Peripheral arterial disease and ulcers: Clinical sciences

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Introduction0:00–0:54

Peripheral arterial disease, also known as PAD, is when an extremity, typically the lower limb, does not receive enough blood supply to meet the needs of its tissues.
It’s often caused by chronic narrowing of the artery’s luminal diameter, simply known as stenosis, due to atherosclerosis, inflammation, or trauma.
Over time, the stenosis decreases the blood supply to the tissue, which can lead to the formation of ischemic ulcers at distal zones of the affected arteries, like the toes.
A more severe form of PAD is called chronic limb-threatening ischemia, or CLTI for short. Keep in mind that CLTI is sometimes called critical limb ischemia, so if you hear that name, don’t be confused.
Alright, your first step in assessing a patient with a chief concern suggesting PAD or an ulcer is to perform a focused history and physical exam.

Focused History & Physical Examination0:54–2:57

On history, patients typically report intermittent claudication, which is a crampy pain in the calves when walking, and sometimes even pain at rest if the patient progresses to CTLI.
You can expect patients to have some underlying comorbidities or risk factors, such as a history of smoking, hypertension, diabetes mellitus, hyperlipidemia, or chronic kidney disease.
Common physical exam findings include cool lower extremities with trophic changes like hair loss, as well as absent or reduced distal pulses, and abnormal capillary refill.
An important part of performing a vascular physical exam is to thoroughly assess for pulses. If you’re unable to palpate a pulse, use a handheld Doppler to listen for a signal.
Sometimes you might hear Doppler signals for a pulse that’s not palpable. Make sure to examine proximal vessels like the femoral or popliteal arteries, as well as distal vessels, such as the anterior or posterior tibial arteries.
When examining vessels, don’t forget to compare them bilaterally. Next, if you auscultate the femoral artery, you might hear a bruit, which is a sign of a turbulent blood flow in the vessel due to stenosis.
Finally, in some cases, you’ll see signs of tissue loss, like an arterial ulcer with punched-out edges and a dry base, or even necrosis or gangrene.
If you find these characteristics, suspect PAD. Here’s a clinical pear!
Not all ulcers on a physical exam will be arterial. They might present with a neuropathic, or a venous stasis ulcer as well.
Okay, now that you suspect PAD, obtain an ankle-brachial index or ABI to assess the blood flow through arteries. The test involves measuring blood pressure at the ankle and the arm.

ABI & TBI2:57–5:31

Then, the ankle pressure is divided by the arm pressure to calculate the ABI. Here, you should measure both a pre and post-exercise ABI, because sometimes exercise can increase the blood flow to the legs accentuating a greater difference in blood pressure distal to the arterial lesion.
In other words, obtaining the ABI post-exercise can increase the sensitivity of the results.Alright, let’s look at our possible ABI results.
Now, an abnormal ABI of less than 0.9 means that there’s an arterial insufficiency. Next, you should determine the severity of their condition by assessing for signs of severe disease, including rest pain, ulcer, necrosis, or even wet or dry gangrene.
Okay, before we move on to treatment, let’s talk about other possible ABI findings first. If the ABI results are normal, between 0.9 and 1.4, you should consider an alternative diagnosis.
This can include musculoskeletal causes of limb pain and venous or neuropathic causes of ulcers.Here’s a clinical pear! Sometimes ABI might be borderline ranging from 0.91 to 0.99.
If this happens, definitely obtain the post-exercise ABI to get a real idea of what’s going on! Now let’s go back and talk about the last ABI result.
An ABI greater than 1.4 can indicate calcified arteries that cannot be compressed with an external blood pressure cuff. This is commonly encountered in diabetic patients due to the chronic glycation of their arterial wall leading to stiffening of the vessel.
In these cases, your next step is to measure a toe brachial index or TBI. The arteries of the toe are often spared from being calcified.
If TBI is normal, consider an alternative diagnosis. On the flip side, if TBI is abnormal, the patient has arterial insufficiency.
As with abnormal ABI, you should determine the severity of their condition by assessing for signs of severe disease, including rest pain, ulcer, necrosis, or even wet or dry gangrene.
Okay, If your patient doesn’t have any signs of severe disease, meaning no rest pain, ulcers, necrosis or gangrene, then we are talking about PAD.

