A Closer Look At Combination Therapy For Chronic Wounds
What The Literature Reveals About PRP
Continued research is occurring on PRP, which promotes platelet-derived growth factors, vascular endothelial growth factors and cytokines in the hopes that this will stimulate wound healing. The procedure requires a sample of the patient’s blood that spins down in a centrifuge that separates blood into the red blood cell layer, the “buffy coat” (which is the PRP layer) and the plasma-poor layer. One subsequently injects the isolated PRP layer into the area of concern.
The theory is that tissue healing and microcirculation improve because of the variety of growth factors contained in PRP. Studies show that PRP can restart the healing process in otherwise recalcitrant chronic wounds. In one study, 96.5 percent of wounds had a positive response with area and volume reduction in only two weeks after three treatments.9 Another study showed that in the most common wounds (including pressure ulcers, venous ulcers and diabetic foot ulcers), the use of PRP reduced wound volume, area, undermining and sinus tract/tunneling after 2.8 weeks with 3.2 applications.10
Adverse effects are few. Since PRP is an autologous substance, allergic reactions are rare and transmissible infections are fewer. Unfortunately, research is limited and most insurance companies do not reimburse for the procedure. Patients are therefore required to pay for this treatment on their own.
How Effective Are Bioengineered Skin Substitutes?
Skin substitutes were initially developed for the treatment of patients with burns and physicians now frequently use them in the treatment of chronic foot wounds. Some of these substitutes derive from allogeneic sources while others are bioengineered in the lab. They accelerate wound healing by providing a moist wound environment, act as a structural support and provide a network of cytokines and growth factors.
Skin substitutes consist of an epidermal layer and/or a dermal layer embedded into an acellular matrix, which acts as a support structure.11 This combination of angiogenesis, growth factors and cell adhesion properties allows for a shorter wound healing time when clinicians use skin substitutes in conjunction with other conservative treatments. The three-dimensional skin substitute provides a metabolically active, living scaffold that allows for proliferation of the dermal bed.
Trials have shown that the use of skin substitutes such as Dermagraft (Advanced BioHealing) or Apligraf (Organogenesis) result in a higher incidence of complete wound closure and shorter time to complete wound healing.12 The most promising results of trials involving skin substitutes indicated that the concomitant use of skin substitutes and other modalities of wound treatment, namely debridement, yielded shorter healing time.13
Skin substitutes are contraindicated in actively infected ulcers or those patients with bovine allergies. Infections are low and systemic toxicity is rare. Patients can receive this treatment in the office setting. It is a simple, non-painful procedure.