What is the treatment for transposition of the great vessels?

Treatment for Transposition of the Great Vessels

The primary treatment for transposition of the great arteries (TGA) is surgical correction, with the arterial switch operation (ASO) being the current standard of care for D-TGA, while various surgical approaches exist for L-TGA based on associated defects. 1, 2

Types of Transposition and Initial Management

D-Transposition of the Great Arteries (D-TGA)

• Most common form (5% of all congenital heart disease) 3
• Characterized by the aorta arising from the right ventricle and pulmonary artery from the left ventricle
• Initial management in neonates:
  • Prostaglandin E1 infusion to maintain ductal patency
  • Balloon atrial septostomy (Rashkind procedure) to improve mixing of oxygenated blood
  • Early transfer to a specialized cardiac center 4

L-Transposition (Congenitally Corrected Transposition)

• Less common variant with both atrioventricular and ventriculoarterial discordance
• May not require surgery if uncomplicated, but heart failure develops by age 45 in 67% of patients with associated lesions and 25% without associated lesions 1

Surgical Approaches

For D-TGA:

1. Arterial Switch Operation (ASO) - Current gold standard 2, 5

   • First successfully performed by Jatene in 1975 6
   • Involves transection and "switching" of the great arteries with coronary artery transfer
   • Typically performed within first 2 weeks of life
   • 90% of patients now reach adulthood with this approach 2

2. Atrial Switch Operations (historical procedures)

   • Mustard or Senning procedures - create atrial baffles to redirect blood flow
   • No longer preferred due to long-term complications including systemic right ventricular failure, baffle leaks/obstruction, and arrhythmias 1, 5
   • 20-year survival rate is approximately 80-85% 1

For L-TGA:

1. Physiologic repair - Addresses associated defects while leaving the right ventricle in systemic position 7

2. Anatomic repair (Double Switch) - More complex operation that restores the left ventricle as the systemic ventricle 7

Post-Surgical Monitoring and Complications

After Arterial Switch Operation:

• Coronary artery complications: Stenosis or insufficiency requiring vigilant monitoring 2, 5
• Neoaortic root dilation and regurgitation: Generally well-tolerated but requires surveillance 2
• Pulmonary artery stenosis: Most common cause for reoperation (usually at anastomotic site) 1
• Arrhythmias: Less common than with atrial switch but should prompt evaluation for coronary insufficiency 2

After Atrial Switch (Mustard/Senning):

• Systemic right ventricular dysfunction: Progressive failure of the right ventricle in systemic position 1
• Baffle leaks and obstruction: Require regular imaging assessment 1
• Arrhythmias and sudden death: Higher risk compared to ASO 1

Imaging for Follow-up

• Echocardiography: First-line for anatomic and hemodynamic assessment 3
• Cardiac MRI: Excellent for assessing ventricular function, baffle patency, and great vessel relationships 1, 3
• CT: Alternative when MRI is contraindicated 3
• Chest X-ray: Shows narrow mediastinum due to parallel great arteries; useful for monitoring cardiomegaly 3

Long-term Outcomes and Care

• Prenatal diagnosis significantly reduces mortality and morbidity in TGA 4
• Early ASO improves outcomes with low mortality 2
• Neurodevelopmental abnormalities are common and require monitoring 2
• Lifelong specialized care at adult congenital heart disease centers is essential 3

Clinical Pearls and Pitfalls

• Pitfall: Delayed diagnosis and transfer to specialized centers significantly increases mortality (6% vs. 0% with prenatal diagnosis) 4
• Pitfall: Post-ASO arrhythmias or cardiac dysfunction should raise suspicion for coronary insufficiency 2
• Pearl: Patients with single or intramural coronary arteries have higher surgical risk factors 2
• Pearl: Adult patients may benefit from "exercise-prescription" rather than restriction 2

Regular, lifelong follow-up with specialists in adult congenital heart disease is mandatory for all TGA patients regardless of surgical approach.