Module 4 : Acute Venous Pathology Flashcards
1
Q
venous system characteristics
A
- low pressure system
- spontaneous flow
- demonstrate changes with respiration and augmentation/compression
2
Q
Deep Venous Thrombosis (DVT)
A
- occur when there is an alteration of the normal hemodynamics or architecture of the venous system
- most common reason for a vein exam
+ 50% clinically diagnosed - complication
+ pulmonary embolism
+ 80% originate in LE
+ 30% mortality - chronic venous problems = valves
3
Q
Virchows triad
A
- stasis
- hyper coagulability
- intimal injury
4
Q
venous stasis
A
- MOST COMMON FACTOR
- caused by
+ immobility
+ myocardial infarction
+ congestive heart failure
+ chronic obstructive pulmonary disease
+ obesity
+ pregnancy
+ previous DVT
+ surgery
+ paraplegia
5
Q
hypercoagulability
A
- clotting ability of blood increased
- caused by
+ pregnancy
+ cancer
+ estrogen intake
+ genetic blood factors (deficiency in protein C & S anticoagulants)
6
Q
indications for lower extremity vascular US
A
- suspicion of DVT
- suspicion of pulmonary embolism
- incompetent valves and mass causing symptoms
- edema/swelling especially unilateral
- limb pain and tenderness
- ulceration shallow and round
- discolouration in gaiter area
- varicose veins
- hypercoagulable state
- pallor
- cyanosis
- positive D-dimer test (increase in fibrin strands in blood)
7
Q
indications for upper extremity venous US
A
- suspicion of DVT
- history of catheter lines or drug abuse
- head or neck swelling/edema
- limb redness
- suspected injury after venous puncture (IJV)
- symptoms of PE
8
Q
patient history for LE DVT
A
- acute onset of leg pain
- acute onset of swelling
- persistent leg calf swelling
- redness
- warm skin
- symptoms of PE
- previous DVT
- clotting issues
- trauma
- surgery
9
Q
symptoms of PE
A
- shortness of breath SOB
- chest pain
- hemoptysis
10
Q
thrombus formation
A
- starts in sole sinus and or calf veins a valve cusps
- predominantly due to stasis
- formation begins as aggrgations of red cells near valve cusps due to stasis and eddy currents
- stabilized by fibrin, thrombi become adherent to endothelium and propagation occurs
11
Q
Acute DVT
A
- days to 1-2 weeks old
- dilation of the veins along with lack of compressibility
- echogenic or isoechoic material
- total or partial obstruction
12
Q
disease location
A
- although any venous site can develop thrombus, common origins include \+ gastrocnemius and solar sinus \+ valve sites \+ venous confluence \+ deep venous system \+ superficial venous system \+ perforators * superficial - deep calf veins - proximal
13
Q
sonographic findings of acute DVT
A
- enlarged vein with isoechoic or slightly echogenic
- vein will not coapt
- may not adhere well to wall and appear to float or wave within the lumen
- collateralization may occur rapidly
- retrograde flow
- incompetent valves reverse flow in response to valsalva or compression proximal to site of valve
- continuous venous flow with respiratory phasicity is abnormal and suggest proximal disease
14
Q
sub acute thrombus
A
- 1 to 2 months old
- changes show increasing echogenicity and decreasing venous diameter
- some resumption of flow through recanaliztion and formation of collaterals
15
Q
chronic thrombus
A
- chronic thrombotic scarring months to years after the initial event
- moderate to high echogenicity and may be isoechoic to surrounding tissue and making it difficult to assess the vein
16
Q
sonographic findings of chronic DVT
A
- echogenic thrombus
- vein smaller than artery
- presence of collaterals
- recanalization
17
Q
diagnostic criteria for venous duplex - normal
A
- complete compression of vein walls with light probe pressure
- absent intraluminal thrombus
- color flow fills lumen completely
- normal venous doppler spontaneity, phasicity and augmentation
- no venous dilation
18
Q
diagnostic criteria for venous duplex - abnormal
A
- lack of complete vein compression
- intraluminal echoes present
- decrease or absence of color flow
- abnormal venous doppler spontaneity phasicity or augmentation
