This site is intended for health professionals only

Venous leg ulceration: an introduction

Una Adderley
DN RGN BA BSc
Community Tissue Viability Prescribing Nurse
Scarborough, Whitby and Ryedale PCT

A leg ulcer has been defined as "loss of skin below the knee on the leg or foot which takes more than six weeks to heal".(1) In practice, patients will often wait significantly longer before seeking medical advice. Between 1% and 2% of the British population will suffer from leg ulceration at some point in their lives. At any one point in time between 0.1% and 0.2% of the population will be living with an unhealed open leg ulcer. Women are more likely to experience leg ulceration, and the incidence of leg ulceration increases with age. In the older population, 4.5% of patients will be living with an unhealed leg ulcer.(2)
The majority of leg ulcers (58%) are due to venous hypertension (see Figure 1), while 9% can be attributed to arterial disease and a further 8% are caused by a mixture of venous hypertension and arterial disease. Leg ulcers can also be due to more unusual factors such as diabetes, rheumatoid arthritis, lymphoedema, pyoderma gangrenosum and malignancies.(3)

[[NIP23_fig1_74]]

The arterial supply in the lower limbs provides the legs with oxygenated blood. The action of the calf muscle pumps blood back to the heart via the venous system, which contains a large number of one-way valves to prevent backflow. Venous hypertension occurs when reduced mobility reduces the effectiveness of the calf pump muscle, when veins become obstructed, or when valves in the deep and perforating veins become incompetent. The resulting backflow of blood (reflux) causes a rise in pressure in the superficial veins and capillaries, which become engorged. The pores of the capillaries enlarge and fluid leaks through, resulting in oedema. Oedema contains proteolytic enzymes, red blood cells and fibrinogen, which irritate the skin. Fibrin, which is insoluble, is believed to form a cuff around the leaking capillary and becomes a barrier to the efficient transfer of gases and nutrients between the tissue and the blood supply. This leads to friable skin, varicose eczema and ulceration.
Treatment for venous leg ulceration aims to reverse venous hypertension. The application of graduated compression around the lower limb provides support to the calf muscle pump. This, in turn, supports the veins, improving the competency of the valves, reducing backflow and thus encouraging venous return. However, compression can be safely applied only when there is adequate arterial supply. If the arterial supply is significantly compromised, the application of compression may reduce the arterial supply to inadequate levels, thus compromising the limb. Therefore it is important that the aetiology of a leg ulcer is correctly diagnosed before any treatment is attempted.

Diagnosis
The first step when diagnosing the cause of a leg ulcer is to take a full history, as certain factors can be clues with regard to the likelihood of venous or arterial insufficiency. For example, an elderly, obese woman who has had multiple pregnancies, a history of deep vein thrombosis, and who mentions that her mother and grandmother both suffered with leg ulcers might suggest the likelihood of venous insufficiency. However, if she then describes how she suffered a myocardial infarction last year and is finding it difficult to stop smoking, arterial insufficiency might also seem likely. Of course, it is possible for a patient to have both venous insufficiency and arterial insufficiency.
The next step is to examine the affected limb. The site of the ulcer can give clues as to the aetiology. Ulcers on the feet are likely to be arterial in origin, while ulcers in the gaiter region or around the ankle are more commonly due to venous insufficiency (see Figures 1 and 2). Arterial ulcers are often relatively small and can occur quite suddenly, while venous ulcers tend to have an insidious onset.

[[NIP23_fig1_76]]

The appearance of the ulcer can also give clues. Arterial ulcers usually have a "punched-out" appearance, an absence of granulation tissue and are often sloughy. Venous ulcers are more likely to be shallow and show evidence of granulation.
Oedema can occur for both aetiologies, but in the case of venous insufficiency, oedema worsens as the day progresses. Limbs with arterial insufficiency are often pale and cold to touch; the foot may be dusky when lowered but blanch when elevated. In contrast, a limb with venous insufficiency may show signs of eczema and be darkly pigmented across the gaiter region (lipodermatosclerosis).
Pain can be confusing. Traditionally, pain has been associated with arterial insufficiency while venous ulcers have been regarded as pain-free. Pain from arterial insufficiency typically worsens with exercise, is more severe at night when the limb is elevated in bed, but is relieved when the foot is lowered. However, qualitative studies show that many patients experience considerable pain with venous leg ulceration. Therefore, when considering pain with regard to differential diagnosis, it is important to ask the patient to give a detailed description.
In the past, palpation of foot pulses was regarded as an adequate means of identifying adequate arterial supply to a limb. However, it is known that pulse palpation does not discriminate well between those with and without arterial impairment.(4) Clinical guidelines now recommend that the ankle-brachial pressure index should be measured using a Doppler machine in all cases of venous ulceration before application of compression.(5)

[[NIP23_fig2_78]]
 
