Characteristics and Identification of Wound Types: Arterial and Venous Insufficiency Ulcers

Original Editor - Stacy Schiurring based on the course by Dana Palmer

Top Contributors - Stacy Schiurring, Jess Bell and Tarina van der Stockt

Introduction

This article provides information for those rehabilitation professionals who are new to wound care or have been away from the practise and need a review of wound type identification. This article will not go into specifics on wound assessment or treatment.

The five most common types of chronic wounds include (1) arterial ulcers, (2) venous insufficiency ulcers or venous wounds, (3) neuropathic wounds, or diabetic foot ulcers (DFUs), (4) pressure injuries, formerly known as pressure ulcers, and (5) non-healing surgical wounds.

The terms ulcer and wound will be used interchangeably throughout this article.

Due to the large amount of information to be presented, this topic has been divided into three separate pages. This page will cover arterial and venous insufficiency ulcers. To learn more about neuropathic wounds, please see this article. To learn more about pressure injuries and non-healing surgical wounds, please see this article.

Arterial Ulcers

Arterial ulcers (ischemic ulcers) are caused by poor tissue profusion to the lower extremities. This impaired blood supply causes nutrient and oxygen deprivation, and results in tissue hypoxia and cell death. This leads to wound formation in the overlying skin and tissues. Additionally, decreased blood supply can impair the body's ability to heal, allowing minor scrapes or cuts to develop into ulcers.

• Arterial wounds account for about 10 to 20% of lower extremity ulcers
• Arterial ulcers are the result of peripheral arterial disease

Peripheral arterial disease

Peripheral arterial disease (PAD) is caused by the narrowing or blockage of the arteries, most commonly caused by atherosclerosis. PAD can occur in any artery but it is more common in the legs than the arms. 40% of people with PAD are asymptomatic, knowing what to look for may save a limb or a life

• PAD occurs along a spectrum and progresses incrementally
• It is asymptomatic until it reaches a threshold where the body is no longer able to compensate for the reduced blood flow, which can be when the artery is 60% or more occluded

PAD Screening

Patients with PAD have a higher risk of asymptomatic coronary artery disease, and are at a greater risk of cardiovascular events. Therefore, it is important for the rehabilitation professional to be able to screen for PAD in the clinic or at the bedside. As rehabilitation professionals often spend large amounts of time with their patients and get to know them well, they may be the first healthcare professional to note the possibility of PAD. Simple and efficient bedside screens allow the rehabilitation professional to gather information and initiate the appropriate referral.

The fastest and simplest screening method is to simply check tibialis posterior and dorsalis pedis pulses. If using this method, be sure to document which grading scale you used.

	Screening goal	Procedure	Special hints	Test image
Dorsalis pedis pulse		possible to visualize this pulse locate palpation point by asking patient to lift their great toe, the artery is located just lateral to this tendon pulse is located just past the midfoot towards the ankle region	document which grading scale is being used
Posterior tibial artery pulse		locate the palpation point midway between the medial malleolus and the Achilles tendon	document which grading scale is being used
Capillary refill time (CRT)	beneficial to perform when patient has absent or deminished posterior tibial or dorsalis pedis pulses	provide light compression at the end of a digit or the skin just distal to a wound or area of concern until the colour disappears (blaunches) release the pressure and count how many seconds until the skin returns to its original colour a normal CRT is less than three seconds
Rubor dependency test		the limb is elevated to 30 degrees from horizontal and observed for pallor then it is moved to a dependent position a limb with normal profusion will return to a healthy colour within about 15 seconds of being lowered

If these screening tests are positive, the patient should receive an ankle-brachial index test (ABI).  It assesses the severity of arterial insufficiency of arterial narrowing during walking. ABI is measured by dividing the ankle systolic pressure by brachial systolic pressure. Normal ABI is between 0.90 and 1.30, a lower score may indicate PAD, a higher score may be a sign of arterial calcification.

Other tests that may be considered are the (1) toe-brachial index, (2) transcutaneous oxygen pressure, or (3) segmental perfusion pressure. The gold standard to diagnose PAD is contrast angiography, which is an invasive exam.

