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Deep vein thrombosis

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Deep Vein Thrombosis
Deep Vein Thrombosis
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Deep vein thrombosis

  1. 1. VENOUS THROMBOEMBOLISM Composite term for DVT &PE  The presence of thrombus with in deep veins is termed as deep vein thrombosis  It is a life threatening condition that may lead to sudden death in the short term or long term morbidity due to the development of post thrombotic limb and venous ulceration
  2. 2.  1846 virchow recognised association of thrombus in leg and PE.  1916 J McLean ,a medical student discovered heparin  1937 Heparin introduced to clinical practice.  Last 25 years significant progress made in our understanding of DVT.
  3. 3.  CLASSIFICATION : PROXIMAL DVT :thrombus formed in veins above the knee jt (femoral, iliac, popliteal) DISTAL DVT : those formed below the knee jt (calf veins)
  4. 4. Venous thrombosis are difficult to recognize clinically. The documented cases probably represent only tip of the Ice Berg. SILENT KILLER
  5. 5.  M:F 1.2:1  Age more than 40 years.  VT occur in more than 50% of patient’s having orthopaedic surgical procedures.  10 to 20% of patient with idiopathic DVT have or develop cancer.  1/3rd to 1/4th patient having proximal DVT may develop PE.  About 10% of hospital deaths attributable to PE (from DVT)
  6. 6.  Calf vein - most common  Ilio femoral - most symtomatic  IVC - most lethal
  7. 7.  Blood clots occurring in people sitting at the computer for prolonged periods of time. AIR TRAVEL AND DVT  Up to 1 out of 10 air line passengers develop small asymptomatic blood clots.  Due to hypoxia and reduced cabin pressure.  VT occurs in patients regularly without any damaged to the blood vessels.
  8. 8. VTE Risk Stratification Patient Factors: Clinical  Age  Previous VTE  Malignancy  Advancing age  Obesity  Prolonged immobility  Trauma  Surgery (THR, TKR, HFS)  Pregnancy/ postpartum  Indwelling central venous catheter  Thrombophilia  Deficiency of anti-thrombin III Protein C or S Contd...
  9. 9.  Paralysis of lower limbs  Polycythaemia  Paraproteinaemia  PNH Antibody or lupus anticoagulant  Medical illness ◦ stroke ◦ MI ◦ CHF ◦ pneumonia ◦ COPD ◦ infections ◦ nephrotic syndrome ◦ inflammatory bowel disease  Oral contraceptives  Varicose veins
  10. 10.  Pregnancy and postpartum period.  Immoblisation longer than 3 days  Major surgery in previous 4weeks  Long air or car trips >4hrs in previous 4 weeks
  11. 11.  Predisposing Factors : 1. Stasis 2. Vascular damage 3. Hyper coagulability  Imbalance between thrombogenesis & thrombolytic agents
  12. 12. 1. Propagation 2. Embolization 3. Dissolution 4. Organization & recanalisation  ORGIN DVT usually originates from veins of calf around the valve cusps or with in soleal plexus  A minority of cases occurs directly in ilio femoral veins
  13. 13.  In practical terms the development of VT is best understood as activation of coagulation in areas of reduced blood flow.  Majority of calf vein thrombus dissolve completely.  Only 20% progress proximally.  Propagation occurs before embolisation.
  14. 14.  The process of adherence and organisation of venous thrombus does not begin until 5 to 10 days after thrombus formation.  This non adherent thrombus may propagate or embolise.  Propagation or organisation of venous thrombus  destruction of valves & varying degree of venous outflow obstruction  chronic venous insufficiency.
  15. 15. 1. Fatal PE 2. Non-fatal PE 3. Post-thrombotic syndrome  Rate of fatal PE in gen population >65yrs is . 003%  In ortho pts (THR,TKR) it is 0.3%  10 fold increase in risk of having fatal PE
  16. 16.  Consequence of recanalisation of major venous thrombus  Due to incompetence of valves  Long term morbidity  Causes chronic edema &venous ulcers
  17. 17.  Swelling/edema most specific sign unilateral  Leg pain (50%) non specific  Redness/erythema over the thrombus  Tenderness(75%) calf or along the involved veins does not correlate size, site, extent  Low grade pyrexia  Signs and symptoms of PE 
  18. 18.  Pain or discomfort in leg on forceful dorsiflexion of foot with knee straight  Time honoured sign  Present only in 10% of confirmed DVT  Highly non-specific  Present in 50%of cases with out DVT  Misleading sign  No longer used
  19. 19.  Pts with superficial thrombophlebitis with out coexisting varicose veins & with no other etiology (IV Catheter) are at high risk of having DVT (40%)  Pts with ST extending to sapheno-femoral jn are at high risk of associated DVT
  20. 20.  Painful blue inflammation PHLEGMASIA ALBA DOLENS  Painful white inflammation  Massive IVF thrombus with arterial spasm
  21. 21. In approximately 70% of patients with clinically suspected DVT, alternate diagnoses are ultimately found as follows: Arthritis Cellulitis, lymphangitis Hematoma Lymphedema Muscle or soft tissue injury Neurogenic pain Postphlebitic syndrome Prolonged immobilization or limb paralysis Ruptured Baker cyst Stress fractures or other bony lesions Superficial thrombophlebitis Varicose veins
  22. 22. D-DIMER STUDY  D-dimer fibrin fragments are present in fresh fibrin clots and fibrin dehydration products of cross linked fibrin.  Monoclonal antibodies specific to D-dimer fragment are used to differentiate fibrin specific clots from noncrosslinked fibrin and from fibrinogen. These specific attributes of the D-dimer antibodies account for their high sensitivity for venous thromboembolism.  Elevated in any medical condition where clots form.  Rised in trauma, recent surgery, haemorrhage, cancer and sepsis.  It has high sensitivity and low specificity for VTE.  Levels elevated in DVT for seven days.  After clot organisation and adherence the levels decrease.
