Quiz 4 (lower extremity) Flashcards
what are the 3 lower extremity peripheral artery trees?
- aortoiliac
- femoropopliteal
- tibioperoneal
where does the abdominal aorta bifurcate into the right and left iliac?
level of the umbilicus
where does the internal iliac artery extend?
medially to supply pelvic organs
what branch is distal to the internal iliac arteries?
external iliac arteries
what do the branches below the external iliac arteries supply?
lower extremities
what is the artery called after passing the inguinal canal?
common femoral arteries
what does the common femoral artery bifurcate into?
- femoral artery (superficial femoral artery)
- deep femoral artery (profundal artery)
what artery branches just proximal to the common femoral bifurcation?
lateral circumflex artery
what is the path of the deep femoral artery?
bifurcates laterally from the femoral artery and travels deeply supplying the thigh muscles with many branches
what does the deep femoral artery supply?
thigh muscles
what does the DFA connect?
branches connecting the EIA and popliteal artery
when does the femoral artery become the popliteal artery?
in the distal femur at hunters canal passing obliquely behind the knee in the popliteal fossa
where does the popliteal artery trifurcate?
below the popliteal fossa
what is the trifurcation below the popliteal called?
tibioperoneal trunk
what does the tibioperoneal trunk bifurcate into?
- peroneal artery
- posterior tibial artery
what is the third branch that comes off the tibioperoneal trunk?
anterior tibial artery
what does the anterior tibial artery become at the ankle level?
dorsalis pedis artery which supplies the foot
what does the posterior tibial artery terminate into at the heel level?
becomes the plantar arteries in the foot
what does the peroneal artery supply?
lateral lower leg and heel
what types of veins are in the legs?
- deep
- superficial
- perforating
what do the deep veins do?
accompany the arteries and share their names
where do veins originate?
distally in the foot
what do veins in the foot form?
form the plantar arches which give rise to calf veins
- anterior tibials
- posterior tibials
- peroneal
what veins are paired?
- anterior tibials
- posterior tibials
- peroneal
how many calf veins are there?
6
what do anterior tibial veins arise from and what do they accompany?
arise from the arch and accompany the anterior tibial artery
what is the course of the anterior tibial veins?
rise up the calf from anterior compartment and course between tibia and fibula
what do the anterior tibial veins unite to form?
singular anterior tibial trunk
what does the anterior tibial trunk unite to form what?
anterior tibial trunk unites with the posterior tibial-peroneal trunk to form the popliteal vein
what is the coarse of the posterior tibial veins?
arise from the arch and coarse posterior to the tibia, rise up the calf to form the common tibial trunk
where do the peroneal veins arise?
medial to the lateral malleolus of the ankle
what is the coarse of the peroneal veins?
follow medial surface of the fibula, then course medially to form the common peroneal trunk in the upper third of calf
what do the common tibial trunk and common peroneal trunk converge to form?
tibioperoneal trunk
what deep veins drain the soleus and gastrocnemius muscles?
- soleal sinus
- gastrocnemius vein
are the gastrocnemius veins paired?
yes, join a common trunk before dumping into popliteal vein
which deep vein is not accompanied by an artery?
soleus sinus
where does the soleal sinus dump into?
drain into the posterior tibial and peroneal veins
what are an important part of the calf muscle pump?
venous sinus-act as a reservoir
what converges to form the popliteal vein?
common tibial-peroneal trunk
anterior tibial trunk
what are the valves of the calf veins?
6-12 bicuspid valves
what do the veins in the calf do?
- promote unidirectional flow
- regulate venous pressure in distal lower extremity
what does the popliteal vein do in the popliteal fossa?
extends cephalad to the medial aspect of the femur
what does the popliteal pass through?
hunters canal (adductor hiatus) this is where is becomes the femoral vein
is the popliteal duplicated?
can be
how many valves does the popliteal have?
3-4
what superficial vein dumps into the popliteal vein at the level of the crease?
short saphenous-gastrocnemius is just inferior to this
what is the femoral vein a continuation of?
popliteal vein
where does the femoral vein coarse?
medial aspect of the thigh
how many valves does the femoral vein contain?
