Combining VAC Therapy With Advanced Modalities: Can It Expedite Healing?

Author(s): 
By Stephanie C. Wu, DPM, MS, Hong Yoon, MS, and David G. Armstrong, DPM, MSc, PhD

Does NPWT Help Facilitate An Increased Efficacy Of Regranex?

   Becaplermin (Regranex, Johnson & Johnson) is a hydrogel that contains 0.01% platelet derived growth factor-BB (rhPDGF-BB) and is currently the only commercially available topical growth factor for use in cutaneous wound healing.    Researchers have shown that PDGF-BB promotes wound healing by increasing proliferation and migration of dermal fibroblasts and extracellular matrix deposition. PDGF also promotes chemotaxis of neutrophils, monocytes and smooth muscle cells in wounds.24 Several studies have demonstrated the efficacy and safety of becaplermin.25,26    Some clinicians advocate combining becaplermin with NPWT with the belief that NPWT may remove excess fluid to create an environment that helps facilitate the actions of the PDGF-BB. It has been suggested that the imbalance between levels of matrix metalloproteases and their inhibitors in the fluids of ulcers causes elevated levels of proteases.26 The proteases in turn destroy essential growth factors, extracellular matrix proteins and receptors, including the ones specific for PDGF-BB, to ultimately prevent wounds from healing.20 Others argue that NPWT may indiscriminately remove the PDGF-BB while removing the excess fluid. There is currently no published data pertaining to the combination of becaplermin gel with NPWT. Further research and analysis are necessary to understand, validate and refine this approach to facilitate wound healing.

What You Should Know About Bioengineered Skin Replacements And NPWT

   Researchers have noted that a human fibroblast-derived dermal substitute (Dermagraft, Smith and Nephew) and an allogeneic bilayered cultured skin equivalent (Apligraf, Organogenesis) facilitate angiogenesis and promote the healing of chronic ulcerations. Numerous studies have shown the efficacy of these modalities in the healing of full thickness chronic wounds.27-32    Seroma formation is one of the most common reasons leading to the “failure” of bioengineered skin replacements. The application of NPWT at a lower setting may serve as a mechanical, highly effective bolster dressing to mitigate shear forces and hematoma/seroma formation, and facilitate “uptake.” This would be similar to the technique one would employ to potentiate the uptake of autogenous skin grafts.33-35    Although there are currently no clinical trials that validate the combined use of NPWT with bioengineered skin replacements, there have been anecdotal reports of combining NPWT with other bioengineered tissue equivalents such as regenerative tissue matrix (Graftjacket, Wright Medical Technology), bilayered cellular matrix (Orcel, Ortec), and bilayer matrix wound dressing (Integra, Integra LifeSciences).    Jeschke et. al., examined the healing of deep, complex wounds with the combinational use of bilayer matrix wound dressing and NPWT.36 This combination expedited wound healing and resulted in wounds that were ready for split thickness skin grafts in a mean of 7.25 days. They found that NPWT improved both the take rate and time to vascularization of a bilayer matrix wound dressing when compared to previously published results using the bilayer matrix wound dressing alone.

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