Source: McCulloch , Kloth; “Wound Healing Evidence-Based Management”

Electrical stimulation in wound healing

Application of Electrical Stimulation (ES) mimics the natural current of injury ( explained here) and, thereby, accelerates wound healing The effects of external ES have been extensively verified in vitro. Various cell types (including but not limited to skin epithelial cells, fibroblasts, macrophages, lymphocytes, and neuronal cells) respond to applied electric fields, a phenomenon termed electrotaxis or galvanotaxis. Applied electric fields have been shown to impact cell migration, proliferation, and orientation of cell division. Conversely, a missing electrical current impairs tissue regeneration and wound healing.

ES affects each of the phases of wound healing in the following ways:

Inflammation phase:

Initiation of wound repair process by its effect on the current of injury, increasing blood flow, promotion of phagocytosis, enhancement of tissue oxygenation, reduction of oedema, attraction and stimulation of fibroblasts and epithelial cells, stimulation of DNA synthesis, infection control, and solubilisation of blood products including necrotic tissue.

 

Proliferation phase:

Stimulation of fibroblasts and epithelial cells, stimulation of DNA and protein synthesis, increased ATP generation, improved membrane transport, better collagen matrix organisation, and stimulation of wound contraction.

 

Epithelialisation/Remodelling phase:

Stimulation of epidermal cell reproduction and migration, and production of a smoother and thinner scar.

The impact of electrical currents on cell movements and wound healing has extensive references in literature. One commonly citated example thereof is the Nature article from 2006 by Min Zhao et al (PMID: 16871217). In addition, various in vivo studies demonstrate positive effects of ES therapy for wound healing, including but not limited to, an increase in fibroblast and blood vessels, higher tensile strength, and faster wound healing.

 

A major burden for efficient wound healing is bacterial invasion potentially leading to chronicity of the wound. Traditionally, systemic antibiotic treatments are used to treat severe infections. However, overuse of antibiotics is problematic as it increases bacterial resistance. Studies have shown that ES kills or inhibits the proliferation of common wound pathogens and might therefore prevent colonisation of wounds.

 

In conclusion, ES increases the rate of ulcer healing and is proven to be superior to standard care for wound treatment. In fact, ES is the only method for the treatment of chronic wounds to have attained the highest grade of clinical evidence (Oxford CEBM class 1a evidence).