How Can Deep Venous Thrombosis Be Diagnosed?
Thrombus formation involves a failure of natural anticoagulation, either congenital or acquired systemically, or due to injury locally.
Testing for Congenital Risk of DVT
Congenital risk can be assessed by family history and blood testing. A history of a close relative with pulmonary emboli, deep vein thrombosis (DVT), or sudden death for reasons that were never identified can prompt physicians to test for risks of DVT.
Blood tests for inherited clotting disorders include mutations in Factor V Leiden and prothrombin and congenital deficiencies of antithrombin, protein C, and protein S.
Testing for Acquired Risk of DVT
The following contribute to risk for DVT:
- Trauma or surgical manipulations
- Pregnancy and estrogen replacement
- Renal or liver disease
- Inflammatory bowel disease
Testing for these includes a variety of diagnostic methods, from blood work and imaging (ultrasound, CT, and MRI) to invasive venography.
Tests After Diagnosis of DVT Is Established
Identification of actual thrombus formation mandates that mere diagnostics progress to prevention (pulmonary emboli or thrombus extension) and treatment (anticoagulation or clot removal). Once anticoagulation is begun, the progress of the clot dissolution can be followed by duplex ultrasound testing. The anticoagulation can be monitored via blood tests that measure the amount of anticoagulation and adjustments in dosing can be made accordingly. If interventional (invasive) therapy is necessary, these same blood tests can be used to assure that the coagulation is back to normal to prevent hemorrhagic complications before performing these procedures.
Tests After DVT Is Treated
Post-thrombotic syndrome is a condition that is a combination of reflux due to valvular incompetence and the resulting venous hypertension seen after a prior thrombotic episode. Venous insufficiency with associated pain, vein dilation, edema, skin pigmentation, and venous ulcers are common after treatment and require follow-up via ultrasound surveillance.