Peripheral artery disease refers to any arterial lesion of degenerative or inflammatory origin which has as a result the thickening of the arterial walls, creating variable stenosis which can end with occlusion.
Etiology of peripheral artery disease
The most frequent cause it’s atherosclerosis. Another causes can be inflammatory diseases ( Buerger disease, Takayasu disease ) or colagenosis ( Horton disease, Lupus erythematosus, Polyarteritis nodosa) .
Peripheral arterial occlusive disease
Most of the lesions are located at the bifurcation sites.
The reduction of the arterial lumen under 70 % means an important blood flow reduction which will cause muscle hypoxia during effort or even during rest, of course depending upon the grade of stenosis.
Diagnosis of peripheral artery disease
The most common sign will be intermittent claudication. Patients will accuse pain similar to cramps, which appears during effort, after a variable distance and which stops during rest. The pain reappears when starting again the effort, at the same distance. Pain’s location will help us determine where the stenosis is. For example, a stenosis on the abdominal aorta and Iliac arteries , called Leriche syndrome, causes hip and back pain and also sexual impotence in case of men. So, claudication starts down the stenosis, where blood flow is lowered or even absent.
Pain can change and take an atypical aspect regarding location and intensity depending on the clinical stage of the disease.
Inspection: – we look for particular aspects of the skin and appendages such as color, local temperature, trophic changes
Palpation: symmetric and comparative palpation of the arterial pulse.
Auscultation: in case of stenosis there will be systolic murmurs on the artery trajectory.
A simple and accurate parameter which you can take during physical exam is the ankle brachial index.
Ankle brachial index represents the ratio between maximal systolic pressure at the ankle and maximal systolic pressure at the arm.
The normal value is around 1- 1,3. An index below 0.90 points a significant proof for peripheral artery disease.
After we went through all the steps of clinical exam we can stage the degree of the disease by Leriche- Fontaine clinical stadialization.
Leriche – Fontaine clinical stadialisation
Stage I : asymptomatic patient;
Stage II: intermittent claudication;
Stage III: pain during rest, lowered in orthostatism.
Stage IV: trophic changes ( ulcerations, gangrene) and permanent pain.
Duplex ultrasound – it’ s a test which shows how the blood moves through the arteries and veins; this test combines traditional ultrasound with Doppler ultrasound allowing you to see the location, the grade of arterial stenosis and also the presence of collateral circulation.
CT angiography vs MRI angiography
The advantages of CT angiogram in comparison with MRI are that the quality of the image is superior to the MRI one and it’s also quicker to get. The disadvantage of CT angiogram when compared with MRI is that it carries the risk of radiation. The risk might be small but it’s significant, for example in case of pregnant women. Also, CT scans use a contrast material which can lead to allergies and damage the kidneys, whereas MRI uses a different material contrast which has less side effects.
Digital substraction angiography ( DSA )
This investigation is the GOLD STANDARD for artery occlusions.
Using complex computerised x-ray equipment, DSA procedure allows to visualize arteries, veins, and organs. This requires an injection of a special ‘dye’, called contrast agent which will highlight the blood supply to the place of interest. The contrast material is harmless and will get out of the body through urine in the following hours.
Treatment of peripheral artery disease
General medical treatment is based on controlling the risk factors, frequent physical exercise, rigorous hygiene of feet - cold prevention, accidents, comfortable shoes.
Depending on the severity of the disease the following steps can be taken:
STOP smoking ! it is well-known that cigars promote PVD and are also huge risk factors for cardiovascular diseases;
Management of comorbidities: e.g diabetes, hypertension, high cholesterol;
Regular exercise will definitely improve symptoms in patients with claudication; the effect of exercise is to open up collateral flow available and decrease limitation in walking.
Foot care is very important! the basic steps in your foot care plan : – Wash your feet daily;
Keep your skin smooth and soft;
Trim you toenails so that they have round edges;
Check your feet everyday for changes in color, sores, cuts, pain etc.
Vasoactive drugs: Pentoxyfilline, Buflomedil, Naftodrofuryl relieve symptoms of claudication
Hypolipidemic agents for secondary prevention of
atherosclerosis. Medication with aspirin, clopidogrel and statins can prevent the progression of the disease by reducing clot formation and cholesterol levels. In addition, these will address the other cardiovascular risks that the patient might have.
New drugs: Inositol, Proteoglycans, Prostaglandins seem efficient, yet they need more ample clinical studies.
As the term implies, ‘’revascularisation’’ means the restoration of perfusion to the ischemic artery. This should be the first choice every time the arterial lesion allows it.
As simple as it sounds it’s actually a very fine, yet elegant procedure.
In order to do this, they use a long tube, called catheter which has a small balloon on its tip. This long and thin tube goes through the vessel up until the blockage where it is inflated to flatten or compress the plague against the artery wall.
After this, a stent which is small, mesh-like device made of metal is placed inside. The stent acts as a support , keeping the vessel wide open.
Depending on the site of the implant and the type of the stent, the patient must undergo anticoagulant treatment for a long time.
Lumbar sympathectomy surgery
This type of surgery removes the nerves that make the artery contract, therefore leading to vasodilatation.
- Thromboendarterectomy with or without patch
This is a surgical procedure which consists of the excision of an obstructing thrombus together with a portion of the intima and atheromatous material from a narrowed vessel.
There are many anatomical combinations for bypass grafting in the lower extremities depending on the location of the disease, but the principle of use is the same. Basically, you take blood flow from a normally vascularised area to an area which is deficient in blood flow.
A graft is used to reroute the blood supply and this can be either a plastic tube or a blood vessel from your body which is taken during the same surgery.
Bibliography: 1. Braunwald's Heart Disease; 2. Harrison's Principles of Internal Medicine; 3. European Society of Cardiology - Clinical Practice Guidelines.