Duplex ultrasound, clinical score, thrombotic risk, and D-dimer testing for evidence based diagnosis and management of deep vein thrombosis and alternative diagnoses in the primary care setting and outpatient ward
Abstract
First episodes of calf vein thrombosis (CVT) and proximal DVT are frequently elicited by risk factors. Congenital venous thrombophilia is present in every third first DVT, increased FVIII in every fourth first DVT.
Routine thrombophilia testing for FV Leiden/prothrombin mutation and FVIII as main risk factor for venous thrombosis is recommended. Primary superficial venous thrombosis (SVT) and DVT patients with a autosomal dominant family history of DVT are candidates for thrombophilia trstiny for congenital AT, PC and PS deficiency.
The requirement for a safe diagnostic strategy of CVT and DVT should be based on an objective post-test incidence of venous thromboembolism (VTE) of less than 0.1% with a negative predictive value for exclusion of DVT of 99.9% during 3 months follow-up. Modification of the Wells score by elimination of the "minus 2 points" for AD is mandatory and will improve the diagnostic accuracy of CVT/DVT suspicion in the primary care setting and outpatient ward.
The sequential use of complete DUS, ELISA D-dimer testing and modified clinical Wells' score assessment is safe and effective for the exclusion and diagnosis of CVT, DVT and AD. About 10% to 20% of patients with DVT develop overt post-thrombotic syndrome (PTS) at one year post-DVT, and both PTS and DVT recurrences further increase to about 30% during long-term follow-up.