Introduction

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.

 

Pathophysiology

Arterial ulcers

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 ulcers

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.

 

Mixed ulcers

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.

 

Neuropathic ulcer

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.

 

Aetiology

Arterial ulcers

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.

 

Venous ulcers

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.

Symptoms and signs

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.

Short saphenous vein Great saphenous vein

Appearance

The appearance of the ulcer will also help you decide whether the aetiology is arterial or venous.

Arterial ulcers tend to be:

  • Small 
  • Have well defined edges 
  • Have a punched out appearance 
  • Appear deep
  • Have slough and necrotic tissue at the base 

 

This is an image of a typical arterial ulcer.

 

Arterial ulcer

Venous ulcers tend to be:

  • Large
  • Have gradually sloping edges
  • Have slough on the surface 
  • Have no necrotic tissue

 

This is an image of a typical venous ulcer.

 

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:

  • Delayed capillary refill
  • Pallor
  • Weak or absent pulses
  • Paraesthesia (pins and needles) 
  • Claudication (cramping in the affected area, at first with exercise but can progress pain at rest)

In venous disease you would expect any of:

  • Varicose veins (dilated torturous vessels caused by increased pressure, see image below)
  • Venous eczema (irritation to the skin caused by the break down of red blood cells that have leaked from the capillaries)
  • Lipodermatosclerosis (inverted champagne bottle appearance of the leg due to tightening of the tissue, this is likely due to inflammation that has occurred as a result of the leaked venous blood)
  • Atropic blanche (this is a pale scar with prominent red dots within it, this is a healed ulcer with dilated capillaries)
  • Pitting oedema
  • Increased blood loss from wounds in the area

Varicose veins

This table summarizes the key characteristics of an ulcer that will discriminate an arterial ulcer from a venous ulcer on history and examination. 

Key features of vascular ulcers

Investigations

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.

 

Summary

In summary the investigations for arterial disease are:

  • Ankle brachial pressure index (ABPI)
  • Duplex ultrasound scan
  • MRI or CT angiogram with contrast

 

In summary the investigations for venous disease are:

  • Handheld doppler
  • Duplex ultrasound scan

 

Arterial ulcer

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.

  1. The patient should be rested and supine
  2. Locate the tibialis posterior or the dorsalis pedis pulse by palpation or using the doppler
  3. Inflate the cuff around the calf until the pulse can no longer be detected by the doppler
  4. Record this pressure (systolic) and divide it by the pressure taken to occlude the brachial pulse by inflating the cuff around the upper arm

Here is a table of how to interpret the result:

 

Ankle brachial pressure index interpretation

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.

 

Venous ulcer

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.

 

Management

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.

 

Venous ulcers

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.

 

Arterial ulcer

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.

 

Summary

In summary a venous ulcer should be managed with:

  • Four layer compression bandaging
  • Graduated compression stockings
  • Regularly elevation

 

In summary an arterial ulcer should be managed with:

  • Non-compression dressing

Complications

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. 

 

Summary

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.

 

OSCE approach

In a clinical examination of a vascular ulcer, an appropriate structure would be:

 

  1. Introduction, patient identification, consent, wash hands
  2. Inspect the patient from the end of the bed observing for oxygen, tobacco, walking aids etc
  3. Uncover the lesion and inspect. Look back at the symptoms and signs section for the important things to look for
  4. Inspect the whole of the legs on both sides for the associated signs mentioned above
  5. Palpate for temperature changes, comparing both legs and areas on the legs
  6. Perform a capillary refill, if they have had an amputation already (for peripheral vascular disease) then move proximally to skin which is covering a bony prominence
  7. You should have a good indication by this stage as to whether the ulcer is arterial or venous and should continue your examination based on this. You could examine both systems fully however this depends on the time allocated for your OSCE stations. To avoid repetition, please look at the examination of varicose veins and the peripheral vascular exam section of the vascular skills section
  8. To complete the examination thank the patient and wash your hands
  9. Present a summary of your findings to the examiner, state whether you believe the ulcer to be arterial or venous and offer investigations to confirm your decision

 

Useful resources

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

 

References

http://student.bmj.com/student/view-article.html?id=sbmj0604140

http://www.iewg.it/cont/020lis/0411/2300/11737all1.pdf

NICE CG147 - Lower limb peripheral arterial disease: diagnosis and management

NICE CG168 - Varicose veins in the legs

http://medical-dictionary.thefreedictionary.com/ulcer

http://cutimed.com/therapy-approaches/venous-leg-ulcer/pathogenesis/

http://www.gpnotebook.co.uk/simplepage.cfm?ID=-1563426745

Image http://upload.wikimedia.org/wikipedia/commons/3/30/Arterial_ulcer_peripheral_vascular_disease.jpg

Image http://upload.wikimedia.org/wikipedia/commons/5/51/Great_saphenous_vein.png

Image http://upload.wikimedia.org/wikipedia/commons/6/62/Gray582.png

Image http://meded.ucsd.edu/clinicalimg/extremities_venous_ulcer.htm

 

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