Management of Deep Vein Thrombos in Total Joint Arthroplasty

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Management of Deep Vein Thrombos in Total Joint
Arthroplasty

• Total Hip and Knee Symposium
• Los Cabos, Mexico

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Frank R. Ebert, MDAssistant Chief
DepartmentofOrthopædics

• The Union Memorial Hospital
• Baltimore, Maryland

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Number of Orthopedic Replacement Procedures/Year

• Total knee replacements 267,000/year in
  the US
• Total hip replacements more than 168,000/y
  ear in the US

AAOS Website availiable at http//orthoinfo.aaos
.org/booklet/bookviacfm?Thread_ID2topcategorykn
ee http//orthoinfo.aaos.org/booklet/bookview.cfm
?Thread_ID2topcategoryhip
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The Cost of DVT

• Risk persists for a long time following surgery.
• 90 of medical re-admissions following TJR are
  due to DVT substantial direct inpatient costs
  related to DVT

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Venous ThromboembolismPathogenesis

• Venousthrombi
• Usually form in regions of sluggish or altered
  flow in large venous sinuses
• May break off, travel to lung PE
• Pathogenic factors
• Activation of blood coagulation
• Venous stasis
• Vascular injury

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Venous ThromboembolismNatural History

• Hip Procedures
• Have a higher frequency of proximal clots
• Knee Procedures
• Deep calf veins
• Usually asymptomatic
• Thrombi tend to be small
• Propagation is an issue

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Venous ThromboembolismNatural History (contd)

• Proximal vein thrombi
• Popliteal
• Superficial femoral
• Common femoral
• Iliac veins
• Spontaneous lysis of large thrombi uncommon
• Strong association between DVT and PE

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Venous ThromboembolismDiagnosis

• Clinical Exam 50/50
• Venous duplex ultrasound
• Venography

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Venous ThromboembolismDiagnosis (contd)

• Venous duplex ultrasound
• Noninvasive
• Assesses vein compressibility
• Very sensitive in proximal thrombi
• Less sensitive in distal

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Venous ThromboembolismDiagnosis (contd)

• Venography
• FDA standard for DVT
• Clinically outmoded

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Pulmonary EmbolismDiagnosis

• Screening
• V/Q scan
• Effective non-invasive technique
• Probability of PE based on degree of mismatch
  between ventilation and perfusion

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Pulmonary EmbolismDiagnosis (contd)

• Definitive test
• Pulmonary angiogram
• Spiral CT

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Venous ThromboembolismPrognosis

• Proximal DVT postoperative, good, if treated
  for 3 months with anticoagulant therapy
• Recurrent events 5
• After discontinuation of anticoagulant therapy
• 5 to 10 after 1 year
• Approximately 30 after 8 years

Hirsh J, Hoak J. Circulation. 1996932213.
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Clinical Risk Factors for DVT

• Major surgery (eg, total joint arthroplasty)
• History of DVT
• Age 40
• Obesity
• Prolonged immobility
• Genetic predisposition to hematologic
  abnormalities
• Trauma
• Other malignancy, coronary syndromes (eg,
  unstable angina)

Anderson FA Jr, Wheeler HB. Clin Chest Med.
199516236.
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Hip Fracture, Hip Arthroplasty, Knee
Arthroplasty, and VTE Risk (Upper Limits) in
Patients without Anticoagulative Prophylaxis
100
Hip arthroplasty
90
84
80
Knee arthroplasty
70
60
Hip fracture surgery
57
60
of patients
50
40
36
36
30
20
20
12.9
0.7
10
0.4
0
All DVT
Proximal DVT
Fatal PE

• DVT prevalence statistics obtained by use of
  mandatory postoperative venography.
• Represents the upper limit of prevalence
  statistics for each procedure.
• Geerts WH, et al. Chest. 2001119(suppl)140S.

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Patients Not Receiving Anticoagulation
Prophylaxis Summary

• Orthopedic surgery creates the ideal conditions
  for the development of DVT
• Vascular damage
• Venous stasis
• Hypercoagulability
• 50 of patients undergoing orthopedic surgery
  will develop DVT
• Most frequently utilized agents all demonstrate
  superiority compared with placebo

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Current Strategies for DVT Prophylaxis

• Mechanical prophylaxis
• Pharmacologic anticoagulant therapy
• Combination therapy
• Regional anesthesia

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Current StrategiesMechanical Prophylaxis

• Intermittent pneumatic compression (IPC)
• Pneumatic plantar compression (foot pump)
• Literature supports use Sarmiento JBJS 1999
• Ineffective when BMI gt 25 kg/m2

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Current StrategiesMechanical Prophylaxis
(contd)

