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.