PAD risk factors

Let's look at the risk factors for PAD and arterial ulcers. The first is smoking. Cigarette smoking doubles the risk of PAD, and this risk increases cumulatively with the number of cigarettes smoked as well as the number of years spent smoking. The next is age. So the numbers on this vary but about 5-10% of those aged 50 to 80 and 20-30% of those over 80 have PAD. So this is something to consider if you work a lot with the older population. The third is patients with diabetes. They have two to three times the increased risk of PAD, even though it may be undiagnosed at the time. The next is hypertension. Particularly systolic blood pressure above 120 is something to keep in mind. The next is high cholesterol or dyslipidemia. This also increases the risk of both PAD and ulcers. The next is a sedentary lifestyle. The next is a family history. So here both genetics as well as a similar lifestyle may be playing a role. So most people typically eat the same foods and do the same activities or lack of activity as their family, in addition to sharing genes with them.

I'd like to address sex differences. In the past, it was thought that biological males had a greater risk of PAD than biological females, but newer research tells us that males may just be more likely to present with claudication symptoms and females may be more likely to be asymptomatic. So that's something to keep in mind even if your female patients aren't complaining of symptoms, there's other signs you can look for.

PAD differential diagnosis

There's a key differential diagnosis that I think is really valuable to discuss here and that's spinal stenosis. Spinal stenosis can present with symptoms similar to peripheral arterial disease. So it's important to distinguish between the two, especially because this is a condition that is commonly seen in physiotherapy practice. Ischaemic claudication pain in the early stages can be relieved with rest and in the later stages is present at rest and does not change except for occasionally when the limb is placed in a dependent position. So that's what you're going to be looking for with PAD. In contrast, pain associated with spinal stenosis claudication is typically relieved with a change in position that reduces the compression at the spine. So such as moving from standing to sitting or sitting to lying or extension into flexion. Looking at the other signs and symptoms of PAD will also help to differentiate between the two. And remember that it's possible for both of these things to be occurring together.

Arterial wound characteristics

Now let's look at how to identify arterial ulcers. The primary characteristics of arterial wounds are they occur on the lower third of the leg. And they're often seen on the lateral side and distally. So examples are the mid-tibia region, the lateral malleolus, the toes, the web spaces and the heels. The wound bed tends to be pale with well-defined edges or a punched out appearance. The wound bed is typically dry and has minimal drainage and does not usually bleed. Necrotic tissue is common, especially black eschar. The surrounding skin is commonly shiny, brittle, and hairless and you may see slow-growing, brittle, or rigid toenails as well. The posterior tibial and/or dorsalis pedis pulses are diminished or absent. The skin is pale, darkened, or cyanotic. The lower leg is often cool to the touch and muscle atrophy is seen in the calves or feet. So this is also commonly seen in neuro conditions and with diabetes as well when there's motor neuropathy.

Symptoms of PAD and arterial ulcers. You're going to see slow healing wounds. Feet usually feel cold, tingly or numb. Muscle cramping is common, especially with exercise or climbing stairs. Arterial ulcers are typically quite painful. So you may hear that from your patients. While symptoms are often reported unilaterally, approximately 80% of patients may have significant bilateral disease. So if one side is more severe, it may just be masking symptoms on the contralateral side. Pain is commonly relieved with dependency and you may see some oedema in the limb as a result of them keeping it dependent so often for relief. So this is important to keep in mind because sometimes this oedema is misattributed to venous disease. Pain is often worse with elevation and can be seen when lying down in bed at night or sitting back in a recliner with their legs up. Often people with PAD cannot walk more than two to three blocks without stopping to rest because of cramping, weakness, or pain. If this comes on and resolves predictably and consistently, PAD should be considered. So distinguish this between other types of walking pain: pain due to nerve or muscle may stay the same or worsen with increased activity and feel better at rest, but also take longer to resolve with increased activity or multiple trials. Whereas joint pain may improve with activity and then worsen or feel more stiff with rest. In the later stages of PAD, rest pain and burning in the toes and the soles of the feet are common or is common.

