Written by Chris Thom
Spoon Feed
This case report details a real-time embolization event of a deep vein thrombosis (DVT) during POCUS compression.
Can the clot dislodge if you press too much?
In this adult ED patient case report, a DVT is identified during probe compression with POCUS at the level of the mid-femoral vein in the thigh. Initially, the femoral vein is non-compressible at the site of the thrombus, which is consistent with a DVT. In the course of probe compression, the clot is visualized suddenly migrating off of the field of view and then disappearing. The femoral vein is subsequently fully compressible where the DVT had just previously been identified. Shortly thereafter, the patient has a CTPA that demonstrates an acute pulmonary embolism.
How will this change my practice?
This is an interesting case report and dovetails with a scant area of literature exploring this theoretical risk. It perhaps makes sense, in theory, that if you press firmly enough with the ultrasound probe, then you could risk dislodging a clot. However, probe compression is a necessary part of any DVT evaluation and must be done in order to have an accurate test. In addition, there are only rare cases where this is documented to have occurred, with one review only identifying 8 total cases. Perhaps this provides a lesson that one should only apply the pressure necessary to make the diagnosis.
POCUS Pro-Tips
Compression ultrasound for DVT evaluation is a great tool for the practicing clinician. For the groin evaluation of the common femoral vein and greater saphenous vein, I tend to have the leg in the “frog leg” position to allow for easier imaging. The CFV-GSV junction is often more proximal than you might suspect. In general, the vein should collapse by the time the pressure from the probe is starting to deform the arterial wall. For the popliteal vein evaluation, I am an advocate for the prone position when possible, though this is not always feasible in all settings. You can also have patients roll to the side or have the supine patient flex their knee to gain access to the popliteal vessels.
Source
Real-Time Capture of Thrombus Embolization During Point-of-Care Lower-Extremity Compression Ultrasonography. Ann Emerg Med. 2026 Mar;87(3):374-376. doi: 10.1016/j.annemergmed.2025.07.020. Epub 2025 Sep 16. PMID: 40956252.
