Peripheral Vascular Disease
What is peripheral vascular disease? What is a vascular ulcer and how
do you treat it ?
What is peripheral vascular disease ?
Peripheral vascular disease means narrowing of the lumen of arteries
in the legs, causing a reduction in circulation. It can occur in
individuals without diabetes but is more common and more severe in
people with diabetes. Why this is the case is not clear, but it is well
established that smoking makes peripheral vascular disease much worse.
Although both big and small blood vessels can be affected by diabetes
(known as macro vascular and micro vascular disease respectively), in
diabetic peripheral vascular disease it is blockage of the larger
arteries in the thigh and leg which causes most of the clinical
problems. Peripheral vascular disease can affect both legs but is often
more severe on one side (contrast with peripheral neuropathy which
affects both feet symmetrically).
The large arteries are blocked, causing problems. Here are the
typical sites of blockages of the arteries (shown in green)
What problems can be caused by peripheral vascular disease?
If it is mild, peripheral vascular disease can be completely without
symptoms. However, as blood supply becomes progressively inadequate, it
can cause claudication, rest pain or vascular ulceration:
Claudication is development of pain in the calf after walking for a
distance or up an incline or stairs. The distance a person can walk
before such pain occurs is referred to as claudication distance. The leg
and foot look and feel normal as long as the person is resting. As
claudication distance becomes shorter and shorter, physical activities
become more and more restricted. Cessation of smoking is most important
before one gets to this stage. Regular exercise by walking through the
pain threshold can sometimes increase the claudication distance. In many
cases to relieve the symptom it is necessary to have either an
angioplasty (an instrument is threaded down the artery to widen the
blocked area) or by-pass surgery (a vein from other part of the body or
an artificial tubing is used to by pass the blockage, allowing blood to
Three examples of typical bypass surgey.
The blockages are shown in green and the bypasses are shown in red.
Rest pain is pain in the foot even when not walking. This is
distressing and difficult to obtain respite. It is therefore important
not to get to this stage by refraining from smoking. It is a more severe
stage of peripheral vascular disease than claudication. The affected
foot looks purplish in colour and feels cold to touch. The foot pulses
are not palpable. Angioplasty and by-pass surgery are the only available
treatment. Sometimes, amputation is required as the last resort to
An ischaemic foot which is purplish, cold and painful
The wounds of patients with severe vascular disease heal poorly because
of inadequate blood supply. Therefore minor trauma or pressure often
leads to ulceration. This is called a vascular ulcer (sometimes also
known as arterial ulcer or ischaemic ulcer). It tends to be situated on
the edge of the foot or toes because blood supply is the poorest at
these sites. A typical vascular ulcer is shown below. In a purely
vascular ulcer, nerve function is normal and sensation is intact, hence
vascular ulcers are usually painful.
A typical vascular ulcer
Therefore, a typical vascular ulcer is :
- not surrounded by callus
- associated with absent or poor foot pulses
- associated with a foot that is cold to touch
- at the edge of the foot or toes
A vascular ulcer should not be confused with a venous ulcer which is
due to varicose veins. Varicose ulcers are situated on the leg (rather
than in the foot), associated with varicose veins and often accompanied
by swelling and a brownish discoloration of the leg. A typical varicose
ulcer is shown bellow.
A typical varicose ulcer
Are you are at high risk of developing a vascular ulcer ?
is dealt with more thoroughly in the section on
you are at risk if :
- you have had a foot ulcer before
- you have poor circulation in the feet when you doctor tested it
- you have mishaped feet eg:clawed toes or bunions
- you have claudication or rest pain
- you do not follow advice to protect your feet with good footwear
What sort of treatment is required for a vascular ulcer ?
The important measures are:
- Remove the precipitating cause eg. get rid of the shoes that are
- Clean and dress the wound with non-caustic materials. In
contrast to the treatment of neuropathic ulcers, do not debride
aggressively. In the presence of vascular disease debridement could
make the ulcer worse.
- Taking antibiotics if the ulcer is infected. Remember that signs
of infection such as local redness, heat and swelling are often
masked by vascular disease.
- Rest the feet as much as possible because this helps to minimize
trauma to the ulcer. Walking is not a good exercise for someone who
has a vascular ulcer (or someone at great risk of developing one).
If you suspect an ulcer is vascular it is necessary to assess the
severity of vascular blockage to see if it can be treated by angioplasty
or by-pass surgery. Briefly, the steps to be taken are:
Measure the blood pressure at the ankle and compare it with the
pressure in the arm to determine if there is enough blood supply to the
foot. This measurement is called the Ankle-Brachial Index and is done
with a Doppler machine.
Because the arteries in the ankle may be calcified in diabetes, blood
pressure readings at this site is often unreliable. In this situation it
is more accurate to measure pressure at the toe.
Once a Doppler test has established that circulation is poor in the
leg, further tests such as a Duplex scan or angiogram can be done to
evaluate the obstruction of arteries more accurately to determine if
surgery is needed to help the vascular ulcer to heal.