Peripheral Arterial Flashcards
What are the risk factors for peripheral arterial disease? (13)
- diabetes
- hypertension
- hyperlipdemia
- CAD
- previous CVA or MI
- smoking
- age
- family history
- male
- obesity
- sedentary lifestyle
- elevated levels of homocysteine
- excessive levels of c-reactice protein
- history of radiation
A high incidence of occlusive disease occurs in which arteries in someone with diabetes?
Popliteal and tibial arteries (medial wall)
There is an increased incidence of what in a person with hypertension?
Peripheral and cerebral atherosclerosis
What are the four main signs of physical change with peripheral arterial disease?
- Skin changes
- Palpations
- Auscultation (bruits)
- Difference in limb pressures
List the possible skin changes a person may have with peripheral arterial disease: (9)
- Pallor
- Rubor
- Dependent rubor
- Cyanosis
- Cold temperature
- Painful tibial ulcers
- Gangrene
- Trophic changes (thick nails, hair loss, scaly skin)
- Slow capillary refill time
Define pallor:
Pale color secondary to deficient blood supply
Define rubor:
Dark reddish color or discoloration from dilated or damaged vessels
Define dependent rubor:
Limb takes on pallor when elevated, but becomes abnormally red when hanging dependent
Define cyanosis:
Bluish color of the skin and mucous membranes that results from a concentration of deoxygenated hemoglobin
What are examples of palpations we can assess for peripheral arterial disease?
Pulses and aneurysms
Diminished or absent pulses suggest what?
Arterial insufficiency
What is a bounding pulse and what condition has them?
4+
Aneurysms
A bruit will not be heard in what case?
A stenosis >90%
How are bruits and pulses graded?
Bruits = 1+ to 3+ (mild to severe)
Pulses = 0-4+ (no pulse to bounding)
What may indicate disease when assessing upper and lower limb pressures?
Difference of 20mmHg in lower limb pressure
Difference of 30 mmHg in upper limb pressure
What are symptoms of peripheral arterial disease? (4)
- Intermittent claudication
- Ischemic rest pain
- Necrosis
- Pseudoclaudication
What is claudication?
Muscle pain that occurs during exercise and subsides at rest that is reproducible and caused by a lack of blood supply to muscles.
In claudication, where is the site of the disease?
Proximal to affected muscle group
Ex. Calf claudication = fem/pop disease
Thigh claudication = CFA/iliac disease
Buttock claudication = aorta/iliac disease
If claudication is left untreated, what may it become?
Ischemic rest pain
What is ischemic rest pain?
Severe and constant pain usually affecting the foot and toes that is not relieved by rest and indicates advanced multi-segment disease
Which symptom of peripheral arterial disease is considered a precursor to limb loss unless medically or surgically treated?
Ischemic rest pain
What is the most severe symptom of peripheral arterial disease?
Necrosis
What is pseudoclaudication?
Pain caused by other factors such as degenerative joint disease, spinal stenosis, and herniated discs
How can pseuodclaudication be differentiated from claudication?
Claudication is reproducible and pseudo is not.
What is the most common arterial pathology?
Atherosclerosis
What are three mechanisms of peripheral arterial disease?
- Atherosclerosis
- Embolism
- Aneurysm
A hemodynamically significant obstruction requires what percentage of diameter and area reduction?
50% diameter and 75% area
What are the most common locations of obstruction in the lower extremeties?
1 = SFA at the adducter canal
- Bifurcations
- Popliteal artery
What is the most common cause of an embolism?
Plaque breaking loose from the heart or a proximal aneurysm
What are common areas for aneurysms? (4)
- Abdominal aorta
- Femoral
- Thoracic
- Popliteal arteries
What are subclavian aneurysms due to?
Thoracic outlet syndrome (compression of the subclavian)
What are ulnar syndromes due to and what is this called?
Trauma from using the hand as a “hammer”
Hypothenar hammer syndrome
What is the normal PSV for the Subclavian and Axillary arteries?
70-120 cm/s
What is the normal PSV for the Brachial artery?
50-120 cm/s
What is the normal PSV for the Radial and Ulnar arteries?
40-90 cm/s
When a stenosis is seen, you should obtain representative waveforms in which three places?
1) 2 cm proximal
2) At the highest PSV
3) Distal to the stenosis
Normal lower extremity arterial waveforms possess what kind of phasicity?
Triphasic
What is a normal mean peak systolic velocity in the external iliac artery?
120 +- 22cm/s
What is a normal mean peak systolic velocity in the common femoral artery?
114 +- 25cm/s
What is a normal mean peak systolic velocity in the proximal SFA?
91 +- 14cm/s
What is a normal mean peak systolic velocity in the distal SFA?
94 +- 14cm/s
What is a normal mean peak systolic velocity in the popliteal artery?
