The Clinical Utility of Powdered and Flowable Matrices in Wound Repair and Tissue Regeneration.

Cellular and matrix-like products come in many forms. Among them, powdered and micronized formulations have become increasingly available and popular owing to their unique properties and advantages. Powders have increased tissue contact which many believe can enhance granulation tissue formation, they fill irregular and deep cavities, and they can be used in concert with sheet-like products and skin grafts for improved healing. Despite their advantages, powdered products do have certain limitations that hinder their use, including poor insurance coverage and a lack of CPT coding for adequate reimbursement in an outpatient setting, making their use primarily limited to the operating room. Also, most published data on powdered products consists of smaller case studies and case series, with few reports evaluating the efficacy and utility of powdered formulations compared to their sheet-like progenitors. In this manuscript, we organize available powdered matrix products by type of substrate: xenograft, allograft, placental-based, and synthetic, and review the data in support of various products in specific wound types. This review of the supporting literature provides the current body of evidence on the utility of powdered matrices in wounds.

Arterial Leg Ulcers in the Octogenarian.

Arterial leg ulcers are a debilitating sequela of chronic ischemia, and their management, particularly in the octogenarian, is an immense challenge. ALUs are frequently a manifestation of end-stage peripheral arterial disease, and their presence portends a high morbidity and mortality. Management primarily relies on restoration of flow, but in the geriatric population, interventions may carry undue risk and pathologies may not be amenable. Adjunctive therapies that improve quality of life and decrease morbidity and mortality are therefore essential, and understanding their benefits and limitations is crucial in developing a multimodal treatment algorithm of care for the uniquely challenging octogenarian population.

Autologous Blood-Derived Products (ABDPs) for the Treatment of Chronic Wounds.

Autologous blood-derived therapies have emerged as a unique and promising treatment option for chronic wounds. From whole blood clots to spun-down clot constituents, these therapies are highly versatile and tend to have a lower cost profile, allow for point-of-service preparation, and inherently carry minimal to no risk of rejection or allergic reaction when compared to many alternative cellular and matrix-like products. Subsequently, a diversity of processing systems, devices, and kits have surfaced on the market for preparing autologous blood-derived products (ABDPs) and many have demonstrated preclinical and clinical efficacy in facilitating chronic wound healing. However, not all ABDPs are created equal, and the lack of standardization among product formulations and cell concentrations as well as varying complexities in preparation protocols has led to unreliable substrate viabilities and overall inconsistent conclusions on efficacy. Additionally, external factors, such as the ease of drawing blood, the health of a patient's blood, and the reimbursement landscape have dissuaded some practitioners from incorporating ABDPs into an algorithm of care for recalcitrant wounds. Here, we attempt to categorize ABDPs into "classes" and examine their efficacy, advantages, and limitations when used as both a primary therapy and an adjunct for treating chronic wounds as well as comment on some potential considerations that may help gear future product development and application.

The Shift to Synthetics: A Review of Novel Synthetic Matrices for Wound Closure.

Since the late 1990s, a growing number of "skin substitutes" have become available to practitioners seeking to heal large surface wounds. These extracellular matrices were originally from xenograft sources, and then from very highly engineered living human cellular tissues. More recently, they consist of biosynthetic materials that are combinations of silicone, collagen and chondroitin. The list of xenograft materials as well as minimally manipulated human tissues, such as human skin-, amniotic- and placental-based products, has grown exponentially. Over the last 5 years, truly synthetic materials have become part of the armamentarium available for closing large wounds. The first notable product in this category was made of polyurethane. These purely synthetic products do not have any components made of naturally occurring structures, such as collagen. In this review, we seek to create a rudimentary framework in which to understand these synthetic products and to review the current literature that supports the use of these novel yet intriguing therapies.

Implantable Biologics for Soft Tissue Surgery Reinforcement.

