Lecture 15: PAD Part 1 Flashcards
What is PAD?
Stenosis or occlusion in the aorta or arteries in the limbs
MCC of PAD
Atherosclerosis in patients > 40y
Hallmark sign of PAD
Intermittent claudication
Claudication = muscle pain due to hypoxia but relived by rest.
What kind of vessels does PAD tend to affect?
Middle-large size vessels
MCC two arteries affected in PAD
Femoral and popliteal arteries
Esp at arterial branch points/bifurcations
Strongest risk factors for PAD
- DM
- Smoking
- Hypercholesterolemia
- HTN
- Renal insufficiency
1st two are most important
Who gets evaluated for PAD?
- > =70
- 50-69 w/ smoking or DM
- 40-49 w/ DM and additional risk factor
- Anyone with known atherosclerosis
MC sites of atherosclerosis in PAD
- Femoral-popliteal
- Tibial artery
- Distal aorta and proximal common iliac disease (white smokers)
smoking is also the main risk factor for AAA, which is the location of #3
What are the common clinical presentations for PAD?
- Asymptomatic
- Atypical leg pain (MC)
- Classic claudication
- Critical limb ischemia
Describe claudication.
- Occurs during exercise and relieved with rest
- Reproducible symptom
- The most typical symptom of PAD.
2 MCC of pseudoclaudication/neurogenic claudication
- Spinal cord stenosis
- Herniated disc impairment or scaiatic nerve
Claudication vs pseudoclaudication chart
What is often the first sign of vascular insufficiency in PAD?
Rest pain or ulceration that is confined to the dorsum of the foot and requires dependency.
Often occurs at night.
Dependency means the patient needs to hang their foot over the side of the bed
What characterizes critical limb ischemia?
- Ischemic rest pain
- Ulceration
- Gangrene
Essentially claudication, but the pain does NOT relieve with rest.
What is the MC anatomic classification scale used in PAD?
Trans-Atlantic Inter-Society Consensus (TASC II)
What classification is used for clinical severity of chronic lower extremity ischemia?
WIFi (Wound, ischemia, and foot infection)
Used to determine if you need to amputate.
Classic findings in patients with PAD
- Decreased or absent pulses distal to the obstruction
- May need to use hand-held doppler
What are normal pulses graded as on PE?
2+, brisk, expected
Buerger/leg lift test for PAD
- Elevate leg to 60deg for 1 minute
- Positive if pallor occurs since arterial pressure is lacking.
- Extremely positive if dependent rubor also occurs (when u drop the foot back down and it gets extremely red)
A normal foot shouldn’t turn white that fast
First-line screening for PAD
Ankle brachial index test
When is further testing of PAD required?
Only if ABI is a false negative or invasive interventions are needed.
Otherwise, it is a clinical diagnosis.
How to diagnose PAD
Clinically, only need ABI(<0.9) + history + PE
What is diagnostic of PAD on ABI?
Anything less than 0.9
How do you measure ABI?
Highest SBP of PT or DP
divided by brachial SBP
Must do ABI on each side.
PT = posterior tibial
DP = dorsalis pedis
Limitations of ABI
- Incompressible arteries (> 1.4)
- Resting may be useless if good collateral circulation was made
- Does not measure the degree or severity or location of PAD.
When do we do toe brachial index screening?
When ABI > 1.40
aka non-compressible arteries
What is abnormal/diagnostic TBI?
TBI <= 0.7 = PAD
What do TBIs predict?
Better value = better healing
When can you not use a treadmill test for PAD?
- Non-compressible vessels (ABI > 1.4)
- Cannot walk on a treadmill (unstable angina, etc)
What is diagnostic of PAD for treadmill stress tests?
Decrease in ABI of more than 20% following exercise.
What is segmental limb pressure used for and what is considered diagnostic?
Specific location of artery that has PAD, which is diagnosed by a decrease of >30 mm Hg between two consecutive segments.
What is arterial duplex mainly used for?
Determining severity and to assess risk/benefit for intervention.
Never use as a screening tool!!!!!!!!!!
When is MRA indicated and what is the primary CI?
MRA is indicated to assess benefit of surgery and gadolinium cannot be used in ppl with GFR < 30
Does not use ionizing radiation or ionized contrast
NOT SCREENING TEST
Difference between MRA and CTA
CTA uses iodinated contrast and ionized radiation.
MRA uses gadolinium, which is not iodinated.
What is the gold standard imaging test for PAD?
Digital subtraction angiography (DSA)
Done by IR to guide intervention.
What two antiplatelets are indicated for PAD?
ASA alone or plavix alone for symptomatic atherosclerotic lower extremity PAD
Only reasonable for asymptomatic
Do not do DAPT until they have had intervention.
What should you advise a patient on EVERY SINGLE VISIT for PAD?
Smoking cessation
What is the MOA and indication for cilostazol?
- Vasodilator + antiplatelet that improves symptoms in PAD.
- Protein-bound (can’t eat with food)
- No vasodilation in renal arteries
- PDE inhibitor
100mg PO BID
Who is cilostazol CId in?
Heart failure patients
When is bypass or endovascular therapy indicated for PAD?
Continued intermittent claudication sx’s or CLI.
What are the 3 types of endovascular therapy?
- Angioplasty
- Stenting
- Atherectomy