  23. 23.  Current evidence strongly supports the use of a D- dimer assay in the clinical algorithm of suspected DVT. A negative D-dimer assay R/O DVT in patients with low-to-moderate risk (Wells DVT score <2). All patients with positive D-dimer assay and all patient with a moderate-to-high risk of DVT ( Wells DVT score >=2) require a diagnostic study.
  24. 24.  Protein S, protein C, anticromin III, factor V Leyden, prothrombin 20210A mutation, antiphospholipid antibodies and homocysteine levels can be measured.  investigations for these abnormalities are primarily indicated when DVT is diagnosed in patients younger that 35 years or when venous thrombosis is detected in unusual sites.
  25. 25. CONTRAST VENOGRAPHY  Gold standard for DVT.  Used when other test are inconclusive.  It is either contra indicated or non diagnostic in as many as 20-25% of patients.  Drawbacks : Allergic reactions, contrast induced DVT, technical problems, inter observer variability and lack of availability.  It is replaced by non invasive studies as initial diagnostic test.
  26. 26.  Combination of real – time ultrasonographic imaging with Doppler flow studies.  Sensitivity for proximal DVT is 97% for calf veins is 73%.  Overall specificity is 95%.  Helpful to differentiate from haematoma, baker cyst, abscess and other causes of leg pain and edema.
  27. 27.  Primary disadvantage : Inherent inaccuracy in diagnosis of calf vein thrombosis. Those proximal to the inguinal ligament are also difficult to visualize. Non occluding thrombi may be difficult to detect. Not able to differentiate to old and new clots in patients with acute recurrent DVT. Depends on experience of radiologist
  28. 28.  Based on recording changes in blood volume of an extremity, which are directly related to venous outflow.  Sensitive and specific for proximal vein thrombosis.  Cannot differentiate between thrombotic occlusion and extra vascular compression of the vein.  Insensitive for calf vein thrombosis, non-occluding proximal DVT and ileofemoral DVT.
  29. 29.  Increasingly used.  Accuracy approaches to that of contrast venograghy.  Diagnostic test of choice for suspected iliac vein & IVC thrombosis.  2nd &3rd trimester of pregnancy (gravid uterus alters doppler flow characteristics).  In suspected calf vein thrombosis it is more sensitive than other non invasive study.  Expense, lack of general availability and technical issues limit its use.
  30. 30.  Used for pelvis vein thrombosis. NUCLEAR MEDICINE IMAGING STUDIES  I125 labeled fibrinogen.  Takes longer than 24 hrs.  No longer used.
  31. 31. PRIMARY OBJECTIVES 1. To prevent PE. 2. Reduce morbidity. 3. Prevent or minimize risk of developing the postphletic syndrome. SURGICAL TREATMENT 1. Indicated when anticoagulant therapy is ineffective, unsafe or contraindicated. 2. Major surgical procedures : clot removal and partial interruption of IVC to prevent PE.
  32. 32.  To restore venous patency and valvular function.  Alone it is not indicated because rethrombosis is frequent.  Heparin therapy is a necessary adjunct.  Best reserved for patients with massive IF vein thrombosis when limb viability is at risk. FILTERS FOR DVT  First suggested by Trousseau in 1868.  Today introducing intracaval devices percutaneosly and floating them into position with fluoroscopy is the procedure of choice for filter placement.
  33. 33.  Severe hemorrhage complications of anticoagulant therapy.  Absolute contra indications to anticoagulation.  Failure of anticoagulation such us new or recurrent VTE or PE.
  34. 34.  Bed rest  Affected limb is elevated above the level of heart.  Anticoagulant prevent thrombus propagation and allow the endogenous lytic system to operate  Pain relief.
