Pseudoaneurysm vs Hematoma in Limb: Diagnostic and Treatment Approach
Immediate Diagnostic Imperative
Physical examination alone is unreliable and misses over 60% of pseudoaneurysms—duplex ultrasound must be obtained immediately whenever a pseudoaneurysm is suspected, regardless of clinical presentation. 1, 2
Key Distinguishing Features
Clinical Presentation Differences
- Pseudoaneurysm: Pulsatile mass, palpable thrill, audible to-and-fro murmur, persistent communication with artery through arterial wall defect 3, 4
- Hematoma: Non-pulsatile swelling, no thrill or bruit, contained blood collection without arterial communication 3
- Critical caveat: Pseudoaneurysms can present atypically without classic signs (no pulsatile mass, absent thrill/bruit), making imaging mandatory rather than optional 5
Diagnostic Algorithm
- First-line: Duplex ultrasound with Doppler confirms diagnosis, shows pseudoaneurysm sac size, degree of clotting, arterial communication, and flow velocity patterns 1, 4
- Gold standard for surgical planning: CT angiography when intervention is anticipated 6
- Never rely on clinical examination alone—imaging is mandatory when vascular injury is suspected 2, 6
Treatment Algorithm for Pseudoaneurysm
Size-Based and Symptom-Based Management
Small Asymptomatic Pseudoaneurysms (<2.0 cm)
- Conservative management is appropriate, as 61% resolve spontaneously within 7-52 days 1
- Re-evaluate with ultrasound at 1 month; if persistent at 2 months, proceed to definitive treatment 1
- Avoid cannulation of affected segments if alternative sites exist 7
Large or Symptomatic Pseudoaneurysms (≥2.0 cm)
- First-line intervention: Ultrasound-guided thrombin injection (100-3000 IU bovine thrombin) with 93% success rate 1, 3
- Alternative: Ultrasound-guided compression therapy with 75-90% success rates for accessible pseudoaneurysms 1
- Rare complication: Distal thromboembolism occurs in <2% with thrombin injection 1
Absolute Indications for Urgent Surgical Repair
- Active hemorrhage or skin erosion 7, 1
- Rupture into surrounding tissues or retroperitoneum 1, 2
- Infected pseudoaneurysm with sepsis 6
- Venous thrombosis or painful neuropathy from compression 1
- Failed endovascular treatment with ongoing life-threatening hemorrhage 6
- Anastomotic pseudoaneurysms (usually require definitive surgical treatment) 7
Surgical Approach
- Open surgical repair is the definitive treatment for symptomatic, large, or rapidly expanding pseudoaneurysms 7
- Covered intraluminal stent grafts are reserved only for patients with contraindications to surgery or lack of surgical options, due to infection risk (28.9% complication rate, with relative risk ratio of 5 compared to stenosis treatment alone) 7
- If stent grafts are used, avoid cannulation over the stent segment 7
Treatment for Hematoma
Conservative Management
- Simple hematomas without arterial communication typically resolve with observation, compression, and time 3
- No specific intervention required unless complications develop (compartment syndrome, infection, or diagnostic uncertainty about pseudoaneurysm)
Critical Pitfalls to Avoid
- Misdiagnosis: Pseudoaneurysms are easily confused with hematomas or abscesses on clinical examination—always obtain imaging 1, 8
- Delayed diagnosis: Deep femoral artery pseudoaneurysms have 33% rupture rates, emphasizing need for prompt diagnosis 2
- Inadequate follow-up: For conservatively managed pseudoaneurysms, mandatory ultrasound at 1 month and definitive treatment if no resolution by 2 months 1
- Inappropriate stent use: Stent grafts for pseudoaneurysms carry high infection risk and are not FDA-approved for this indication 7
Special Considerations for Dialysis Access
- Check for aneurysm/pseudoaneurysm at each dialysis session 7
- Educate patients on emergency procedures for rupture 7
- Presence of pseudoaneurysm alone without symptoms is NOT an indication for definitive treatment 7
- Obtain imaging of arterial inflow and venous outflow to assess for stenotic problems before definitive treatment 7