What is the recommended treatment for a bicuspid aortic valve in pediatric patients?

Treatment of Bicuspid Aortic Valve in Children

Treatment of bicuspid aortic valve (BAV) in children is primarily determined by the presence and severity of aortic stenosis (AS) or regurgitation, not by the bicuspid anatomy itself. Most children with isolated BAV without significant valve dysfunction require only surveillance, as the majority remain asymptomatic during childhood with slow progression of disease 1, 2.

When Intervention is NOT Indicated

• No intervention is recommended for asymptomatic children with isolated BAV who have a resting peak systolic valve gradient (by catheter) <40 mm Hg and no symptoms or ST-T-wave changes on electrocardiography 3.
• Balloon dilation is contraindicated in children with isolated valvar AS who also have a degree of aortic regurgitation that warrants surgical aortic valve replacement or repair 3.

When Intervention IS Indicated

Critical Indications (Class I)

Aortic valvuloplasty is indicated regardless of valve gradient in newborns with isolated critical valvar AS who are ductal dependent or in children with isolated valvar AS who have depressed left ventricular systolic function 3.

Aortic valvuloplasty is indicated in children with isolated valvar AS who have a resting peak systolic valve gradient (by catheter) >50 mm Hg 3.

Aortic valvuloplasty is indicated in children with isolated valvar AS who have a resting peak systolic valve gradient (by catheter) >40 mm Hg if there are symptoms of angina or syncope or ischemic ST-T-wave changes on electrocardiography at rest or with exercise 3.

Conditional Indications (Class IIb)

• Aortic valvuloplasty may be considered in a child or adolescent with a resting peak systolic valve gradient (by catheter) >40 mm Hg but without symptoms or ST-T-wave changes if the patient desires to become pregnant or to participate in strenuous competitive sports 3.
• Aortic valvuloplasty may be considered for asymptomatic patients with a catheter-obtained peak systolic gradient <50 mm Hg when heavily sedated or anesthetized if a nonsedated Doppler study finds the mean valve gradient to be >50 mm Hg 3.

Choice of Intervention: Balloon Valvuloplasty vs. Surgery

Balloon aortic valvuloplasty has replaced open surgical valvotomy as the treatment of choice for children with moderate to severe congenital valvar AS in the majority of centers 3.

Expected Outcomes of Balloon Valvuloplasty

• A technically adequate balloon dilation typically reduces the catheter peak-to-peak systolic valve gradient to 20-35 mm Hg, achieving approximately 60% reduction in the peak systolic aortic valve gradient 3.
• The optimal ratio of balloon-annulus diameters is 0.9 to 1.0; larger-diameter ratios are associated with significantly greater risk of aortic regurgitation 3.
• Balloon dilation is palliative, not curative: freedom from reintervention is 86% after 1 year, 67% after 5 years, and 46% at 12 years 3.
• For newborns with critical AS, reintervention-free survival is only 48% at 5 years 3.

Surgical Repair Considerations

When surgical repair is performed, outcomes are excellent if the repair can be accomplished without the addition of pericardial patches 4.

• The 10-year freedom from any significant event is 60% for repairs without patch material, whereas nearly all patients with patch repair had an adverse event at that time 4.
• Independent predictive factors for event-free outcome include not using patch material (hazard ratio 12) and shorter bypass time 4.
• When repair results in bicuspid anatomy, freedom from aortic valve replacement at 10 years is 75.8%, which is superior to tricuspidization approaches (49.7% at 10 years) 5.

Management of Aortic Dilation

Intervention on the aorta itself is very rare during childhood and adolescence, as aortic dilation progresses slowly in pediatric patients 1, 2.

• Aortic dilation is significantly related to the presence and degree of aortic stenosis but not to aortic regurgitation 6.
• Aortic dilation-related complications are extremely rare in children 2, 6.
• Surgical intervention on the aortic root or ascending aorta is indicated when the diameter reaches ≥5.5 cm in asymptomatic patients with BAV 3.
• Intervention is reasonable at ≥5.0 cm if additional risk factors are present (family history of aortic dissection or aortic growth rate ≥0.5 cm per year) 3.

Surveillance Strategy

Children with isolated BAV without stenosis, regurgitation, or dilation require follow-up intervals that increase from 7±4 months in the newborn period to 28±14 months at 18 years of age 7.

• More frequent follow-up is recommended for younger patients and those with greater disease severity 7.
• CMR is recommended to assess the aorta and LV function every 1-3 years in children and adolescents if echocardiography is insufficient or pathology is suspected 3.

Common Pitfalls

• Avoid overestimating aortic dilation: traditional Z-score nomograms may overestimate the prevalence of aortic dilation in children compared to newer Q-score calculators (31.2% vs 15.4% prevalence in one study) 6.
• Do not perform balloon valvuloplasty with balloon-annulus diameter ratios >1.0, as this significantly increases the risk of aortic regurgitation 3.
• Risk factors for suboptimal outcomes after balloon valvuloplasty include patient age <3 months, higher predilation valve gradient, balloon-annulus diameter ratio <0.9, and presence of unrepaired coarctation 3.
• The risk of sudden death after balloon aortic valvuloplasty is highest in infants with elevated pulmonary artery pressure beyond 1 month of age 3.