An ulcer is a deep loss of skin on the lower leg of foot and often occurs after an injury to the leg. Healing can take weeks or months. Chronic leg ulcers (present for more than six weeks) are common and become more frequent with increasing age. The following are types of leg ulcers:
SURGICAL TREATMENT OF LEG ULCERS
This type of ulcer is the most common of chronic leg ulcers. Of every 10 cases of leg ulcer, about six or seven are due to venous disease.
A venous ulcer is caused by the increased pressure of blood in the veins. Leg veins contain important valves that permit blood to flow only toward the heart. If the valves of the deep veins or the veins themselves become damaged, high pressure in the veins can develop due to the large volume of pooled blood (venous hypertension). Valve damage is mostly due to previous deep vein thrombosis (DVT), either diagnosed or unknown. Varicose veins and age are also factors. Venous ulcers usually occur on the lower calf and are associated with calf and ankle swelling.
If one or more leg arteries become narrowed or blocked, an ulcer may develop. A lack of arterial blood supply to the tissues is called ischaemia. Ischaemic ulcers tend to occur on the toes, foot and calf. Of every 10 cases of leg ulcers, about one or two are due to ischaemia.
Vasculitis is caused by the inflammation of arteries, usually the small arteries (arterioles). Larger arteries can also be affected. The inflammation may be caused by a wide range of conditions. This type of ulcer is often very painful. Of every 20 cases of leg ulcers, about one is a vasculitic ulcer.
Damage to the nerves of the leg can result in ulcers developing as the protective effects of pain are lost. These “neuropathic ulcers” commonly occur over the tips of the toes, side of the foot, the heel and bony prominences. They are often painless. Diabetes is the most common cause of neuropathic ulcers, with spinal injuries and other diseases causing some cases. Of every 10 cases of leg ulcers, about one or two are a neuropathic ulcer. A neuropathic ulcer may also be a part of an arterial or venous ulcer.
Arterial and venous disease
Combination arterial and venous disease may be present. The arterial disease is often corrected first.
Other causes of leg ulcers
In addition to the above causes, other conditions can cause a chronic leg ulcer, including skin cancer, trauma, blood disorders and infectious diseases.
When foot pulses are difficult to detect, an ankle:brachial pressure index (ABPI) is performed. This test uses a Doppler probe to measure the blood pressure at the ankle and compare it with the pressure at the elbow or wrist. A normal ABPI is 0.9 to 1.2.
A ABPI less than 0.7 suggests that arterial blood supply to the ulcer is impaired. In patients with diabetes, kidney problems or leg swelling, the ABPI may be high even if the blood supply to the ulcer is reduced.
Venous incompetence duplex scan
This is a non-invasive ultrasound test that shows which veins are patent (open) and whether the veins are competent (valves working or not). This test is also useful if no venous skin changes are present and the cause of the ulcer is uncertain. The test should be able to confirm or exclude underlying venous disease.
If the diagnosis is venous ulceration, compression therapy is usually commenced. A four-layered compression system is often used and is generally applied weekly.
Your doctor may recommend or perform a biopsy of the ulcer, that is, the removal of a small part of the ulcer. The biopsy is examined by a pathologist. A biopsy may be needed if the ulcer is not healing despite treatment after six months. Usually the biopsy is taken under a local anaesthetic.
Arterial duplex scan
This ultrasound test is often performed when arterial disease is suspected (that is, pulses are absent and/or the ABPI is too low). This test shows whether a stenosis or blockage is present, but does not tell the surgeon how much blood is getting to the ulcer.
In this invasive test, a needle is placed in the femoral artery in the groin on the side of the ulcer or occasionally in the other groin. A catheter is then inserted into the artery. A special dye is injected, and the exact location of the arterial problems can be seen under X-ray examination. This is performed under local anaesthetic. Tell your doctor if you think you may be allergic to this dye.
TREATMENT OF A VENOUS ULCER
Compression therapy is the initial treatment of choice for venous ulcers. If the venous duplex scan shows mostly superficial venous incompetence (that is, valve problems in the saphenous veins or perforators with minimal or no deep vein problems), then venous surgery may be recommended. This surgery can increase the rate of healing and should decrease the risk of ulcer recurrence.
“Stripping” is the standard treatment for varicose veins and involves removal of abnormal saphenous veins. Each leg has a long and a short saphenous vein. Through a small incision in the groin (in the case of the long saphenous vein) or behind the knee (for the short saphenous vein), the branches of the main vein are tied off and cut. A long instrument is inserted into the long saphenous vein and threaded down as far as the knee or upper calf. When the surgeon withdraws the instrument from the leg, the vein is pulled out with it.
Multiple phlebectomy: sometimes called a “nick and pick”, this operation involves removal of the small varicose veins (adjacent to the ulcer) through many tiny “stab” incisions. These cuts are often so small that they do not require stitches but some may require stitches. The patient wears compression stockings for a few weeks after the operation but is able to shower normally during the recovery period. After about six weeks, the bruising typically fades.
Sclerotherapy: This involves injection of a chemical into superficial varicose veins followed by a compression bandage that causes the veins to collapse and then close. This treatment diverts blood to larger veins and takes the pressure off the veins under the skin. The blood flow in the veins improves and the condition of the skin improves, allowing ulcers to heal and helping to prevent the development of more ulcers. This technique may also be used to occlude the saphenous vein.
Endovascular ablation: A number of minimally invasive techniques are used to occlude the incompetent saphenous veins without surgery. Your specialist can discuss these techniques with you.
TREATMENT OF AN ISCHAEMIC ULCER
Angioplasty or stenting of an artery: If the narrowing or blockage of an artery is over a relatively short segment, the surgeon may recommend balloon angioplasty. This is performed through the femoral artery in the groin and may be undertaken at the same time as the angiogram. To improve blood flow, a stent may be placed in the artery if the result from balloon angioplasty is not satisfactory. Angioplasty is usually performed under local anaesthesia.
Arterial bypass surgery: This procedure may be recommended if the patient has an ischaemic ulcer caused by an arterial blockage that probably cannot be treated by angioplasty. A segment of vein is taken from the same or other leg (or an arm) and used to bypass the arterial blockage in the leg. Sometimes, a prosthetic graft made of synthetic material is used.
To assist healing of the ulcer, a skin graft may be needed. Surgeons use many methods of grafting including split-thickness skin grafts, punch grafts, mesh grafts, and flap or pedicle grafts, among others. In some cases, sheets of skin grown in the laboratory are used. In the case of some ischaemic ulcers where the leg’s circulation is very poor, a flap of muscle may be needed to cover the ulcer before a skin graft is applied.