Chronic Foot Wounds

Photobiomodulation therapy involves the use of photons from specific frequencies of the visible light spectrum to stimulate the wound healing process. The use of blue light (wavelength 400-450 nm) in particular has been shown to have anti-inflammatory properties, reducing bacterial load and promoting the tissue regeneration process particularly in venous leg ulcers.

NPWT is a special wound management device used for complex larger open wounds. It uses gentle suction (negative pressure) via a wound dressing and a small electrical pump to help wounds to heal faster.

NPWT helps wounds to heal by:

• Maintaining a moist wound environment
• Removing excess fluid and infectious material
• Reducing swelling
• Promoting blood supply to the wound
• Promoting healthy tissue to grow

Granulox is designed to provide wound bases with supplemental oxygen through facilitated diffusion (Figure 1). Granulox aims to provide topical, and hence extrinsic, oxygen supply via diffusion to promote healing. It has been shown to overcome the amount of exudate that chronic wounds make when applied to the wound bed directly after cleaning.

Hyperbaric oxygen therapy (HBOT) involves breathing 100% oxygen at an ambient pressure within a special chamber. It has been recommended as a useful adjunct for patients with wounds that fail to respond to standard wound care. HBOT has been shown to be effective in improving wound healing and against severe infection, especially in the setting of diabetic foot ulcers. In diabetics the small vessels within the foot are sometimes too small to open with balloon angioplasty and therefore if the blood cannot reach those areas near the toes, oxygen from outside down a pressure gradient can sometimes be an effective substitute.

Natrox™ topical oxygen therapy (Inotec AMD Ltd, Hertfordshire, UK) employs a small battery-powered “oxygen generator” to concentrate atmospheric oxygen and feeds pure, moist, oxygen through a fine, soft tube to a dressing-like “oxygen distribution system”, which is placed over the wound and is held in place by a conventional dressing. This has proved highly satisfactory from the patient perspective and has helped reduce time to complete healing with some difficult diabetic foot wounds from our OTONAL study data from Singapore. This may be used instead of HBOT, when some patients cannot tolerate the pressure within the oxygen chamber.

This technology stimulates the motor neurones within the nerve bundle, that carry signals to the muscle fibres to cause contraction within the leg muscles causing the veins in the leg to empty intermittently. This has been shown to be effectively to heal some chronic venous leg ulcers and diabetic foot wounds.

Split-thickness skin grafting is sometime carried out to cover wounds with a large defect. It is a surgical procedure which involves removing the top layer of skin from one area of the body, usually the thigh, and moving it to cover the wound defect. The top layer from the donor site normally heals without an issue as the skin graft taken is very thin in nature. Skin grafting has been shown to increase the healing rate of diabetic foot ulcer and minimise complications such as major lower limb amputation.