Arterial wound management

Okay. So now let's talk about the three most important factors in arterial wound management. So even if you're not doing these things, you know how to educate and who to refer to. The first is perfusion. It's very important to address this before anything else. Tissue perfusion needs to be restored as soon as possible. So avoid compression and elevation in these patients. If your screening tests indicate poor perfusion, the patient should receive an ankle-brachial index test or a referral back to the doctor or to a vascular specialist for more testing. The next most important thing is smoking cessation. So while this is important for all wounds, many other health issues, this is especially a priority for those with PAD. This is the largest modifiable risk factor for arterial ulcers. Smoking just one cigarette reduces tissue oxygenation concentrations. Smoking cessation has been shown to restore the tissue microenvironment and cellular functions within about four weeks time. And then that continues the longer that they abstain from smoking. The third most important factor is nutrition. So adequate hydration along with reducing trans fats and inflammatory foods will all help to manage blood pressure, cholesterol, and inflammation. Ideally, each patient should work with a dietitian to develop a customised nutrition plan, but a list of basic inflammatory foods can be found in the resources section for this course. For hydration of an otherwise healthy person, an average recommendation is to take the body weight in pounds and divide by two to get the number of ounces of water per day, or approximately 25 to 30 millilitres of fluid per kilogram of body weight. So if someone is healing from a wound, has other health conditions, a diet with low water content, lives in an environment that's really dry or really humid, they may have different water requirements. And this is why a personalised assessment is really important, but that gives you a baseline of perhaps where to start.

Venous Insufficiency Wounds or Venous Ulcers

Moving on to venous insufficiency wounds or venous ulcers. This is the most common type of chronic wound accounting for more than 70% of all leg ulcers and it is the result of venous insufficiency. Approximately one-third of adults have venous insufficiency and the prevalence increases with age. It is about three times more common in biological females than biological males. This is primarily due to the effect that estrogen and progesterone have on vein function. It is important to note that about a quarter of those with CVI will have concomitant arterial disease and they should be screened for this mixed presentation, okay, with the perfusion tests that we discussed before.

Venous ulcer characteristics

The characteristics of CVI and venous wounds. They occur on the lower third of the leg in the gaiter area and are more common on the medial side, although they can occur laterally as well. Examples are above the medial or lateral malleolus. If the wound occurs directly on the malleolus, on the calf, or on the proximal lower leg, it's not likely to be a venous origin. Venous wounds are of insidious onset and they are often proceeded by changes in colour and the texture of skin. So it may appear inflamed, thickened, crusty, scaled, shiny or tight. Typically redness is seen in lighter skin tones and a purple-grey or ashen tone is seen in darker skin tones. These are signs of stasis dermatitis. The next sign is varicose veins. They may be present, but it's not always the case. There can be insufficiency of the deep system without it manifesting in the superficial system. The next is staining of the skin. Haemosiderin staining is a brownish speckly staining of the skin that is a result of the breakdown of red blood cells and haemoglobin molecules that become trapped in the skin after being leaked from distended vessels. Atrophie blanche is a whitish discolouration due to occlusion of the small vessels in the skin. So it can be seen in skin that has healed ulcers and may also be seen as a precursor to ulceration. Venous wounds tend to be shallow, they have uneven edges and a granular or a gelatinous fibrotic base. This is in contrast to the punched out appearance of arterial ulcers. Yellow slough may be seen, but black or brown eschar is rare. Venous wounds tend to be wet. Serous exudate seeps from the wound, and then also sometimes from the surrounding skin. So you'll tend to see a lot of exudate with these types of wounds.

