Is it safe for a patient with a femoral hematoma, with pseudo‑aneurysm excluded, to sit?

Sitting Is Permitted with a Femoral Hematoma (Pseudoaneurysm Excluded)

Yes, sitting is safe for a patient with a simple femoral hematoma once pseudoaneurysm has been definitively excluded by duplex ultrasound imaging. 1

Critical Distinction: Hematoma vs. Pseudoaneurysm

The key to answering this question lies in understanding that a simple hematoma (contained blood collection without arterial communication) behaves completely differently from a pseudoaneurysm (pulsatile mass with ongoing arterial flow through a wall defect). 2

Why Imaging Is Mandatory

• Physical examination alone fails to detect more than 60% of pseudoaneurysms, making clinical assessment unreliable for distinguishing between a benign hematoma and a potentially dangerous pseudoaneurysm. 1, 3
• Duplex ultrasound must be performed immediately whenever a groin mass is suspected after femoral access, as pseudoaneurysms can be mistaken for simple hematomas or abscesses on clinical exam alone. 1
• The characteristic "to-and-fro" Doppler flow pattern confirms a pseudoaneurysm, while its absence indicates a simple hematoma without arterial communication. 1, 2

Activity Restrictions: Hematoma vs. Pseudoaneurysm

For Simple Femoral Hematoma (Pseudoaneurysm Excluded)

Once duplex ultrasound has definitively ruled out pseudoaneurysm, a simple hematoma requires minimal activity restriction:

• Sitting is permitted because there is no ongoing arterial communication and no risk of rupture or expansion from positional changes. 4
• Standard post-catheterization precautions apply (avoid heavy lifting, straining, or vigorous activity for 24-48 hours), but strict bed rest is unnecessary. 4
• The hematoma will resorb spontaneously over days to weeks without specific intervention. 4

For Pseudoaneurysm (If Present)

In stark contrast, asymptomatic pseudoaneurysms < 2 cm require strict bed rest or minimal ambulation during the observation period:

• No heavy lifting, straining, or vigorous activity for at least 1-2 months during conservative management. 1
• Weekly clinical assessments combined with ultrasound examinations are mandatory until complete thrombosis is documented. 1
• Pseudoaneurysms ≥ 2 cm warrant aggressive treatment (ultrasound-guided thrombin injection or surgical repair) rather than observation, making activity restriction moot until definitive treatment is completed. 1

Common Pitfalls to Avoid

• Never assume a groin mass is "just a hematoma" based on physical exam alone—imaging is obligatory to exclude pseudoaneurysm, which carries high risks of rupture, venous thrombosis, arterial compression, and progressive enlargement. 1, 3
• Do not confuse the management of simple hematomas with pseudoaneurysms—the former requires minimal restriction once confirmed by imaging, while the latter demands strict activity limitation or definitive intervention depending on size and symptoms. 1, 4
• Untreated pseudoaneurysms inevitably enlarge and can rupture catastrophically, with deep femoral artery pseudoaneurysms carrying rupture rates as high as 33%. 3, 5

Algorithmic Approach

1. Obtain duplex ultrasound immediately for any groin mass after femoral access. 1, 3
2. If pseudoaneurysm is excluded (no to-and-fro flow, no arterial communication): sitting and normal activity are safe; standard post-procedure precautions apply. 2, 4
3. If pseudoaneurysm is confirmed < 2 cm and asymptomatic: strict bed rest, weekly ultrasound, mandatory 1-month follow-up imaging. 1
4. If pseudoaneurysm ≥ 2 cm or symptomatic: ultrasound-guided thrombin injection (93% success rate) or surgical repair; activity restriction until resolution confirmed. 1