Non-healing wound: what to do?

While many types of wounds heal on their own within a few weeks or reduce their size by 40% after four weeks of optimal treatment, some heal more slowly or not at all and do not respond to prescribed care. These are referred to as chronic wounds, wounds that are physiologically altered due to a disruption/interruption of the natural healing process. There are four common categories of slow-healing injuries.

• Pressure Ulcers (Bedsores): This type of wound is a hypoxic or anoxic lesion that affects the skin and underlying tissues, resulting from prolonged pressure on a body area. Pressure ulcers typically develop in bony areas (tailbone, buttocks, hip, heel, etc.), although they can occur on any part of the body. They arise due to a decrease in blood supply to the area, leading to the death of skin cells and the formation of an ulcer. These types of wounds only worsen if they are not treated.

• Ischemic Wounds : Also known as arterial ulcers, ischemic wounds occur in cases of arterial circulatory disorders. The arteries supply nutrients and oxygen to the body's tissues. When they are narrowed or blocked, a lack of tissue and skin irrigation is observed, which leads to a wound or a delay in healing. This type of wound most often appears at the tips of the toes, on the heel, or at the edge of the foot.

• Diabetic Foot Ulcers: Diabetes can cause neuropathy, which can lead to a total loss of sensation in the foot, as well as leg arthropathy, which can result in minor foot injuries, ulcers, infections, and even gangrene. These open wounds are most often found on the legs or the soles of the feet. Research suggests that 15% of people with diabetes will suffer from diabetic foot ulcers in their lifetime.

• Veinous Ulcers: This type of wound most commonly develops between the knee and the ankle, and is associated with a disorder in the venous system of the legs (varicose veins, phlebitis). Veins are the blood vessels that return blood to the heart. Therefore, if the blood in these veins stagnates, it creates significant and constant pressure within the veins, gradually damaging the blood vessels and leading to the formation of ulcers.

Chronic wounds can quickly worsen and become infected, particularly without appropriate treatment. Indeed, these slowly healing wounds can lead to long-term health issues, such as extreme pain, loss of function and mobility, or extended hospitalization. In some cases, these types of injuries can result in amputation.

If your wound is not improving, do not hesitate to consult a vascular doctor or a specialist in chronic wounds. Treatment typically begins with a physical examination that includes an inspection of the wound and gathering information about the patient's medical history (information about chronic health problems, recent surgical procedures, and current medication) in order to identify any underlying condition that could affect the body's ability to heal.

In many cases, it will first be necessary to address the underlying causes of the wound before healing can begin. The patient may undergo blood and urine tests, a wound biopsy, and/or a wound culture to search for potential pathogenic microorganisms. That being said, here are some approaches a doctor might use to improve wound healing which depend on the patient's age, health status, and the nature of the wound.

• Wound Debridement: This is a process under local anesthesia that involves removing dead, devitalized, and necrotic tissues using surgical instruments (tweezers, curette, scalpel). An enzyme-based gel is sometimes also applied to help clean the wound. This helps a wound heal faster and ensures the growth of healthy tissues.

• Dressing the wound: Dressings can be particularly important for preparing the area for healing, removing excess fluid from the wound, protecting it from infections, and controlling humidity levels.

• Prescription of Pain Relievers: Pain can cause a constriction of the blood vessels, which slows down the healing process, in addition to deteriorating the patient's quality of life. Therefore, the doctor may find it necessary to prescribe pain relievers (acetaminophen, ibuprofen) to alleviate mild to moderate pain. However, if these are not sufficiently effective, the doctor may prescribe a more potent analgesic.

• Antibiotics: If a wound is infected, it has less chance of healing. Antibiotics can be prescribed to prevent and treat infection in cases of ulcers. They can either be applied to the wound using an ointment, or placed on the wound using a dressing.

• Nutritional Support: Patients suffering from significant chronic wounds may be predisposed to chronic malnutrition. Studies both experimental and clinical support that the administration of dietary supplements (zinc, arginine, glutamine, vitamin A, vitamin B5, vitamin C, vitamin D) may have beneficial effects on chronic wounds. However, further research is needed to better define the mechanisms of action, potential side effects, and the overall risk-benefit ratio of human application.

• Compression Therapy: If venous issues are the cause of the chronic wound, compression stockings can help it heal more quickly. The pressure applied by the stockings helps to decrease venous pressure, reduce swelling, and improve circulation to promote wound healing.

• Hyperbaric Oxygen Therapy: in the context of chronic and complicated wounds, this type of treatment may be necessary. The patient is exposed to a high concentration of pure oxygen (2 to 3 times higher than normal) for 90 to 120 minutes in a pressurized chamber. This type of therapy helps to increase the concentration of oxygen in the blood, which improves blood supply to the injured area, helps to destroy harmful bacteria responsible for infection, stimulates the formation of new blood vessels and increases the rate of collagen deposition, promoting healing. It is particularly useful for people suffering from diabetic ulcers, chronic bedsores, venous ulcers, or radiological wounds.

• Negative Pressure Therapy (Vacuum-Assisted Closure system): In this therapy, an airtight dressing, connected to a suction device, is placed over the wound. The pump continuously draws exudates out of the wound, creating negative pressure across the wound. This form of therapy promotes angiogenesis, helping to increase blood flow to the wound site, and enhances cellular proliferation and migration within the wound. In this therapy, the wound remains moist, which improves and accelerates the healing process.

• Ultrasound Therapy (Ultrasonotherapy): This treatment utilizes ultrasonic waves, which are high-frequency mechanical vibrations (beyond 20,000 Hz) that are imperceptible to the human ear. It involves covering the wound area with a hydrogel film and emitting ultrasound, which warms the tissues promoting blood circulation and encourages tissue regeneration.

• Skin grafts: In this procedure, skin is taken from another part of your body, usually your thigh, and transplanted onto the wound, increasing the chances for chronic wounds to close more quickly. There are also grafts made from human cellular products and synthetic materials.

• Adjuvant Therapy: available in gel form or impregnated on dressings, growth factors are important for wound healing. This includes platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), keratinocyte growth factor (KGF), epidermal growth factor (EGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF).

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• YARMUSH M. L. & al. Co-delivery of a growth factor and a tissue-protective molecule using elastin biopolymers accelerates wound healing in diabetic mice. Biomaterials (2017).

• LEE J. W. & al. Effects of structurally stabilized EGF and bFGF on wound healing in type I and type II diabetic mice. Acta Biomaterialia (2018).

• LI M. & al. Vitamin D ameliorates impaired wound healing in streptozotocin-induced diabetic mice by suppressing NF-κB-mediated inflammatory genes. Bioscience Reports (2018).