1. DEEP VENOUS THROMBOSIS

2. Definition
formation of a blood clot in one of the deep veins of the body, usually in the leg

3. Anatomy

4. Etiology and risk factors
3 main factors contribute in development of DVT
Stasis
Endothelial injury
Hypercoagulability

5. 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

6. 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
all stages of pregnancy
the first three months postpartum,
after elective abortion, and
during treatment with oral contraceptive pills

7. Inherited disorders of coagulation
deficiencies of protein ‘S’,
protein ‘C’ and
antithrombin III.

8. 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.

9. Inflammatory processes, such as systemic lupus erythematosus (SLE),
sickle cell disease, and
inflammatory bowel disease (IBD),
also predispose to thrombosis, presumably due to hypercoagulability

10. AND THESE TWO UPPER CASES ARE LIMB THREATENING CONDITION!!
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!!

11. Phlegmasia cerulea dolens Venous gangrene

12. 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)

13. 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)

14. 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 D-dimer
ELISA
latex agglutination
blood agglutination test - SimpliRED

15. 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

16. Imaging Studies Invasive venography, radiolabeled fibrinogen
Noninvasive
ultrasound,
plethysmography,
MRI techniques

17. 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.

18. 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.

19. Venogram shows DVT

20. Ultrasonography
color-flow Duplex scanning is the imaging test of choice for patients with suspected DVT
inexpensive,
noninvasive,
widely available
Ultrasound can also distinguish other causes of leg swelling, such as tumor, popliteal cyst, abscess, aneurysm, or hematoma.     

21. clinical limitations reader dependent
Duplex scans are less likely to detect non-occluding 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

22. 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

23. Color duplex scan of DVT

24. The only disadvantage of duplex study is that, it is highly operator dependant!!!

25. 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.

26. 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.

27. Complication of DVT Recurrent DVT Varicose vein
Chronic venous insufficiency
Post phlebitic syndrome (pain, oedema and ulceration) PE

28. + warfarin Low clinical probability High clinical probability
Patient with suspect symptomatic
Acute lower extremity DVT
negative
Venous duplex scan
Low clinical probability
observe
positive
High clinical probability
negative
Evaluate coagulogram /thrombophilia/ malignancy
Repeat scan /
Venography
Anticoagulant therapy
contraindication
yes
IVC filter No
pregnancy
LMWH
OPD
LMWH
+ warfarin
hospitalisation
UFH
Compression treatment

29. Management The aim of management is: Prophylaxis against DVT
Treatment of ongoing DVT

30. Methods of Prophylaxis:
1) Mechanical
Leg elevation
Graded compression stocking
Early ambulation
Pneumatic compression boo.

31. 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.

32. Warfarine (coumadine):-
Decrease incidence of DVT by 66% and PE by 80%.
Disadvantages:
Sever hemorrhage
Must be started 2-3 days preoperative.
Require careful monitoring for PT.

33. Warfarine nomograph

34. 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

35. 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.

37. Heparin nomograph

38. 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.

39. 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).

40. 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.

41. Treatment of DVT
A: - anticoagulation
Heparin bolus 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

42. 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)

43. C:-venal cava interruption (IVC filter)
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.

44. 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.

45. Thrombolytic therapy does not prevent
clot propagation,
rethrombosis, or
subsequent embolization.
Heparin therapy and oral anticoagulant
therapy always must follow a course of
thrombolysis.

46. 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.

47. Catheter directed-thrombolysis
Consider in: Acute< 10 days iliofemoral DVT.
Long-term benefit in preventing post-phlebitic syndrome is unknown.

48. Filters for DVT Indications for insertion of an inferior
vena cava filter :
Pulmonary embolism with contraindication to anticoagulation
Recurrent pulmonary embolism despite adequate anticoagulation

49. Filters for DVT Controversial indications:
Deep vein thrombosis with contraindication to anticoagulation
Deep vein thrombosis in patients with pre-existing pulmonary hypertension
Free floating thrombus in proximal vein
Failure of existing filter device
Post pulmonary embolectomy

50. 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.

52. 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.

53. These pulmonary emboli removed at autopsy look like casts of the deep veins of the leg where they originated.

54. This patient underwent a thrombectomy
This patient underwent a thrombectomy. The thrombus has been laid over the approximate location in the leg veins where it developed.

55. Prognosis:
All patients with proximal vein DVT are at long-term 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

56. thank you