- dilated or contracted veins noted
19
Q
thrombosis descriptions and characteristics - acute
A
- light to medium echogenic or anechoic
- spongy lecture on compression
- poorly attaches or free floating
- dilated vein
20
Q
thrombosis descriptions and characteristics - chronic
A
- bright heterogenous echoes
- irregular texture
- attached
- same size as artery or vein is contracted
- collateral vein may be seen
21
Q
can veins be partially or completely incompressible in the two acute and chronic
A
yes
22
Q
can DVT be both acute and chronic
A
- yes
0 acute on top of chronic thrombosis
23
Q
can we determine age of thrombus
A
- no
24
Q
calf vein DVT
A
- solar sinus most common site of formation
- clinical importance is uncertain
- propagation into pop vein varies widely
- current treatments
+ surveillance with duplex US to check propagation into larger veins
+ therapeutic anticoagulation for 6 weeks
25
iliac DVT
- difficulty in imagingiliac veins with ultrasound
- indirect assessment with doppler signal
- confirmation of diagnosis with venography
- compare bilateral CFV waveforms to rule out iliac obstruction
26
monophonic CFV flow
- steady continues flow suggest proximal DVT or extrinsic compression
27
axiallosubclavian veins
- use of centra venous catheters is causing increase in DVT of upper extremity
- patient history of mediastinal lymphoma, previous radiation therapy, trauma or surgery can predispose them to thrombus formation
- spontaneous thrombosis
28
acute disease facts and perspectives
- originates at cusps of valves
- disease mechanism
- superficial venous thrombosis is benign and usually diagnosed clinically
- deep venous thrombosis is common and potentially fatal
- 90% of PE originates from lower extremity
- 60% of patient with DVT for on to have chronic venous insufficiency
- thrombus anywhere is life threatening
- calf vein DVT may cause PE but thrombus to little to be lethal
29
acute disease treatment - medical treatment
- anticoagulation = 3-6 months on heparin or warfarin prevents clot propagation does not dissolve thrombus
+ STANDARD TREATMENT
- thrombolytic agent = injected to dissolve thrombus
- control risk factors = not lots of rest, compression socks, check hyper coagulability
30
acute disease treatment - surgical treatment
- IVC filter = patients who can't be anti coagulated
- venous thrombectomy = patient with impending limb loss if thrombolytic agent does not work
- bypass grafting = caval occlusion
31
endovascular treatment
- catheter directed thrombolysis ( acute DVT)
- balloon venoplasty and stenting (chronic iliofemoral DVT)
- mechanical thrombectomy (acute DVT)
32
venography
- contrast injected into small veins of the foot
- x ray taken of entire leg to demonstrate any disease that may be present
- ascending acute disease
- descending valve disorders
- complete thrombus seems as lack of filing with contrast in expected location
- can be painful = chemical phlebitis
- differentiation between chronic and acute is hard
- GOLD STANDARD
33
pulmonary angiogram
- radiographic test using contrast to evaluate the lungs for PE
34
VQ scan (ventilation quotient) / lung scan
- nuke med
- involves inhaling radioactive gs to demonstrate PE
- indicates perfusion and ventilation of lungs
- doppler stiff can be negative with positive VQ scan
- VQ scan reported as high probability normal or non high
35
isotope venographer
- nuke med
- requires I-125 injection to evaluate peripheral and pulmonary veins
- not utilized often in case of suspected acute thrombus because takes 24 hours fro isotope to tag thrombus
36
D- dimer assay
- lab test to detect formation of acute thrombus indication probably presence of absence of DVT
- results are reported as negative (<500 ug/L) or positive (>500ug/l)
- d-dimer show positive in majority of patients with recent surgery trauma pregnancy and active malignancy
+ not ordered as primary test
37
Wells Score (DVT probability)
- estimate probability of DVT
- patient suspected of having DVT given a Wells score
