Thromboprophylaxis

VTE is a common cause of morbidity and mortality in the surgical population.

Risk Assessment

  • Patients should be risk stratified so VTE prevention methods are used appropriately

Must factor in:

  • Risk of thrombosis versus risk of bleeding
  • Surgical factors
    Major determinant.
  • Patient factors

Thrombosis Risk Prediction

  • This is light on detail because:
    • Although prediction models exist (e.g. CAPRINI), the model is complex and has limited validation which has limited its uptake and use
    • Centres will have their own policy that should be followed
    • Treatment options are limited and most patients will be at least moderate risk, so detailed risk stratification does not usually refine management
  • The below thresholds just cover surgical risk factors, and so give a minimum risk level for any procedure; any additional VTE risk factors that a patient has will ↑ their risk category

Very low risk (<0.5%):

  • Small day-case procedures
    • General surgical
    • Gynaecological
    • Plastics procedures

Low risk (0.5-1.5%):

  • Minor elective abdominal surgery
    • Appendicectomy
    • Laparoscopic cholecystectomy
  • Minor thoracic surgery
    • Diagnostic VATS
  • Elective spinal fusion

Moderate (1.5-3%) risk:

  • Major surgery
    • Gynaecologic
    • Urologic
    • General surgical
    • Bariatric surgery
    • Neurosurgery
  • Trauma not involving brain or spine

High (3-6%) risk:

  • Cancer surgery
  • Extensive thoracic or abdominal surgery
    • Distal colorectal surgery
    • Extensive pelvic surgery
  • Acute spinal cord injury
  • Major trauma

Bleeding Risk Prediction

  • The below thresholds just cover surgical risk factors, and so give a minimum risk level for any procedure; any additional risk factor for bleeding that a patient has will ↑ their risk category

Low bleeding risk (<2%):

  • Most uncomplicated surgery
    • General
    • Bariatric
    • Vascular
    • Thoracics

High bleeding risk (>2%, or consequences of bleeding would be devastating):

  • Spinal surgery
  • Intracranial surgery
  • Reconstructive surgery

Management

Very low VTE risk:

  • Early and frequent ambulation

Low VTE risk:

  • Mechanical prophylaxis recommended
    • Intermittent pneumatic calf compressors
      • Should be used for at least 18 hours per day
      • Remove when walking
    • Graduated Compression Stockings
      • No additional benefit seen (for VTE) over pharmacological methods
      • Have additional uses (e.g. peripheral oedema)

Moderate VTE risk and Low bleeding risk:

  • Pharmacological prophylaxis suggested
    • Enoxaparin
    • UFH acceptable if concerns about renal failure or receiving dialysis, or cost is prohibitive
    • Fondaparinux if HITS

High VTE Risk and Low bleeding risk:

  • Combined mechanical and pharmacological prophylaxis
    Additional benefit suggested by combining methods, but evidence is poor.

High bleeding risk:

  • Mechanical prophylaxis
  • Vena cava filters should not be used routinely
  • Administration of pharmacoprophylaxis should occur as soon as practicable