DR SAMI KUMAR SHAH UCMS -TH

1. Deep Vein Thrombosis(DVT)
Moderator :Dr.Santosh Shah
Presenter :Dr.Sami Kumar Shah
2081/10/07

2. Outline
1. Introduction
2. Clinical Presentation and Diagnosis
3. Prophylaxis
4. Medical and Surgical Treatment

3. Introduction
Deep vein thrombosis is a blood clot form in a deep vein
More common in deep vein of legs(calf) than arms
About 80 cases per 100000 population annually
M:F=1.2:1
Age >40 yrs

4. Etiology-Virchow’s triad

5. Risk factors for DVT
Primary /idiopathic DVT: in absence of any risk factors
Secondary DVT: occurring in setting of recognized risk factor

6. Risk Factor Description
• Age - Higher incidence associated with advanced age
- Incidence of DVT increased 30-fold from those age 30 to those older than 80
years
- Elevated P-selectin, tissue factor (TF), antiphospholipid antibodies, and
procoagulant microparticles contribute to the risk
• Immobilization- Stasis in veins and behind valve cusps due to inactivity of calf muscle pumps
- DVT present in 15% of patients dying after 0-7 days of bed rest vs. 79-94% of
those dying after 2 to 12 weeks
- Stroke patients with paralyzed extremities have a significantly high incidence of
DVT
- Neurological disease and extremity paresis/plegia increase risk 3-fold for DVT
and PE
• Travel
- Prolonged travel ("economy class syndrome") associated with cramped
positions during flights
- Risk of severe PE increases with travel >5000 km
- WHO recognizes a probable link between travel and DVT

7. • History of
Thrombosis
- 33-26% of patients with acute DVT have a prior history of thrombosis
- Impaired fibrinolysis increases risk
• Malignancy - 20% of all first-time VTE events associated with malignancy
- High rates associated with pancreatic and gastric malignancies
- Tumors release procoagulant molecules, increasing thrombotic risk
• Surgery - Influenced by patient age, type of procedure, and extent of trauma
- Half of postoperative lower extremity thrombi develop in the operating room
- Strongest predictors include myocardial infarction and infections
• Blood Group - Higher prevalence of VTE in blood type A and lower prevalence in blood type O

8. • Geography and Ethnicity
- Postoperative DVT in Europe is nearly twice that of
North America
• IBD
- Crohn’s disease and ulcerative colitis increase the
risk of VTE
• SLE
- A syndrome associated with thrombosis when
accompanied by antiphospholipid antibodies
• Varicose Veins
- Patients with varicose veins have a higher risk of
VTE
• Obesity - BMI > 25–30 kg/m² increases risk

9. Clinical Presentation and Diagnosis
Signs and Symptoms:
1. Dull ache or pain in the leg
2. Swelling
3. Tenderness
4. Erythema
5. Cyanosis
6. Warmth
7. Venous gangrene: A rare condition usually seen in patients with
cancer, heparin-induced thrombocytopenia (HIT) with thrombosis, or
warfarin-mediated protein C depletion

10. Feature Phlegmasia Alba Dolens
Phlegmasia Cerulea
Dolens
Alternate Name  Milk leg or white leg  Painful blue leg
Pathophysiology
 Deep vein thrombosis
causing occlusion of
deep veins
 Occlusion of both deep
and superficial veins
Appearance  Pale, white leg
 Cyanotic, swollen, blue
leg
Symptoms
 Sudden onset, mild
pain
 Severe pain, significant
swelling
Complications
 Relies on superficial
veins for drainage
 Risk of gangrene and
pulmonary embolism

11. Diagnostic Tests
Test 1.D-Dimer 2.Duplex Ultrasonography
• Action
Measures fibrin degradation products (D-
dimers)
-Ultrasound used to visualize blood flow and detect
thrombus
• Use
Helps in diagnosing DVT, but does not
exclude DVT
-Dominant diagnostic test of choice for DVT
• Advantages
- Can indicate presence of thrombus
- Cost-effective
- Accurate
- No radiation
- Portable
- Non-invasive
- Relatively cost-effective
• Characteristic
Findings
Not applicable
- Increased venous diameter
- Inability to collapse vein
- Absence of spontaneous blood flow
• Disadvantages
- Does not exclude distal thrombi,
anticoagulation use, or delayed testing
- Poor evaluation of calf veins, fresh thrombi, and
small thrombi
- Inaccurate in obese patients or significant edema

12. Test 3.Venography 4.CT Venography
• Use
Historically used, now rarely due to
drawbacks
-Used for detecting thigh and pelvic
DVT
• Sensitivity ~96%
-100% for pelvic DVT, high for thigh
DVT
• Specificity ~91%
-High specificity for thigh and pelvic
DVT
• Advantages
- "Gold standard" for diagnosing
acute DVT
- 100% sensitivity/specificity for
pelvic DVT
- Valuable for thigh DVT
• Disadvantages
- Expensive
- Invasive
- Patient discomfort
- Expensive
- More operator-dependent than
duplex ultrasonography

