Dr Swapnil Pawar
Shownotes written by Dr Ashly Liu
Classifications of Peripheral Artery Disease
Peripheral artery disease is usually a result of atherosclerotic disease resulting in peripheral arterial obstruction, which may present silently in the initial stages of the disease. Arterial insufficiency clinically manifests as pain due to a lack of blood flow in the musculature relative to the metabolism.
Peripheral arterial disease can remain asymptomatic
Common clinical manifestations include
|Chronic Limb-Threatening Ischaemia
|High risk patients
Red flags: wet gangrene, acute limb ischaemia
|Screen with ABI
|Measure ABI (see below) and if positive, consider
Medical therapies for positive PAD
|Referral to vascular specialist to consider revascularisation
|Referral to vascular specialist
If wet gangrene or progression to acute limb ischaemia
|Moderate to severe claudication
|Ischemic rest pain
|Ischemic rest pain
|Ulceration or gangrene
|Minor tissue loss
|Major tissue loss
This is an investigation that can be performed by the bedside and should be measured in patients who have symptoms suggestive of peripheral arterial disease.
ABI is the ratio of the ankle systolic blood pressure divided by the brachial systolic blood pressure (all detected with a Doppler probe).
|Ankle systolic pressure
Higher systolic pressure of posterior tibial or dorsalis pedis on ipsilateral leg
Brachial systolic blood pressure
Higher systolic pressure of left or right arm
|ABI < 0.9
|ABI 0.9 – 1.3
|Diagnostic for PAD
|Doppler ankle waveforms
Patients with diabetes or ESRD could have falsely elevated ABIs
*Toe brachial index is a more reliable indicator of limb perfusion in patients with diabetes and end stage renal disease as the digital vessels are frequently spared from medial calcification.
Duplex ultrasound is often the initial non-invasive vascular imaging obtained for patients with suspected peripheral arterial disease. It is also able to identify aorto-iliac/femoral arterial disease by measuring peak systolic velocity. The limitations of this study is that this is operator dependent and limited by staffing hours and availability.
CT Angiogram Runoff
CT angiogram run-off can image from the aorta to the bilateral lower limb extremities with a contrast bolus, identifying locations of obstruction in the blood vessels. The limitations of this study include reduced accuracy for distal vasculature, the use of contrast bolus in patients with renal impairment, and artifacts in scans for those with metal stent placements.
Digital Subtraction Angiography
Catheter-based digital subtraction angiography is the gold standard for the diagnosis of peripheral vascular disease. The limitations of this study is that this is operator-dependent and is an invasive procedure with risks including access site haematomas, vascular dissection and thromboembolism.
This is focused on the optimisation of risk factors and medical conditions as well as prevention of complications of peripheral vascular disease:
If there is persistent symptoms despite compliance with risk reduction strategies and supportive management, they can be referred for interventions which include:
They can also receive a hybrid of the two interventions, depending on the location and the extent of the patient’s disease.
Uptodate, Clinical features and diagnosis of lower extremity peripheral artery disease, “https://www.uptodate.com.acs.hcn.com.au/contents/clinical-features-and-diagnosis-of-lower-extremity-peripheral-artery-disease”
Uptodate, Advanced vascular imaging for lower extremity peripheral artery disease, “https://www.uptodate.com.acs.hcn.com.au/contents/advanced-vascular-imaging-for-lower-extremity-peripheral-artery-disease”
Uptodate, Noninvasive diagnosis of upper and lower extremity arterial disease “https://www.uptodate.com.acs.hcn.com.au/contents/noninvasive-diagnosis-of-upper-and-lower-extremity-arterial-disease”
Uptodate, Management of claudication due to peripheral artery disease “https://www.uptodate.com.acs.hcn.com.au/contents/management-of-claudication-due-to-peripheral-artery-disease”
Dr Swapnil Pawar October 3, 2023
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