Prognosis and Management of Complex Congenital Heart Disease with Hypoplastic Left Ventricle, Hypoplastic Aortic Arch, and DORV
The constellation of findings including hypoplastic left ventricle (HLV), hypoplastic aortic arch (HAA), interrupted aortic arch (IAA), subaortic valve stenosis, and double outlet right ventricle (DORV) represents a severe form of complex congenital heart disease that requires staged surgical palliation with a Norwood procedure followed by eventual Fontan completion, as these defects are not amenable to biventricular repair.
Understanding the Diagnosis
Your fetal echocardiograms show a progression of complex cardiac anomalies:
- 24-week echo: Hypoplastic left ventricle (HLV), hypoplastic aortic arch (HAA), enlarged pulmonary artery (PA) and right ventricle (RV)
- 32-week echo: Interrupted aortic arch (IAA), subaortic valve stenosis, very small left ventricle, double outlet right ventricle (DORV)
These findings represent a "univentricular heart" condition classified as "Great Complexity" (Class III) according to the ACC/AHA guidelines 1. This constellation of defects creates a situation where:
- The left ventricle is too small to support systemic circulation
- Blood flow to the body is obstructed by the interrupted aortic arch
- The right ventricle is the dominant functioning chamber
- Both great arteries (aorta and pulmonary artery) arise predominantly from the right ventricle
Prognosis
The prognosis for this complex combination of defects is guarded:
- Without intervention, this condition is not compatible with life after birth
- With modern staged surgical palliation, survival rates have improved significantly:
Management Pathway
Management involves a staged surgical approach:
Stage 1: Norwood Procedure (Neonatal Period)
- Performed shortly after birth
- Creates a new aorta using the pulmonary artery and establishes systemic blood flow
- Provides controlled pulmonary blood flow through a shunt
- Ensures unrestricted blood mixing at the atrial level
Stage 2: Bidirectional Glenn/Hemi-Fontan (4-6 months of age)
- Connects the superior vena cava directly to the pulmonary arteries
- Reduces volume load on the single functioning ventricle
- Improves oxygen saturation
Stage 3: Fontan Completion (2-4 years of age)
- Connects the inferior vena cava to the pulmonary arteries
- Completes the separation of pulmonary and systemic circulations
- Creates a "series circuit" with the single ventricle pumping to the systemic circulation only
Special Considerations for Your Case
The combination of IAA with subaortic stenosis and DORV presents specific challenges:
- Subaortic stenosis must be addressed during surgical planning as it can lead to poor outcomes if not managed appropriately 3
- The interrupted aortic arch requires reconstruction during the Norwood procedure
- The very small left ventricle confirms that a biventricular repair is not feasible
Monitoring and Follow-up
After birth, your baby will need:
- Immediate stabilization with prostaglandin E1 to maintain ductal patency
- Comprehensive cardiac evaluation including echocardiography
- Genetic testing to rule out associated syndromes (such as DiGeorge syndrome or Trisomy 18) 4
- Evaluation for associated non-cardiac anomalies
Important Caveats
- Timing of surgery is critical - delays can lead to pulmonary overcirculation or inadequate systemic perfusion
- The presence of severe subaortic stenosis with IAA requires special surgical consideration to avoid postoperative low cardiac output 3
- Long-term complications after Fontan completion include arrhythmias, ventricular dysfunction, protein-losing enteropathy, and thromboembolism
- Lifelong specialized ACHD (Adult Congenital Heart Disease) care will be required
This complex cardiac condition requires management at a specialized congenital heart center with expertise in single ventricle palliation and a multidisciplinary team approach.