An ulcer can be defined as a local defect or excavation of the surface, of an organ or tissue, produced by sloughing of necrotic, inflammatory tissue. “Vascular” describes the aetiology of the ulcers, in that they are caused due to a disease process affecting either the arterial or venous system.
A poor supply of oxygenated blood results in ischemia, leading to necrosis of the cells within the skin, in the distribution of the affected vessel.
Venous backflow causes pooling of blood in the vessels of the lower leg. This pooling leads to capillary hypertension preventing oxygenated blood, in the arteries, passing into the capillaries and supplying the living tissue.
As well as pure arterial or pure venous ulcers you may also have heard of mixed ulcers. Don’t let this confuse you, this is simply when there is both arterial and venous disease causing the ulceration.
This is not a type of vascular ulcer however it may co-exist in patients with vascular ulcers. Repetitive trauma causes damage to skin with reduced sensation because the patient does not make attempts to stop it. A neuropathic ulcer is usually due to disease of the nervous system (usually peripheral but can be central), and is frequently diabetes-related.
The most common cause of arterial ulcers is peripheral arterial disease (also known as peripheral vascular disease, PVD). This is a disease process such as atherosclerosis or inflammation of vessels, leading to stenosis, that reduces the arterial blood supply to the peripheries. More detail on PVD can be found in another Fastbleep article.
These are most commonly caused due to failure of the valves, which normally prevent backflow, within the veins of the superficial venous system of the lower limb. This is termed venous insufficiency and causes pooling of deoxygenated in the distal leg. Venous ulcers are usually accompanied with varicose veins.
It is often possible to differentiate the aetiology of an ulcer based on the history and examination. Important factors to determine are as follows.
Site of the ulcer
Arterial ulcers, caused due to disease of large or medium sized vessels, tend to be present on the bony prominences of the foot and ankle. When examining a patient it is very important to examine between the toes and on the plantar surface of the toes as these are common places for arterial ulcers that can easily be missed.
Venous ulcers are usually present on the gaiter region of the leg. If they are on the medial aspect of the leg then the great saphenous vein is likely to be diseased whereas if the ulcer is on the posterior or lateral aspect then the diseased vessel will be the short saphenous vein (see images below).
This is true in most cases but should be confirmed with investigations. Also be aware that both vessels may be affected.
The appearance of the ulcer will also help you decide whether the aetiology is arterial or venous.
Arterial ulcers tend to be:
This is an image of a typical arterial ulcer.
Venous ulcers tend to be:
This is an image of a typical venous ulcer.
Pain or tenderness
It is also useful to ask the patient if they are experiencing pain or tenderness at the site of the ulcer. An ulcer that is painful is most likely arterial whereas venous ulcers usually don’t cause much pain.
Associated symptoms and signs
There are associated symptoms and signs that accompany ulcers due to the underlying disease process. To avoid repetition of the varicose veins and peripheral vascular disease section of this website I will discuss these briefly but recommend that you read the full articles as it is important to know about the underlying cause of these ulcers.
In arterial disease you would expect any of:
In venous disease you would expect any of:
This table summarizes the key characteristics of an ulcer that will discriminate an arterial ulcer from a venous ulcer on history and examination.
If a patient is found to have an ulcer on examination then investigations are frequently required to confirm whether the ulcer is arterial or venous and also what the underlying cause of disease is. This is especially important if it is unclear from examination what type of ulcer the patient has, as they may have a mixed ulcer caused by both arterial and venous disease.
In summary the investigations for arterial disease are:
In summary the investigations for venous disease are:
If an arterial ulcer is suspected the first and easiest test to perform is an ankle brachial pressure index. This test can be done with a handheld doppler and a blood pressure cuff using the following steps.
Here is a table of how to interpret the result:
If the patient is to be considered for surgical intervention then a duplex ultrasound scan, which measures structure and blood flow, is required. This should determine the location of narrowing or turbulent blood flow and the extent of the disease, this information is not required if surgery is not to be considered.
Rarely, if an ultrasound is inconclusive then an MRI or CT angiography with contrast is required. This is avoided if possible as there is a 1% risk of a CVA due to the contrast used.
If a venous ulcer is suspected then the main investigation used to confirm venous insufficiency is a duplex ultrasound scan. This is usually performed with the patient supine and standing in order to demonstrate venous backflow. A handheld Doppler can also be used in clinic to find venous backflow however the definitive investigation is a duplex ultrasound scan.
This section will focus on the management of ulcers specifically. Patients with arterial, venous or mixed ulcers often require other management to control the causative disease process. This will be covered in the other related Fastbleep articles.
The principles of managing a venous ulcer is to allow repair of the skin and ultimately remove, and stop, the pooling of blood in the distal leg. This is commonly achieved with a four layer bandage.
The first layer (closest to the lesion) is a sterile layer that is in contact with the ulcer covered by a loosely applied padding bandage, the second layer is a support layer that holds the first layer in place, the third layer applies compression followed by the fourth layer which is adhesive and protects the other layers.
An alternative to compression bandaging is graduated compression stockings. Graduated compression provides greatest compression distally and tapers off before the knee joint with the least amount of compression.
When a patient has any kind of compression treatment it is important to warn them to return if they experience numbness, pain or paraesthesia as these suggests arterial supply has been lost to the distal leg. It is also important to advise the patient to routinely elevate their affected leg in order to allow venous return.
An arterial ulcer should be dressed in a similar way however the main, and very important difference, is that compression will worsen arterial disease. Therefore, compression should never be applied if an ulcer is arterial or mixed.
Both ulcers should be cleaned and surgically debrided if there is a large amount of slough or necrotic tissue present. Antibiotics are reserved for ulcers with surrounding cellulitis.
In summary a venous ulcer should be managed with:
In summary an arterial ulcer should be managed with:
The main complication of vascular ulcers is bacterial infection causing cellulitis. With good management, as described above, this should be avoided. If cellulitis does occur then oral antibiotics should be used and topical antibiotics avoided, as they may cause irritation to the damaged skin.
To summarise this topic in a few sentences;
Arterial ulcers are caused by peripheral vascular disease (AKA peripheral arterial disease), they are deep lesions usually found on the distal foot and are treated without compression.
Venous ulcers are usually caused by venous insufficiency (which also causes varicose veins), they are found on the gaiter areas of the leg, have a gradual edge and are best treated with compression and elevation.
In a clinical examination of a vascular ulcer, an appropriate structure would be:
This article on the BMJ has good images of the associated signs that may be seen. http://student.bmj.com/student/view-article.html?id=sbmj0604140
NICE CG147 - Lower limb peripheral arterial disease: diagnosis and management
NICE CG168 - Varicose veins in the legs
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