Peripheral arterial disease5:31–7:05

The initial treatment for these patients includes graded exercise programs, which will help improve their function and reduce symptoms.
Next, remember that atherosclerosis is a systemic disease, which puts your patient at risk of some other vascular disease like myocardial infarction or stroke.
So, you need to address any risk factors the patient might have. First, advise them to stop smoking.
Be sure to provide support, refer to smoking cessation programs, or even pharmacotherapy to help them quit smoking. Next, start them on medical management to control their comorbidities, such as antiplatelet agents like aspirin or clopidogrel.
Another important factor to control is diabetes mellitus. Ideally, HbA1c should be kept below 7%.
Next, be sure to prescribe a high-intensity statin, or another lipid-lowering medication like ezetimibe or PCSK9i if needed to keep LDL-C lower than 70.
Finally, it’s important to control their blood pressure, and ideally keep it under 140 over 90. Now, if symptoms don’t improve or there’s only minimal improvement after 4 to 6 weeks of therapy, consider adding cilostazol and consult the surgical team for angiography.Alright, let’s take a step back and talk about patients with signs of severe disease, including rest pain, ulcer, necrosis, or gangrene lasting more than 2 weeks, which means you can diagnose CLTI.

Chronic limb-threatening ischemia7:05–9:19

Before we talk about treatment, here’s a clinical pear! Since CLTI is a more severe form of PAD, patients might need additional assessments like Doppler ultrasound or CTA to determine the degree of their disease.Additionally, here’s a high-yield fact!
Wet and dry gangrene exist on a continuum of physical exam findings. Wet gangrene often has a significant amount of drainage from the wound with surrounding erythema likely from a superimposed bacterial infection.
Because the infection can progress rapidly, wet gangrene is considered an emergency and needs to be treated right away. On the other hand, dry gangrene looks like mummified necrotic tissue, which is actually not painful because their nerves are also dead.
It usually doesn’t have an associated infection, so it can be managed in a less urgent manner. Keep in mind that sometimes, revascularization of a compromised limb can result in the conversion of dry gangrene to wet gangrene and will require surgical debridement.Once the diagnosis of critical limb-threatening ischemia has been made, you should start the treatment right away.
Treatment includes smoking cessation; as well as the same medical management as PAD, so antiplatelets, managing their diabetes mellitus, lipid-lowering medications, and blood pressure control.
In addition, patients with CLTI might need pain management. You can prescribe them acetaminophen, but keep in mind that some patients might have severe pain requiring opioids.
Next, be sure to refer them for wound care. As for the surgical management, most patients will need revascularization.
However, if they present with infected wounds, severe necrosis, or gangrene, call the surgical team for emergent wound debridement and possibly amputation.Alright, as a quick recap… Peripheral arterial disease or PAD is when an extremity, typically the lower extremity, doesn’t receive enough blood supply to meet end tissue demands.

Review9:19–10:32

When PAD presents with severe signs, such as rest pain, ulcers, necrosis or gangrene, it’s called chronic limb-threatening ischemia or CLTI.
First, obtain an ABI; if it’s abnormal, assess for signs of severe disease to diagnose PAD or CLTI. If ABI is non-diagnostic, you’ll need to obtain a TBI as well.
For patients with PAD, treatment involves exercise programs and addressing risk factors, including smoking cessation, antiplatelet therapy, diabetes management, lipid-lowering medications, and blood pressure control.
If they don’t improve, you can add cilostazol to treatment and call the surgical team for revascularization. For CLTI, management also includes addressing risk factors.
Additionally, you should offer pain management, wound care, and surgical treatment like revascularization, or even wound debridement and amputation in the most severe
Peripheral arterial disease and ulcers: Video | Osmosis