69 +- 13 cm/s
A staccato waveform indicates an occlusion where?
Distal
The extent of an occlusion can often be established if what is visualized?
Large collateral seen at the proximal and distal ends
When the proximal artery is occluded and the vessel is supplying collateral flow, what may happen?
Blood flow direction may reverse
<30% increase in PSV from proximal segment indicates what percent of stenosis?
1-19%
30-100% increase in PSV from proximal segment indicates what percent of stenosis?
20-49%
> 100% increase in PSV from proximal segment indicates what percent of stenosis?
50-99%
Describe the proximal and distal waveform when there is 1-19% stenosis:
Normal (triphasic) proximally and distally with minimal spectral broadening
Describe the proximal and distal waveform when there is a 20-49% stenosis:
Normal (triphasic) proximally and distally with prominent spectral broadening
Describe the distal waveform when there is a 50-99% stenosis:
Waveforms become monophasic distally
Describe the waveform in the collaterals with an occlusion:
Collateral waveforms are monophasic with reduced PSV
What is a pseudoaneurysm?
A pulsating hematoma that originates from a leaking artery and is confined by surrounding tissue
Most false aneurysms result from what?
Arterial puncture
What must be evident to be a true pseudoaneurysm?
Communicating channel between the main artery and pulsating mass
What is arteritis?
Inflammation of the arterial wall affecting tibial arteries and distal arterioles
What is the most common form of arteritis and who does it affect?
Beurger’s disease/Thromboangitis obliterans
Men younger than 40 who are heavy smokers
What may aortic coarctation result in?
Lower extremity ischemia
What is Reynaud’s phenomenon?
Intermittent ischemia in the fingers or toes in response to cold exposure or emotional stress
What are the two types of Reynauds?
Primary (spastic) and secondary (obstructive)
What is primary Reynaud’s disease and who does it affect?
Intermittent digital ischemia caused by arterial spasm when exposed to abrupt cold temperatures. (Does not progress and has good prognosis)
Women bilaterally.
What is secondary Reynaud’s disease?
Same as primary except the reaction of the tissue to cold is due to underlying obstructive, systemic disease such as lupus, scleroderma, Beurger’s, or frostbite (chronic can lead to ulcers, gangrene and amputation).
What is the treatment of compression/entrapment syndromes?
Fasciotomy
What is popliteal entrapment and who is commonly affected?
Caused by compression of the popliteal artery by the gastrocnemius muscle in the calf
Young adults and children
When is popliteal entrapment indicated?
When there is a decreased arterial diameter when the patient points their foot downward resulting in a visualized stenosis or loss of pulse
What is ACD and what is the findings?
Adventitial cystic disease
Popliteal artery compressed by a cyst causing stenosis
What is thoracic outlet syndrome?
Compression of subclavian artery/vein/nerves as they emerge from the thoracic outlet, leading to hand and arm ischemia and pain or weakness
What is the an AV fistula, what is it’s spectral trace and what is the most likely site?
1) Congenital or traumatic communication between and artery and adjacent vein
2) Colour bruit, high velocity, low resistance
3) CFA/CFV post catheterization
What is blue toe syndrome and what is the treatment?
Toe ischemia due to micro-emboli released from atherosclerotic lesions
Treatment = removal of emboli
What are types of lower extremity bypass grafts?
Synthetic, autogenous, and composite
What are the types of synthetic bypass grafts?
1) PTFE (polytetrafluoroethylene)
2) Dacron
What are Autogenous bypass grafts and what what are the types?
Grafts that use veins
1) In-situ vein
2) Reversed vein
Describe an autogenous in-situ vein bypass:
Vein left in original location with valves cut out and branches ligated
Describe an autogenous reversed vein bypass:
Vein is ligated, reversed, and attached to arteries
What are four commonly used autogenous veins?
GSV, SSV, basilic, and cephalic
Describe a composite bypass grafts:
Synthetic graft connected to an autogenous vein
Early graft failure (less than 30 days) is usually due to what?
Errors in the bypass construction
Intimal hyperplasia can cause what within 1 month to 2 years of graft placement?
Hemodynamically significant stenosis
Stenting is being used more frequently to treat what?
More complicated lesions and occlusions
What should the PSV and Vr be in the body of the graft/stent?
PSV <180cm/s and Vr <2.0
Describe the PSV and Vr of an SFA stent:
PSV <190 cm/s and Vr <1.5
What is a normal distal anastomosis Vr?
<3.0
What is a normal inflow artery?
Triphasic with a Vr of <2.0
A decrease in ABI >0.15 on a f/u exam indicates what?
Marked disease progression in the inflow, graft, stent, or outflow arteries
In the inflow artery, a Vr >2.0, post-stenotic turbulence, and waveform changes indicate what?
Hemodynamically significant lesion within the inflow artery
In any graft body, a >50% stenosis will have a PSV and Vr of what?
