The most common cause of leg ulceration in Western countries is venous disease of the lower limb. However, many patients have other causes for their leg ulcer. The most frequent associated cause is peripheral arterial disease, which may be the sole cause for ulceration or may occur with venous disease. Because of this common association with arterial disease, patients presenting with leg ulceration should be investigated for arterial disease as well as for vein problems. In addition, a number of other common conditions may cause leg ulceration.
Examination and investigation
Clinical examination should be performed carefully. The ulcer itself should be examined to establish its location. Venous ulcers usually lie just proximal to the medial or lateral malleolus, although they may extend to the ankle and dorsum of the foot. Venous ulcers are accompanied by lipodermatosclerosis and haemosiderosis. If these are not present then the ulcer is probably not of venous origin. The presence of obvious varicose veins should be recorded, although these are often not present or not visible in patients with venous ulcers. The peripheral pulses should be palpated to assess the peripheral arteries. The presence of loss of sensation in the foot or area of ulceration should be assessed, especially in a diabetic patient. Diabetic leg ulceration usually affects the foot and is almost always associated with peripheral neuropathy.
In patients suspected of suffering lower limb venous or arterial disease as the cause of the ulceration, complete examination of the venous system by duplex ultrasonography combined with measurement of Doppler ankle blood pressures is the most appropriate investigation in the firstinstance. This investigation is highly effective in establishing the location of incompetent veins and assessing the extent of post-thrombotic vein damage. In those patients with venous ulceration, between 40 and 50 per cent have ulceration due to superficial venous insufficiency alone. Simple noninvasive tests can exclude those patients with arterial occlusion and identify those with deep and superficial venous insufficiency. Patients with pure superficial venous insufficiency, i.e. varicose ulcers — ulcers due entirely to varicose veins, respond well to surgical treatment of their varicose veins. Where severe arterial disease is found it may be necessary to undertake detailed duplex ultrasound or angiographic examination of the arteries. Should the vascular system prove to be normal, blood tests may be done to test for systemic inflammatory disorders [e.g. rheumatoid disease, systemic lupus erythematosus (SLE)]. In addition, a biopsy of the ulcer may be helpful when it is not clearly due to an arterial or venous cause. A small proportion of leg ulcers is of malignant origin and any persistent ulcer, especially in an unusual place, should be biopsied to detect malignancy. Squamous cell and basal cell carcinomas are the most frequent cause of leg ulceration due to neoplasms, although occasionally malignant melanomas are found. In addition, malignant change may complicate a long-standing venous ulcer (Marjolin’s ulcer). This should be suspected where part of an ulcer shows evidence of proliferation. This type of tumour is usually a squamous cell carcinoma.
Management of venous leg ulcers
In patients who have venous ulceration due to superficial venous incompetence alone, varicose vein surgery is effective in producing ulcer healing in those patients who are fit enough to undergo this treatment. In the authors’ experience it is not necessary to delay surgery until the ulcer has healed. The ulcer is covered by a dressing during surgery and prophylactic antibiotics are given to prevent infection of the surgical wounds with any bacteria present in the ulcer. Ulcers managed in this way usually heal rapidly (within 4 weeks) following surgery.
In those patients with deep venous insufficiency or who are unfit or unwilling to undergo surgery, standard ulcer management should be used. The mainstay of this is local ulcer management combined with the application of compression. The ulcer is cleaned by soaking in tap water (the use of sterile water is unnecessary) and debriding the ulcer to remove any slough. The skin of the leg often becomes very scaly beneath compression dressings and should be treated with emulsifying ointment. No topical application has been shown to speed the healing of a venous leg ulcer, and patients with venous disease of the lower limb are very likely to become allergic to dressing materials. Topical antibiotics are ineffective in healing leg ulcers and are particularly likely to produce skin sensitisation. They should never be used in the management of venous ulceration. Patients who have eczematous reactions around their ulcers may require the use of topical steroids to treat the allergic response.
The most important factor in achieving healing is the use of high levels of compression. The use of dressings alone leads to a very slow rate of ulcer healing. It has been found that pressures of 3 0—45 mmHg applied to the ulcer are much more effective than lower levels of compression. These can be achieved by the use of compression stockings or by bandaging. Class 3 stockings exert about 30 mmHg compression at the ankle but require the patient to have sufficient strength in their hands to apply these. They are useful in younger patients who wish to manage their own ulcer. Frail patients often cannot manage this type of stocking, but may be able to apply two stockings of lower compression to the limb or use a stocking with a zip fastener in the seam. The compressionneed only be applied to the ulcer region, so patients with venous leg ulcers should wear below the knee stockings. Patients who are unable to manage with stockings are treated using multilayer bandaging regimes. These must be applied by a person trained in the procedure, as the use of lower pressures leads to slow ulcer healing and too high a pressure may cause injury to the leg. The best known of these techniques is the ‘four-layer bandage’ developed at Charing Cross Hospital in London. This method achieves pressures of 45 mmHg at the ankle and has been shown to produce healing of 70 per cent of venous ulcers within 12 weeks. The bandage must be changed once or twice per week (Fig. 16.31). The requirement that, for leg dressings, a nurse must change the dressing leads to a great deal of investment in the provision of community nursing services. Community nurses spend about 30 per cent of their time attending to leg ulcers and this leads to enormous expenditure by the National Health Service on this problem. It has been estimated that in the UK between £600 million and £800 million per annum is spent in the management of leg ulcers.
Prevention of recurrence
Even when healing has been achieved there is a risk that further ulcers may develop. Patients with healed ulcers should be encouraged to wear support stockings and rest with their feet elevated whenever possible. Recurrence rates of 25 per cent per year are accepted as the norm for such patients. In those who have been treated surgically for superficial venous incompetence the risk of reulceration is about 2—3 per cent per year.
Drug treatment for leg ulcers
No drugs have been found which are more effective than compression bandaging in the management of venous leg ulceration. Antibiotics have no effect on ulcer healing but are required if infection develops around an ulcer. This usually takes the form of cellulitis but, surprisingly, only occurs occasionally. A few drugs have been investigated to assess their efficacy in venous ulcer healing. These have included aspirin, oxpentifylline (Trental, Hoechst), prostaglandin El analogue and diosmin (Daflon 500 mg, Servier). All of these have an effect on leg ulcer healing but none is currently in widespread use. Future developments in understanding of the pathology of leg ulcers may lead to improvements in drug treatment for this condition.
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