What is Critical Limb Ischemia?
Critical leg ischaemia is lack of blood flow that endangers all or part of the leg and is usually defined as persistently recurring rest pain for more than two weeks, or ulceration or gangrene of the foot. Many patients with critical limb ischaemia are elderly and frail, and this is reflected in the prognosis of the condition. Even with treatment, 25% of these patients die within a year and only half survive more than 5 years, mainly due to deaths from myocardial infarction and stroke. Treatment aims are ulcer healing & limb salvage relatively short term and focus on quality of life as well as long term durability of any procedure.
What are the symptoms of critical limb ischaemia?
The pain of severe limb ischaemia is felt in the toes and forefoot and is typically worse at night. Patients wake up in the early hours with severe pain, relieved by hanging the leg out of the bed allowing blood to flow down to the foot. Some patients take to sleeping in a chair. Many patients get up and walk around in the night which stimulates flow and reduces pain. During the day the patient may suffer short distance intermittent claudication. This pattern of symptoms: calf claudication by day and rest pain in the toes at night is strongly suggestive of critical limb ischaemia.
What are the consequences of critical limb ischaemia?
Without treatment, critical limb ischaemia will progress, causing worsening pain and debility. Ulcers develop on the lower leg and foot, and ultimately gangrene sets in. If the problem is left too late it can become impossible to salvage the leg and amputation may become the only way to save the patient's life
How is critical limb ischaemia treated?
Most patients suffering from critical limb ischaemia have other serious medical conditions, and it is important to make sure these are as well treated as possible. In many cases for instance, attention from a cardiologist can improve cardiac output to such an extent that the limb improves without any specific intervention to its blood supply. Duplex scanning is the first method used to assess the affected limb and establish where the main blockages are that are limiting the blood flow. Other methods may sometimes be needed, for example angiography, but in most cases duplex scanning is sufficient to plan treatment.
Angioplasty and/or stenting
Angioplasty and stenting are described in the Techniques and Services section of the website. Endovascular therapy with angioplasty is usually first line treatment. The durability of angioplasty is not as good as surgery but the effects may be sufficient to heal the limb. Moreover, late blockage of the treated artery frequently does not result in clinical deterioration and an attempt at angioplasty seems not to prejudice subsequent surgical intervention should that become necessary.
Severe limb ischaemia is often the result of very extensive blocked arteries. It may be impossible to unblock these with angioplasty techniques. In such cases surgical bypass can successfully save a leg where angioplasty would fail. Bypass for critical limb ischaemia typically involves using vein from the patient's leg and using it to bypass the lengthy section of blocked arteries to carry blood into the lower leg and foot below the diseased vessels. There are numerous different artery reconstructions any bypasses to improve leg blood flow; some are described in the Treatments, Techniques and Services section of the website.