  35. 35.  Initial bolus 7500 to 10000 IU followed by continuous in infusion to 1000 to 1500 IU/hr.  Infusion rate adjusted so that aPTT is approx twice the control value  Every 6 hrs aPTT monitered till therapeutic range is reached  Duration :5 days  Discontinue when platelet count <75,000
  36. 36.  Effective and better than conventional heparin.  Different preparations available.  Administered SC in fixed doses once or twice daily.  Duration -7 to 14 days  Anticoagulant effect by inhibiting the activated factor X.  Hemorrhagic complications doesn’t occur
  37. 37.  LMWHs are individual, distinct compounds that exhibit unique physical, pharmacokinetic and pharmacodynamic profiles  LMWHs exhibit distinct non-antithrombin III- mediated effects, including unique tissue factor pathway inhibition and von Willebrand factor release profiles.
  38. 38.  Currently four LMWH are available. Enoxaparin Tinazaparin Dalteparin Nadroparin  Only enoxaparin and tinazaparin are approved by FDA for DVT prophylaxis.
  39. 39.  To be taken along with heparin for initial 4 to5 days.  Dose adj to maintain prothrombin time at INR 2.0 to3.0  Continued for 3 to6 months for pts with acute idiopathic DVT  For recurrent DVT/PE low intensity warfarin continued indefinitely maintaining INR 1.5 to2.0
  40. 40.  Early administration a) Prompt resolution of symptoms b) Accelerate clot lysis c) Preserve venous valves d) Decrease the potential for developing post- phlebitic syndrome
  41. 41.  Does not prevent clot propagation or rethrombosis.  Heparin and oral anti coagulant therapy must follow a course of thrombolysis.  Haemorraghic complications reduced by regionally administering with flouroscopic control.  Streptokinase,urokinase,tPA (alteplase)
  42. 42.  Lepirudin or aragatroban  Used when heparin is contra indicated due to HIT(heparin induced thombocytopenia)
  43. 43.  LOW RISK: young pts ,minor illness, surgery lasting <30 mt with no risk factors  MODERATE RISK: >40yrs with deblitating illness undergoing major surgery but no risk factors  HIGH RISK: >40 yrs with serious medical condition undergoing major surgery with additional risk factors
  44. 44.  YES - Overall reduction in DVT and PE is by 40% to 60%
  45. 45.  Three pronged approach  Designed to address stasis & coagulation  Usually combination of therapies I. EARLY MOVT & REHABLITATION II. MECHANICAL METHODS lower extremity exercises graded compression stockings
  46. 46. intermittent pneumatic compression devices CPM III PHARMACOLOGICAL PROPHYLAXIS a) ASPIRIN easy to administer low cost few bleeding complications
  47. 47.  Most commonly used  Takes 36 hrs to start action  Started day before surgery  Low doses are used LOW MOLECULAR WT HEPARIN  More effective than conventional  Lesser bleeding
  48. 48.  Low molecular wt heparinoid  For pts with HIT Fondaparinux  Synthetic pentasaccharide
  49. 49.  Graduated compression stockings  Exercise  Avoid alcohol &sleeping tablets HIGH RISK PATIENTS  LMWH ,single dose SC before the flight
  50. 50.  PAGET VON SCHROTTER DISEASE  Axillary and sub clavian vein thrombosis  Reduced incidence  Thoracic outlet synd &cervical ribs  Thrombolytic therapy is treatment of choice  Since restoring venous patency more important in upper limb
  51. 51.  Early - Progression Pulmonary embolism Paradoxical embolism Acute compartment syndrome venous gangrene  Late - Rec DVT, Post phlebitic syndrome
  52. 52.  Special group of pts  very high risk for DVT & may reach up to 60 to 80% with out prophylaxis (THR)  Assymptomatic DVT common in >50% of all patients  PE develop in 10 to 20 %of pts  Even with prophylaxis DVT & PE remains the most common cause for emergency readmission and death in joint replacement pts
  53. 53.  •Pre-op Immobilization (stasis) •Trigger of tissue factor reamed products (THR) tissue debris ,fat  activation of coagulation • Distortion of Femoral and Poplietal viens retraction,twisting,manipulation – damage to vessel wall •Prolonged post-op Immobilization.
  54. 54.  THR, TKR  Hip fracture surgery  Spine surgery [ malignancy, neurological deficit]
  55. 55.  Although thromboprophylaxis is routinely given to patients who undergo major orthopedic surgery, it is usually stopped at discharge.  Coagulation cascade remains abnormal upto 4 weeks.  Risk of propagation of the DVT, and PE, remains active during this period.  Patients undergoing THA TKA or HFS receive Thromboprophylaxis with LMWH Fondaparinux or VKA for a minimum of ten days. [can be cont. for 4 – 5 wks]
  56. 56.  Not an uncommon condition in clinical practice  DVT OCCURS ONLY IN POST-OP PATIENTS’ IS A MYTH  Awareness is most important for early diagnosis  Prompt treatment can prevent lethal complications  Diagnosis can be made using noninvasive methods  Long term follow up is necessary to identify patients who develop chronic venous insufficiency.

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