What is balloon pulmonary valvuloplasty (BPV) for pulmonary stenosis (PS) in heart disease?

Balloon Pulmonary Valvuloplasty (BPV) for Pulmonary Stenosis

Balloon pulmonary valvuloplasty is the treatment of choice for significant valvular pulmonary stenosis, relieving obstruction through commissural splitting with minimal complications and excellent outcomes. 1, 2

What BPV Is and How It Works

Mechanism of Action:

• BPV is a percutaneous catheter-based procedure that relieves pulmonary valve obstruction by splitting fused commissures of the stenotic valve 1
• The procedure has been the gold standard since 1982, replacing surgical valvotomy as first-line therapy for classic domed valvular pulmonary stenosis 1
• In the VACA registry of 784 cases, mean transvalvular gradients decreased from 71 to 28 mm Hg in typical pulmonary stenosis 1

Technical Procedure Details

Procedural Approach:

• Access is obtained through the right femoral vein 1
• Balloons are intentionally oversized to 1.4 times the measured pulmonary annulus diameter for optimal results 1
• In adults, a double-balloon technique is frequently used to achieve adequate oversizing 1
• Success is defined as achieving a final valvular gradient less than 20 mm Hg 1

Clear Indications for BPV

Class I Recommendations (Must Perform):

For Asymptomatic Patients with Domed Valve:

• Peak instantaneous Doppler gradient >60 mm Hg OR mean Doppler gradient >40 mm Hg (with less than moderate pulmonary regurgitation) 1
• RV-to-pulmonary artery peak-to-peak gradient >40 mm Hg at catheterization 1, 2

For Symptomatic Patients with Domed Valve:

• Peak instantaneous Doppler gradient >50 mm Hg OR mean Doppler gradient >30 mm Hg (with less than moderate pulmonary regurgitation) 1
• RV-to-pulmonary artery peak-to-peak gradient >30 mm Hg at catheterization 1, 2

Important Caveat: Peak instantaneous Doppler gradients systematically overestimate catheterization peak-to-peak gradients by approximately 20 mm Hg; mean Doppler gradients correlate better with catheterization measurements 1

When Surgery Is Preferred Over BPV

Surgical therapy is recommended instead of BPV for: 1

• Hypoplastic pulmonary annulus
• Severe pulmonary regurgitation already present
• Subvalvular or supravalvular pulmonary stenosis
• Most dysplastic pulmonary valves (though BPV may be reasonable in selected cases)
• Associated severe tricuspid regurgitation
• Need for concurrent surgical Maze procedure

Expected Outcomes and Efficacy

Success Rates:

• Immediate success (gradient <50 mm Hg) achieved in 88% of cases 3
• Results are comparable to or better than surgical valvotomy 4
• Restenosis rates are low (0-4.8%) in patients without valve dysplasia 1
• Dysplastic valves have less impressive results, with gradients declining from 79 to 49 mm Hg (versus 71 to 28 mm Hg for typical stenosis) 1

Complications and Safety Profile

Common Acute Complications (Generally Minimal): 1

• Vagal symptoms during balloon inflation
• Catheter-induced ventricular ectopy
• Right bundle-branch block (occasionally)

Less Common but Important Complications: 1

• Pulmonary valve regurgitation (mild regurgitation common; moderate regurgitation occurs in 39% of cases)
• Pulmonary edema from increased blood flow to previously underperfused lungs
• Cardiac perforation and tamponade
• High-grade AV nodal block
• Transient RVOT obstruction ("suicidal right ventricle")

Critical Pitfall - "Suicidal Right Ventricle":

• This refers to abrupt infundibular obstruction occurring after relief of valvular obstruction 1
• Occurs in 25% of cases, particularly with valvular dysplasia 3
• Managed with volume expansion and beta blockade 1
• This postprocedural infundibular obstruction regresses over time 1

Long-Term Follow-Up Requirements

Surveillance Protocol:

• Periodic clinical follow-up recommended for all patients after BPV 1
• Specific attention to degree of pulmonary regurgitation, RV pressure/size/function, and tricuspid regurgitation 1
• Frequency determined by severity of hemodynamic abnormalities but at least every 5 years 1
• Clinical evaluation and echocardiography-Doppler every 1-2 years based on severity 2

Special Populations

Dysplastic Valves:

• BPV may be reasonable (Class IIb) in asymptomatic patients with peak gradient >60 mm Hg or mean gradient >40 mm Hg 1
• BPV may be reasonable (Class IIb) in symptomatic patients with peak gradient >50 mm Hg or mean gradient >30 mm Hg 1
• Results are less impressive than with typical domed valves 1

Neonates and Complex Defects:

• BPV is applicable to critical pulmonary stenosis in newborns 3
• Can be used for pulmonary stenosis associated with complex cardiac defects 4
• Previous surgery is not a contraindication 4