Deep vein thrombosis

Mr. Naresh

Govindarajanthran

Vascular Surgery

HKL

Venous anatomy of the lower limbs

Superficial system

Long saphenous vein

Short saphenous vein

Deep system

Femoral veins

Popliteal veins

Calf veins

Virchow’s triad

Abnormalities of blood flow (stasis)

Abnormalities of blood (coagulation

disorders)

Injury to the vessel wall

Risk factors

Age

Cancer

Smoking

Coagulation disorders

Obesity

Oestrogen substitution

Surgery (hip or knee arthroplasty, cancer surgery in the

abdominopelvic area)

Immobilization

Previous DVT

Hypercoagulability

Inherited

Common

Factor V Leiden

Prothrombin gene mutation (G20110A)

Rare

Antithrombin deficiency

Protein S deficiency

Protein C deficiency

Dysfibrinogenemia

Homozygous homocystinuria

Acquired

Age

Surgery and trauma

Immobilization

Malignant disease

Previous venous thromboembolism

Pregnancy and puerperium

Oral contraceptive and hormone replacement therapy

Antiphospholipid antibodies

Unknown (Probably Multifactorial)

Elevated levels of factor VIII, IX, and XI and fibrinogen

Diagnosis

Combination of

clinical assessment

laboratory studies

imaging

Signs and Symptoms

Symptoms

Calf pain and oedema of the calf or the whole leg

may be asymptomatic especially acute

pulmonary embolism

Signs

Calf tenderness with pitting oedema

massive DVT

cyanotic-phlegmasia cerulae dolens

Phlegmasia

Lab investigation

D-dimer

rapid, simple and inexpensive test

predictive value of negative D-dimer

improves greatly when used as part of an

algorithm

may be raised in inflammation, surgery or

cancer

Duplex ultrasound

Femoropopliteal vein

Sensitivity 98.7%

Specificity 100%

Below knee veins

Sensitivity 70%

Specificity 60%

Compressibility

Diagnosis

**A score of 2 or more indicates probability of DVT is high

Wells et al. NEJM 2003; 349: 1227-35

Primary prevention

Physical methods

postoperative early ambulation

graduated compression stockings

intermittent pneumatic compression

Anticoagulation

UFH

LMWH

vitamin K antagonist

Long term prevention

Warfarin started simultaneously with

heparin

INR 2.0-3.0

stop heparin after 5-7 days

LMWH with warfarin for 3 months prevents

recurrence in 95% and has a risk of severe

bleeding of 1% Hull et al. N Eng J Med 1990;

322:1260-4

Questions asked?

LMWH or UFH?

LMWH

100IU/kg twice daily or 150IU/kg daily

as effective as bolus and infusion UFH

LMWH

more predictable dose response relationship (no need

monitoring)

longer half life

lower risk of HIT

lower risk of osteoporosis

caution with renal failure as LMWH is excreted via kidneys

Dolovich et al Arch Intern Med 2000; 160:180-88

Newer agents

Fondaparinaux

synthetic specific antifactor Xa

pentasaccharide with the same active site

as heparin

doesn’t cross react with PF-4

(development of HIT)

Newer agents

Direct thrombin inhibitors (DTI)

recombinant hirudin, lepirudin, argatroban

intravenous administration

monitored with APTT

Ximelagatan

oral DTIs

predictable bioavailability and does not require monitoring

transient elevation of liver enzymes but normalizes after 4

months

rare cases of fulminant hepatic flexure

How long?

Duration

Proximal DVT related to reversible and

time-limited risk factors (surgery,

trauma,long haul airplane flights)

3 months of warfarin

First episode of idiopathic DVT

6-12 months of warfarin

Duration

DVT and mild thrombophilic conditions

(protein C and S deficiency, heterozygous

factor V Leiden, hyperhomocysteinaemia)

6 months of warfarin

DVT with stronger thrombophilias

(antithrombin deficiency, anti-phospholipid

antibodies, homozygous factor V Leiden)

indefinite anticoagulation

Thrombolysis required?

Thrombolysis

Who may benefit

Required in limb threatening DVT

Possibly young patients with extensive iliofemoral DVT

systemically (ineffective) or via catheter directed

complete of substantial resolution of thrombus possible in 85%

with DVT <10days

diminishes pain, swelling and valve destruction but no effect on

incidence of post phlebitic syndromes

has an increased risk of bleeding

Contraindications

Recent surgery (<7days) esp neurosurgery

and ophtalmic surgery

Bleeding daisthesis

Haemorrhagic stroke within 2 months

Pregnancy

Thrombolysis

Streptokinase

Urokinase

rTPA

has an increased risk of bleeding

currently infrequent due to cost consideration, contra-indication to

thrombolysis, perceived high risk of thrombolytic agents

Role of Surgery or

Percutaneous Mechanical

Thrombectomy

Surgical ThrombectomyInvasive

Blood loss

does not obviate the need for

anticoalgulation

must be done within the first 3 to 7 days

Role

young patients with isolated iliac

thromboses

phlegmasia cerulae dolens

Percutaneous Mechanical

Thrombectomy

Rotating devices

Venturi effect (Angiojet device)

Results are poor

Limited to patients with contraindications

to

anticoagulations

thrombolysis

IVC filters?

IVC filters

Effective in preventing short term incidence

of pulmonary embolism but not mortality

THROMBOGENIC

doubles the recurrence risk

IVC filters

Should be used in

contraindications to anticoagulants

recurrent pulmonary embolism despite

adequate anticoagulation

chronic thromboembolic pulmonary

hypertension

Conclusion

diagnosis is a combination of clinical,

laboratory and imaging.

mainstay of treatment is anticoagulation

limited role of IVC filters

duration of anticoagulation depends on the

cause

Thank you

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