Use of three-dimensional acellular collagen matrix in deep or tunnelling diabetic foot ulcers: a retrospective case series

Objective: While most xenograft wound matrices are flat sheets not designed for deep or tunnelling wounds, three-dimensional acellular collagen matrices (3D-ACM) can fill deep wound beds and enable full wound wall apposition. This case series examines the use of 3D-ACM in treating diabetic foot ulcers (DFUs) that are deep, tunnelling, undermining, or irregularly shaped. We report outcomes of cases where 3D-ACM was applied to deep or tunnelling DFUs present for at least four weeks. Method: In this retrospective case series, 3D-ACM was applied, healing was monitored and measurements were collected. Additional 3D-ACM was applied as needed. Results: In total, 11 patients with 13 wounds were treated. Improved wound appearance and reduced size were observed at most follow-ups. Mean initial wound depth was 1.6cm, and several wounds showed significant depth reductions shortly after therapy initiation. In total, 62% of wounds (8/13) reached 50% closure by four weeks. Additionally, 54% (7/13) were fully closed by 12 weeks. The remaining 46% (6/13) took between 12-22.3 weeks to heal. Overall mean therapy time was 13.1 weeks (range: 2.0-22.3 weeks). Deeper wounds generally took longer to close. Conclusion: The findings of this case series showed that 3D-ACM could offer a protective microenvironment for wound management for deep or tunnelling DFUs. While some took >12 weeks to close, this may be attributable to large initial depths and volumes, rather than a failure to respond to the treatment modality. Other wounds that require a conforming 3D matrix, enabling full wound wall apposition, may benefit from 3D-ACM. Further investigations would be beneficial to understand the capabilities of this treatment modality. Declaration of interest: RJA is a paid consultant of Reprise Biomedical, Inc., US, ProgenaCare Global, US, and Imbed Biosciences, Inc., US. ALC is a consultant of Reprise Biomedical Inc. In our consultancy roles, we provide expertise, advice, and guidance on matters related to the treatment of wounds. We affirm that these interests have not influenced the design, conduct, or reporting of the research presented in this manuscript.