Treatment
For patients whose leg ulcer is due to venous insufficiency, there is robust evidence that graduated, multi-layer compression bandaging is the most-effective way of achieving healing.(6) In the UK, four-layer bandaging is regarded as the "gold-standard" compression system, while short-stretch bandaging is widely used in Europe and Australia. A recent UK randomised controlled trial compared the effectiveness and cost-effectiveness of both systems and concluded that four-layer bandaging appeared to be slightly more clinically and cost-effective.(7) However, the authors commented that it was likely that clinical effectiveness was closely linked to proficiency. Since four-layer bandaging was a more familiar compression system within the UK, this may have partly accounted for the apparent increase in effectiveness of this system when compared with the less familiar short-stretch bandaging.
Patients with venous leg ulceration are known to be particularly sensitive to irritants and potential allergens.(8) Therefore it makes sense to aim for simple dressings and emollients to minimise the risk of allergy. There is evidence that knitted viscose (such as Tricotex; Smith and Nephew) is as effective under a compression system as more complex dressings.(9) With regard to emollients, washing the leg in a simple nondrying cream, such as aqueous cream, will promote skin hygiene by gently removing skin plaques that may harbour bacteria. The application of simple ointments such as 50% white soft paraffin/50% liquid paraffin will promote skin hydration while minimising the risk of allergy. Varicose eczema can be treated with a short course of a sufficiently potent steroid cream before reverting to a bland ointment to maintain hydration and thus reduce the risk of recurrence.

[[NIP23_pp_78]]

Follow-up
After healing is achieved, it is important to continue to support the patient to prevent recurrence. Venous leg ulceration is a chronic condition that requires lifelong care. While patients should be encouraged to self-care as far as possible, regular nursing input will still be required for ongoing assessment of arterial sufficiency and the provision of appropriate compression hosiery to minimise the risk of recurrence. In short, a leg ulcer patient should never be discharged.

Concordance
Although no trials exist to confirm the benefits of compression for preventing ulcer recurrence, not wearing compression is associated with recurrence. Recurrence rates may be lower in high-compression hosiery than in medium-compression hosiery, and patients should therefore be offered the strongest compression with which they can comply. Prevention of recurrence appears to be more strongly related to patient concordance than grade of compression.(9) A recent study that examined factors that influence concordance with compression hosiery concluded that two main factors are a belief in the worth of wearing compression hosiery and a belief that stockings are comfortable.(10) Involving the patient in selecting hosiery and encouraging them to wear hosiery increases the chances of achieving concordance.

Conclusion
Venous leg ulceration is a common and distressing condition. Unfortunately, it is often not recognised or appropriately treated, which can lead to significant unnecessary suffering. By recognising the signs and symptoms early and delivering appropriate care, nurses can make a significant contribution to improving the quality of life for their patients and, through providing appropriate and cost-effective care, deliver benefits for the NHS.

References

  1. Dale J, Cameron M, Ruckley C, et al. Chronic ulcers of the leg: a study of prevalence in a Scottish Community. Health Bull (Edinb) 1983;41:310-4.
  2. Briggs M, Jose Closs S. The prevalence of leg ulceration: a review of the literature. EWMA J 2003;2(3):14-8.
  3. Salaman RA, Harding KG. The aetiology and healing rates of chronic leg ulcers. J Wound Care 1995:4:320-3.
  4. Callam MJ, Harper DR, Dale JJ, Ruckley CV. Arterial disease in chronic leg ulceration: an underestimated hazard? Lothian and Forth Valley leg ulcer study. BMJ 1987;294:929-31.
  5. Royal College of Nursing.The management of patients with venous leg ulcers. London: RCN; 1998.
  6. Cullum N, Nelson EA, Fletcher AW, Sheldon TA. Compression for venous leg ulcers. Cochrane Database Syst Rev 2001;2:CD000265.
  7. Iglesias C, Nelson EA, Cullum NA, Torgerson DJ, on behalf of the VenUS Team. VenUS 1: a randomized controlled trial of two types of bandage for treating venous leg ulcers. Health Technol Assess 2004;8:29.
  8. Cameron J. Skin care for patients with chronic leg ulcers. J Wound Care 1998;7:459-62.
  9. Nelson EA, Bell-Syer SEM, Cullum NA. Compression for preventing recurrence of venous ulcers. Cochrane Database Syst Rev 2000;4:CD002303.
  10. Jull AB, Mitchell N, Arroll J, et al. Factors influencing concordance with compression stockings after venous leg ulcer healing. J Wound Care 2004;13:90-2.

Resources
Royal College of Nursing Clinical Practice Guidelines
The management of patients with venous leg ulcers
W:www.rcn.org.uk/publications/pdf/guidelines/venous_leg_ulcers.pdf

Scottish Intercollegiate Guidelines Network
The care of patients with chronic leg ulcer W:www.sign.ac.uk/pdf/sign26.pdf

CREST
Guidelines for the assessment and management of leg ulceration
W:www.crestni.org.uk/publications/leg_ulceration.pdf