D DEEP VEIN THROMBOSIS(DVT) VENOUS THROMBOEMBOLISM(VTE) Dr

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DDEEP VEIN THROMBOSIS(DVT)VENOUS
THROMBOEMBOLISM(VTE) Dr. NAIR G.R
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DVT VTE

• Importance.
• Short term Embolism- sudden death
• Long term morbidity CVD PAH

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Clinical features

• Subclinical (up to 30)
• Symptomatic DVT
• PE
• Recurrent PE PAH
• CVD

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Clinical features

• Normally starts in CALF VEINS
• 10-20 extend proximally
• 1-5 fatal PE
• In half no predisposing factors

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Epidemiology

• More common in developed countries !
• 30 go undetected
• USA UK Hospital deaths due to PE
• 3 of Surgical 10 of all

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Pathophysiology

• Virchows triad
• Stasis (decreased blood flow)
• Hypercoagulability(thrombophelia)
• Intimal damage
• Thrombophelia most important
• arm of triad
  

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Natural antithrombotic mechanisms

• Prostacyclinnitric oxidefibrinolytic system-
• (tissue plasminogen activator TPA )
  
• Cell surface glycosaminoglycans(heparin
• 
  sulphate)
• Physiological inhibitors of clotting
• ( antithrombin protein C protein S )

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Intimal damage

• Endothelial damage - Direct
• Indirect
• 
  -stasis-hypoxia
• Plasminogen activatorlt-gtPlaminogen-
• (both produced by activator-
• endothelium)
  inhibitor-1
• Trauma major surgery -gttemporary
• increase in PAI-1(acute phase
  reaction)
• lasting for first 7-10 days

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Patho contdThrombophelia

• Inherited Thrombophelia
• Acquired Thrombophelia

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Thrombophilia

• _at_ Inherited
• Antithrombin III, protein C, protein S,
• deficiency
• protein C resistance
• Prothrombin 20210 A mutation
• Lupes anticoagulant antibody
• factor V Leiden gene defect
• Dysfibrinogenaemias
• _at_ Acquired
• Antiphospholipid antibodyMalignancy
• Oral contraceptive pills HIT

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Other common risk factors

• Other risk factors

Long haul air travel
Immobility Medical SurgicalTrauma
e-Thrombosis ( ethrombosis )
SepsisPregnancyobesityIncreasi
ng Age Heart
disease ( MICHFLow flow state)
Polycythemia (MPD) TTP

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Incidence

• Increases exponentially with age
• Sex
• Idiopathic VTE - 25 to 50
• Thrombophelia 50 to 75

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Clinical featuresLocal symptoms

• Pain DD
• Mild fever Ruptured Bakers
  cyst
• Swelling/edema(gt3 cm) Infective cellulitis
• Erythema Torn calf
  muscle/Hge
• Tenderness
• Dilated superficial veins
• Homans sign non specific dislodge clot

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Clinical features

• 
  points
• Tenderness- entire deep vesystem 1
• Swelling of entire leg
  1
• Calf circumference gt 3 cm 1
• Pitting edema
  1
• collateral superficial veins
  1
• Risk factors
• Active cancer
  1
• Immobility/paralysis
  1
• Recent surgery/major illness
  1
• Alternate diagnosis- ?
  - 2

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Clinical features

• Modified pretest probability for DVT
• Clinical features (one point each)
• Risk factors (one point each)
• Alternate diagnosis present(2 neg poi)
• Score gt 3 high probability
• 1-2 Moderate pro
• 0 Low pro
• Objective diagnosis - important

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Risk

• post OP DVT-50 start intraoperatively
• 50 resolve spontaneously within 72 hrs
• Risk of VTE highest within 2 wks of surg
• Risk can be maintained for up to 2-3 mon
• 10 of symptomatic PE die within the First hr
• PAH develop in 5 of survivors
• 2/3 of DVT ambulatory venous hypert
• Up to 50 post-phlebitic skin changes
• Ulceration in 5 of cases

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Objective tests

• Compression Ultrasonography.
• The non invasive test of choice
• Above knee- Sen spe gt 95
• Calf 70
• Pelvic vein less
  accurate
• Suspected DVT neg US in untreated pts
• repeat US in a wk time if neg-chance of proximal
• ext/or subsequent dvt risk lt2

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Objective test -contd

• Gold standard test Venography
• Newer imaging techniques.
• MRV pelvic veins
• Spiral CT SVC,IVC,PE
• Impedance plethysmography/Isotope-
• labelled fibrinogen scan.

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Blood test

• D dimer (gt500ug/l)-surrogate marker
• sensitivity
  98
• specificity
  39
• positive predictive value 44
• NEGATIVE predictive value 98
• P selectin to measure platelet
• activation gt
  4.3
• sensitivity
  74
• specificity
  94

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Pulmonary Embolism ( PE )Clinical features

• Breathlessness
• Haemoptysis
• Pleuritic pain
• Shock
• Clinical probability score can predict PE
• 6 high 2-6mode lt1.5low

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PE

• Gold standard testpulmonary Angiograph
• invasive
• 0.5
  mortality
• VQ Scan-technetium 99m-microspheres
• more widely
  used
• non specific
• diagnostic only
  in 30
• Spiral CT more reliable
• limited to
  embol. in large
• vessels
• D-dimer US helpful

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Thromboembolic stratification for surgery patients

• Low risk agelt40 with no immobility,no
• risk factor,uncomplicated surg
• Moderate risk age 40-60 with any surg
• age lt40 with major
  surg
• age any with 1or more
• risk factors
• High risk Major surgery
• agegt60
• age 40-60 with 1or more
  risk fa
• 
  
  

