ABC of Vascular Disease
Critical Limb Ischaemia
1. What is critical limb ischaemia?
Critical limb ischaemia (CLI) is a severe form of occlusive arterial
disease. There is reduction of blood flow to
parts of the limb to such an extent that these parts of the limb are at risk of developing
gangrene. CLI is associated with severe pain at rest which is often worse
at night and there may also be ulcers on the leg and foot.
2. What causes critical limb ischaemia (CLI)?
Critical limb ischaemia is a severe form of occlusive arterial disease where
there are blocked arteries at more than one point in the leg. Most
patients with CLI have a long history or worsening arterial disease, often for
many years, and may have had previous investigations and operations. Only
a small proportion of patients with intermittent claudication will develop CLI,
particularly if the risk factors are treated early.
3. What do I do if I think I have CLI?
CLI is a serious condition and the first thing is to see your GP urgently.
GP will probably refer you to a vascular surgeon for urgent investigation, advice
4. How can CLI be treated?
As with all occlusive arterial disease it is important to identify and treat any
risk factors that may be accelerating or aggravating the condition. In CLI
the collateral arteries have reached the limit of their ability to compensate
and spontaneous improvement is unlikely. CLI is strongly associated with
arterial disease elsewhere, particularly in the heart, and this increases the
risk of serious complications. In general, unless some action is taken, a
patient with CLI has a significant chance of developing gangrene in the affected
leg and requiring an amputation. The most effective treatment is an
operation to bypass the blocked arteries and to restore a good blood flow to the
leg and foot. This is a major operation and can only be offered if the
patient is well enough to undergo an anaesthetic. Occasionally it is
possible to do a lesser operation which does not completely relieve all the
occlusions but improves the blood supply sufficiently to relieve the worst
symptoms and avoid an amputation. In some cases it is possible to improve
the blood supply by angioplasty. In order to decide which form of
treatment is possible your vascular will need to get an x-ray of the
With this information your vascular surgeon can discuss the possible treatment
Only a few patients are unsuitable for a bypass operation or angioplasty, and
in for these unfortunate cases the treatment options are limited. There
are no drugs or other treatments that have been shown to be very
effective. Often strong pain killers are the only option to control the
If the pain is uncontrollable or gangrene and infection become established
then an amputation may be necessary as a life protecting operation because
without it there is a risk of the infection spreading and causing blood
5. What if I need an amputation?
Amputation is always the last option but occasionally it is the only
one. Amputation operations are done to remove as little of the leg as
possible to allow optimum mobility afterwards. If possible the amputation
is done below the knee because this preserves the knee joint which is very
important for walking. After the amputation wounds have healed a process
of rehabilitation starts. For most patients this will involve making and
fitting an artificial leg and learning how to walk with it. Many patients
achieve better pain-free mobility afterwards than they had when their leg was