PSV >180 cm/s and Vr >2.0
In any graft body a >70% stenosis will have a PSV and Vr of what?
PSV >300 cm/s and Vr >3.5
In an SFA stent a >50% stenosis will have a PSV and Vr of what?
PSV >190 cm/s and Vr >1.5
In an SFA stent a >80% stenosis will have a PSV and Vr of what?
PSV >275 cm/s and Vr >3.5
Impending graft failure of a vein graft is indicated by what?
PSV <40-45 cm/s
Obstruction in the inflow tract is indicated by what kind of waveform in the graft?
Monophasic waveform (tardus parvus)
Distal anastomotic or outflow tract obstruction are indicated by graft waveforms that display what kind of waveform?
High resistance with no end diastolic velocity or a staccato pattern
Define the classification of normal to <20% graft stenosis:
Vr <1.5, mild spectral broadening, PSV >40 cm/s and <150 cm/s
Define the classification of 20% to 50% graft stenosis:
Vr 1.5-2.5, spectral broadening, PSV >150 cm/s
Define the classification of 50% to 75% graft stenosis: (moderate)
Vr >2.5, severe spectral broadening, reverse flow, PSB >180 cm/s
Define the classification of >75% graft stenosis (most severe):
Vr >3.5, jet flow present, PSV >300 cm/s, EDV >100 cm/s
Describe aneurysmal dilatation:
Focal enlargement twice the proximal arterial segment
A patient is experiencing thigh claudication, where is the most likely location of disease?
Iliac artery
If a collateral is present, what can they help identify?
Extent of an occlusion
What is a normal PSV of the CFA?
114 +/- 25 cm/s
What kind of resistance would reactive hyperemia have?
Low resistance
What is the most common site of atherosclerosis of the lower extremity?
Distal FA
Thoracic outlet syndrome can result from compression of what?
Subclavian vein, subclavian artery, and brachial nerve plexus
What are two common causes of peripheral emboli?
Proximal aneurysm and the heart
How would a significant stenosis affect the distal blood pressure post-exercise?
Decrease
Compared to the proximal normal segment, what effect would a >70% stenosis have on the velocity?
Tripled
What is the most common cause of early graft failure (<30 days post-op)?
Errors in graft construction
What conclusions can be made when you observe a monophasic waveform?
Significant inflow disease
What would an ABI of 0.7 most likely indicate?
Moderate, single-level disease
Why is the normal Vr at the distal anastomosis of a graft <3.0?
Due to vessel size change
What is the term for “pins and needles”?
Parestheisa
What is the term for weakness?
Paralysis
An ABI decrease greater than what previous ABI indicates disease?
ABI > 0.15 compared to previous
Where does the brachial artery lie?
The medial groove of the tricep/bicep muscles
What is the normal PSV of the palmar arch and digits?
Lower than the RA and UA (lower than 40-90)
What is Vr?
V2/V1 where
V2 = Max PSV of stenosis
V1 = PSV of prox normal segment
Describe a biphasic arterial signal (3)
- Strong forward flow in early systole (sharp upstroke)
- Loss of flow in early diastole (no flow below baseline)
- Decreased late diastolic flow
(Biphasic is triphasic w/o reversal)
Describe a monophasic signal? (3)
- Decreased pulsatility
- No reversal in late systole
- Blunted systolic flow
What arterial signal is commonly seen distal to a significant stenosis/occlusion?
Monophasic
What does a velocity increase ≥ double that of the proximal signal indicate?
> 50% stenosis
What does a velocity increase ≥ triple that of the proximal signal indicate?
> 70 % Stenosis
What are compression/entrapment syndromes caused by?
Swelling within osteofascial compartments (muscles/nerves/fascia) that increases pressure and decreases blood flow
What is a fasciotomy?
Fascia is cut to relieve tension/pressure and allow blood flow
What methods are used to treat pseudoaneurysms?
- Compression with probe on ten mins off ten mins
2. Thrombin injection into area
What are the US features of a pseudoaneurysm?
- Swirling colour in “hematoma”
- Communicating tract to artery
- To and fro doppler signal in “neck”
- 1-5 cm
- High velocity and turbulent
- Spectral broadening
What is a sympathectomy?
Sympathetic nerves are cut to prevent vasoconstriction so veins stay dilated
What are the surgical methods of peripheral arterial disease? (6)
- Bypass graft
- Atherectomy
- Direct focal repair
- Resection
- Sympathectomy
- Amputation
What is artherectomy?
Catheter with blade to remove plaque
What is resection and when is it done?
Cut out diseased part and reattach
Aneurysmal disease
What are the endovascular methods to treat peripheral arterial disease?
- Angioplasty
- Stent
- Intra-arterial directed thrombolysis
What is angioplasty?
Unblocking using balloon
What is a stent?
Tubular support placed inside vessel