13. Test 5.Magnetic Resonance Venography (MRV)
• Use
-3D imaging to detect thrombus and assess venous
structures
• Advantages
- Detects thrombus in centrally located veins
- Differentiates acute thrombus from tumor thrombus
• Disadvantages
- Long imaging times
- Artifacts from below-knee veins
- Gadolinium toxicity in renal dysfunction patients

14. 6.18 F-FDG PET /CT shown
To detect acute DVT
To determine thrombus age
To differentiate acute thrombus from tumor thrombus

15. Diagnostic Strategies
1. Antithrombin Deficiency (AT): Increases DVT risk 5–50 times
2. Protein C Deficiency: Increases DVT risk 3-fold
3. Protein S Deficiency: Increases DVT risk 10-fold
4. Elevated Factor VII and IX, hyperhomocysteinemia,
dysfibrinogenemia, and hypofibrinolysis: Increase DVT risk 2-fold
5. Wells’ Score: Assigns one point for each of nine characteristics and
subtracts two points if an alternative diagnosis is as likely as DVT
• Wells’ Score Interpretation:
 2 points or more: Likely DVT
 1 point or less: Unlikely DVT

16. Wells’ Score Table:
Clinical Feature Points
o Active cancer (treatment ongoing or within 6 months) 1
o Paralysis, paresis, or recent immobilization of lower limbs 1
o Recently bedridden for 3+ days or major surgery within 12 weeks 1
o Localized tenderness along deep venous system 1
o Entire leg swollen 1
o Calf swelling > 3 cm compared to asymptomatic side 1
o Pitting edema confined to symptomatic leg 1
o Collateral superficial veins 1
o Previously documented DVT 1
o Alternative diagnosis as likely as DVT -2

17. Prophylaxis
 General measures
Adequate hydration, analgesia, and ambulation
Immobile patients-advised to use active flexion and extension of the
ankle joints and leg elevation-reduces stasis by enhancing venous flow
Early and progressive ambulation MUST be encouraged rather than
early angulation or having patients seated in a chair*

18. Mechanical Methods of DVT Prophylaxis
1.Elastic Compression Stockings (ECS):
Aspect Details
• Effect Reduces the diameter of veins, increasing venous blood flow velocity
• Optimal Pressure 18-23 mmHg at the ankle and 8 mmHg at the popliteal fossa
• Advantages
- Cost-effective
- Easy to use compared to IPC devices
- Can be combined with pharmacologic agents
• Limitations
- Lack of standardization of pressure levels
- Difficulty in application for patients with atypical leg shapes or sizes
• Contraindications
- Peripheral arterial disease with absent foot pulses
- ABPI < 0.8
- Severe leg edema due to heart failure
- Dermatitis or skin conditions
• Complications
Incorrect application can lead to the "garter effect," causing localized
constriction and swelling

19. 2.Intermittent Pneumatic Compression (IPC):
Aspect Details
• Effect
Uses sequential inflation to promote venous blood flow, starting
distally and progressing proximally
• Device Characteristics
Portable, effective during both preoperative and early
postoperative periods
• Advantages
- Improves venous hemodynamics
- Stimulates the body’s natural fibrinolytic activity
- Reduces the risk of postoperative DVT in major surgeries
• Limitations
- Requires proper fitting and adherence to protocols
- Certain patients may be contraindicated, especially if leg
mobility is limited due to casts or fixators
• Contraindications
- Skin infections and severe edema of the legs secondary to
congestive heart failure
- Acute DVT

20. Pharmacologic Methods
Class Anticoagulant Action Key Characteristics
1.Antiplatelet o Aspirin
 Inhibits platelet clotting
(thromboxane A2)
 Low doses (<100 mg)
2.Vitamin K Antagonist o Warfarin
 Inhibits clotting factors II,
VII, IX, X
 Slow onset (3-5 days),
requires INR monitoring
3 Heparin
o Unfractionated Heparin
(UFH)
 Inactivates thrombin and
factor Xa
 High molecular weight,
requires aPTT monitoring
o Low Molecular Weight
Heparin (LMWH)
 Inhibits factor Xa and
thrombin
 More predictable, no routine
monitoring needed
4.Synthetic Heparins o Fondaparinux  Inhibits factor Xa
 Synthetic, long half-life,
subcutaneous injection
5.Direct Oral Anticoagulants
(DOACs)
o Dabigatran  Inhibits thrombin
 Oral, no routine monitoring
needed
o Edoxaban  Inhibits factor Xa
 Oral, no routine monitoring
needed
o Apixaban  Inhibits factor Xa
 Oral, no routine monitoring
needed
o Rivaroxaban  Inhibits factor Xa
 Oral, no routine monitoring
needed

