Definition
formation of a blood clot in one of
the deep veins of the body, usually
in the leg
Anatomy
Etiology and risk factors
3 main factors contribute in development of DVT
Stasis
Endothelial injury
Hypercoagulability
Venous stasis
prolonged bed rest (4 days or more)
a cast on the leg
limb paralysis from stroke or spinal cord
injury
extended travel in a vehicle
heart failure
Hypercoagulability
Surgery and trauma - responsible for up to 40%
of all thromboembolic disease
Malignancy
Increased estrogen (due to a fall in protein ‘S)
Increased estrogen occurs during
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all stages of pregnancy
the first three months postpartum,
after elective abortion, and
during treatment with oral contraceptive pills
Inherited disorders of coagulation
 deficiencies of protein ‘S’,
 protein ‘C’ and
 antithrombin III.
Acquired disorders of
coagulation
nephrotic syndrome results in urinary
loss of antithrombin III, this diagnosis
should be considered in children
presenting with thromboembolic disease
Antiphospholipid antibodies accelerate
coagulation and include the lupus
anticoagulant and anticardiolipin
antibodies.
Inflammatory processes, such as
• systemic lupus erythematosus (SLE),
• sickle cell disease, and
•inflammatory bowel disease (IBD),
also predispose to thrombosis, presumably due to
hypercoagulability
Symptoms:
Dull pain, heaviness, oedema and warm limb
With extensive DVT:-massive oedema, cyanosis, dilated
superficial collateral veins and low grade fever.
With ilio-femoral DVT:Phlegmasia cerulea dolens (cyanosed limb due to
obstructed vein)
Phlegmasia alba dolens (pale, pulseless cold limb due
to concurrent arterial spasm)
AND THESE TWO UPPER CASES ARE LIMB
THREATENING CONDITION!!
Phlegmasia cerulea dolens
Venous gangrene
Signs
HOMAN'S sign
(tenderness during
passive dorsiflexion of
foot). And it was
contraindicated because
of it’s role in thrombus
deattachment and thus
emobilization
Hotness, cyanosis,
oedema (non-pitting)
Diagnostic Studies
- Clinical examination alone is able to confirm only
20-30% of cases of DVT
- Blood Tests
the D-dimer - have predictive value for DVT
INR - useful for guiding the management of
patients with known DVT who are on warfarin
(Coumadin)
D-dimer
D-dimer is a specific degradation product
of cross-linked fibrin. Because concurrent
production and breakdown of clot
characterize thrombosis, patients with
thromboembolic disease have elevated
levels of D-dimer
three major approaches for measuring Ddimer
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ELISA
latex agglutination
blood agglutination test - SimpliRED
False-positive D-dimers occur in patients
with:
recent (within 10 days) surgery or trauma,
recent myocardial infarction or stroke,
acute infection,
disseminated intravascular coagulation,
pregnancy or recent delivery,
active collagen vascular disease
metastatic cancer
Imaging Studies
Invasive
venography,
radiolabeled fibrinogen
Noninvasive
ultrasound,
plethysmography,
MRI techniques
Imaging studies:
*The standard tool for diagnosis is
phlebography using fluoroscope. The use of
this study limited by is complications which
are allergy, nephropathy and phlebitis.
*Duplex ultrasound:
Test of choice
Sensitivity and specificity >95%
Able to detect other pathology like BAKER
cyst.
Venography
"gold standard” modality for the diagnosis
of DVT
Advantages
venography is also useful if the patient has
a high clinical probability of thrombosis and
a negative ultrasound,
it is also valuable in symptomatic patients
with a history of prior thrombosis in whom
the ultrasound is non-diagnostic.
Venogram
shows DVT
Ultrasonography
color-flow Duplex scanning is the imaging
test of choice for patients with suspected
DVT
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inexpensive,
noninvasive,
widely available
Ultrasound can also distinguish other
causes of leg swelling, such as tumor,
popliteal cyst, abscess, aneurysm, or
hematoma.
clinical limitations
reader dependent
Duplex scans are less likely to detect nonoccluding thrombi.
