What is the management approach for a patient with a right aortic arch?

Management of Right Aortic Arch

The management of a patient with right aortic arch should be guided by the presence of symptoms, associated vascular anomalies, and specific anatomical features, with surgical intervention recommended for symptomatic patients or those with significant anatomical abnormalities such as Kommerell's diverticulum exceeding size thresholds. 1

Initial Evaluation

• Dedicated thoracic aortic imaging with CT or MRI is essential for all patients with right aortic arch, as this anomaly is associated with thoracic aortic aneurysm in 2-8% of cases 1
• Assess for symptoms of compression, which may include:
  • Dysphagia (difficulty swallowing) due to esophageal compression 1, 2
  • Respiratory symptoms from tracheal compression 1, 2
  • Hoarseness from recurrent laryngeal nerve involvement (Ortner's syndrome) 3
  • Chest pain, pressure, fatigue, or neck/jaw/back pain 3
• Evaluate for the presence of Kommerell's diverticulum, a persistent remnant of the primitive dorsal aortic arch that may be present in 20-60% of patients with aberrant subclavian artery 1
• Screen for associated cardiac anomalies, as right aortic arch can be associated with congenital heart defects 4, 5
• Consider genetic testing, particularly for 22q11 deletion, which has been associated with right aortic arch variants 6

Key Measurements and Anatomical Assessment

• Two critical diameter measurements should be obtained using cross-sectional imaging 1:
  • The diverticulum orifice (measured radially and longitudinally at the aortic wall)
  • The combined diameter of the diverticulum and adjacent descending thoracic aorta
• Determine the specific type of right aortic arch:
  • Right arch with aberrant left subclavian artery
  • Right arch with mirror image branching
  • Double aortic arch (can be misdiagnosed as simple right arch) 6
• Assess whether the arch forms a complete vascular ring around the trachea and esophagus 2

Management Algorithm

Asymptomatic Patients

• For asymptomatic patients with normal-sized aortic arch:
  • Regular imaging surveillance is recommended 3
  • For isolated arch aneurysms <4.0 cm, reimaging with CT or MRI at 12-month intervals 3
  • For isolated arch aneurysms ≥4.0 cm, reimaging with CT or MRI at 6-month intervals 3

Symptomatic Patients

• For patients with symptoms attributable to the right aortic arch who are at low or intermediate operative risk, open surgical intervention is recommended 3, 2
• Symptoms warranting intervention include:
  • Respiratory distress from tracheal compression 2
  • Dysphagia from esophageal compression 2
  • Superior vena cava syndrome from vascular compression 3

Intervention Criteria Based on Anatomy

• Surgical or endovascular intervention is recommended when 1:
  • Kommerell's diverticulum orifice is >3.0 cm
  • Combined diameter of the diverticulum and adjacent descending aorta is >5.0 cm
  • For isolated aortic arch aneurysms ≥5.5 cm in asymptomatic patients with low operative risk 3

Surgical Approaches

• For right aortic arch forming a vascular ring:

  • Division of the left ductal ligamentum through a left thoracotomy is the standard approach 2
  • If Kommerell's diverticulum is present and >1.5 times the diameter of the subclavian artery, resection of the diverticulum and translocation of the aberrant subclavian artery is recommended 2

• For aneurysmal disease extending into the proximal aortic arch:

  • Hemiarch replacement is reasonable when extending from the ascending aorta 3
  • Open replacement requires cardiopulmonary bypass, hypothermia, and neurologic protection strategies 3

• For disease extending into the proximal descending thoracic aorta:

  • An elephant trunk procedure may be considered 3
  • Either traditional elephant trunk or frozen elephant trunk techniques can be used depending on anatomy 3

• For high-risk patients:

  • A hybrid or endovascular approach may be reasonable for those who meet criteria for intervention but have high risk from open surgical repair 3

Postoperative Considerations

• Most patients experience symptom resolution within months to years after surgery 2
• Some patients may have persistent tracheobronchial narrowing despite surgical intervention 2
• Long-term follow-up imaging is essential to monitor for recurrence or development of new aortic pathology 3

Important Caveats

• Prenatal diagnosis of right aortic arch warrants careful postnatal evaluation, as fetal ultrasound may not accurately distinguish between right arch and double aortic arch 6
• Right aortic arch can be misdiagnosed; what appears to be a simple right arch may actually be a double aortic arch with atresia of one segment 6
• The presence of right aortic arch should prompt evaluation for associated genetic syndromes, particularly 22q11 deletion 6
• Surgical outcomes are generally favorable, with low mortality and morbidity primarily related to associated cardiac anomalies rather than the arch repair itself 2