Peripheral Arterial Disease Flashcards
structural atherosclerotic narrowing of any non-coronary vessel which limits blood flow to the limbs
anatomical definition of PAD
aterial narrowing causing a mismatch between organ supply and demand causing intermittent symptoms of claudication and or tissue ischemia
functional definiton of PAD
what are the classifications of PAD?
Lower extremity arterial disease
* typically known as PAD
* pain in the legs with walking or at rest (severe)
Abdominal
* aortic aneruysm
* renal artery
* mesenteric
Cerebral vascular (carotid)
microvascular
What are common causes of PAD?
- tobacco (single most important modifiable cause
- diabetes mellitus
- dyslipidemia
- hypertension
- inflammatory mediators (homocysteine, fibrinogen, c-reactive protein, lipoprotein (a), renal disease
- age, gender (male) and ethnicity (african american)
- obesity and physical inactivity
who is at risk for lower extremity PAD?
- Age < 50 years. with diabetes and one additional risk factor (smoking, lipidemia, hypertension etc.)
- age 50-69 years and history of smoking or diabetes
- age 70 years and older
- known atherosclerotic coronary, carotid, or renal artery disease
Symptoms of PAD?
- analogous to angina pectoris
- intermittent limb claudication (dull aching muscular discomfort induced by exercise and relieved by rest, often at discrete threshold of work)
- atypical features common (fatigue, heaviness, dysesthesia or cold sensation)
- not nocturnal cramps
what are indications to perform an ankle-brachial index (ABI) measurement?
Obtain history of walking impairment and/or limb ischemic symptoms
*obtain a vascular review of sx: leg discomfort with exertion; leg pain at rest; non-healing wound; gangrene
*Then review: no leg pain, atypical leg pain, classic claudication, chronic critical limb ischemia, acute limb ischemia-
*ALL of the above are reasons to perform ABI
How do you perform the ABI exam?
- Perform with the patient resting in the supine position
- all pressures are measured with an arterial doppler and appropriately sized cuff
- systolic pressures will be measured in the right and left brachial arteries followed by the right and left ankle arteries
how do you calculate the ABI?
ABI= Ankle systolic pressure/ higher brachial artery systolic pressure
What are the value ranges of the ABI?
1.00-1.29= normal
0.91-0.99= boderline, low normal
0.41-0.90= mild to moderate disease
< 0.40 = severe disease
> 1.30 = noncompressible
when is an exercise ABI indicated? what does it assess? what would support a PAD diagnosis?
- Indicated when the ABI is normal or boderline but symptoms are consistent with claudication
- assesses functional capacity (patient symptoms may be discordant with exercise capacity)
- An ABI fall post exercise supports a PAD diagnosis
Aterial duplex ultrasound testing of the extremities can be used for candidates for?
- endovascular intervention (Stent/ PTA)
- surgical bypass
- to select the sites of surgical anastomosis
What is considered Abdominal vascular disease?
- aortic aneurysm
- mesenteric artery disease
- renal artery disease
Atherosclerotic etiology
* increased prevalence in pts with CAD, CVD, PAD
* Risk factors essentially the same for each
Fibromuscular dysplasia (FMD)
* accounts for 40% of cases
* also seen in the carotid arteries
* congenital arterial abnormality of fibrous, muscular and elastic components
Renal Artery Stenosis
caused by renal artery stenosis (kidney senses low blood flow because of the blockage)
* secondary to atherosclerosis- usually origin and proximal segment of renal artery
* fibromuscular dysplasia- usually mid to distal segment of renal artery or carotid artery
* occlusion
Renovascular hypertension
Where is the most common place for aortic aneurysms to occur?
infra-renal aorta
how would patients with an abdominal aortic aneurysm present?
- most patients are asymptomatic
- symptomatic (unruptured)- presents with abdominal, flank or back pain. On examination, abdominal bruits may be heard and a pulsitile abdominal mass may be palpated
- symptomatic (ruptured)- hypotension or syncope, flank ecchymosis
how should AAA be diagnosed?