During the second half of pregnancy,
ultrasound becomes less specific,
because the gravid uterus compresses the
inferior vena cava, thereby changing
Doppler flow in the lower extremities
The finding are:
Acute DVT:
• Absence of spontaneous flow.
• Loss of flow variation with respiration.
• Failure to increase the flow after distal augmentation.
• Not visible thrombi (anechoic thrombi).
Chronic DVT:
Not well established
Narrow vein
Patent collateral
Visible thrombi
Color duplex scan of DVT
The only disadvantage of duplex study is
that, it is highly operator dependant!!!
Magnetic Resonance Imaging
It detects leg, pelvis, and pulmonary
thrombi and is 97% sensitive and 95%
specific for DVT.
It distinguishes a mature from an
immature clot.
MRI is safe in all stages of pregnancy.
Differential diagnoses:
Unilateral limb involvement: muscular
strain, tendon rupture, cellulites,
lymphodema or retroperitoneal fibrosis
pressing over the vein.
Bilateral limb involvement: liver, heart or
renal failure or IVC obstruction.
Complication of DVT
Recurrent DVT
Varicose vein
Chronic venous insufficiency
Post phlebitic syndrome (pain, oedema
and ulceration)
PE
Patient with suspect symptomatic
Acute lower extremity DVT
Venous duplex scan
negative
Low clinical probability
High clinical probability
positive
observe
negative
Evaluate coagulogram /thrombophilia/ malignancy
Repeat scan /
Venography
Anticoagulant therapy
contraindication
IVC filter
yes
No
pregnancy
OPD
hospitalisation
LMWH
LMWH
UFH
+
warfarin
Compression treatment
Management
The aim of management is:
Prophylaxis against DVT
Treatment of ongoing DVT
Methods of Prophylaxis:
1) Mechanical
Leg elevation
Graded compression stocking
Early ambulation
Pneumatic compression boo.
2) Pharmacological agents:
Aspirin (anti platelet factor) not
recommended currently.
Dextran solution (40 and70) branched
polysaccharide. Decrease platelets
adhesiveness and aggregation.
Disadvantages:
 Increase rate of bleeding
 Pulmonary edema (due to overload)
 Allergic reaction in 1%
Recommended dose is15-20 cc/h IV infusion
before surgery.
Warfarine (coumadine):Decrease incidence of DVT by 66% and PE by
80%.
Disadvantages:

Sever hemorrhage
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Must be started 2-3 days preoperative.
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Require careful monitoring for PT.
Warfarine nomograph
Heparin
Unfractionated heparin:
Inhibits AT III and potentiate disintegration of thrombi
that form while it administered
Low dose regimen is 5000 IU twice daily SQ two
hours pre-operatively then q12hours post operative
till the patient is completely ambulating.
For morbidly obese patient: - micro-heparin drip at
1u/kg/hour
Disadvantages:
Risk of bleeding
Thrombocytopenia (rare)
Contraindicated in patient with actively bleeding
peptic ulcer, uncontrolled HTN, bleeding disorder or
recent use of ASA
Heparin-dihydroergotamine (DHE)
combination:
Cause vasoconstriction of capacitance veins
and thus increase the venous return.
Particular effectiveness in orthopedic cases.
Contraindicated in case of hypotension, IHD
and peripheral arterial occlusive diseases.
Low molecular weight (enoxaparin):
Lesser effect on thrombin and platelets
aggregation.
Longer life time so the dose will be once
daily.
More expensive than unfractionated heparin.
Heparin nomograph
Fibrinogen-depleting compound
New class of anticoagulants but not well
known.
Prophylactic IVC filter placement.
Also known as Greenfield filter.
Used in high risk patient when other
methods are contraindicated.
Effective in preventing PE not DVT.
An approach to Prophylaxis
1. determine patient at risk
Low risk (<40 years old, ambulating,
minor surgery)
Moderate risk (>40 years old, abdominal,
pelvic or thoracic surgery)
High risk (>60years old, prior DVT or PE
malignancy, orthopedic surgery
hypercoagulability state).
