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Deep Venous Thrombosis
TURANDOT SAUL, M.D.
SEPTEMBER 12TH, 2007
ST. LUKE’S ROOSEVELT HOSPITAL
DEPARTMENT OF EMERGENCY MEDICINE
Virchow Triad
• Venous stasis
• Vessel wall injury
• Hypercoagulable state
Incidence
 Likely underestimated
- Misdiagnosis
- Occult resolve without complication
- Non-occlusive
- Venous collaterals develop rapidly
Risk Factors
 General
- Age
- Immobilization > 3d
- Pregnancy / post-partum
- Major surgery < 4 weeks
- Trip (>4h) in past 4 weeks
 Medical
- Cancer
- Previous DVT
- CHF
- Sepsis
- Nephrotic syndrome
 Trauma
- CNS / spinal cord injury
- Burns
- Lower extremity fractures
 Hematologic
- Thrombocytosis
- Anti-thrombin III deficiency
- Protein C deficiency
- Protein S deficiency
- Factor V Leiden
 Drugs
- OCP
- Estrogens
The Life of a Clot…
 Valve cusps of deep calf veins
- Dissolve
- Adherence and Organization
- 5-10 days
- Propagate
- Embolize
- Chronic Venous Insufficiency
History and Physical
 Edema
 Leg pain
 Tenderness
 Superficial thrombophlebitis
- Increased risk of DVT
 Fever
Alternate Diagnosis
 Achilles tendinitis
 Lymphedema
 Arterial insufficiency
 Muscle / soft tissue injury
 Arthritis
 Neurogenic pain
 Cellulitis / lymphangitis
 Postphlebitic syndrome
 Extrinsic vein compression
 Ruptured Baker cyst
 Hematoma
 Fracture / bony lesions
 Superficial thrombophlebitis
Wells Clinical Score for DVT
Clinical Parameter
Score
Active cancer
+1
Paralysis or recent immobilization of extremities
+1
Recently bedridden for > 3 days or major surgery <4 weeks
+1
Tenderness along distribution of deep venous system
+1
Entire leg swollen
+1
Calf swelling > 3cm circumference difference from unaffected leg
+1
Pitting edema
+1
Previous DVT
+1
Collateral superficial veins
+1
Alternative diagnosis as likely or more likely than DVT
-2
High Probability
≥3
Moderate Probability
1 or 2
Low Probabillity
0
D-dimer
 Fragments
- Degradation of fibrin by plasmin
 Elevated in any condition where clots form
- Trauma, recent surgery, cancer, sepsis
 Low specificity
- r/o DVT
 Elevated for 7 days
Who Should We Study?
Imaging Studies
Study
Notes
Contrast Venography
- “Gold standard”, 99% sensitive
- Allergic reaction, availability,
IV contrast, costly
- Good for calf, iliac veins, IVC
MRI
- Useful in pregnancy
- Can distinguish acute from chronic
- Good for calf, iliac veins
- Cost, accessibility
CT
- Can do PE study at same time
- Good for calf, iliac veins
Duplex Ultrasonography
- No radiation, bedside, cost
- Non-occlusive thrombi
- Cannot distinguish acute from chronic
- Poor visualization of calf, iliac veins
Lower Extremity Venous Anatomy
 External Iliac
 Common Femoral Vein
- Deep femoral vein
- Superficial Femoral Vein
- Popliteal Vein
- Anterior Tibial Vein
- Posterior Tibial Vein
- Peroneal Vein
Some Logistics
 High frequency linear array probe
(7-10MHz)
 Head of bed to 45⁰
 Patient Positioning
What is Duplex Ultrasound?
B-mode Imaging + Doppler Ultrasound
Doppler Ultrasound: Color
Doppler Ultrasound: Spectral
Ultrasound for DVT
 Major criterion - Failure to compress vascular lumen
- Not visualization of lumen
- Acute thrombus can be anechoic
- Slow flowing blood can have internal echoes
 Minor criterion - Absence of normal doppler signals
- Absence of flow
- Absence of respiratory variation in flow
- Decreased augmentation with distal compression
- Distension of vessel
Major Criteria: Compressibility
 Collapse of lumen of vein
- Complete apposition of anterior and posterior wall
 Compress with transducer in transverse
- Longitudinal compression slides off vessel wall
leading to false negative
- Use to follow course of vein
 May visualize thrombus; not necessary for diagnosis
Compressibility: Normal Findings
A
A
V
Compressibility: DVT
A
V
A
V
Compressibility
Ultrasound for DVT
 Major criterion - Failure to compress vascular lumen
- Not visualization of lumen
- Acute thrombus can be anechoic
- Slow flowing blood can have internal echoes
 Minor criterion - Absence of normal doppler signals
- Absence of flow
- Absence of respiratory variation in flow
- Decreased augmentation with distal compression
- Distension of vessel
Minor Criteria: Flow
Minor Criteria: Respiratory Variation
Minor Criteria: Respiratory Variation
Minor Criteria: Augmentation
Femoral Vein
 Begin at inguinal ligament
 Distally bifurcates into superficial and deep femoral
veins
 Compression in Hunter’s
canal difficult because
of depth
Femoral Vein
Popliteal
 Positioning
 Vein superficial to artery
 Scan to trifurcation point
Popliteal
Diagnostic Difficulties
 False negatives
- Adductor canal
- Complete occlusion
- Ilio-femoral DVT
- Duplicated vessels
- Technical difficulties
- obese patients
- significant lower
extremity edema
 False positives
- Chronic vs. acute
- Proximal obstruction
limits compressibility
- Superficial vein filled with
thrombus
 Operator Dependence
How Good is it?
