Deep vein thrombosis screening

Overview:Value of screening
In-spite of identifying patients at increased risk of VTE, there is no clear clinical value for screening, the following reason explains
 * The strongest risk factor for VTE recurrence is the prior VTE event itself.
 * VTE patients with unknown cause have a high rate of recurrence, after discontinuation of warfarin, irrespective of the presence of inherited thrombophilia.
 * Anticoagulant prophylaxis is rarely recommended in asymptomatic affected family members outside of high risk situations.

Who should be screened?
Patients having any of the following, should be screened for inherited Thrombophilia
 * Initial thrombosis occurring at age<50, without an immediately identified risk factor
 * Positive family history of thromboembolism at age<50
 * Recurrent venous thrombosis
 * Thrombosis occurring in unusual vascular beds such as portal, hepatic, mesenteric, or cerebral veins
 * History of warfarin-induced skin necrosis.

Who should not screened?
Screening is not routinely recommended for people with inherited coagulation disorder, also if they have any of the following conditions


 * Active malignancy
 * Recent major surgery or immobilization
 * Systemic lupus erythematosus
 * Inflammatory bowel disease
 * Myeloproliferative disorders
 * Preeclampsia at term
 * Retinal vein thrombosis
 * Upper limb venous thrombosis

Probability scoring
In 2006, Scarvelis and Wells overviewed a set of clinical prediction rules for DVT, on the heels of a widely adopted set of clinical criteria for pulmonary embolism.

Wells score or criteria
(Possible score -2 to 9)


 * 1) Active cancer (treatment within last 6 months or palliative) -- 1 point
 * 2) Calf swelling >3 cm compared to other calf (measured 10 cm below tibial tuberosity) -- 1 point
 * 3) Collateral superficial veins (non-varicose) -- 1 point
 * 4) Pitting edema (confined to symptomatic leg) -- 1 point
 * 5) Swelling of entire leg - 1 point
 * 6) Localized pain along distribution of deep venous system -- 1 point
 * 7) Paralysis, paresis, or recent cast immobilization of lower extremities -- 1 point
 * 8) Recently bedridden > 3 days, or major surgery requiring regional or general anesthetic in past 12 weeks -- 1 point
 * 9) Previously documented DVT -- 1 point
 * 10) Alternative diagnosis at least as likely -- Subtract 2 points

Interpretation

 * Score of 2 or higher - deep vein thrombosis is likely. Consider imaging the leg veins.
 * Score of less than 2 - deep vein thrombosis is unlikely. Consider blood test such as d-dimer test to further rule out deep vein thrombosis.

Cases have been reported, even when the well score was zero.