Arterial LE Flashcards
Abdominal aorta bifurcates to common iliac arteries at _________
L4
CIA bif into internal and external Iliac arteries at ________
Lumbosacral junction
External iliac artery becomes common femoral artery at ________
Inguinal ligament
Internal iliac artery is aka
Hypogastric artery
CFA bifurcates into FA and DFA/profunda
FA passes through _______ and becomes pop artery
Adductor canal aka hunters canal
Pop artery bifurcates into
ATA and tibioperoneal trunk
Tibioperoneal trunk aka trifurcation becomes
PTA and Peroneal artery
First branch of distal pop artery
ATA
ATA passed through __________ and runs along anterior deep aspect of leg.
ATA becomes DPA
Interosseous membrane
2 branches of DPA
Dorsal metatarsal
Deep plantar artery
PTA divides into ________ and _______ to feed soles of feet.
Medial plantar artery
Lateral plantar artery
Lateral plantar artery unites with _______ to complete plantar arch
Deep plantar artery
LE arterial Doppler indications
Claudication. (Pain in calf, posterior thigh, or butt after walking)
Decreased pulses (femoral, popliteal, pedal)
Cold feet (acute)
Gangrene/necrosis (toes)
Dependent rubor (reddish pigment of leg dependent positioning. When hanging legs off chair)
Prior history of PAD
Falsely elevated pressures due to calcified vessels in patients with ________
Diabetes
Doppler waveform acquisition
4-8MHz Doppler pencil probe.
45-60 degrees
Avoid signal interference of venous flow by compressing thigh above or have patient take a breath in
Acquire waveforms at prox FA, distal FA, Pop A, PTA, DPA
Multiphasic = triphasic
Atypical = biphasic (abnl in legs, normal in arms)
Monophasic
:)
Plethysmography
Evaluates volume changes that occur during cardiac cycle.
Used pulse volume recordings PVRs aka VPRs
Evaluation of volume changes in toes is accomplished by
Photo plethysmography
Uses a photo emitting diadoid to detect absorption of light by the digit
PVRs
LE PVRs are done by the use of BP cuffs. 4 cuff method.
Cuffs are inflated 60-80mmhg. Patient must be still. Doppler taken below cuff once inflated.
PVRs are not affected by calcified arteries
PVRs can differentiate between collateral and true vessel.
PVRs can differentiate profunda and FA
4 cuff method
Ankle, below knee, above knee, and high thigh.
Segmental pressures
4 cuff method.
3 cuff method used in people with short legs bc don’t want cuffs overlapping or at knees. But cannot differentiate aortic inflow disease from FA disease because only 1 cuff at thigh.
Systolic pressure increases distally.
Width of cuff should be 20% greater than limb diameter.
If cuff is too large,
BP falsely decreased.
If cuff too small
BP falsely elevated
If BP cuff put on too loose
Can falsely increase blood pressure
ABI
Highest PTA or DPA unilaterally divided by Highest bilateral brachial pressure
Don’t take arm pressure in patient with a fistula, dialysis graft, or mastectomy.
ABI values
Normal: 0.9-1.3 Mild PAD: 0.8-0.9 Moderate: 0.5-0.8 Claudication Severe: <0.5 Rest Pain Critical: <0.3
Diabetic calcified vessel: >1.3 false. Incompressible
Toe pressures. When ankle pressures are too high and inaccurate
> or = 0.8 : no significant PAD
0.2-0.5 : claudication
<0.2 : rest pain
Photoethysmography PPG
Diodoes attached to each toe and taped or clipped in place. Pt needs to hold still.
Can also be combined with toe pressure cuffs. Evaluates perfusion in toes prior to foot amputation.
Shows blood volume changes in digits.
Exercise
True vs pseudo claudication.
Treadmill speed 1.5-2mph
< or = 12% elevation
Post exercise ABI obtained at 2-3 minute intervals until pressure returns to pre exercise level. Normally pressures increase slightly or remain the same. Abnormally they will decrease.
Contraindications: short of breath, cardiac instability, poor ambulation, critical resting ischemia ABI < 0.3
If contraindicated, do toe raises.
Reactive hyperemeia
Temporary increase in blood flow to an area after a period of arterial occlusion.
Used when patients can’t walk or exercise to increase extremity blood flow and vasodilation.
Thigh cuff:
20-30mmHg above brachial pressure
Occlude blood flow 3-5 minutes : causes ischemia and vasodilation distal to cuff.
After releasing air in cuff, ankle pressure will usually drop 20-30% and should return to baseline after 1 minute.
Ankle pressure measured 30 sec intervals for 3-6 minutes or until ankle pressure return to normal level.
If patient has <50% drop in pressure, then they have single level disease. If multi level disease, then there’s a >50% drop in pressure.
Stenosis velocities
Ratio = Max PSV at stenosis / PSV prox to stenosis.
Ratio 2:1 = 50% stenosis
Normal: <150 cm/s ratio: <1.5:1
30-49% stenosis 150-200cm/s 1.5-2:1
50-75% stenosis 200-400 cm/s 2-4:1
> 75% stenosis >400 cm/s >4:1
Occlusion no flow
Claudication
Walk 1/2 mile and get leg pain. Relieved by rest.
Rest pain
Severe pain, wakes you up while sleeping. Due to critical ischemia in their legs. Pain lessens when hang or dangle legs off side of bed. Or dependent rubor.
Dependent rubor
Pain only relieved by hydrostatic pressure and putting legs down by side of bed.
