Week 6: Lower Extremity Venous Scanning Flashcards
Insufficiency leads to chronic_____, too much venous pressure
venous hypertension
Purpose of a venous duplex exam is to directly visualize the veins for assessment of its _____
patency
What is patency?
openess
The pros of a venous duplex exam are:
- non invasive
- inexpensive
- quick (30 min average)
- high _____ & ______
sensitivity, specificity
What are the 2 main reasons to perform a venous duplex exam?
- rule out DVT
- detect a presence of a PE
More than ____ % of PE cases are caused by thrombi traveling form the lower extremeties.
90
Veins have a thinner ____ than arteries.
tunica media
The lower extremety venous system has 3 systems. What are they?
- deep system
- superficial system
- perforating veins
What are the characteristsics of deep system veins? (2)
What is the landmark to identify them?
- follow the arterial trees
- (for lower extremity) located in the muscular sheath
*landmark is “facia” - deep system veins are below the facia.
What are the characteristsics of superficial system veins? (3)
- does NOT have arterial counterpart
- is NOT encased in a muscular sheath
- located more superficial to the dermis area
What are the characteristsics of perforating veins? (2)
- connect superficial to deep
- superficial veins drain into deep vein via perforating veins
Name deep system veins knees below: (5)
- posterior tibial veins
- peroneal veins
- anterior tibial veins - directly branch off from popliteal vein
- popliteal vein
- tibioperoneal trunk - branch off into posterior tibial vein and peroneal vein
Name the 3 calf veins
-
posterior tibial veins
- more lateral
- empty the back/medial aspects of the leg into the tibioperoneal trunk
- located just posterior ro the medial malleous -
anterior tibial veins
- anterolateral
- begin at the anterior surface of the leg & run lateral course between the tibia & fibula -
Peroneal veins
- more central
- close to fibula
What are the characteristics of popliteal vein (pop v)?
- formed by the confluence of the ______ & ________.
- becomes the ________
tibioperoneal trunk, anterior tibial veins
superficial femoral vein
tibioperoneal trunk is formed by ______ & ________
posterior tibial veins, peroneal veins
What are the characteristics of superficial femoral vein?
- aka: ____1____ (used this term when performing LE venous exam)
- flow continues cephalad and becomes the __2__ at the confluence of the __3__ and __4__.
- femoral vein
- CFV
- profunda (deep) femoral vein
- superficial femoral vein
What are the characteristics of CFV (common femoral vein) ?
- __1__ joins/drains into the CFV just cephalad to the jointure of the __2__ and the _3__.
- CFV is __4__ to the common femoral artery
- GSV (greater saphenous vein)
- profunda femoral vein
- femoral vein
- medial
What are the characteristics of external iliac vein?
- slightly cephalad to the jointure of the __1__ and __2__ , called __3___
- __4__ becomes the external iliac vein
- joined by the __5__ (drains the gonadal areas) to form the common iliac vein
- GSV
- CFV
- saphenofemoral junction
- CFV
- internal iliac vein
____ formed by the confluence of the common iliac veins
IVC
The left iliac vein passes ____ to the proximal right common iliac artery to form the ICV
posterior
What is the longest vein in the body?
greater saphenous vein
What are the 2 superficial veins?
- greater saphenous vein aka: long saphenous vein
- lesser saphenous vein aka: short saphenous vein
What are the characteristics of GSV?
- aka: 1
- 2 vein in the body
- runs from the 3 to the 4 on the 5 side
- drains into 6
- easier to see/locate in 7 plane
- this vein is used for 8
- long saphenous vein
- longest
- inguinal region
- ankle
- medial
- CFV (common femoral vein)
- transverse
- graft
What are the charcteristics of lesser saphenous vein?
- aka: 1
- 2 in diameter than the GSV
- located in the 3 calf
- runs directly along the 4 of the back of the leg (from ankle to 5 )
- drains into the 6
- short saphenous vein
- smaller
- posterior
- center
- popliteal fossa
- popliteal vein
What are the charcteristics of perforating veins?
- aka: 1
- communicating veins between the 2 system and 3
- each perforator has at least 4
- very small vessels
- perforators
- superficial
- deep paired veins
- one valve
Double or multiple venous system in the leg are common. They are usually at the: (3)
- femoral level
- popliteal level
- the greater saphenous geins (both in the thigh and calf)
Venous Valve characteristics:
* Venous flow is of 1 pressure
-Needs assistance to induce pressure differences for flow to occur
* Try to force the blood to return in the direction to the heart -Tips of valves always point towards the 2
* Essential for the dynamics of fluid
* Valves are attached to the 3 layer of the vessel wall
* Malfunctioning valves result in allowing the blood to flow in reverse, disturbing the normal rhythmical flow
* Clot can become trapped 4 , leading to clot in the lumen
- low
- heart
- intimal
- behind valves
venous valves
prevent blood from flowing backward.
