence that active wound dressings were more effective in comparison with traditional dressing techniques but required more randomized trials for additional support.

Although these techniques are well-suited for small wounds, larger wounds (>500 cm2) often require additional and/or more advanced treatment steps. There are difficulties in treating large, complex, acute wounds with advanced wound care products, as the larger wound size and necessity for multiple treatments often can preclude many of these grafts. Skin autografting is considered the gold standard mainstay for complex wounds with extensive dermal tissue loss and damage;[6,7] however, the donor site necessary for creating a large graft causes its own complications, including donor site morbidity, pain, and scarring.[6,7] Large wounds with defects in vascularity may be treated with local or free tissue flap transfers, but proper healing is subject to prolonged immobilization and control of comorbidities. Comorbidities including diabetes, chronic obstructive pulmonary disease, and smoking increase the difficulty of administering treatment and reduce the success rate of flaps, highlighting the need for alternative treatment modalities. An alternative that has been employed in some cases is the use of a dermal substitute; these grafts have been used to alleviate the need for full-thickness grafting by promoting neodermis to provide coverage of underlying tissue, including bone, tendons, and other structures.[8–15] As a second step, a split-thickness autograft is often placed.

Many of the currently available dermal matrix products are scaffolds taken from a collagen source and used as a temporary extracellular matrix. A fetal-derived bovine acellular dermal matrix (FBADM; PriMatrix Dermal Repair Scaffold; Integra LifeSciences Corporation, Plainsboro, NJ) has been used in partial- and full-thickness wounds and shown to significantly accelerate healing compared with standard therapies,[16,17] including in patients who were not ideal candidates for flap coverage.

Tissues derived from placental membranes have been utilized as an adjunct to chronic wound healing by many groups.[18,19] Amniotic suspension allograft (ASA; NuCel; Organogenesis Inc, Canton, MA) consists of growth factors and cells from the amniotic fluid, along with particulated amniotic membrane in a cryopreserved suspension. Placental-derived tissue has been reported to be nonimmunogenic, anti-inflammatory, and have antibacterial properties.[20–25] These tissues have been shown to promote proliferation and migration of cells important to wound healing, including fibroblasts, keratinocytes, and endothelial cells.[26,27] Amniotic tissue also has been reported[28–34] to reduce scar tissue formation and pain at the site of application and protect against infection by serving as a biological barrier. In addition, amniotic tissues have demonstrated improvements in aesthetic results and decreased hypertrophic scarring when compared with conventional dressings in split-thickness skin graft (STSG) donor sites.[35]

While most previous works examining alternatives to traditional wound healing techniques used small wounds in patients with less complex comorbidities, this study aimed to investigate the safety and efficacy of ASA as an adjunct to FBADM application within a complex patient population undergoing treatment for various large acute wounds. The authors hypothesized the physiologically relevant growth factors and cytokines released from the ASA product would facilitate healing of complex wounds on a larger scale.

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