Acute limb ischemia
Sudden arterial obstruction that threatens limb viability.
Most likely to occur if no collaterals are developed.
6 P’s:
Skin changes
Color: pallor, rubor, cyanosis Temperature should be warm. Thickened nails Scaly skin Loss of hair Ulcers
Palparían and auscultation of pulses
Venous vs arterial vs neurotrophic ulcers.
Venous: located in gaiter area between ankle and calf. Venous insufficiency. Irregular borders. Granulating base. Over medial malleolus. More common type. Prone to infection. Can be present with associated cellulitis.
Arterial: well defined borders. Arterial insufficiency. Small deep lesions. Necrotic base. MC distal to trauma site and pressure areas (the heel). Cold limbs. Reduced pulse.
Neuropathic: painless ulcers over areas of abdominal pressure. Often secondary to joint deformities in diabetics. Also patients with B12 deficiency. Due to peripheral neuropathy. Loss of protective sensation leading to repetitive stress and unnoticed injuries forming.
Ischemic ulcers
Arterial. Located near pressure points. Toe, heel, and dorsum of foot. Painful.
Neurotrophic ulcers
Diabetic. On some of foot or under callus. Painless.
Stasis ulcer.
Venous. Located in gaiter zone. Mild pain.
Gangrene.
Tissue death. Black.
Risks
Diabetes HTN Hyperlipidemia Smoking Age Family history Male Atherosclerosis
6 P’s
Associated with acute arterial occlusion.
- Pain
- Pallor
- Pulselessness
- Paresthesia: numbness. Tingling. Prickling.
- Paralysis: complete loss of strength. (Poor prognosis)
- Poikilothermia: inability to maintain constant core temp.
Acute limb ischemia causes
- Thrombosis: atherosclerosis, thrombosis embolism.
- Embolic (thrombus breaks off and heads to the feet)
- Trauma
- Aortic/arterial dissection
- Popliteal entrapment: rare. Pop artery follows abnormal course below knee and is trapped by gastruc nemus muscle during plantar flexation.
- Popliteal adventitial cyst: cystic swelling of arterial wall. Results in claudication due to artery compression. Young patients.
Popliteal entrapment syndrome.
Pop artery is trapped/compressed by gastruc nemius muscle during plantar flexation. Young athletes.
Popliteal adventitial cyst aka cystic adventitial disease
Fluid accumulates in artery wall causing narrowing or occlusion. Pop artery MC affected. Results in claudication due to artery compression. Males 40-50 years old.
Symptoms: claudication, bruit
Nutcracker syndrome
Left Renal vein entrapment between SMA and Aorta.
Median arcuate ligament syndrome
Compression or proximal part of celiac trunk by median arcuate ligament of the diaphragm during expiration.
SMA syndrome aka Wooky syndrome
3rd part of duodenum is compressed by abdominal aorta and the SMA.
Thoracic outlet syndrome
Compression is nerves, subclavian, or axillary artery.
Compartment syndrome
Caused by swelling or pressure within an enclosed space in body such as leg, arm, or abdomen. Due to bleeding and swelling after injury. Or after surgery.
Pressure exceeds capillary perfusion pressure, decreasing perfusion and blood flow to tissue.
Nerves are most susceptible to ischemia.
Paresthesia, pain, weakness of muscle, tension of compartment, late stage will have loss of pulses.
Treat by fasciotomy. To relieve tension/pressure.
Diffuse plaque
Long segment
<50% diameter reduction
Velocities not increased.
Recannulization
Occluded vessel may resume flow distal to occlusion with a collateral vessel. Flow may be retrograde.
If there’s a CFA occlusion, you may see retrograde flow in
Profunda
May see reversal flow in _______ to feed dorsalis pedis
PTA
Tibial artery evaluation used for patients undergoing
Bypass surgery
Arteriovenous fistula AVF
Abnormal communication between high pressure artery and low pressure vein.
Trauma (heart cath) (1 connection)
Congenital (numerous connections)
Blood shunts from arterial to venous. Size important in development of CHF and or limb ischemia.
Arterial has inc flow prox to avf
Venous has increased vel and pulsatility prox to AVF
Within fistula elevated peak and end diastolic vel assoc with spectral broadening. Can be bidirectional and or turbulent.
Speckle appearance in fistula
Distal to AVF it can vary but BP will reduce distally.
Pseudoaneurysm (false aneurysm FA)
Pulsating hematoma with active communication to artery
Hole in arterial wall
Blood pocket is contained by adj tissue
Caused by trauma usually a catheter from angiography or endovascular procedure or dialysis.
To and Fro at neck/track of pseudoaneurysm. Yin yang
Treatment:
May spontaneously thrombus, manual compression, thrombin injection, surgery
FA compression for closure aka Fem Stop
Size and location of FA are important. Location determines if candidate for US guided compression or does patient need surgery. Will need to completely compress the neck between native artery and pseudoaneurysm.
Contraindication:
Pt on anticoagulant
Inability to compress FA tract
Multiple channels
FA thrombin injection under US guidance
Contraindication: allergy to thrombin/bovine materials Ischemia of overlying skin Groin infection Distal limb ischemia Wide or short FA tract
FA surgery
When fem stop or thrombin injection is not an option
When neck cannot be compressed or when FA too large to close by compression. Or if thrombin injection is too risky for patient.
AVM vs AVF
AVM: congenital, multiple connections artery to vein
Avf: abnormal connection artery and vein due to trauma.