Blood is pushed by the calf muscle aka: (2) and the name of the calf muscles are: (3)
calf muscle pump, calf muscle heart
soleus
gastrocnemius
tibial anterior
The difference between intraluminal pressure (within the lumen) and interstitial pressure (outside the
vessel wall) is called:
transmural pressure
-Equals the weight of the column of blood extending from the heart to the level where pressure is
being measured
-Directly related to specific gravity; acceleration due to gravity and distance from heart
what is this?
hydrostatic pressure
*note: gravity is the culprit; laying supine ; HP is minimal 15 mmHg while standing, HP at the ankle is 102 mmHg
What are the consequences for elevated venous pressure? (4)
edema
ulcerations
gaiter zone
phlebitis
What is Gaiter Zone?
Refers to the brownish discoloration of the lower leg to ankle
* Results from chronic insufiency
* Fluid, red blood cells, and fibrinogen leak into surrounding tissues
*iron deposite from the blood - once color turns brown, the condition is permanent
indication/symptoms of elevated venous pressure: (5)
- swelling/edema - especially acute unilateral edema
- pain
- redness
- warmth
- gaiter zone (discoloration in the region of the ankle)
3 ponts to check for patient assessment:
*clinical evaluation is only 50% sensitive in an accurate diagnosis of DVT
- redness: localized vs diffuse
- palpable lump: dilated veins
- presence of varicose veins
- primary: hereditary
- secondary: result from DVT, obesity, pregnancy
What are the differentials mocking DVT? (7)
Injury/muscle spasm
* Muscle tear
* Baker’s cyst
* Cellulitis
* Lymphangitis
* Heart failure (right sided heart overload)
* Extrinsic compression -Pregnancy, obesity, ovarian mass
What are the risk facators for DVT?
Virchow’s Triad
- age
- obesity
- pregnancy
- oral contraceptives
- trauma
- varicose veins
- surgery
- infection
- CHF
- previous DVT
- prolonged immobility
- cancer
- dehydration
What is the Virchow’s triad?
3 factors that carry development of thrombosis:
1. trauma
- damage to the intimal lining
- trauma promoted aggregation of platelets and starting the clotting process
- it can be subtle
-
stasis
- can be due to increased viscosity
- slow down blood flow - leading to thrombus formation
- immobility, CHF, obesity, pregnancy, hypotenstion - hypercoagualability
- increased blood viscosity due to cancer, pregnancy, estrogen, blood disorder, smoking
What are the 7 qualities of venous assessment via duplex scanning?
1.** patency** - evaluate presence/absence of thhrombosis
2. spontaneity - PW should display natural flow that chnages with respiration = spontaneous flow
3. phasicity - natural response to respiration
4. nonpulsatility *veins should not have pulsatility - it could be a sign of CHF
5. **compression **- with minimal to mild TDR pressure, vein walls should compress togethere completely
6. **augmentation **- Response that occurs when the extremity is manually “squeezed” distal to the area of the transducer
7. competence - Usually, no flow signal when you compress the limb proximal to the probe
-Competent valves = flow stops with proximal compression
-Incompetent valves will show reflux/reversal of flow with proximal compression
Thrombus can be anechoic.
T or F ?
T
venous study patient postioning
- Patient 1 with leg of interest turned out and flexed
- __2__ can help visualize veins due to hydrostatic pressure
- If a patient is sitting up too much, vessels in the 3 region can compress
- When imaging calf veins, patient can flex knee to relive pressure on the lower leg which may compress the calf veins
- Have patient lay 4 when imaging the lesser saphenous vein
- supine
- 30 degrees Trendelenburg
- iliac/groin
- prone
Most venous duplex exams are performed using a __1__, and __2__ can be used for large legs or deep veins
- linear array probe
- curved-linear probe
Scan Technique:
- Start with __1__ image
-Start at the __2__ (at the groin)
-Utilize __3__ (image on left of screen without compression, image on right of screen with compression)
-Slowly move distally on the leg and do frequent compression images- every __5__ (proximal, mid, & distal FV, popliteal vein, calf veins)
- transverse
- CFV
- side by side imaging
- 2-3 cm
T or F ?
The FV at the distal thigh is not always easy to compress due to the muscle surrounding it. If vein does not compress with transducer pressure, it can be helpful to take non scanning hand and apply pressure to the posterior aspect of the thigh to compress the vein
T
Name the blood vessels 1-3
- GSV (greater saphenous vein
- CFV (common femoral vein
- CFA (common femoral artery)
What is this vessel?
common femoral vein in SAG on left
CFV/GSV - SFJ: saphenofemoral junction
another name for DFV?
profunda
femoral vein is ____ to the femoral artery
posterior
The popliteal vein runs ____ to the popliteal artery anatomically.
