about deep vein thrombosis

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

36. Thanks…..
skm25®