Evaluation of two absorbent silver dressings in a porcine partial-thickness excisional wound model

Abstract

To investigate and compare the performance of two widely used silver-containing, fibre-based dressings (Silvercel and Aquacel Ag) in terms of exudate management, wound-site adherence, dressing integrity, retention of dressing debris within wounds, frequency of debris-associated foreign body reactions and the impact of both debris and tissue reactions on wound-tissue integrity. The dressings were evaluated in a porcine partial-thickness exudating wound model (an in vivo model of moderate to high exudation up to post-wounding day 4, and low exudation from days 4 to 7). Dressing performance was assessed using a panel of semi-quantitative scales.Wound-exudate retention, dressing structure following exposure to exudate, and adherence to wound tissues were compared macroscopically; the extent of trapped dressing debris, any ensuing tissue reactions and the level of resulting tissue disruption were compared histologically. Silvercel was found to be significantly more effective in terms of wound exudate management than Aquacel Ag. On exposure to high levels of wound exudate, Silvercel retained its shape and mechanical strength, and remained at the site of application. In contrast, Aquacel Ag formed a fluid (semi-fibrous) gel, with minimal mechanical integrity and variable retention at the wound site. Silvercel was significantly more adherent to wound tissues than Aquacel Ag, but the level of trapped dressing debris, the frequency of ensuing foreign body reactions and the level of consequent wound-tissue disruption was lower, although not statistically, in the Silvercel-treated wounds. These results suggest that the potential adverse clinical consequences of unmanaged wound exudate may be less likely in Silvercel than Aquacel Ag-treated wounds. In addition, the adverse effects of dressing adherence may be less likely in Aquacel Ag-treated wounds, although such benefits may be negated by the potentially deleterious effects of elevated dressing debris deposition. In view of these findings, further development of absorbent fibre-based dressings should be directed at maximising exudate management, minimising dressing adherence and preventing dressing-debris entrapment.