- CT scan with IV contrast- best initial test in symptomatic, hemodynamically stable patients
- ultrasound- initial study of choice in hemodynamically unstable patients
- Asymptomatic with suspected AAA- abdominal ultrasound is is the initial test
MRA can also be used
- sudden brain damage; lack of blood flow to the brain caused by a clot or rupture of a blood vessel
- ischemic = clot
- hemorrhagic = bleed
- dx= carotid bruit
- suspicion leads to ultrasound of carotid arteries
- any abnormality on ultrasound: confirm with MRA or CT
Stroke
What are the major goals of treating PAD?
Limb outcomes
* Improved ability to walk (increase in peak walking distance, improvement in quality of live
* prevention of progression to CLI and amputation
Cardiovascular morbidity and mortality outcomes
* decrease in morbidity from non-fatal MI and stroke
* decrease in cardiovascular mortality from fatal MI and stroke
getting the pt walking will help grow new collateral arteries
ways to treat the underlying causes of PAD?
- Smoking cessation (laser, licorice, medications, hypnotism)
- antiplatelet therapy
- hyperlipidemia (lifestyle and/or medications
- hypertension (pts should receive hypertension tx)
- keep diabetes under good control
- get active, lose weight
indications lower extremities:
* persistent limiting claudication, preventing working and/or ADL
* rest pain
* tissue loss/non healing ulcers (get pt walking!!)
abdominal aorta or renal arteries
carotid arteries
Treatment with Angioplasty/Stent
Lower extremity arterial disease
* bypass (eg. femoral to popliteal artery)
* vein or synthetic graft used (synthetic if patient does not have viable veins or if they are too small)
Abdominal aorta
* use criteria set, when the risk of rupture outweighs the risk of this procedure
carotid endarterectomy
Treatment with Surgery
what are microcirculatory diseases?
raynaud phenomenon
buerger’s disease
repetitive episodes of
* biphasic colour change (at lease 2 of pallor, cyanosis, erythema)
* in either cold or normal environment
primarily affects fingers, can affect toes, thumbs, nipples, nose, earlobes
episodes accompanied by pain +/- numbness
pulses present
necrosis/tissue damage suggestive of secondary cause
Raynauds
what is the pathogenesis and causes of raynauds?
pathogenesis
* increased vasoconstriction, decreased vasodilation, reduced blood flow/procoagulant tendency, endothelial damage
Causes
* primary (10-15% of healthy population, female predominance)
* secondary (drugs eg beta blockers, connective tissue disorders, eating disorders, haematological, vascular occlusion, occupation e.g vibrating tool use, hypothyroidism, carpal tunnel syndrome
treatment of raynauds
indentify and treat underlying etiology
* maintenance of core temp, avoidance of cold exposure, cessation of vasoconstrictive rx e.g beta blockers, gloves (heated), smoking cessation
Promote vasodilation
* calcium channel blockers, dyhropyridine (nifedipine better than amlodipine), nitrates, prostaglandins, phosphodiester V inhibitors
Prevent vasoconstriction
* ACEi/ARB, alpha blockers, SSRIs, endothelial receptor antagonists
- Thromobangiitis obliterans
- combination of acute inflammation and thrombosis of arteries and veins
- upper and lower extremities affected
- obstructs bloodflow to tissues; pain, damage
- can lead to skin ulcerations and gangrene
- advanced stages- can affect other parts of the body
Buerger’s disease
symptoms of buerger’s disease?
- pain or tenderness
- numbness and tingling in the hands/feet
- skin ulcers or gangrene of the fingers/toes
- discoloration
- two or more limbs affected
- pain may increase with activity such as walking and decrease with rest
- pulse may be decreased/absent in the affected extremity
- symptoms may worsen with exposure to cold or with emotional stress
causes and diagnosis of buerger’s disease?
Causes
* associated with moderate-heavy tobacco use
* seen in both cigarette and tobacco chewing
* thought to be autoimmune reaction triggered by tobacco
Diagnosis
* suspicion- start evaluation of vascular/rheumatological diseases early
* doppler ultrasound
* angiogram of upper/lower extremities
* skin biopsies rarely used
