Electrical Stimulation Therapy and Wound Healing: Where Are We Now?

Background: Healing chronic wounds is an ongoing challenge for clinicians and poses a serious public health burden. Electrical stimulation (ES), broadly defined as the application of electrical current via electrodes placed on the skin adjacent to or directly within the wound, has been proposed as a therapeutic modality over a century ago, and recent advances in understanding the biology of electrical phenomena in the skin have rekindled an interest in this modality. The Problem: Despite evidence that has shown ES to be effective for wound healing, it has been slow to gain acceptance in the United States. Also, there has been no consensus in terms of standardization of parameters to devise a systematic protocol for implementation of this technology. Basic/Clinical Science Advances: The epidermis maintains a "skin battery'' that generates an endogenous electric field and current flow when wounded. Experimental models have demonstrated that most of the cell types within the wound can sense an electric field in the range of that endogenously generated in the wound, and respond with a variety of biological and functional responses that can contribute to healing. Multiple animal wound models have demonstrated enhancement of a number of parameters of healing when ES is exogenously supplied. Clinical Care Relevance: Clinical trials have investigated the efficacy of multiple forms of ES for improving healing in a wide variety of human chronic wounds. In 2002 the Centers for Medicare and Medicaid Services approved reimbursement for use of ES in a clinical setting for certain chronic wounds. Conclusion: There remain many voids in our knowledge base: clinical evidence is limited by deficiencies in the design of many of the trials, a multiplicity of ES application modes and waveforms used in trials prevent selection of an optimal modality, and lack of uniformity in reporting ES dosages leave us not much advanced from our clinical knowledge base a decade ago.