URR Lower Extrem Arterial Disease Flashcards
what is arteriosclerosis
-intimal thickening, calcification and loss of wall elasticity
-“hardening of the arteries”
-most common sites in legs
most common sites for arteriosclerosis?
1 SFA in adductor canal
#2 CFA bifurcation
#3 calf vessels and other vessel origins
what is atherosclerosis obliterans?
-atherosclerotic changes produce progressive obstruction
-most common cause of arterial occlusive disease
-accumulation of lipids in intima which causes narrowing
-usually affects extrems in a diffuse manner but increased incidence in pop and calf arteries
-focal stenosis and diffuse stenosis can coexist
-symptoms of moderate disease usually exacerbated w/ exercise and relieved w/ resting in dependent position
arteritis
-inflammation of the artery walls causing flow stasis w/ thrombus formation
-usually affects peroneal arteries, posterior and anterior tibial arteries and smaller distal arteries/capillaries
thromboangiitis
refers to diffuse inflammation of the intimal wall layer
what is kawasaki disease?
-affects small to medium arteries
-coronary arteries are commonly affected; causes dilatation and potential aneurysm formation
-usually seen in peds patients age 2-5 years old
-more common in the Japanese population
buerger disease/ thromboangiitis obliterans
-occlusive disease of small to medium size arteries caused by inflammation of arterial wall and surrounding connective tissue
-digital, plantar, tibial, peroneal, radial, and ulnar arteries
-always associated with heavy smoking
-most common in men, age 20-30
-associated with collagen disease, such as lupus
-acute onset in plantar or palmar arteries then moves centrally
-always bilateral but one side can be affected more significantly than the other
-most patients have at lease 3 out of 4 extrems affected
-ischemic rest pain and distal ulcers are common
-associated with in step claudication
-evaluated by doppler and PPG techniques
takayasu arteritis
-presents as hypertrophic areas of inflamed tissue usually found in the Ao and its branches
-associated with supravalvular stenosis and aortic coarctation
-90% cases involve the CCAs
-can also affect the renal As
-most commonly seen in young females (20-40 yrs)
-most common in Asia and India than the US
-symptoms include absence of peripheral pulse, asymmetric brachial blood pressures, amaurosis fugax, hemiparesis, diplopia, vertigo and upper extrem claudication
takayasu arteritis sonographic appearance?
-presents similar to stenosis
-clinical exam important for differentiation from atherosclerotic disease
-increased PSV and diastolic flow
-2D appearance shows more diffuse involvement and more homogeneous thickening of the vessel walls than seen with atheroma formation
giant cell arteritis
-usually presents in the cranial arteritis (temporal arteritis), but can be seen in the extrems
-usually seen in patients 70-80 years of age
-more common in women
-blood tests performed (to measure the erythrocyte sedimentation rate, to measure C-reactive protein)
-temporal arteritis with headaches and tenderness over the artery
-asymmetric brachial blood pressures seen in patients with arteritis in extrems
-other symptoms include pain and or stiffness in the neck, jaw claudication, and visual disturbances
-biopsy is the best method for diagnosis
-treated with corticosteroids like prednisone
giant cell arteritis sonographic appearance?
-causes diffuse or focal thickening of the muscle layer
-may see increased vascularity in the wall of the inflamed segment
-halo sign = a ring of thickened vessel wall tissue surrounding the vessel
-doppler findings
-focal dilation of the arterial wall
-caused by a breakdown of the media and adventitia is most commonly affected
-leads to decreased flow velocity and stasis of flow in the areas of flow separation
-thrombus can form in the areas of stagnant flow
aneurysm
pop aneurysms are usually
bilateral
-> 60% of patients with a pop aneurysm also have a AAA
when is surgical repair recommended for aneurysms?
-if the extrem exceeds 2.5 - 3 cm in diameter
-if aneurysms in the ao that exceed 5.5 cm in diameter
sonographic appearance of aneurysm?
-increased arterial diameter
-AAA > 3 cm diameter
-pop artery aneurysm > 1 cm diameter
-color has low velocity, turbulent, swirling flow, yin/yang sign
-doppler eval will demonstrate low velocity, low resistance flow
what is embolization?
-obstruction of a vessel by a foreign substance such as plaque or thrombus
-most arterial emboli are from a cardiac source
-atrial fibrillation is the most common cardiac abnormality associated with embolization
-embolic material lodges in distal artery causing ischemia/necrosis
-an air bubble can also be harmful embolism
-other causes include thrombus in aneurysm, arteritis, ulcerated atherosclerotic lesions, some angioplasty procedures
what is blue toe syndrome?
-discoloration of the digits caused by acute ischemia
-caused by small pieces of plaque or thrombus breaking loose from a more proximal site
-commonly seen in patients with AAA after a recent angiography procedure
what is a pseudoaneurysm?
-blood escapes through all 3 layers of the arterial wall into surrounding tissues and is encapsulated within the tissues
-a connection is made through a neck or stalk
-typically caused by trauma or invasive procedures (cardiac cath, cangioplasty)
-groin is most common for pseudoaneurysm
-primary symptoms are palpable, pulsatile mass, and a bruit
-anticoagulation therapy should be discontinued to aide in closure
how is pseudoaneurysm treated?
-compression or thrombin injection
-treatment selected based on size of the pseudoaneurysm and the diameter of the neck
-smaller ones can clot spontaneously
contraindications for US guided compression therapy for pseudoaneurysm?
-patient unable to tolerate the procedure due to pain
-infection at the puncture site and surrounding tissues
-diameter > 4 cm
-stalk diameter > 5 cm
-present for more than 1 month
-patients on anticoagulant therapy
contraindications for thrombin injections?
-small diameter
-indefinable neck/stalk location
-associated AVF
-current anticoagulant therapy
what does a pseudoaneurysm look like?
-rounded anechoic structure adjacent to main artery
-measure size of body of the aneurysm in 2 planes
-measured diameter of the neck at the widest point
-color shows connection between artery and structure, turbulent flow, yin/yang sign
-doppler has high resistance to and fro flow in the stalk and low resistance to and fro flow in the body
-compression applied to close the stalk and stop the flow
-compression done in 10 one minute intervals with reevaluation of flow and color after each
-larger stalk pseudo can take longer than an hour of compression before treatment works
-should use PPG or toe pressures to monitor for changes
what is thrombin?
clotting agent injected into pseudoaneurysm to close the opening and clot the blood that has escaped; requires sterile field
-thrombin more effective in treatment for larger stalk pseudo
-all types of treatments are less effective on pseudos with large stalks
what is a traumatic AV fistula?
-if femoral A and vein are both punctured during the procedure, the resulting needle tract can provide a lumen for flow from high pressure arterial system into the low pressure venous system
-groin puncture can cause AV fistula between the femoral vessels
-can be complication of an invasive procedure, most commonly right heart cath