Soft tissue reinforcement focuses on medical grafts that are designed to support and regenerate soft tissue under or near suture lines. Soft tissue is defined as areas of similarly specialized cells that function to connect, support, and surround other structures and organs of the body. These tissues include skin, subcutaneous tissue, fascia, ligaments, tendons, fibrous tissues, fat, synovial membranes, and muscle. Most of the implantable devices used for this purpose are made of collagen, the most abundant protein in mammals and a key component of the extracellular matrix of soft tissues that allows for tissue repair. For suture line reinforcement, exogenous collagen from various sources is implanted under or in continuity with the suture line to allow for increased strength and better healing. First introduced in the field of breast reconstruction, this practice is now also used in hernia repair, dural repair, vaginal slings, amputation reinforcement, tendon repair reinforcement, and even dental soft tissue regeneration.

Acellular Fish Skin for Tissue Replacement.

In modern practice, xenografts play a crucial role in wound management due to their regenerative properties. Of the various xenografts currently available on the market, acellular fish skin (AFS) grafts have emerged as a more effective alternative to existing xenografts and other standard of care (SOC) treatments for wound healing. Since AFS grafts require minimal processing, they maintain their structural integrity and natural properties, including an abundance of Omega-3 fatty acids, which is a distinctive, pro-regenerative feature. AFS grafts are also unique in that they are not derived from mammalian tissue, so there is no risk of viral transmission and no cultural or religious barriers to use. AFS grafts have been shown to be more cost-effective in the treatment of diabetic foot ulcers (DFUs) and result in a higher percentage of healed wounds, fewer amputations, and better patient quality of life. Several studies and case reports have highlighted the versatility of AFS in not only acute and chronic wound healing, but also for burn wound skin regeneration. Additionally, AFS may have promise as an implantable biologic matrix for suture line reinforcement in hernia repairs or breast and dura reconstruction.

Use of negative pressure wound therapy for the treatment of venous leg ulcers.

NPWT has probably been the most important addition to wound care in the current century. Despite this fact, its use in the treatment of VLUs remains very limited. This review first examines the documented and potential VLU wound environment changes that can be facilitated by NPWT. The data supporting the use of NPWT for VLU wound bed preparation, the management of fluid drainage, and the bolstering of skin grafts are evaluated. The similarities and differences between suNPWT, traditional NPWT, and NPWTi are outlined. Included in this review is when and where each therapy may have a place in the treatment of VLUs. Finally, a brief algorithm to enhance the use of NPWT in the treatment of VLUs is presented.

Novel Reconstructive Ladder for Reestablishing Functional Skin Graft Coverage in Chronic Lower Extremity Wounds.

Background: Chronic lower extremity (LE) wounds frequently require significant interventions to close. The success of any method depends on an adequately prepared wound bed, while factors including wound size, perfusion, contamination, or exposed tissue structures can thwart efforts. We propose a standardized algorithm of care utilizing an acellular dermal matrix, split-thickness skin graft (STSG), and negative pressure wound therapy (NPWT) for the treatment of LE wounds. Methods: This was a single-center, retrospective cohort study examining patients who underwent LE wound debridement, placement of fetal bovine dermis (FBD), and STSG between 2016 and 2022. The primary outcome was wound closure, while secondary outcomes were wound infection and amputation-free survival. Results: Twenty patients (mean age 59 years, M:F 12:8)-including 24 LE venous ulcers (29.4%), amputation sites (29.4%), diabetic foot ulcers (25.0%), and atypical wounds (16.7%) with an average area of 39.15 cm2-underwent debridement and FBD placement followed by STSG a median of 61 days thereafter. Of these patients, 83.3% received NPWT after FBD and STSG with 86% closure. There was successful engraftment in 92% of wounds whose FBD placement was within 2 months of STSG. Of wounds that had <50% engraftment, 75% had a STSG placed over 2 months after FBD placement. Of those patients with post-STSG infection, 75% had the graft placed >2 months after FBD placement, one of which required proximal amputation. Conclusions: By following a treatment plan including debridement with treatment of infection, application of FBD with placement of STSG within 2 months thereafter, and reinforcing NPWT, chronic wounds will have an increased rate of successful reepithelialization. Many cases experienced delays from FBD engraftment until STSG application due to schedule and insurance impediments, which led to less favorable outcomes. Therefore, a protocol that involves scheduling the placement of STSG 4 weeks after successful engraftment of FBD has been adopted.