Deep vein thrombosis (DVT) is the formation of a blood clot in a deep vein, usually in the legs. It occurs in about 1 in 1000 people in the US each year and risk increases with age. DVT is caused by Virchow's triad of endothelial damage, stasis, and hypercoagulability. Common risk factors include surgery, trauma, cancer, and genetic mutations. Most DVTs are asymptomatic but can cause leg pain, swelling, and redness. Diagnosis involves blood tests like D-dimer and imaging like ultrasound or CT scans. Treatment involves blood thinners like heparin or warfarin to prevent clots from growing or dislodging. Prevention includes early

1. Deep Vein Thrombosis

2. • Formation of a semisolid coagulum in deep veins, usually
in lower extremities

3. Incidence
• DVT-PE causes~50,000 to 200,000 deaths per annum in west.
• DVT occurs in every 100/100,000 population in US.
• Incidence increases with increase in age.
• Only 40% of DVT patients have clinical symptoms

4. Etiology
• 3 factors described by RUDOLF VIRCHOW
1. Contact of blood with abnormal surface—ENDOTHELIAL
DAMAGE
2. Abnormal flow – STASIS
3. Abnormal blood- HYPERCOAGULABLE STATE

5. ENDOTHELIAL DAMAGE
• Surgical procedures
• Trauma
• Invasive procedures
• Central line insertion
• eg: Hip,knee surgeries> urological procedures> abdominal
surgeries>neurosurgeries> gynaecological surgeries.

6. STASIS
• Prolonged bed rest (>3days)
• Paralysis of lower limbs,
• Spinal injuries
• Long travel
Stasis in lower limb – causes initiation of dvt formation in soleal sinuses( MC
SITE)

7. HYPERCOAGULABLE STATES
• Factor V leiden mutation, prothrombin gene mutation
• Factor C,S, antithrombin 3 deficiency,
• Pregnancy, perperium, high dose ocp/ estrogen therapy.
• Malignacy( higher in mucin producing adeno Ca, pancreas,GIT, lung Ca.)
• nephrotic syndrome, homocystenimea

8. Pathology
• Virchows triad-> platelet aggregates->+ fibrin forms initial clots->
• Rbcs get trapped-> thrombus formation -> dislodges->emboli

10. Clinical features
• Pain / tenderness of lower limbs
• Swelling with pitting pedal edema
• Warmth/ redness of limb
• Superficial venous dilation
• Only 40% have symptoms
• Look for tachycardia, tachypnoea, breathlessness.-PE

11. Rare findings
• Phlegmasia alba dolens
• Due to total occlusion of deep
ileofemoral vessels.
• Painful white swollen limb
• Blenching +, no cyanosis

12. • Phlegmasia cerula dolens
• Massive edema causes
compromised arterial flow
• Painful blue leg

13. • Venous gangrene
• If blood flow is not retained

14. Homans sign
• Resistance( pain) of calf muscle to
forcible dorxiflexion

15. Moses test
• Gentle squeezing of calf muscle- pain
• not following now

16. MODIFIED WELLS CRITERIA
• Helps in early risk stratification and diagnosis of DVT

18. Diagnosis
• Blood investigations:- D-DIMER – NON SPECIFIC
• A FIBRIN DEGRADATION PRODUCT
• 90-95% SENSITIVITY
• 99% NEGATIVE PREDICTIVE VALUE
• ALSO positive in recent surgeries, pregnancies, DIC, ACUTE MI,
collagen vascular diseases, etc

19. IMAGING STUDIES
1. VENOGRAPHY
• Most accurate method to confirm position of DVT.
• Torniquet is applied to block superficial veins->
dye is injected to venous system
• Invasive technique

20. Nuclear scanning
• I125 labelled fibrinogen is injected
• Helps to identify old and new thrombus

21. Impedence plethysmography
• Measures change in venous capacitance and rate of emptying of venous
volume on temporary occlusion and release

22. 2. Duplex scan
• Current test of choice for diagnosis
• Inexpensive , non invasive
• Also helps to distinguish from other causes- tumour, popliteal cyst, abscess,
aneurysum, hematoma, etc.
• Unable to detect pelvic and small vessel thrombosis.
• Operator dependent results

23. MR venous imaging
• Best for pelvic and ivc thrombosis.
• costly

24. Management
• GENERAL MEASURES.
• Bed rest
• Encourage to do gentle foot/leg exercise every hourly.
• Avoid deep calf massage

25. Specific measures
• ANTICOAGULANT THERAPY.
• Traditionally inj. HEPARIN 5000 IU/80IU/Kg bolus within 24 hours of
diagnosis then 18U/Kg/hr to maintain APTT between 60-80sec. for
atleast 5 days
• Followed by WARFARIN to obtain an INR of 2.5-3.0( in an overlap-
start within 72 hours) for minimum 3 months.
• Now LMWH is widely used

26. LMWH
• Selectively inhibits factor XA
• Good bioavailability and efficacy
• No monitoring needed
• Subcutaneous OD/BD doses
• No thrombocytopenia.
• Eg.( Enoxaparin(clexane), daltiparin, tinzaparin)
• .(Enoxaparin 1 mg/kg SC q12hr, OR 1.5 mg/kg SC qDay (administer at same time
each day)

27. Thrombolytic therapy
Advantages
• Sudden reversal of symptoms
• Restore venous circulation
• Prevent pulmonary embolism
• Preserve venous nalvular function
Disadvantages
• clot propagation and embolism, rethrombosis,

28. Surgery for DVT
• Major procedure is clot removal and partial interruption of ivc to prevent
pulmonary embolism
• Indicated when anticoagulant therapy is
unsafe

29. Endovascular reconstruction
• Using percutaneous catheters
• -recanalization by balloon
dilation or stent placement
• first line therapy in ilial occlusions

30. Vena cava filters
• INDICATIONS
• Recurrent dvt despite of anticoagulants
• DVT with anticoagulant use is contraindicated
• c/c pulmonary embolism
• Propagation ileofemoral venous thrombous in anticoagulation
• Complications of anticoagulants
Retrivable filters used in trauma, short term uses, contraindicated anticoagulants

32. Prophylaxis
MECHANICAL
1. Advise to start walking within 24-48 hours of surgery
2. Leg excercises
3. Graded compression stalkings
4. Intermittent pneumatic compression devices

35. Medical prophylaxis
• Low dose unfractionated Heparin 5000 U s/c Q12H-Q8H( traditional)
• LMWH – Subcutaneous dose- OD ( Anti factor Xa& IIa)
• Enoxaparin(CLEXANE) 4000IU/40 mg/ 0.4ml s/c OD in abdominal
surgeries

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