Chronic oedema is worse after prolonged standing. So initially, this oedema is pitting, which means an indent stays when you press on the skin. In more advanced disease, this oedema may become firm and a 'woody' consistency. And this is due to fibrosis of the underlying tissue. This presents as a dark, discoloured, firm, and nonpitting oedema. Late stages of the disease may present with a 'champagne bottle' shape of the lower leg. It's important to note that oedema in CVI is generally only observed below the knee. So if the oedema extends up into the thigh, it's more likely to be due to lymphoedema than venous insufficiency. CVI oedema is also more likely to be unilateral, although in long-standing disease, you may see it bilaterally. It's still more likely to be more severe on one side compared to the other. If oedema is bilateral and equal, it is more likely due to medications or another systemic condition like congestive heart failure or something along those lines. Pulses are not typically absent in venous insufficiency, except in cases of severe oedema where there's so much swelling that it interferes with palpation of the pulse. Finally, the lower leg is typically warm to the touch. Now this is in contrast to arterial ulcers where the limb is typically cool to the touch.

So let's talk about symptoms of CVI and venous ulcers. You will commonly see wounds that tend to improve and regress multiple times. 60-70% of those that have had a venous wound will have a recurrence within 10 years. So these are ones that come and go a lot of the time, you will often see aching or cramping in the leg. This is due to distension of the vessels, blood pooling in those muscles, and then reduced oxygenation to the tissues. The leg will also feel heavy or tired. This is due to the oedema and the reduced oxygenation. So that's a common thing that you hear. Itching or tingling of the skin is really common, especially when you've got stasis dermatitis. This is due to distension of the vessels, and then the inflammation that's caused by the accumulation of all that fluid and proteins that are in the interstitial spaces. Discomfort is often seen or relieved with elevation, sorry, and worsened with dependency or prolonged standing. This is in contrast to the relief with dependency with arterial ulcers. The patient may see symptoms of frequent urination at night. So, because the legs are elevated, the fluid is draining. The kidneys have to offload that, but keep in mind that this symptom could be due to other causes as well. Finally, the lower leg may ache. Venous wounds are typically not as painful as arterial wounds, but they sort of report more aching of like the whole leg region.

CVI screening

Let's talk about clinical screening for CVI. Examination should begin with an assessment of the skin, looking for visible varicose veins, oedema, any skin changes that are commonly seen with VIN, venous insufficiency. Those are going to tip you off right away. The next is to look at arterial circulation with palpation of the posterior tibial and dorsalis pedis pulses. If these are not palpable, check capillary refill. If it is intact, the lack of pulses are more likely due to venous oedema that's interfering with your palpation rather than due to arterial insufficiency occluding the vessels. And finally, the Brodie-Trendelenberg's and Perthe's tests can be used clinically to test for venous backflow and links to these tests can be found in the resources for this course.

Venous ulcer management

Okay, let's look at the three most important factors for venous wound management. The first is, hands down, compression. With an open wound, the patient should have compression dressings that are changed regularly to keep up with the leg circumference. That might mean every other day or every three to four days, depending on their situation. These dressings are kept on 24 hours a day and they should not get wet. So care needs to be taken with bathing. Once the wounds have healed and oedema is stable. The limb should be measured for custom compression stockings. These should be worn all day but can be removed for sleep. Prior to applying any compression you need to ensure that the patient has adequate tissue perfusion and that the level of compression is appropriate for them. So this requires an ankle-brachial index testing. If the patient already has compression stockings, it's important to ensure that they still fit and that they are wearing them. So these typically need to be changed every six months. And if possible, the patient should have two pairs so that they have something to wear while one of them is being washed. The next important thing is nutrition. As discussed with arterial ulcers, you need to ensure adequate hydration and reduce foods that can cause inflammation of the blood vessels. Again, if possible, each patient should work with a dietitian to develop a customised nutrition plan, but if that's not possible, some of the general recommendations in the resource section can be beneficial to sort of get them at least started on the right path.

The next important thing is exercise. A few ideas are a walking programme or bicycling. So these have the advantages of many other health benefits, right? The next is soleus stretches and ankle mobility to optimise ankle joint range of motion. Ankle pumps, circumduction, ankle alphabet, heel-toe raises in both sitting and standing positions. Ankle rocker board exercises. You can also use an exaggerated heel-toe sequence during ambulation or over a step. And you can combine these exercises with elevating the leg higher than the heart to maximise the benefit. So now you're using gravity and then you can still do all those exercises that's going to activate the muscle pump and all of that is going to be feeding to getting the fluid out of that limb.

Resources

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