2. prohylaxis of choice
Encourage all patients to ambulate as soon as
possible
Low risk patient don't need prophylaxis.
Moderate risk pneumatic compression boot or
low dose heparin prophylaxis.
High risk combination of pneumatic
compression boot and low dose heparin
prophylaxis or Dextran.
Coumadine or IVCfilter are considered.
Ophthalmology or neurosurgery patient are
NOT candidates for prophylaxis.
Treatment of DVT
A: - anticoagulation
Heparin bolus 100-150 u/kg IV stat then
followed by constant infusion of 1000 u/hour
with checking aPTT q 4-6hours and keeping
the ratio 50-70sec.
Coumadine (Warfarine) usually started at day
3-5 after initial heparin is given and continue
for 3-6 months . PT should be 17-20sec. and
INR 2.0-2.5.
Duration of anticoagulation in patients with
deep vein thrombosis
Transient cause and no other risk factors:
3 months
Idiopathic: 3-6 months
Ongoing risk for example, malignancy: 6 12 months
Recurrent pulmonary embolism or deep vein
thrombosis: 6-12 months
Patients with high risk of recurrent thrombosis
exceeding risk of anticoagulation: indefinite
duration (subject to review)
B:-thrombolytic treatment( alteplase,
streptokinase, urokinase)
Promote rapid thrombus lysis. Used in cases of
sever PE . They have more bleeding
complication.
C:-venal cava interruption (IVC filter)
Prevent further embolism of thrombi
D:- venous thrombectomy
May be necessary in venous gangrene and
septic thrombosis.
Thrombolytic therapy for DVT
Advantages include
prompt resolution of symptoms,
prevention of pulmonary embolism,
restoration of normal venous circulation,
preservation of venous valvular function,
and prevention of postphlebitic syndrome.
Thrombolytic therapy does not prevent
clot propagation,
rethrombosis, or
subsequent embolization.
Heparin therapy and oral anticoagulant
therapy always must follow a course of
thrombolysis.
Thrombolytic therapy is also not effective once
the thrombus is adherent and begins to
organize
The hemorrhagic complications of thrombolytic
therapy are formidable (about 3 times higher),
including the small but potentially fatal risk of
intracerebral hemorrhage.
Catheter directed-thrombolysis
Consider in: Acute< 10 days iliofemoral
DVT.
Long-term benefit in preventing
post-phlebitic syndrome is unknown.
Filters for DVT
Indications for insertion of an inferior
vena cava filter :
Pulmonary embolism with contraindication
to anticoagulation
Recurrent pulmonary embolism despite
adequate anticoagulation
Filters for DVT
Controversial indications:
Deep vein thrombosis with
contraindication to anticoagulation
Deep vein thrombosis in patients with preexisting pulmonary hypertension
Free floating thrombus in proximal vein
Failure of existing filter device
Post pulmonary embolectomy
Filters for DVT
Inferior vena cava filters reduce the rate of
pulmonary embolism but have no effect on
the other complications of deep vein
thrombosis.
Surgery for DVT
Indications:
when anticoagulant therapy is ineffective
unsafe,
contraindicated.
The major surgical procedures for DVT are
clot removal and partial interruption of the
inferior vena cava to prevent pulmonary
embolism.
These pulmonary emboli removed at autopsy
look like casts of the deep veins of the leg where
they originated.
This patient underwent a thrombectomy. The thrombus has
been laid over the approximate location in the leg veins where
it developed.
Prognosis:
All patients with proximal vein DVT are at longterm risk of developing chronic venous
insufficiency.
About 20% of untreated proximal (above the
calf) DVTs progress to pulmonary emboli, and
10-20% of these are fatal. With aggressive
anticoagulant therapy, the mortality is
decreased 5- to 10-fold.
DVT confined to the calf virtually never causes
clinically significant emboli and thus does not
require anticoagulation