Letter to the Editor: Autolytic Dressings

Dear Editor:
  In the June/July 2014 issue, Thomas and Thayer¹ cite a 2005 study by König et al,² which compared a collagenase product to autolytic support in the treatment of chronic leg ulcers. The König study findings were not statistically significant, but there seemed to be better appearance of the re-epithelialized area, granulation tissue, and remaining eschar in wounds treated with the autolytic dressing. To avoid potentially confusing or misleading the US wound care community, it is important to clarify this citation.

  The collagenase product used by König was Iruxol® N, a product not available for sale in the US. The original article mistakenly claimed that Iruxol N is the same product as the US-marketed product, Collagenase Santyl® Ointment (Santyl). In fact, these are two different collagenase-based products. Iruxol N and Santyl are derived from different cell lines and are manufactured using meaningfully different methods. There has been no clinical evaluation comparing these two products; however, in vitro testing has identified that the products’ activity levels are not comparable, presumably due to the different source materials and manufacturing processes.

  Additionally, König identified several methodological issues with the study that could have contributed to the perceived better appearance of wounds treated with the autolytic dressing. These included statistical issues arising from randomization problems, inconsistent therapeutic responses, and the subjective visual assessment of the wounds. Newer data suggests that visual assessment of the wound surface correlates poorly with actual measurements of wound area reduction and closure.³ Consequently, this brings into question the value of relying exclusively on subjective visual assessment when making treatment decisions.

Sincerely,
  Herbert B. Slade, MD, chief medical officer, Smith & Nephew Biotherapeutics; & David E. Mire, PhD, director, strategic planning, Smith & Nephew Biotherapeutics.

References

1. Thomas AB, Thayer WP. Debridement of chronic wounds: A review of past & present treatment strategies. TWC. 2014;8(5):16-20.

2. König M, Vanscheidt W, Augustin M, et al. Enzymatic versus autolytic debridement of chronic leg ulcers: A prospective randomised trial. J Wound Care. 2005;14(7):320–3.

3. Motley TA, Lange DL, Dickerson JE Jr., Slade HB. Clinical outcomes associated with serial sharp debridement of diabetic foot ulcers with and without clostridial collagenase ointment. Wounds. 2014;26(3):57-64.

Editor’s Note: TWC shared this letter, prior to publication, with the article authors, who determined that the claims made in the letter are accurate and that no response was necessary.