3-6 valves
where does the common femoral vein lie?
medial to the common femoral artery within Scarpa’s triangle
how many valves does the common femoral vein have?
3-5 valves
where does the superficial-great saphenous vein dump into the common femoral vein?
at the level of the groin crease-anteromedially
how many valves does the external iliac vein contain?
a single valve
what is the longest superficial vein?
great saphenous vein
where does the great saphenous vein coarse?
extends from the anterior aspect of the medial malleolus upwards to the groin
where does the great saphenous vein drain?
into the CFV anteromedially
what does the great saphenous vein drain blood from?
drains blood from the superficial tissues (skin and fat) into the deep system
what is the coarse of the small saphenous vein?
extends from the posterior aspect of the lateral malleolus and runs up the center of the calf and dumps into the popliteal vein at the popliteal fossa crease level
occasionally where can the SSV dump into?
continue up the posterior part of the leg and dump into the GSV
if the SSV does not dump into the popliteal vein at the fossa level, what is the vein called?
vein of giacomini
what is upper thing extension of the SSV?
the SSV may continue up the thigh into the deep system at the femoral vein
where is pressure greater in veins?
in the superficial system
what is the direction of flow in veins?
superficial to deep
what are perforators?
short vessels that connect the 2 systems and have valves conducting the flow-anastomosis between deep and superficial systems
what is a large perforator?
hunterian perforator
what can cause varicosities?
larger perforators (hunterian)
what flow characteristics can sonography evaluate in venous flow?
- spontaneity
- phaticity
- augmentation
- competence of valves
- absence of pulsatiity
- compression images
what are some sonographic features of normal veins?
Thin (invisible) wall Smooth wall Anechoic lumen Compressible Unidirectional flow toward the heart Flow augmentation with distal compression Spontaneous flow Phasic flow Flow ceases with valsalva maneuver
where does spontaneous flow occur?
veins closest to heart
less in popliteal
not seen in calf veins
where is pressure lowest in veins?
furthest from heart
what will have an effect on spontaneous flow?
- augmentation
- Valsalva
- respiration
- pumping the calf muscle
what veins are phasic with respiration?
lower extremities
blood flow in lower extremities ______ with inspiration and __________ with expiration
ceases and augments
what may pulsatiity of flow be caused by?
right sided heart failure or veins close to the heart
what happens to lower extremities with inspiration?
stopped
what is the most important feature to rule out DVT?
compressibilty
what happens to flow with augmentation?
flow is increased when manually compressed with hand
what does augmentation confirm?
patency of veins between the level where compression occurs and the level where the probe is situated
if reversal of flow does not occur during Valsalva, what does this mean?
there are competent valves
what rouleaux?
slower, sluggish flow (does not mean disease)
what affects venous flow?
Respiratory variations Cardiac function Calf muscle pump Competent venous valves Venous pressure Exercise
is DVT’s higher in men or women?
women
DVT’s is highest in which nations?
African americans
DVTs are lowest in which nations?
Asian and native americans
what is ultrasound the gold standard in?
evaluating the lower extremity venous system
what are the hereditary risk factors for DVT’s?
- blood disorders
- antithrombin deficiencies
- elevated clotting factors
- plasminogen deficiency
- prothrombotic disease
what are the acquired risk factors for DVT’s?
- age, obesity
- advanced malignancy
- recent surgery
- trauma
- immobilization
- pregnancy
- OC use
where does DVT’s most commonly originate?
in calf at valve leaflets and may extend proximally into the calf and thigh
what are signs and symptoms of DVT’s?
- lower extremity swelling
- pain
- positive homan’s sign (pain on forced dorsiflexion of foot)
what is Virchow’s Triad?
- endothelial damage
- venous stasis
- hypercoagulable state
D-Dimer assay
measures fibrin degeneration products that accumulate in the blood when thrombus forms
What does D-Dimer assay have to be if DVT is unlikely?
negative
what are some causes of false positives for D-Dimer assay?
not helpful in patients over 80, hospitalized, pregnant, cancer, its usually elevated in this group
what is PT-prothrombin time?
time it takes plasma to clot
want is PT affected by?
