Reply: Outcomes and Predictors of Wound Healing among Patients with Complex Diabetic Foot Wounds Treated with a Dermal Regeneration Template (Integra)

Sir:

We thank Dr. Sun for the thoughtful insight and questions regarding our article.¹ While we agree that we are not the first to apply dermal regeneration templates to treat complex diabetic foot wounds, this is the first such study to use a validated lower extremity threatened limb classification system to quantify the risk of major amputation. Further, our favorable limb preservation rates justify publication of our methods and protocols. It has been our experience that application of negative-pressure wound therapy combined with split-thickness skin grafting after débridement does not work as well as when the wound has exposed bone and tendon. In these cases, application of the dermal regeneration template along with negative-pressure wound therapy results in a wound base that is then ready for split-thickness skin grafting.

In response to Dr. Sun’s specific questions, avoiding any postoperative infection begins with thorough wound preparation, aggressive debridement, and gentle irrigation with saline using cystoscopy tubing with a volume of 3 to 6 liters, before application of the dermal regeneration template (Integra; Integra LifeSciences, Princeton, N.J.). On a case-by-case basis, we may also utilize hydrosurgery to obtain a clean wound that easily accepts the template. After homogenous incorporation of the membrane and removal of the silicone layer, a neodermis exists that usually requires additional maturing. To complete the process, we utilize a collagen dressing to attract fibroblasts (collagen should be type 1 and have native integrity) to the wound to facilitate deposition of collagen supplementing the development of angiogenesis and granulation. Home nursing staff are trained by our multidisciplinary team, if possible, to perform dressing changes every 5 days. We discharge patients with a written detailed postoperative Integra protocol sheet as well. We also advocate using a contact layer on the wound to maintain a moist environment. Finally, when necessary, we recommend wound cleansing with hypochlorous acid, rather than peroxide or povidone iodine, which are both toxic to fibroblasts. We did trial instillation negative-pressure therapy, but we found the results to be too variable. We ultimately stopped this technique because it was laborious to construct, and the choices of solution were unsubstantiated.

If the wound responds adequately, then we move forward with a split-thickness skin graft as early as is reasonable. With the depth and destruction of complex wounds, it may take another few weeks to have a stellar wound bed for grafting. The cost of collagen is inexpensive, and it has been our experience that wound maturation results in a better “take” of the skin graft.

We have developed three phases of complete healing for limb salvage: (1) abate the infection, (2) heal the wound, and (3) achieve foot functionality. In most cases, the original ulceration area will not exhibit any recurrence, but foot plantar peak pressures will vary, translocate, and result in ulceration recurrence else-where on the foot. We recently demonstrated that ulcer recurrence rates for complex diabetic foot wounds are 31 percent and 64 percent at 1 and 3 years after healing, respectively, but that only 13 percent of recurrent ulcers occur at the same site as the initial wound.² We currently have an ongoing gait analysis research study detailing the changing of temporal peak pressures of the foot after reconstruction. In many cases, patients will require extradepth diabetic shoes with cushioned multidensity custom insoles for long-term functionality. DOI: 10.1097/PRS.0000000000008075