From the Research
The most common origin of pulmonary embolism (PE) without deep vein thrombosis (DVT) is typically de novo thrombosis in the pulmonary arteries, as suggested by recent studies 1, 2. In cases without an identifiable DVT, blood clots can form in the pulmonary arteries due to factors such as prolonged immobility, recent surgery, or underlying conditions that increase blood clotting risk. It's essential to note that even when no DVT is found, it doesn't necessarily mean one didn't exist. Sometimes, a DVT may have already embolized completely, leaving no trace in the leg veins. For patients with suspected pulmonary embolism without obvious DVT, a comprehensive evaluation is crucial. This typically includes:
- CT pulmonary angiography to confirm the presence of pulmonary embolism
- Echocardiogram to assess heart function and look for right heart strain
- Pelvic vein imaging (CT or MRI) if other sources are not identified Treatment generally involves anticoagulation, typically starting with low molecular weight heparin (e.g., enoxaparin 1 mg/kg twice daily) or direct oral anticoagulants (e.g., rivaroxaban 15 mg twice daily for 21 days, then 20 mg daily), for at least 3-6 months, as recommended by recent guidelines 3. The exact duration depends on the underlying cause and risk factors for recurrence. Understanding the potential origins of pulmonary embolism beyond DVT is crucial for proper diagnosis and management, especially in cases where the source is not immediately apparent, and considering the latest evidence from studies such as 4 and 2.