Who should a patient with an aberrant right subclavian artery consult?

Management of Patients with Aberrant Right Subclavian Artery

Patients with aberrant right subclavian artery should be referred to a cardiovascular surgeon or interventional radiologist for evaluation, especially if symptomatic or if associated with Kommerell's diverticulum. This vascular anomaly requires specialized assessment and potential intervention based on specific anatomical features and symptomatology.

Understanding Aberrant Right Subclavian Artery (ARSA)

Aberrant right subclavian artery is the most common congenital anomaly of the aortic arch, occurring in approximately 0.5-1% of the population 1. This condition is characterized by:

• The right subclavian artery arising as the fourth branch from the aorta, distal to the left subclavian artery
• A retroesophageal course in approximately 80% of patients 2
• Potential association with Kommerell's diverticulum in 20-60% of cases 2

Clinical Presentation and Evaluation

Symptoms

• Many patients are asymptomatic, with ARSA discovered incidentally on imaging
• When symptomatic, patients may present with:
  • Dysphagia (dysphagia lusoria)
  • Respiratory symptoms
  • Recurrent laryngeal nerve palsy 2
  • Rarely, subclavian steal syndrome 3

Imaging Assessment

• If ARSA is discovered without thoracic aortic imaging, dedicated imaging to assess for thoracic aortic aneurysm (TAA) is reasonable (Class 2a recommendation) 2
• CT or MRI should be used to evaluate:
  • Presence of Kommerell's diverticulum
  • Diverticulum size measurements:
    • Diverticulum orifice diameter
    • Combined diameter of diverticulum and adjacent descending aorta 2

Referral and Management Algorithm

1. For asymptomatic patients without complications:

   • Cardiovascular specialist consultation for risk assessment
   • Regular surveillance imaging may be appropriate

2. For symptomatic patients:

   • Urgent referral to cardiovascular surgeon or interventional radiologist

3. For patients with Kommerell's diverticulum:

   • Surgical intervention is recommended when:
     • Diverticulum orifice is >3.0 cm, OR
     • Combined diameter of diverticulum and adjacent descending aorta is >5.0 cm 2

4. For patients requiring aortic repair:

   • If the patient has an aberrant left vertebral artery origin arising from the thoracic aorta requiring reconstruction, revascularization of the vertebral artery is reasonable 2

Treatment Options

Treatment approaches depend on symptoms, anatomy, and associated conditions:

• Open surgical repair: Involves resection of the aneurysmal segment of the subclavian artery (diverticulum) and adjacent aorta with graft replacement 2
• Endovascular approach: Exclusion of the right subclavian artery origin and adjacent aorta using an aortic endograft 2, 3
• Hybrid approaches: Combination of open and endovascular techniques based on patient anatomy and comorbidities 2

Special Considerations

• In pediatric patients with ARSA and associated cardiac anomalies (e.g., atrial septal defect), median sternotomy approach may provide adequate exposure for simultaneous repair 4
• Patients with ARSA should be evaluated for other potential congenital anomalies
• The presence of ARSA may complicate certain thoracic surgical procedures, such as esophagectomy 5

Follow-up

For patients not requiring immediate intervention, regular follow-up with cardiovascular imaging is recommended to monitor for:

• Development of symptoms
• Aneurysmal dilatation
• Development or enlargement of Kommerell's diverticulum

Early detection and appropriate specialist referral are crucial for optimal management of this vascular anomaly to prevent potentially life-threatening complications such as aneurysm formation, dissection, and rupture.