Deep Vein Thrombosis

Basics

Description

  • Deep vein thrombosis (DVT) is a blood clot in veins beneath the fascia (deep veins), distinguishing them from superficial veins located closer to the skin surface
  • DVT can be upper or lower extremity, as well as distal or proximal
  • Upper-extremity DVT accounts for only 4% of all diagnosed DVTs
  • Proximal DVTs above the knee involve the common femoral vein, femoral vein, superficial femoral or the popliteal vein
  • Distal DVTs below the knee involve anterior tibial, posterior tibial, peroneal (fibular) veins, or occasionally the muscular veins such as the gastrocnemius and soleus vein
  • Pulmonary embolism (PE) and DVT are different ends of the clinical spectrum of the same disease process (venous thromboembolism, VTE)
  • DVT and PE occurs in 1–2 individuals per 1000 each year, which is between 300,000 and 600,000 annual events in the US
  • Prevalence increases with advancing age and in both medical and surgical hospitalized patients
  • Diagnosis is more accurate using active surveillance rather than clinical suspicion

Pediatric Considerations

  • DVT in children is unusual, but when cases do occur, search for an underlying reason for hypercoagulability
  • Also, upper-extremity DVT is associated with central IV lines in children

Etiology

  • Clot formation/dissolution is a delicate balance influenced by factors outlined in Virchow triad
    • Hypercoagulability
    • Venous stasis
    • Endothelial injury
  • Hypercoagulable states
    • Often multiple concomitant
    • Cancer (particularly lung, pancreas, colorectal, kidney, and prostate)
    • Myeloproliferative disorders
    • Nephrotic syndrome
    • Sepsis
    • Inflammatory conditions:
      • Ulcerative colitis, Crohn disease
    • Hormone alterations:
      • Pregnancy
      • Exogenous hormones (OCPs, HRT)
      • Testosterone supplements
    • Antiphospholipid syndrome
    • Protein S, C, and antithrombin deficiencies, factor V Leiden, prothrombin gene mutations, lupus, others
  • Venous stasis:
    • Prolonged bed rest and immobility (from a cast) or prolonged sitting such as in an employment setting
    • Long plane, car, or train rides
    • Neurologic disorders with paralysis
    • CHF
    • Obesity
  • Vascular concerns/damage:
    • Trauma
    • Surgery, particularly orthopedic surgeries
    • Intravenous drug abuse
    • Dialysis
    • Anatomic anomalies (May–Thurner syndrome, congenital heart disease, Paget–Schroetter)
    • Central lines/pacemaker placement:
      • Especially upper-extremity DVT
  • Multifactorial issues:
    • Advancing age
    • Comorbid conditions (diabetes, hypercholesterolemia, hypertension)
    • Other medications (hydralazine, procainamide, phenothiazines, tamoxifen, glucocorticoids, bevacizumab, some antidepressants)
    • Tobacco use
    • Prior DVT or PE
  • Genetics:
    • Family history of DVT/PE is an independent risk factor; ask about family history of clotting
    • There is no consensus about which patients with VTE to test for inherited thrombophilias

Pregnancy Considerations

Pregnancy is a risk factor for DVT up to 6 wk postpartum. Often affects left side preferentially due to anatomy and may involve pelvic veins. Treatment choices are more limited in pregnancy. Shared decision making regarding treatment should include the patient and OB/Gyn whenever possible

Geriatric Considerations

Age in and of itself is a risk for DVT (and PE). As with many diseases, the presentation may be atypical in the elderly. Treatment considerations more complicated due to comorbid conditions, fall risk, etc.

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