Treatment of Necrotizing Fasciitis With NovoSorb Biodegradable Temporizing Matrix and RECELL Autologous Skin Cell Suspension: A Case Series

This case series reviews the management of 2 patients who developed a rare, aggressive soft tissue infection, necrotizing fasciitis treated with a synthetic polyurethane dermal regenerative template, Biodegradable Temporizing Matrix (NovoSorb BTM) in conjunction with an off-label use of RECELL device applying autologous skin cell suspension and a split-thickness skin graft for reconstruction. The clinical relevance describes a non-traditional patient's course of treatment and clinical outcome using BTM and RECELL for necrotizing fasciitis. The 2 patients survived with acceptable outcomes and timely healing despite a high chance of mortality and likely amputation secondary to the extensive surface area and anatomical location of the infection.

Design matters: A comparison of natural versus synthetic skin substitutes across benchtop and porcine wound healing metrics: An experimental study

Background and Aims

Skin substitutes, essential tools for helping close full thickness wounds with minimal scarring, are available in both collagen-based and synthetic polyurethane constructions. Here we explore fundamental differences between two frequently used skin substitutes and discuss how these differences may impact in vivo performance.

Methods

Polyurethane- and collagen-based matrices were characterized in vitro for pore size via scanning electron microscopy, hydrophobicity via liquid contact angle, conformability via bending angle, and biocompatibility via fibroblast and keratinocyte adhesion and proliferation. These matrices were then evaluated in a full-thickness excisional pig wound study followed by histological analysis. Statistical analysis was performed using t-tests or one-way analysis of variances with Tukey's multiple post hoc comparisons, where appropriate.

Results

Average pore diameter in the tested polyurethane matrix was over four times larger than that of the collagen matrix (589 ± 297 µm vs. 132 ± 91 µm). Through liquid contact angle measurement, the collagen matrix (not measurable) was found to be hydrophilic compared to the hydrophobic polyurethane matrix (>90°). The collagen matrix was significantly more conformable than the polyurethane matrix (9 ± 2° vs. 84 ± 5° bending angle, respectively). Fibroblast and keratinocyte adhesion and proliferation assays elucidated a significantly greater ability of both cell types to attach and proliferate on collagen versus polyurethane. While the porcine study showed minimal contraction of either matrix material, histological findings between the two treatments were markedly different. Collagen matrices were associated with early fibroblast infiltration and fibroplasia, whereas polyurethane matrices elicited a strong multinucleated giant cell response and produced a network of comparatively aligned collagen fibrils.

Conclusions

The more favorable in vitro properties of the collagen matrix led to less inflammation and better overall tissue response in vivo. Overall, our findings demonstrate how the choice of biomaterial and its design directly translate to differing in vivo mechanisms of action and overall tissue quality.

A novel use for the biodegradable temporizing matrix

Biodegradable Temporising Matrix (BTM), a skin substitute, has been recently developed as a novel adjunct to the plastic surgeon’s reconstructive repertoire. Its use has been described in literature in a variety of settings and complex wounds, including those that previously would have been described as “non-graftable”, with favourable outcomes. We present the case of a patient with a wound to the right foot and ankle following extravasation injury. Following surgical debridement, this injury was managed with BTM, which allowed granulation and production of a “neo-dermis”. A split-thickness skin graft was subsequently applied. The characteristics of the BTM allowed the resulting skin graft and scar to be pliable, avoiding tendon tethering and joint contracture. To the authors’ knowledge, this skin substitute has not been reported in a wound of this aetiology before. It is our hope that this report will provide evidence to colleagues that this is a valuable adjunct that may be used in complex wounds.

Level of evidence: Level V, therapeutic study.

Surviving an Extensive Burn Injury Using Advanced Skin Replacement Technologies

There have been significant improvements in the technology available for treating extensive burns in the past decade. This case presents two unique, skin replacement technologies that were used to treat an 86% surface area flame burn in a pediatric patient. A temporary dermal replacement, known as "Novosorb™ Biodegradable Temporizing Matrix" was first used to stabilize the burn injury and remained in place for approximately three months. Given the large burn size and lack of available donor skin for grafting, a permanent skin replacement product known as "Self-Assembled Skin Substitute (SASS)" was then utilized to cover the burns. SASS is a novel technology that was developed to replace skin as an autologous skin graft and is currently available in Canada through a clinical trial for major burns. Ultimately, the concurrent use of these two technologies allowed for the unprecedented survival of a child following an extensive and life-threatening burn injury.