Efficacy of Hydrofiber Silver Dressing in the Treatment of Posttraumatic Skin Wounds in Children

Three case reports on conservative treatment of posttraumatic open conquassant wounds in children are presented. In 2 cases, the wounds opened after rejection of a previously applied skin graft, whereas in the third case, the wound was consequential to toe amputation and treated conservatively. Based on the authors’ long-standing favorable experience with this type of dressing in healing of deep burns in children, treatment was continued with the use of a hydrofiber supportive silver-containing dressing (AQUACEL Ag, ConvaTec, Bridgewater, NJ). From the beginning of treatment, wound dressing was performed on an outpatient basis and without antibiotic therapy. The wounds healed within 4-8 weeks. The process of wound healing and treatment, the mechanisms that may compromise it, and the possibilities offered by hydrofiber silver dressing in conservative treatment of posttraumatic conquassant skin wounds are discussed.

Skin lesions occur consequentially to various types of trauma, which are common in older people and children. The basic rule of treatment is primary closure of each skin defect which, in the case of major defects, implies covering the wound with skin grafts of varying thickness. If tendons, bones, and neurovascular elements are exposed, then free flaps in the form of skin, subcutaneous tissue, and muscle transfer are used. Open conquassant skin wounds generally involve deep structures and require special treatment due to primary wound contamination, thus influencing the process of healing. When deciding on the method of treatment of these wounds, it should also be taken in consideration that a number of other factors favoring infection, such as hematoma, necrotic tissue, and impaired circulation are also present in these wounds. That is why such acute posttraumatic wounds frequently turn into chronic wounds. Besides infection as the major factor hampering wound healing, inadequate debridement performed immediately before wound covering with skin graft or some other coverage is a common cause of chronic posttraumatic wound development and subsequent graft rejection.¹ Currently, there are a number of known methods that facilitate treatment of these wounds, such as negative pressure therapy,² ultrasound or polarized light therapy, use of growth factors, and specific cytokines. In addition to these methods, the use of supportive hydrofiber dressings has been advocated for more recently, especially because of the favorable effect of these dressings on infection during wound healing.

Three cases of conquassant wounds treated with hydrofiber silver dressing (AQUACEL Ag, ConvaTec, Bridgewater, NJ) are presented. Due to the mechanism of injury infliction and aspect of the wounds, it was clinically clear that the wounds appeared contaminated in all 3 cases, increasing the likelihood of infection and additional complications during treatment. Considering the broad spectrum of antimicrobial action of dressing used by the authors, cultures were not performed.

Case 1. An 11-year-old girl presented to the Clinical Department of Pediatric Surgery, Clinical Hospital Center Rijeka, Croatia, with an open forearm wound caused by a fall on an escalator. Immediately after admittance, the skin graft was set. Graft rejection occurred a few days after covering the wound with a free skin graft, silicone tape, and sterile gauze (Figure 1A). Outpatient treatment was continued with a hydrofiber silver dressing with wound redressing daily for the first 4 days following discharge, then every 3-4 days afterwards. Sterile gauze was used as a secondary dressing. Considerable reduction of the wound area was evident within less than a month (Figure 1B), and complete epithelialization occurred within 6 weeks (Figure 1C). Epithelization was not measured, but the wound healing was documented photographically during the entire period. Conservative therapy appeared to lessen the appearance of the resulting scar. The authors did not find this surprising since the process of wound healing includes the phase of contraction, which is more pronounced with conservative treatment than with a skin graft (Figure 1D). Following epithelialization, treatment was continued with silicone tape for 2 months. 

Case 2. A 7-year-old boy presented to the Clinical Department of Pediatric Surgery, Clinical Hospital Center Rijeka, Croatia, with a skin defect of the hand following a motor saw amputation of 4 fingers. The skin graft was set immediately after admittance. Graft rejection occurred several days after surgical debridement and covering of the defect with a skin graft, silicone tape, and sterile gauze (Figure 2A). Treatment was continued with a hydrofiber silver dressing and covered with sterile gauze, which resulted in considerable reduction of the wound area within 2 weeks (Figure 2B) and complete wound epithelialization within 1 month (Figure 2C). The scar left after this treatment showed the thickness of cover was adequate, and the scar was not atrophic, hypertrophic, or keloid, in spite of the injury causing tendon and bone exposure (Figure 2D). 

Case 3. A 12-year-old girl presented to the Clinical Department of Pediatric Surgery, Clinical Hospital Center Rijeka, Croatia, with an open conquassant foot wound caused by a tire in a traffic accident (Figure 3A). After amputation of the big toe, the open wound of the foot was, on the parents’ demand, treated conservatively with hydrofiber silver dressing and not by skin graft. Sterile gauze was used as a secondary dressing. The wound was dressed daily for the first 4 days postinjury because of sufficient wound fluid present and every 3-4 days following. Using this method of redressing, gradual debridement was initially performed by the hydrofiber silver dressing. It should be noted the dressing should not be soaked with saline before removal. Epithelialization of nearly 50% of the wound area occurred within less than 1 month (Figure 3B). This therapeutic option left a smaller scar behind than if a skin graft had been used (Figure 3C). Once complete epithelialization was achieved, the scar was treated with silicone tape for 2 months, with a satisfactory result: the scar was soft, and not atrophic, hypertrophic, or keloid (Figure 3D). 