21. Management
• Medical management
Aspect Details
o Treatment Goal
Stabilize thrombus, prevent extension/embolization, support
natural fibrinolysis with anticoagulants
o Contraindications for Outpatient
Treatment of lower extremity DVT
- Active or high-risk bleeding
- Severe symptomatic venous obstruction
- Thrombocytopenia
- Poor hepatic function
- Unstable renal function
- Noncompliance
- Poor home environment
o Objectives of Treatment
- Immediate reduction of morbidity and mortality
- Reduction of long-term post-thrombotic morbidity

22. Anticoagulation
Initiation:
Initiate as soon as there is a high level of suspicion for DVT along
with a Well’s score of 2 or more with a positive D-dimer
Should not be delayed for confirmation with objective imaging

23.  Unfractionated Heparin
Aspect Details
• Bridge Therapy Used for 5-10 days to bridge oral anticoagulation with warfarin
• Dosing
- 80 units/kg IV bolus, then 18 units/kg/hr infusion
- 5000 units IV bolus, then 1300 units/hr infusion
- 250 units/kg SC, then 250 units/kg every 12 hours
• Monitoring Necessary to maintain the therapeutic range
• Therapeutic Range INR 1.5-2.5 times the control
• Drawbacks
- Requires hospitalization
- Frequent blood draws
- Variable responses
- Difficulty achieving therapeutic range
- Risk of life-threatening allergic reactions

24.  Low Molecular Weight Heparin (LMWH) and Parenteral Direct
Thrombin Inhibitors (DTIs)
Aspect
Low Molecular Weight Heparin
(LMWH)
Parenteral Direct Thrombin
Inhibitors (DTIs)
• Examples Enoxaparin, Tinzaparin, Dalteparin
Lepirudin, Argatroban,
Bivalirudin
• Advantages
- Better bioavailability
- More consistent response
- Predictable pharmacokinetics
- Direct thrombin inhibition,
blocks interaction with substrates
• Drawbacks
Not recommended for patients with
severe renal insufficiency
- Used in heparin-induced
thrombocytopenia (HIT), requires
careful monitoring
• Indication
Used for anticoagulation in DVT, PE,
and as bridge therapy
Used when HIT occurs, or in
other thrombotic conditions

25.  Vitamin K Antagonists (VKAs) and Direct-Acting Oral Anticoagulants
(DOACs)
Aspect Vitamin K Antagonists (VKAs)
Direct-Acting Oral Anticoagulants
(DOACs)
• Action
 Inhibit production of vitamin K-dependent
coagulation factors
- Rivaroxaban, Apixaban, Edoxaban
target Factor Xa
- Dabigatran targets thrombin
• Overlap with Parenteral
Anticoagulants
 Parenteral anticoagulants used for initial 4-5
days to prevent thrombus propagation
 Not applicable
• Monitoring
 Requires monitoring of INR (2.0-3.0 for VTE
treatment)
 No routine monitoring required,
simplifies therapy management
• Effect of Antibiotics
 Antibiotics that destroy gut flora may prolong
INR by reducing vitamin K availability
 No significant effect from
antibiotics
• Indication
 Standard treatment for VTE, needs bridging
therapy with parenteral anticoagulants
 Used for VTE treatment, with
Dabigatran being the only DTI
approved for VTE

26. Adjunctive Measures
1. Elevation of Legs: Reduces edema and pain
2. Bed rest is no longer recommended for patients with VTE
3. Structured Leg Exercise: May reduce post-thrombotic syndrome

27. Thrombolytic Therapy
Catheter-based procedures -replaced systemic thrombolysis as the preferred
method
Intrathrombus Catheter-directed Thrombolysis:
o Mechanism: Activation of fibrin-bound plasminogen and resultant
production of plasmin*
o Disadvantages:
Unacceptably long treatment times
Bleeding risk
High cost
ICU care
o Aspiration thrombectomy is an effective alternative technique

28. Operative Venous Thrombectomy
Steps:
1. Identify the cause of extensive venous thromboembolism
2. Define the full extent of the thrombus
3. Perform complete thrombectomy
o Iliofemoral venous thrombectomy
o Inferior vena cava thrombectomy if required
4. Prevent recurrent thrombosis with anticoagulation therapy

29. IVC filter
Indications for a vena cava filter
Recurrent thromboembolism despite adequate anticoagulation
Deep venous thrombosis in a patient with contraindications to anticoagulation
Chronic pulmonary embolism and resultant pulmonary hypertension
Complications of anticoagulation
Propagating iliofemoral venous thrombus in anticoagulation

30. Complications of DVT
 Recurrent thrombosis
 Post-thrombotic syndrome(PTS)
 Chronic venous insufficiency(CVI)
 Mortality-primarily related to pulmonary embolism

31. Post-Thrombotic Syndrome (PTS)
•Definition:
Signs and symptoms resulting from acute DVT
Consequence of venous hypertension from valve reflux or luminal
obstruction
•Etiology:
1. Ambulatory venous hypertension (AVH) -to elevated venous pressure
during exercise
2. Anatomic contributors include valvular incompetence and luminal
obstruction
3. Obstruction of the distal popliteal vein may cause significant PTS

32. Approach -Summary

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