Related Experiment Videos
Diagnosis of deep-vein thrombosis in the year 2000
1Department of Medicine and Epidemiology and Community Medicine, Ottawa Hospital and the University of Ottawa, Ontario, Canada. pwells@ottawahospital.on.ca
Insights
Diagnosing deep-vein thrombosis (DVT) is improved with a validated clinical model and D-dimer testing. This combination enhances diagnostic safety, effectiveness, and patient convenience, reducing the need for serial ultrasonography.
Area of Science:
- Vascular Medicine
- Diagnostic Imaging
- Hematology
Background:
- Deep-vein thrombosis (DVT) is a common condition with potentially fatal consequences if untreated.
- Ultrasonography is a primary noninvasive diagnostic tool for DVT, but it has limitations, including false-negative results, particularly for calf vein thrombi.
- Serial testing of the proximal venous system was adopted to address limitations but is inconvenient and costly.
Purpose of the Study:
- To evaluate the effectiveness of a validated clinical model combined with D-dimer testing for DVT diagnosis.
- To improve the safety, efficacy, and convenience of DVT diagnostic strategies.
- To reduce reliance on serial ultrasonography when clinical probability is low and ultrasonogram is normal.
Main Methods:
- Utilized a validated clinical model to stratify patients into low, moderate, and high probability categories for DVT.
- Incorporated the fibrin degradation product D-dimer assay, known for its high negative predictive value.
- Integrated clinical assessment with D-dimer results into diagnostic algorithms.
Main Results:
- The validated clinical model accurately categorizes DVT risk.
- D-dimer testing demonstrates high negative predictive value, useful in diagnostic algorithms.
- Combining clinical models with D-dimer testing allows for elimination of serial testing in specific patient groups (low probability, normal ultrasonogram).
Conclusions:
- The integration of a validated clinical model and D-dimer testing significantly enhances DVT diagnostic strategies.
- This combined approach offers a safer, more effective, and convenient alternative to traditional methods like serial ultrasonography.
- Optimized diagnostic pathways improve patient management for suspected deep-vein thrombosis.
Abstract:
Deep-vein thrombosis is a relatively common disease, amenable to therapy but with a potentially fatal outcome if untreated. The diagnosis can be made in most patients with the noninvasive imaging procedure ultrasonography, but limitations exist. As with all tests, there is a potential for false-positive and false-negative results. The latter are especially an issue for calf vein thrombi, and this in part has led to the concept of serial testing of the proximal venous system and not imaging the calf. The premise of the repeat (serial) test is that only thrombi that extend to the proximal system are clinically relevant and such thrombi will be detected on the repeat test. However, despite the safety of the serial testing concept, it is inconvenient and expensive. In the last few years, the diagnostic process has been improved by the validation of a clinical model that accurately categorizes patients as having low, moderate, or high probability. Among the improvements this provides is the elimination of serial testing if the ultrasonogram is normal and the clinical probability low. The fibrin degradation product D-dimer has been demonstrated to have a high negative predictive value and has also proven useful in diagnostic algorithms. The combination of the D-dimer with clinical model assessment will enable diagnostic testing strategies that are more safe, effective, and convenient for patients.