Wound healing is a complex body response to broken skin integrity. The process of healing proceeds through several phases driven by various stimulants and inhibitors formed within the body, known as growth factors, cytokines, and matrix metalloproteinases.³ The healing process is influenced by many factors, of which infection is most important, in addition to blood perfusion and systemic illnesses.⁴ Four phases are distinguished in the process of wound healing: hemostasis, inflammation, proliferation, and remodeling.⁵ Hemostasis requires the presence of factors such as factor XII and factor IX, a lack of which will interrupt the course of healing.^6,7 This is followed by inflammation, where inflammatory cells, neutrophils, and macrophages enter the wound area.⁶ Their main function is wound cleansing, as they are involved in phagocytosis and debridement; however, they also represent a rich source of cellular regulators necessary for healing progress. Inflammatory cells release cytokines and growth factors into the wound, thus stimulating fibroblasts, keratinocytes, and endothelial cells to regenerate damaged blood vessels.⁷ Proliferation occurs through a number of steps, such as formation of granulation tissue, angiogenesis, epithelialization, and wound contraction. Granulation tissue consists of mesenchymal and non-mesenchymal cells incorporated in the extracellular matrix, which makes a basis for cell differentiation and consists of soluble and insoluble proteins, of which collagen is most abundant.⁸ Its function is to ensure integrity and firmness. Angiogenesis is the formation of blood vessels from the existing capillaries from wound margins. This is followed by epithelialization, the goal of which is reconstruction of the skin protective barrier. In the phase of wound contraction, the wound area is reduced, thus shortening the time of wound healing. During the final phase of remodeling, tensile strength of the healed wound is increased. As emphasized above, the whole process of wound healing can be retarded or interrupted in any phase, with infection as the most common cause, particularly in acute wounds. Supportive wound dressings that maintain a favorable milieu for cells and all pathophysiological events in the process of wound healing play a major role in wound care. Recently, biofilm has come into the focus of interest; it is described as a community of bacteria embedded in a thick, slimy barrier protecting bacteria from external influence. It should be noted these are generally heterogeneous communities of microorganisms that are continuously changing. Although some studies demonstrate the presence of biofilms in only 6% of acute wounds,⁹ it should also be taken into consideration when choosing a supportive wound dressing.

Hydrofiber dressings have a high capacity for exudate absorption and retention. The hydrofiber silver dressing acts by exudate absorption while releasing silver, which destroys pathogenic bacteria in the wound. Between the wound and the dressing, a gelatinous layer is formed where bacteria are trapped, thus preventing their further action in the wound (Figure 4). Metallic silver is inert in the presence of human tissues but ionizes in the presence of moisture, body fluids, and secretions to release the biologically active silver ion which shows a strong affinity for sulphydryl groups and other anionic ligands of proteins, cell membranes, and tissue debris.¹⁰ At low concentrations, as in the hydrofiber silver dressing used in the described cases, silver toxicity is minimal because the percutaneous absorption of silver is exceedingly low,¹¹ and the possibility of developing resistance is less than with antibiotics since silver acts upon a number of target sites within bacterial cells.¹² Silver binds to the bacterial cell membrane, damaging it and  causing the release of its content. Upon entering the cell, silver ions impair its function by binding to proteins, thus interfering with energy production, enzyme function, and cell replication.¹³ Ionic silver has been demonstrated to exert broad antimicrobial action even upon methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE).¹⁴ The authors’ long-term experience and favorable results in the management of deep burns in children confirm the broad spectrum of hydrofiber silver antimicrobial action.¹⁵ The hydrofiber silver dressing has also been demonstrated to exert potent antifungal action,¹⁶ also witnessed at the authors’ institution in the treatment of kerion caused by Microsporum gypseum exclusively with the hydrofiber silver dressing.¹⁷ The dressing acts as a reservoir of silver and responds to changes in the components of wound fluid with increased silver ion availability as needed.¹⁸ It should also be noted only a minor portion of silver in the dressing is involved in the antimicrobial process, while the majority of silver remains in the dressing, and only a very small portion undergoes systemic absorption.¹⁹ 

Considering simple use and favorable results of conservative treatment of posttraumatic conquassant skin wounds with hydrofiber silver dressing, the authors conclude that, in children, not only should this dressing be considered as an option in the case of a wound that transforms to a chronic posttraumatic wound, but it should be considered as a primary therapeutic option. In this way, if applicable to the wound type, operative procedure is avoided, the scar area reduced, and the child enabled normal functioning.

Affiliations: Clinical Department of Pediatric Surgery, Clinical Hospital Center Rijeka, Croatia; and the Department of Pathology, School of Medicine, University of Rijeka, Croatia

Correspondence:
Nedeljka Glavan, MD
Clinical Department of Pediatric Surgery,
Clinical Hospital Center Rijeka, 
Istarska 43, 51000 Rijeka Croatia
neda.glavan@ri.t-com.hr

Disclosure: The authors disclose no financial or other conflicts of interest.