However, the image obtained from the popliteal fossa (posterior approach) shows the popliteal vein ____ to the popliteal artery.
posterior
anterior
While evaluating the popliteal vein, always assess the popliteal fossa for a______.
Baker’s cyst
What is Baker’s cyst?
A Baker cyst is a fluid-filled growth behind the knee. It causes a bulge and a feeling of tightness. Also called a popliteal cyst, a Baker cyst sometime causes pain. The pain can get worse when with activity or when fully straightening or bending the knee.
Posterior tibial veins
* More laterally located set of calf veins (paired)
* Located just posterior to the ________
* Image at the medial aspect of the lower leg
medial malleolus
Name of the veins?
posterior tibial veins
Acute vs Chronic Thrombus
Indication of acute thrombus (4)
- hypoechoic/anechoic
- dilated vein
- non-compressible or partially compressible
- abnormal Doppler signal
Acute vs Chronic Thrombus
Indication of chronic thrombus (6)
- echogenic clot
- small vein
- possible thick walls of vein
- incompressible, rigid
- absent or diminished Doppler signals
- recanalization or collateral vessels
PW on deep femoral vein
- cephalad uniform flow (maintained by venous valves
- low resistive waveforms
Spectral waveform should be (4) :
phasic, non-pulsatile, spontaneous, augmentable
which vessel waveform?
CFV
Which vessel waveform?
femoral vein, mid thigh
Which vessel waveform?
popliteal vein
Which vessel waveform?
posterior tibial vein
Thrombi that are isolated in the calf vessels are usually not a serious issues
-Can be painful
-____% propagate proximally
15% to 20%
More worrisome when the thrombi travels proximally into the: (4)
popliteal, femoral veins, iliac system, and IVC
What are 2 thetreatments for Lower Extremity DVT?
- blood thinners
- Heparin
- Lovenox
- Coumadin (more long-term treatment) - IVC filter
-Small device placed in the IVC to prevent blood clots from moving up and reaching the
lungs. Placed in interventional radiology (IR)
-Commonly used in cancer patients and patients with recurring lower extremity DVTs
What is the purpose of the venouse insufficiency testing?
look for incompetent valves within the lower extremities for both deep and superficial veins
incompetent valves cause pooling of blood distally and end up creating _______.
varicose veins and spider veins
What are the causes of the damaged valves/varicose veins?
- hereditary/non-hereditary
- previous DVT
- increased pressure due to a pelvic mass causing increased pressure of the iliac veins
- prolonged standing
- obesity
What are the symptoms of venous insufficiency?
- Leg pain, aching, swelling, heaviness, or fatigue
- Itching of legs
- Skin discoloration or ulcers
- Browning of the skin particularly around the ankles
- Pain and tenderness of varicose veins
- Restless leg syndrome or cramping
Duplex evaluation patient position (2)
- **Supine **in a **reverse Trendelenburg **position
-
Standing
-BEST position for evaluation
-Creates a greater pressure due to gravity
-May be more reliable than reverse Trendelenburg
-Particularly with both deep and superficial
-Want to place the sample gate __1__ the level of the valves
-Add __2__ compressions by pressing proximal to the area of the transducer with your non-scanning hand
-Venous flow should cease within the hand is released
-OR have the patient perform Valsalva: have the patient take a deep breath in with a “bearing down” maneuver
-Venous flow should cease when the patient __3__ and return to normal once they release
-Valsalva may not determine reflux distally
- at
- proximal
- “bears down”
Positive reflux in the femoral vein with valsalva maneuver
For extending scan, look for: (3)
GSV (follow down ankle)
LSV
perforators
Identify the anatomy
- PTV (posterior tibial vein)
- peroneal vein
peroneal vein is located ____ to PTV
posterior
Can perform unilateral or bilateral venous duplex -If unilateral- always assess the contralateral _____
CFV
what are the 3 reasons to perform a bilateral exam?
- Patients with an increased risk of malignancy
- Bilateral lower extremity edema
- Symptomatic bilateral lower extremities
If bilateral extremity veins are lacking spontaneity- look @ the____ to rule out thrombus
IVC
interpretation of normal venous duplex exam (5)
- compression of the vein at all levels
- good augmentation
- phasicity
- spontaneity
- no intraluminal echoes
What are the Doppler optimization technique to interrogate the possible thrombus formation in the venous system? (4)
- color Doppler - make sure to visualize the color filling wall to wall (*in sagittal view)
- look for partial clots that may be anechoic or isoechoic to the blood
- low PRF (both color & spectral)
- low wall filter
positive DVT: femoral vein
positive DVT: peroneal veins
positive DVT: PTVS
Insufficiency leads to chronic venous hypertension, too much venous pressure; Some labs measure the time the reverse flow lasts and quantities.
A reflux time of more than 0.5 second is widely used as criterion for significant valvular insufficiency in the ____veins and 1.0 second for _____ veins
*The longer the time of reflux, the more ____ the disease is
superficial
deep
severe