DIC-disseminated intravascular coagulation
what is PTT-partial thromboplastin time?
unexplained bleeding or clotting
what does acute thrombus look like?
faintly echogenic, almost invisible
how are acute thrombus detected?
by limited compression and faint visible edge of clot
my have a long snakelike clot swaying back and forth in lumen
what clot is at most risk for emboli?
acute thrombus
what is chronic thrombus?
complete dissolution of clot over time may occur naturally. May age and become more solid
what does a chronic thrombus look like?
older clot is firmer and more echogenic
what may develop with chronic thrombus?
large collaterals will develop
in chronic DVT the clot may shrink, what does it look like then?
bright echogenic scar along wall or within lumen. May appear as a string or cord within the lumen
what is bilateral lower extremity swelling most likely?
cardiovascular in origin-secondary to right heat failure
is homans sign a reliable diagnostic criterion?
no
are patients with DVT symptomatic?
not usually
what are non specific symtoms of DVT?
pain and swelling
what are some complications of DVT?
Pulmonary embolism Incompetent valves Post thrombotic syndrome Recurrent DVT Varicose veins Chronic venous insufficiency Ulcers
what percent of untreated pulmonary embolism will sustain a a non-fatal PE?
25%
what does pulmonary embolism result in?
emboli breaks off and goes to the lungs and results in pressure on the right ventricle
what are symptoms of PE?
- difficulty breathing
- chest pain on inspiration
- palpitations
what are the clinical symptoms of PE?
- low blood oxygen saturation and cyanosis
- rapid breathing
- rapid heart rate
what are symptoms of PE in severe cases?
- collapse
- abnormally low blood pressure
- sudden dealth
how do you diagnose PE?
D-Dimer
CT
pulmonary angiography
what is the treatment of PE?
anticoagulant-heparin and warfin
what is the surgical intervention of PE?
pulmonary thrombectomy
when may DVT reoccur?
damage to walls and valves
what does chronic venous obstruction and reflux manifests as?
- chronic leg swelling
- ankle pigmentation
- ultimately ulcers form
what is responsible for brown skin pigmentation?
metabolic breakdown of hemoglobin
Increased hydrostatic pressure in deep venous system does ______
not help
how can ulcerations develop?
spontaneously or as a result of trauma-inflammatory reaction in the tissue
what does non phasic flow indicate?
obstruction of flow above this level
-indicates DVT
how do varicose veins develop?
extra pressure in veins largely due to absent or incompetent valves
what happens to flow with onset of Valsalva?
flow reverses
what does Valsalva flow reversal indicate?
severe incompetence of venous valves
what should happen to flow with Valsalva?
flow should cease
what may chronic venous insufficiency be a result of?
recanalized vein post DVT
________of competent valves or be avalvular
congenital absence
where does valvular incompetence occur?
superficial, deep, and perforator veins
what does chronic venous insuffiency result in?
increased venous hydrostatic pressure
varicosed veins
edema
skin changes
what are some ways to check for reflux?
- spectral doppler
- colour flow doppler
- gray scale
what may be used as a graft in the event of arterial disease instead of man made variety?
great saphenous vein
what other veins are used for man made variety?
- great saphenous (legs)
- small saphenous (legs)
- cephalic vein (arm)
- basilic veins (arm)
when is SVT examined?
when signs of thrombosis are apparent
what are symptoms of SVT?
- tenderness and pain
- warm skin
- redness or inflammation of the skin
- palpable cord may be apparent in subcutaneous tissues, hardening of the vein
when is there only a risk of PE in SVT’s?
when thrombus is near the attachment to the deep system or extending into it
primary varicose veins
abnormally dilated and tortuous superficial veins in the absence of deep venous disease
what is primary varicose veins a result of?
valvular incompetence of SFJ
secondary varicose veins
associated with obstruction (DVT) or incompetence of the deep venous system valves