 Noninvasive Diagnosis of Deep Venous Thrombosis
- Large review of US for DVT
- Proximal DVT: sensitivity 95%, specificity 96%
- Calf vein DVT: great variation
- Overall: sensitivity 89%, specificity 94%
-Kearon C, et al.
Limited Ultrasound
 Image entire venous system
- Technically difficult
- Time
 Limited Ultrasound
- Only B-mode compression
- 5 cm inguinal ligament
- 5 cm popliteal fossa
How Good is Limited Ultrasound?
 Detection of Deep Vein Thrombosis by B-mode
Ultrasonography
- Sole criterion was compressibility of common femoral
or popliteal vein
- 100% sensitive for proximal DVT
- 91% sensitive overall
-Lensing, et.al.
How Good is Limited Ultrasound?
 Limited B-mode venous Imaging Versus Complete
Color-flow Duplex Venous Scanning for Detection of
Proximal Deep Venous Thrombosis
- time reduction 37 minutes vs. 5.5 minutes
- Poppiti et.al.
Are DVT in calf veins ok?
 Smaller
 Propagate
 Treatment?
Do You Study the Asymptomatic Leg?
 Unilateral symptoms
- risk in contralateral leg is <1%
 Assist in difficult anatomic interpretations
 Does it matter if anti-coagulating anyway?
Other Ultrasound Diagnosis
 Lymph node
 Baker’s cyst
 Superficial thrombophlebitis
 Popliteal artery aneurysm
Lymph Node
LN
A
Baker Cyst
Popliteal Artery Aneurysm
Upper Extremity DVT
 Massive PE extremely rare
 Lower incidence
- Fewer venous valves
- Higher flow rate
- Less frequent immobility
- Decreased hydrostatic pressure
- Malignancy, catheter induced
 Clavicle prohibits adequate compression
- Evaluate using color or spectral Doppler
What Happens to the Clot?
 Clot retracts and becomes echogenic
 Vein wall becomes thickened, echogenic and
resistant to compression
 In 12-24 months, 50% have complete resolution of
thrombus and normal compressibility
 Difficult to evaluate acute vs. chronic
- Post-treatment baseline study for comparison
Data Forms and Worksheets?
Thank You
 Dr. Resa Lewiss
 The Ultrasound Division
Resources
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Ultrasound diagnosis of deep venous thrombosis. Tracy JA - Emerg Med Clin North Am - 01-AUG-2004;
22(3): 775-96
Cecil Textbook of Medicine, 22nd ed.
Rosen's Emergency Medicine: Concepts and Clinical Practice, 6th ed.
Birdwell BG, Raskob GE, Whitsett TL, et al. The clinical validity of normal compression ultrasonography in
outpatients suspected of having deep venous thrombosis. Ann Intern Med 1998;128:1-7.
Lensing AW, Prandoni P, Brandjes D, et al. Detection of deep-vein thrombosis by real-time B-mode
ultrasonography. N Engl J Med 1989;320:342-5.
Poppeti R, Papanicolaou G, Perese S, et al. Limited B-mode venous imaging versus complete color-flow duplex
venous scanning for detection of proximal deep venous thrombosis. J Vasc Surg 1995;22:553-7.
Kearon C, Julian JA, Newman TE, et al. Noninvasive diagnosis of deep venous thrombosis. McMaster
Diagnostic Imaging Practice Guidelines Initiative. Ann Intern Med 1998;128:663-77.
http://www.vascularweb.org/graphics/northpoint_graphics_jpg/DVT_01_Base_275.jpg
http://radiology.muhealth.org/new_Radiology_Web/Interventional/irImages/DVT_normal_and_embolus
http://www.imvs.sa.gov.au/dvt_likelihood.gif
http://www.imvs.sa.gov.au/dvt_likelihood.gif
http://www.vascularweb.org/graphics/northpoint_graphics_jpg/DuplexUltra_02REV_Base_300.jpg
http://www.thieme-connect.com/
http://www.iame.com/learning/upExtVen/figure1t.gif
http://www.dvthealth.com/dvt_exerciser.htm