Pseudoaneurysm

Question 1

Definition

Answer 1

A pseudoaneurysm (false aneurysm) is a localized hematoma with turbulent blood flow, typically arising after arterial puncture or trauma.

Question 2

Pathophysiology

Answer 2

• Blood leaks from an artery but is contained by surrounding tissue, not by the vessel wall itself.
  
  • A fibrin- and platelet-rich wall forms around the leak site.
  • This wall is weaker than the true arterial wall, making it less stable than a true aneurysm.

Question 3

causes

Answer 3

• Iatrogenic: Most commonly follows arterial puncture (e.g., catheterization).
  • Trauma: Penetrating or blunt trauma.
  • Infection: Arterial wall damage from infectious processes.
• Failure of closure devices
• Double wall entry of the anterior and posterior artery with continued bleeding from the posterior puncture site
• Laceration of the branches of the common femoral artery, including the deep femoral, superficial femoral, or other arteries (eg, external iliac, inferior epigastric)
• Inadequate pressure or length of time holding pressure postprocedure
• Inadvertent access or dilation of the artery during venous procedures

Question 4

Risk Factors

Answer 4

Risk factors for pseudoaneurysms that are iatrogenically caused include:

Hypertension
Female sex
Anticoagulant use
Placement of access to the left femoral artery
Puncture of calcified blood vessels
Larger sheath size, greater than 6 French
Obesity
Lack of ultrasound utilization during an access procedure
Multiple puncture attempts

Question 5

concerning signs

Answer 5

• Expanding hematoma
• An attributable motor or sensory neurologic deficit
• An attributable pulse deficit
• Hemodynamic instability
• Ischemic and extensive skin and subcutaneous damage
• Surrounding or adjacent infection (eg, abscess, purulent drainage, cellulitis, fever, leukocytosis

Question 6

Evaluation-Invx

Answer 6

1. Femoral Pseudoaneurysms
   
   • First-line modality: Duplex ultrasonography
     -Gold standard for diagnosis
     
     • Sensitivity: 100%
     • Assesses size, origin, and anatomy
   • CT Angiogram (CTA):
     
     • May help define anatomical relations if needed
     • Not required for diagnosis

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2. Aortic Pseudoaneurysms
   
   • Preferred imaging: CTA or conventional arteriography
   • Typical etiologies:
     -Prior aortic surgery (e.g. dissection/aneurysm repair)
   • Trauma (blunt or penetrating)
     -Infection
     -Genetic disorders: Marfan syndrome, Ehlers-Danlos

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3. Cardiac Pseudoaneurysms
   Gold standard: Angiography
   - Sensitivity: >85%
   
   • Transthoracic echocardiography (TTE):
     -Detects ~25% of cases
   • Transesophageal echocardiography (TEE):
     -Higher sensitivity (~75%)
     -Shows narrow neck (<40% of maximal diameter)
   • CT or MRI:
     -Additional tools to distinguish true vs. false aneurysms

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4. Visceral Pseudoaneurysms
   
   • Presentation: Bleeding, abdominal pain
   • Imaging: CTA or conventional angiography
   • Used for diagnosis and characterization

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Question 7

Management of Aortic pseudoaneurysms

Answer 7

Aortic pseudoaneurysms:
TEVAR (thoracic endovascular aortic repair or EVAR(Endovascular aneurysm repair)

Question 8

Management of Femoral pseudoaneurysms

Answer 8

Femoral Pseudoaneurysms

Emergent Surgical Evaluation

Indicated if complicated, including:
* Expanding hematoma
* Neurologic deficit (motor/sensory)
* Pulse deficit
* Hemodynamic instability
* Ischemic/necrotic skin and soft tissue damage
* Signs of infection (abscess, cellulitis, fever, leukocytosis)

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Uncomplicated Pseudoaneurysms

Management based on size and symptoms:
* <2–3 cm and asymptomatic:
Observation with interval ultrasound
- May thrombose spontaneously
* >3 cm:
- Require intervention, even if asymptomatic

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Treatment Options:
=>Ultrasound-guided thrombin injection:
- First-line for accessible lesions
- Success rate: 97–100%
- Safe in patients on anticoagulation
- Not for <1 cm due to embolization risk
* Neck <2 mm → higher risk of embolization

=> Ultrasound-guided compression:
- Alternative for very small pseudoaneurysms (<1 cm)

=> Surgical repair:
* Indications:
- Failed thrombin injection or compression
- Anastomotic disruption
- Complicated pseudoaneurysm

-> Options:
* Open surgical repair

*	Endovascular treatment (e.g., coil embolization, stenting)

*	Blood products should be prepped in advance due to bleeding risk

*	Delayed intervention:
*	For monitored pseudoaneurysms that:
*	Enlarge
*	Become symptomatic
*	Remain >1 cm at 6 weeks

Question 9

D/D

Answer 9

• hematoma
• Infection/Abcess
• Seroma
• True aneurysm

Question 10

Complications

Answer 10

=> General Complications (All Types):
* Distal embolization
* Rupture
* Bleeding
* Death

=>Femoral Pseudoaneurysm-Specific:
* May rupture into retroperitoneal space
* Can cause massive, occult bleeding
* May lead to hemodynamic instability and death

=>Ultrasound-Guided Thrombin Injection:
* Distal embolization in up to 2% of cases

Question 11

prognosis

Answer 11

Depends upon size and location
usually good prognosis with high treatment success rate