TURANDOT SAUL, M.D. SEPTEMBER 12TH, 2007 ST. LUKE’S ROOSEVELT HOSPITAL DEPARTMENT OF EMERGENCY MEDICINE Deep Venous Thrombosis

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 days - Propagate - Embolize - Chronic Venous Insufficiency

History and Physical Edema Leg pain Tenderness Superficial thrombophlebitis - Increased risk of DVT Fever

Alternate Diagnosis Achilles tendinitis Arterial insufficiency Arthritis Cellulitis / lymphangitis Extrinsic vein compression Hematoma Lymphedema Muscle / soft tissue injury Neurogenic pain Postphlebitic syndrome Ruptured Baker cyst Fracture / bony lesions Superficial thrombophlebitis

Wells Clinical Score for DVT Clinical ParameterScore 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 Probability1 or 2 Low Probabillity0

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 StudyNotes 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 45 ⁰ 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 V A A

Compressibility: DVT V A V A

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: 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 A LN

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 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 Ultrasound diagnosis of deep venous thrombosis. Tracy JA - Emerg Med Clin North Am - 01-AUG-2004; 22(3): 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: 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: 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: