Contraindications of Pulmonary Artery Banding
The primary absolute contraindication to PA banding is retrograde aortic arch obstruction with a fully patent ductus arteriosus, as stent placement covering the tiny retrograde orifice can cause acute coronary flow obstruction 1.
Absolute Contraindications
- Retrograde aortic arch obstruction with patent PDA: This represents the only clearly defined absolute contraindication in guideline literature, specifically in the context of hybrid stage I palliation for HLHS, where coronary perfusion depends on retrograde flow through a small aortic orifice 1
Relative Contraindications & High-Risk Scenarios
Elevated Pulmonary Vascular Resistance
While not an absolute contraindication, PA banding becomes problematic when:
- PVR >6-8 Wood units·m² without positive vasoreactivity testing 2
- PVR-to-SVR ratio >0.3 that doesn't respond to vasodilator challenge 2
- These thresholds indicate established pulmonary vascular disease where banding may not adequately protect the pulmonary vasculature
Severe Subaortic Stenosis at Presentation
In patients with double inlet left ventricle with transposition (DILV/TGA):
- Severe subaortic stenosis present at initial presentation represents a relative contraindication 3
- However, mild-to-moderate subaortic stenosis is NOT a contraindication if early surveillance and relief are planned
- The key is avoiding long-term banding without addressing progressive subaortic obstruction 3
Clinical Context & Modern Indications
When PA Banding Remains Appropriate
PA banding is not contraindicated in several scenarios previously thought problematic:
- DILV/TGA with aortic arch obstruction (72% survival when combined with early subaortic stenosis relief) 3
- Single ventricle physiology requiring staged palliation 4
- Multiple or muscular VSDs not amenable to primary repair 4
- Complete atrioventricular septal defects in high-risk infants 4
Technical Considerations That Limit Applicability
Several factors make PA banding less suitable but are not absolute contraindications:
- Older children where achieving sufficiently tight banding becomes technically difficult 5
- Complex lesions now amenable to primary repair in experienced centers 4
- Severe ventricular dysfunction or significant tricuspid regurgitation (though these may favor hybrid approach rather than contraindicate banding) 1
Critical Pitfalls to Avoid
Long-term banding without surveillance: The historical poor outcomes with DILV/TGA reflected leaving bands in place long-term without recognizing subaortic stenosis, not the banding itself 3
Inadequate hemodynamic assessment: In older patients with bidirectional shunting, failure to perform vasodilator testing before banding can lead to poor outcomes 2
Ignoring postoperative hemodynamics: Target peak RV-PA gradient >39.5 mmHg and maintain stable mean arterial pressure to reduce prolonged mechanical ventilation risk 6
The role of "treatment and repair" strategies with prolonged PA banding remains controversial and poorly defined, suggesting a conservative approach when upper limits of operability are uncertain 2.