Physical Examination for Suspected Pseudoaneurysm
The physical examination should focus on identifying a pulsatile mass with associated thrill and bruit, while recognizing that physical examination alone misses more than 60% of pseudoaneurysms, making imaging essential for diagnosis. 1, 2
Key Physical Examination Findings
Primary Signs to Assess
- Pulsatile mass: The hallmark finding is a pulsatile, cystic mass at the site of suspected pseudoaneurysm 3, 4
- Palpable thrill: A characteristic vibratory sensation may be felt over the pseudoaneurysm 4
- Audible bruit: Listen with a stethoscope for a to-and-fro murmur or systolic bruit over the mass 4, 5, 6
- Compressibility: The mass should be compressible and may disappear with manual compression of the proximal artery 5
Associated Clinical Features
- Erythema and pain: Patients often present with an erythematous, painful mass, particularly in peripheral locations 3, 2
- Swelling: Localized swelling at the site, which may be tender 2, 7
- Skin changes: Assess for skin erosion or breakdown, which indicates high risk of complications 3, 2
- Inflammatory response: Variable degrees of localized inflammation may be present 2
Critical Warning Signs
- Draining sinus tract: Highly suggestive of infected pseudoaneurysm, particularly in vascular graft-related cases 2
- Cellulitis or abscess: Common in infected pseudoaneurysms, especially in intravenous drug users 3
- Signs of ischemia: Check distal pulses and perfusion for evidence of thrombosis or distal embolization 2, 7
- Active bleeding: Indicates rupture requiring emergent intervention 3, 2
Important Clinical Caveats
Physical examination has significant limitations: More than 60% of pseudoaneurysms are missed by physical examination alone, making imaging mandatory even when clinical suspicion exists 1, 2. Pseudoaneurysms are easily confused with hematomas or abscesses on clinical examination 1, 2.
Fever is unreliable: In infected pseudoaneurysms (mycotic aneurysms), fever is absent in 50-60% of patients and should not be used to rule out infection 3
Location-Specific Examination Considerations
- Femoral pseudoaneurysms: Examine for groin swelling, pain, and bruising, particularly following catheterization procedures 2
- Superficial temporal artery: Look for a pulsatile cystic mass in the temple region that disappears with proximal compression 5
- Brachial artery: Assess for pulsatile mass in the antecubital region in dialysis patients with arteriovenous fistulas 8
Mandatory Next Step
Duplex ultrasound must be obtained whenever pseudoaneurysm is suspected based on physical examination findings, as imaging is essential to confirm the diagnosis and guide management 3, 1. The ultrasound will demonstrate the characteristic "to-and-fro" flow pattern in the neck of the pseudoaneurysm and provide critical information about size, thrombus presence, and arterial flow 3, 4.