- done by assessing the clinical history and signs the patient has giving each positive finding a point
- reported as
+ low probability (0)
+ intermediate probability (1-2)
+ high probability (3)
- low or moderate then a D-Dimer assay next step
- high then patient goes directly to get ultrasound
38
wells score factors - DVT
- malignancy
- limb immobalization
- patient immobilization
- localized tenderness
- entire leg swollen
- calf swelling
- pitting edema
- collateral superficial ceils dilated
- alternative diagnosis more likely than DVt
39
PE probability
- estimate probability of pulmonary embolism patient assessed clinically and each positive criterion given a number value
- low probability (<2)
- intermediate (2-6)
- high (>6)
- low to moderate wells score = D -Dimer test next step
- high wells score = VQ scan directly
40
wells score factors - PE
- signs and symptoms of DVT
- pulse > 100bpm
- immobilization
- previous DVt or PE
- hemoptysis
- malignancy
- PE most likely over other diagnosis
41
phlegmasia alba dolens
- white leg
- decreases venous drainage due to thrombosis of extremity deep veins without collateral drainage
- extensive edema obscures capillary circulation
- arterial spasms
- can progress to phlegmasia cerulea dolens
42
phlegmasia cerulea dolens
- massive venous occlusion due to multisegment thrombosis
- obstruction of venous outflow reduces arterial inflow causing arterial vasoconstriction
- venous congestion causes a blue discolouration to skin
- massive thigh and calf swelling
- acute onset starting with hypoxia leading to gangrene
- surgical emergency
43
may-thurner syndrome
- compression of left CIV by right CIA and spine
| - increase risk for DVT and can result in left CIV stenosis and left leg swelling
44
Paget-schroetter syndrome (effort thrombosis)
- most common axillosubclavian thrombosis in ambulatory healthy people
- men more commonly affected
- caused by anatomical variations of muscle and bone in thoraces inlet
- occurs when thrombosis of axillary/subclavian vein at thoracic inlet
- more common in dominant arm
45
thrombophlebitis
- diagnosed clinically - hard cord
- inflammation with thrombus formation
- ultrasound used to delineate extent of thrombus particularly at major confluences into the deep system
- approximately 20% of superficial thrombosis has concurrent DVT
- treatment is ambulation and compression therapy along with anti inflammatory drug administration
46
congestive heart failure
- bilateral lower extremity edema from increased hydrostatic pressure
- leg edema and dyspnea
- increased pulsatility
- may have (-) d - dimer
- come to rule out DVT
47
hematomas
- accumulation of blood within tissue
- due to trauma, anticoagulation, therapy, vigorous exercise
- hypoechous mass with ill defined borders, contained within muscle tissues
48
abcesss & cellulitis
- result of bacterial infection
- access = and enclosed collection of pus
- cellulitis = diffuse collection of fluid within the subcutaneous
- swelling erthema, pain tenderness resemble signs of DVT
- confirm that the Venous system is patent
49
bakers cyst
- dilation of bursa communicate with knee joint
- degenerative joint disease and rheumatoid arthritis
- as cyst enlarges they extend into muscle planes accusing pain tenderness and swelling
- usually medial to knee joint
- usually anechoic but may contain debris and have septation
- no flow with color doppler
- ruptures cysts
- may dissect into calf muscles and intramuscular septums
- rule out hematoma by demonstrating communication with joint space
50
tumors
- benign or malignant may be encountered with routine US
- usually solid may have necrosis
- may resemble other benign pathologies important to demonstrate blood flow in solid portion
51
enlarged lymph nodes (adenopathy)
- can be mistakes for thromboses vein
| - may cause limb swelling compression of veins
52
popliteal aneurysm
- considered when patient present with a lump or pain behind knee
- color flow seen with aneurysm providing it is patent