• Advantages
• Local antistasis effects
• Systemic humeral effects
• No increase in bleeding risk
• Disadvantages
• Patient intolerance
• Compliance difficulties
• Impractical post-hospital discharge application
• Less effective when BMI gt25

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Current StrategiesAnticoagulant Therapy and
Indications

• Oral agents
• Warfarin (dose-adjusted to INR 2.03.0)
• Prophylaxis of venous thrombosis and its
  extension, and pulmonary embolism
• Aspirin
• May be effective when combined with mechanical
  agents Sarmiento JBJS 1999

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Current StrategiesAnticoagulant Therapy and
Indications

• Injectable/parenteral
• Dose-adjusted unfractionated heparin (UFH)
• Prophylaxis of venous thrombosis and its
  extension
• Low-molecular-weight heparins (LMWH)
• Dalteparin total hip replacement
• Enoxaparin total hip replacement, total knee
  replacement

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Current StrategiesOral Anticoagulant Therapy

• Warfarin
• Reduces DVT and symptomatic PE rate
• Lieberman, et al. JBJS 1997
• In combination with mechanical agents, has a
  reduction in total DVT rate
• Freedman, et al. JBJS 2000

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Current StrategiesOral Anticoagulant Therapy

• LMWHs
• Fractionated Heparin 1/3 molecular weight of
  standard Heparin inhibits Clotting Factor 10
• Binds less to plasma protein, increases
  bioavailability of the LMWHs

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Current StrategiesOral Anticoagulant Therapy

• LMWHs
• Enoxaparin
• Dosage - 30mg SC twice daily
• Treatment begun within 24hrs after THA
• Significant lowering DVT/PE rate comparable to
  Warfarin
• Colwell, et al. JBJS 1994

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Current StrategiesOral Anticoagulant Therapy

• LMWHs
• Enoxaparin
• In TKA may be superior to Warfarin in reducing
  DVT rate.
• Heit, et al. Thromb Haemost. 1997

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Current StrategiesOral Anticoagulant Therapy

• LMWHs
• Dalteparin
• Dosage 2500 IU SC 4hrs post surgery followed by
  5000 IU SC daily
• Dalteparin proved effective in the reduction of
  total DVT and symptomatic PE when compared to
  Heparin
• Hull, et al. Arch Intern Med. 2000

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ANTI-COAGULANT THERAPY LMWHs

• Organon-Highly selective inhibitor for factor X
• FDA approved for Hip Fracture, THA, TKA

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Current StrategiesParenteral Anticoagulant
Therapy

• Disadvantages
• LMWH
• SQ route
• Bleeding risks
• Must initiate at least 12 hrs post surgery
• Contraindicated in regional anesthesia - FDA

• Advantages
• Rapid onset
• No monitoring (LMWH)
• Superior efficacy (LMWH)

Hirsh J, Hoak J. Circulation. 1996932212-2245.
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Current StrategiesAnticoagulant Therapy

• Duration of Prophylactic Treatment
• Clinical trials supports usage of prophylaxis
• Period of hospitalization 4-15 days
• Post-hospitalization (meta-analysis review)
  19-28 days
• Hull, et al. Ann Intern Med. 2001

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Current StrategiesAnticoagulant Therapy

• Indications for Greenfield Filter Placement
• Recurrent history of pulmonary emboli
• Unable to use anticoagulant therapy in the
  presence of a DVT
• Presence of pulmonary emboli despite
  anticoagulation therapy

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ACCP 2001 Recommendations Based on 7 to 10 Days
Treatment
Hip Knee Hip Replacement Replacement
Fracture Stockings Adjuvant Intermittent
Adjuvant Yes Adjuvant pneumatic Grade 2C
Grade 1B compression Aspirin Adjusted
-dose Yes unfractionated Grade
2A heparin Warfarin Yes Yes Yes INR
2-3 INR 2-3 INR 2-3 Grade 1A Grade 1A Grade
1B LMWH Yes Yes Yes Grade 1A Grade 1A
Grade 1B
Geerts WH, et al. Chest. 2001119(suppl)157S.
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SUMMARY

• Treatment of DVT is required following THA,
  TKA,and Hip Fracture
• Aspirin has literature support clearly for THA
• Warfarin and LMWH clearly show effectivenss for
  THA,TKA,and Hip Fracture
• Post discharge usage should be for up to 35 days
  post op

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Summary

• TJA places patients at risk for VTE
• Thromboprophylaxis the standard of care
  following TJA due to high rates of VTE without
  prophylaxis
• Significant variation in prescribing practices
• There are no data for efficacy of combined
  mechanical/pharmacologic treatments
• Novel thromboprophylactic agents potentially may
  improve risk/benefit ratio

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THANK-YOU