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Prevention strategies

• Pharmacological lt--gt Physical
• methods
  
• Pharmacological - drugs
• UFH
• LMWH
• Oral anticoagulants(coumarins)
• Dirict Thrombin inhibitors(hirudin)
• Factor Xa-inhibitors(fondaparinux)

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Prevention contd

• Physical methods
• Graduated compression stockings
• (simple safe moderately effective)
• (18 mm-ankle 14 at calf 8 at knee)
• Intermittent pneumatic compression
• (35-40 mm hg uniform for 10
  seconds
• 
  every minute
• (adding venous return enhance
  fibrinolytic activity)
• Early mobilization

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Antithrombotic prophylaxis

• _at_ GENERAL SURGERY
• Low risk early mobilization
• Moderate risk UFH 5000 iu 12 hourly or
• LMWH 3400 iu OD
  or
• compression stockings
  or
• pneumatic compression
• High risk Like above except dose of
• LMWH isgt3500 iu od
• Very high risk similar to above or peri ope-
• rative warfarin (INR
  2-3)

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Prophylaxis contd

• _at_ MAJOR ORTHOPAEDIC SURGERY
• Elective hip replacement
• Recombinant hirudin 15mgbd
• Fondaparinux 2.5mg bd
• LMWH gt3400 u od
• Perioperative warfarin(INR 2-3)
• Elective Knee replacement similar
• Surgery for hip - similar
• Hirudin/Fondaparinux superior to LMWH/UFH

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Prophylaxis (contd)

• _at_ Elective neurosurgery
• Intermittent pneumatic compression
• prophylaxis of choice
• Of LMWH only Enoxaparin is recomm-
• ended (30 mg
  bd)

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Prophylaxis contd

• _at_ TRAUMA
• Enoxaparin 30 mg bd
• IVC filter if anticoagulation contraindicated
• _at_ MEDICAL CONDITIONS
• CHF LMWH / UFH
• Stroke LMWH superior to UFH
• Acute MI -?
• High risk patients with contraindication to
• 
  Anticoagulation
• IVC Filter (caution-increased chance
  for recurrent
• 
  DVT)

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LMWH

• Dalteparin
• Enoxaparin
• Nadroparin
• Tinzaparin

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Management of calf DVT

• Clinical Diagnosis ?Interium trt-?Investigations
• Positive -? continue trt
• Negative ? stop trt consider other causes
• Duration of treatment
• Heparin 5 -7 days( HITOsteoporosis)
• Warfarin 3-6 months
• If HIT present DanaparoidLeperudin
• 
  ArgatrobanFondopainux

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Calf vein DVT

• Duration of treatment
• 3 -6 months First event with reversible or
• time limited risk
  factor.
• gt 6 months Idiopathic VTE(first event)
• 1 yr to life First event with
• Cancer
• 
  Anticardiolipin antibody
• Antithrombin
  deficiency
• Recurrent event (all
  types)
• Continued treatment-prevents recurrence but
• 
  increases bleeding

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Thrombolytic therapy

• Thrombolytic agents
• Stretokinese
• Urokinese
• rTPA (Actilyse )
• They all lyse Thrombus( unlike heparin
• and
  warfarin )

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NON DRUG treatment

• Physically preventing embolism
• IVC Filter-Permanent or removable(4-6wks)
• Extraction of thrombus from
• - pulmonary artery
• - Ilio femoral vein ( Phlegmasia )

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IVC Filter

• Indications
• Proximal DVT with contraindication to
• anticoagulant
• Recurrent VTE in spite of adequate
• anticoagulation
• Chronic recurrent VTE with PH
• Simultaneous Pulmonary embolectomy or
• 
  endarterectomy

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IVC Filter

• Randomised trial Reduction in PE.
• no improvement in short or long term
• 
  survival
• Leads to recurrent DVT almost doubling
• the risk in patients with filter.

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VTE

• Treatment strategies
• Similar drugs and physical methods

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Surgery

• Pulmonary embolectomy
• Massive PE with cardiac output
• compromise-failed thrombolysis or
• thrombolysis contraindicated
• Catheter transvenous extraction ( Experienced
• surgical team for pulembolectomy-
  abscent.)

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Special situations- PREGNENCY

• UFH LMWH Safe during pregnancy
• do not cross
  placenta
• ORAL anticoagulants
• Fetal bleeding
• Teratogenicity
• SC heparin until delivery
• Warfarin after delivery
• ( Breast feeding ?warfarin secreted in
  milk ?)

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Patients at high risk of bleeding with Warfarin

• Age gt75
• H/O uncontrolled hypertension(sy bpgt180
• di bp gt100)
• Alcohol excess-acute or chronicliver
• 
  disease
• Poor drug compliance or clinc attendance
• Bleeding lesions(GI-peptic ulcercerebral
• 
  hemorrhage
• Bleeding tendencyNSAID
• Instability of INR control and INR gt 3

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Reasons for increased sensitivity to
anticoagulation.

• Lower body weight
• Differences in pharmacokinetics-reduced
• drug
  clearance
• Changes in receptor sensitivity
• Lower dietary intake of vit K-more
• important
  cause

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Areas of uncertainty

• Role o f reduced intencity anticoagulation
• ( INR 1.5
  1.9 )
• Newer anticoagulants
• Parenteral synthetic pentasacharide
• analogues(anti Xa)-
  Fondaparinux
• -
  Idraparinux.
• Oral direct thrombin inhibitors-
• 
  Ximelagatran
• Testing for thrombophelia no unequivocal
• indications in patients or their relatives
• Prevention of POST-THROMBOTIC syndrome
• Graduated stockings ?- role remains
  uncertain
• Thrombolytic therapy has a potential

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Guidelines for treatment of
DVTAmerican college of chest
physiciansAmerican heart association