From the Guidelines
The workup for recurrent Deep Vein Thrombosis (DVT) should start with a thorough clinical evaluation, including a review of the patient's history and physical examination, as the clinical prediction scores and D-dimer levels may not be reliable for diagnosing recurrent DVT 1.
Key Components of the Workup
- Imaging: Lower extremity ultrasound (US) is frequently required to definitively exclude DVT and properly document the extent of venous thrombosis, which is critical for proper therapeutic management of DVT 1.
- Diagnostic Criteria: For patients with suspected recurrent DVT, thrombus in a previously unaffected venous segment or an increase in venous diameter during compression of >4 mm in a region with prior thrombus would be considered diagnostic for recurrent DVT 1.
- Previous Imaging Results: Availability of previous imaging results is essential for comparison and diagnosis of recurrent DVT 1.
- Clinical Evaluation: A thorough clinical evaluation, including a review of the patient's history and physical examination, is crucial in the workup for recurrent DVT, as the clinical presentation can be variable and may not always be apparent until there is involvement above the knee 1.
Considerations
- Anticoagulation Therapy: The decision to extend anticoagulation therapy should be based on the individual patient's risk of recurrent VTE and the risk of anticoagulant-related bleeding 1.
- Risk Factors: Patients with prior VTE are a heterogeneous group, and factors such as sex, the nature of the initial VTE event (provoked vs unprovoked), and presence of ongoing risk factors (e.g., cancer) can influence recurrence 1.
- D-dimer Testing: D-dimer testing may not be reliable for diagnosing recurrent DVT, especially in patients receiving anticoagulation therapy 1.
From the Research
Diagnostic Approach
The workup for recurrent Deep Vein Thrombosis (DVT) involves a combination of clinical evaluation and imaging modalities. The diagnosis of recurrent DVT is complex, and routine diagnostic tests for suspected DVT are less accurate in patients without a prior DVT 2.
Imaging Modalities
- Compression ultrasonography is the imaging technique of choice for suspected recurrent DVT 2.
- Magnetic resonance direct thrombus imaging can be decisive in cases of suspected recurrent ipsilateral DVT with an inconclusive ultrasonography 2.
- Venography, although invasive and costly, is considered the gold standard for diagnosing recurrent DVT 3.
- Serial compression ultrasound (CUS) is a recommended approach, with a quantitative CUS method possessing excellent reproducibility and accuracy 3.
Clinical Evaluation
- Clinical decision rules (CDR) and D-dimer tests have a lower specificity in suspected recurrent VTE, leading to an increase in required diagnostic imaging tests 2.
- A CDR in combination with D-dimer testing can be used to exclude recurrent DVT, but its safety is debated 2.
- Objective testing is mandatory to confirm or refute the presence of recurrent DVT, as only 30% of patients with suspected recurrence have a new documented thrombotic episode 3.
Management Strategies
- The anticoagulant management of acute DVT should be guided by the results of clinical trials, and currently available evidence provides no basis for using ultrasonography to guide the duration of anticoagulation 4.
- Algorithms for the diagnosis and treatment of recurrent DVT can be applied in daily clinical practice, but the scientific evidence regarding the treatment of recurrent DVT is sparse 5.