Venous leg ulcers

Epidemiology

Venous leg ulcers are a common, chronic, recurring condition, with an estimated prevalence of between 0.1% and 0.3% in the UK  . Up to 10% of the population in Europe and North America has venous valvular incompetence, with 0.2% developing venous ulceration  . In the UK, population prevalence rates range for VLU are between 1.2–3.2 per 1,000 people, which means there are 70,000–190,000 individuals in the UK with a venous leg ulcer at any time  .

As the population ages, all these factors will escalate the cost to the patient and healthcare organisations in the future.

Aetiology

Venous leg ulcers are due to chronic venous insufficiency (CVI). This occurs when the valves of the veins (deep or/and superficial or/and perforator veins) do not function correctly and allow the blood to flow back down (reflux) into the section of vein below.

The pathology can also include venous obstruction (e.g. from blood clotting)  . Venous drainage is impaired, which will lead to venous hypertension    . Between 40–50% of venous leg ulcers are due to superficial venous insufficiency combined with perforating vein incompetence, but the deep vein system    is usually normal.

Diagnosis of chronic venous insufficiency is based on clinical characteristics; chronic venous hypertension causes a number of skin changes:

• oedema
• visible capillaries around the ankle
• trophic skin changes such as hyperpigmentation caused by hemosiderin deposit
• atrophie blanche
• induration of the skin and underlying tissue (lipodermatosclerosis) and
• stasis eczema  .

In patients with chronic venous insufficiency, the inability of the calf muscles to pump venous blood contributes to the development and delayed healing of venous ulcers. As a result, compression treatment is used to treat lower limb venous insufficiency     .

There are many risk factors for venous ulceration, including heredity, obesity, venous occlusion, and age   . Importantly, venous leg ulceration reoccurs in up to 70% of people who are at risk  . More than 95% of venous leg ulceration is in the leg below the knee, usually around the malleoli, and ulceration may be discrete or circumferential  .

Clinical and economic burden

In the UK, venous leg ulcers have been estimated to cost the National Health Service £400m per year     . Most of this healthcare cost is due to community nursing services, as district nurses in the UK spend up to half their time caring for patients with leg ulcers    .

Physicians need to be aware that venous leg ulcers have an improved chance of healing if patients can be admitted to hospital for continuous leg elevation.

Too often, early preventive treatment is not undertaken due to the increasing number of patients with venous leg ulcers and the increasing shortage of hospital beds, the high cost of in-patient hospital care, and the need to maintain independence in the mainly elderly population who suffer from venous leg ulcers  .

Effects on patient quality of life

Venous leg ulceration is often a chronic condition and patients experience a prolonged cycle of skin healing and then breakdown, sometimes over decades, with episodes of infection, all of which can impair quality of life  .

Management of leg ulcers occurs mainly in the community, but community nurses and general practitioners have limited time to spend with patients, and this time is usually directed to clinical management  . Psychological and social effects of venous leg ulceration have received little attention in clinical management guidelines but include social isolation, anxiety, and depression, particularly when ulcers are highly exuding and painful  .

In a recent exploratory study undertaken to compare the pain and stress experiences of 49 patients with chronic wounds being treated with atraumatic vs, conventional dressings during dressing change, acute episodes of pain and stress were much lower in patients receiving atraumatic dressings  .

Management

There are several guidelines and consensus recommendations for the management of venous leg ulcers     . Some documents focus on compression therapy    . A comprehensive assessment of the patient, the wound and surrounding skin should be made on initial presentation and at frequent intervals to guide ongoing management      .

Wound bed preparation

The principles of wound bed preparation, e.g. using the TIME acronym, encourage a systematic approach to assessment        .

TIME is a model comprising the four components that underpin wound bed preparation:

• Tissue management
• Inflammation and infection control
• Moisture balance
• Epithelial (edge) advancement   .

Debridement is necessary to remove dead or devitalized tissue to encourage healthy granulation tissue formation    and it can also impact on inflammation and infection control  .

Risk of infection

Chronic non-healing wounds of the lower extremities are susceptible to infection, which can lead to serious complications, such as delayed healing, cellulitis, enlargement of wound size, debilitating pain, and deeper wound infections causing systemic illness    .

Compression therapy and wound debridement can encourage clearance of the infection and help to promote healing  . Antimicrobial dressings may be used short-term for the treatment of wound infection  . There is no evidence to support the routine use of systemic antibiotics to promote healing in venous leg ulcers    .

Exudate in venuous leg ulcer

Patients with venous leg ulcers generally have an increase in wound exudate when compared with patients with other forms of chronic skin ulcers  . Poor management of wound exudate can have a negative effect on patient quality of life and is associated with damage to the wound bed and peri-wound region, increased risk of infection, delayed wound healing, and increased costs to health services  .

The most important factor in reducing exudate levels is appropriate sustained compression therapy, not the dressing  .

Compression therapy

Compression therapy is widely recognised as key to the management of venous leg ulcers, it increases healing rates in comparison with no compression therapy  , and, after healing, reduces recurrence rates  .

A variety of devices are used for compression therapy, including different types of bandages, bandage systems, and garments that provide sustained compression, and pneumatic devices can apply intermittent compression  .

It is essential that before treating a lower leg ulcer with compression therapy that the underlying aetiology has been established and arterial disease has been excluded. This can be done by a combination of holistic assessment and simple investigations. In 15-20% of venous leg ulcers an arterial impairment coexists  , and the ulcers are known as ‘mixed ulcers’. Arterial impairment is assessed by measuring the ratio between the ankle and the brachial pressure (ABPI) which is more than 0,95 in normal subjects  . Compression therapy must be avoided in severe, critical, limb ischaemia  .

The role of dressings in the management of venuous leg ulcers

Ulcers of the skin require wound dressings for protection from further trauma, prevention of progression, and treatment. As venous leg ulcers are associated with high levels of exudate that contain proteases and inflammatory cytokines that may damage surrounding healthy skin, current guidelines recommend the use of wound dressings that manage wound exudate while maintaining a moist wound bed    .

The effective management of wound exudate has been shown to reduce time to ulcer healing, reduce the risk of skin damage and infection, and to enhance patient quality of life and improve clinical and financial outcomes.

The dressing selected should be:

• effective under compression therapy, i.e. retain moisture without leaking when placed under pressure.
• atraumatic without damaging the wound bed or periwound skin on removal
• comfortable and conformable to the wound bed
• of low allergy potential
• still intact on removal
• low profile (unlikely to leave an impression in the skin)
• cost-effective, i.e. offer optimal wear time  .

Other advanced treatments for venuous leg ulcer

After all standard care measures have been implemented, adjunctive treatments for chronic venous leg ulcers should be considered    . Comprehensive care should include compression therapy, local wound debridement, control of infection, wound moisture balance with appropriate dressings, and consideration of the use of pentoxifylline    . The use of hyperbaric oxygen therapy can be used in patients with chronic wounds, but as yet there are limited studies on the effectiveness of this therapy in the management of chronic venous leg ulcers  .