Peripheral Arterial Disease
Peripheral arterial disease (PAD in short) is when the pipework (blood vessels or arteries) which carries blood around your body becomes narrowed. Specifically your legs do not get enough oxygen and nutrients and if you don't get treatment this can damage your legs. It's a common problem that affects 1 in 100 among the 40 to 49 year olds, 3 to 5 in 100 of the 50-59 year old people, 1 in 20 of the age group of 60 to 69 years and in those over the age of 80 years it is more than 1 in 5 (and even more than 1 in 4 men of that age group).
How it develops
Arteries become narrow when lumps of fat (called plaques) deposit (stick) inside the artery wall. If the plaques break off they can cause blood clots that block the artery. This is a condition known as atherosclerosis. Normally, the artery is a hollow tube and the inside has a smooth surface for the blood to travel without any deposits (as in children and healthy young adults).
Gradually over many years, these deposits can build-up and cause the inside of the artery to narrow. This is often called 'furring up of your arteries', and its medical term of PAD is the name given to the condition when it affects the arteries of the limbs of the body, such as in the legs. However, if you have been diagnosed with PAD, it is likely that the same process will be happening in the arteries which supply your brain and heart; leaving you at higher risk of suffering a stroke or a heart attack.
What are the causes of peripheral arterial disease?
You are more likely to get PAD if you are older, if you smoke or if you have diabetes. Other things that make it more likely are if you suffer from:
- high blood pressure (Hypertension) high Cholesterol
- being overweight
- not taking enough exercise
Vascular disease can also be a hereditary condition. If you have a history of vascular disease in your family, you may want to discuss this with your vascular surgeon.
At first you may not know there is anything wrong. Many people with PAD do not know they have it. But as your PAD gets worse you might get aches or cramps in your calf, thigh, foot, or buttock when you walk a certain distance. We call this intermittent claudication. These aches happen consistently at a specific distance while walking flat and only happen when you exercise, but not when first standing up or while resting. In fact, resting for a few minutes should get rid of the pain.
In some people however, the disease progresses and the amount of blood able to go down the leg is not enough to supply the nutrients and oxygen to their feet. In cases like this, you may notice your feet being paler or more red than usual and you may get pain in the skin of your feet even when you are resting in bed. This is known as rest pain and is a symptom of critical limb ischaemia.
Without nutrients and oxygen getting down into the foot, the skin is unable to function properly and can break down into a wound (ulcer) and cuts or bruises do not heal at all or fast enough.
People with very severe PAD may need to have the limb amputated.
Tests to assess if you have peripheral arterial disease
Ankle Brachial Pressure Index (ABPI): This is a method of assessing the blood supply to your feet by measuring the blood pressure of the brachial arteries in your arms and comparing it with the one in the arteries in your feet. The ABPI is the highest of the feet arteries' pressure divided by the higher of the arm pressure. If you have atherosclerosis of your leg arteries it is likely that you would have a lower blood pressure in your feet.
Treadmill Exercise Test: This test combines the ankle brachial pressure index with a treadmill test. The ABPI is performed before and after you walk on a treadmill. If you have atherosclerosis of your leg arteries, it is likely to be a lower blood pressure in your feet after exercise. This is a good test to confirm the diagnosis of peripheral arterial disease. The test may not be accurate in patients with very hardened arteries (e.g. patients with long-standing diabetes mellitus, or renal patients on dialysis).
Duplex (or Triplex, or Colour Doppler) Ultrasound: Duplex ultrasound is a non-invasive investigation that uses a probe and jelly on the skin to look inside your leg and gives a picture of the anatomy of your arteries. This will show any atherosclerosis in the arteries, and whether this is causing a narrowing or blockage.
Computed tomography (CT) angiography is more detailed in its analysis for establishing diagnosis but requires intravenous contrast. It is necessary when a surgeon needs more information to establish the diagnosis or to recommend type of treatment.
Digital Subtraction Angiogram: This is an invasive test (catheterisation) that requires dye to be injected into your arteries. Once the dye is in your legs, x-rays are taken to give a picture of your legs showing where all the arteries are. This test can also be done using a modern body scan.
There are many treatments that can help improve your symptoms and reduce your chances of getting other health problems. You will probably need to take medicines every day for the rest of your life. There are also things you can do to help yourself.
- Stopping smoking. People with PAD who stop smoking are less likely
to die early, have a heart attack, or need to have a limb
- Regulating high blood pressure (< 130 / 80) and blood sugar.
- Anti-platelet medication (such as aspirin which prevents blood clots forming on the atherosclerosis inside your arteries by making your blood less sticky). They also make it less likely that you will have a heart attack or stroke, die early, or need an operation to unblock an artery in your leg. The most common side effect of antiplatelet medicines is bleeding.
- Taking regular exercise (A supervised exercise training programme consists of 30 to 45 minutes per session, 3 times a week for 12 weeks). This should help you to be able to walk further and exercise for longer before you get leg pain. Exercising can improve the blood supply to your legs (as nat- ural bypass channels may form) and help the muscles of your legs to work more efficiently.
- Statins (drugs used to lower LDL cholesterol levels < 1.8 mmol/L or 70 mg/dL) might stop your PAD getting worse. These medicines can help reduce the build-up of plaques in your arteries. People with PAD who take statins are less likely to have a heart attack or stroke or to die early.
- Peripheral vasodilators (medication to relax your blood vessels and allow blood to flow more easily). These may only provide symptom relief sometimes.
- Keeping warm is important because cold weather constricts your blood vessels. Do not use decongestant medicines for colds and hay fever.
Endovascular or open surgical revascularisationIf the arteries to your leg get very narrow, you might need an operation to widen them or to bypass the most damaged parts. These are surgical interventions, minimally invasive if pos- sible (endovascular) or open surgical where appropriate. The following patients should be considered for further intervention, beyond the conservative management:
- Patients with lifestyle-limiting claudication who continue to have limiting symptoms despite supervised training exercise
- Patients with critical limb ischaemia symptoms (ischaemic rest pain, gangrene, non-healing wounds)
- Patients with acute limb ischaemia (sudden decrease in limb perfusion with threatened tissue viability).
In a minimally invasive, endovascular operation, called percutaneous transluminal angiography (also known as angioplasty or PTA), a doctor uses balloons mounted on fine wires to widen the part of your artery that is blocked. He or she might then insert a small stent (artificial tube, the size of your artery), into the artery to try to keep it open. The stent there stays permanently inside the artery and gradually gets incorporated within the wall.
Another possible treatment is bypass surgery. This means either taking a small piece of a healthy vein from your leg (if suitable) or using an artificially made tube (a graft) and stitching it into your damaged artery. In this way, the blockage is “short-circuited” or bypassed, transferring blood from one end to the other, towards the legs using the new passage created.
Like any surgery, both types of operation have some risks. You should discuss the benefits and risks with your vascular surgeon before you decide together which one to go for. Ask your vascular surgeon for the more detailed patient information leaflet of the specific procedure you will be having. In some cases a combination of these methods may be used, such as in the example below:
Need content for this section