In infants with the birth defect tetralogy of Fallot (TOF), often seen in those with Alagille syndrome (ALGS), the use of right ventricular outflow tract (RVOT) stent angioplasty prior to surgical repair can effectively and safely increase pulmonary blood flow.
The findings were reported in a retrospective review published in Heart, Lung and Circulation.
RVOT stenting is often used palliatively in symptomatic patients as an effective, safe bridge prior to undergoing a definitive cardiac surgical repair.
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The current review evaluated all infants with TOF younger than 3 months of age who underwent placement of a primary native RVOT stent between January 2010 and December 2020 at The Children’s Hospital, Westmead, Sydney, Australia. In this institution, clinicians typically use an initial transcatheter approach, which is intended to increase blood flow, followed by actual surgical repair 3 to 9 months later.
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Twenty infants received a primary RVOT stent. Overall, 11 of the patients were male. The median birth weight of the infants was 2.68 kg (range, 1.91-2.98 kg). In all, 25% (5 of 20) of the infants were born prematurely at less than 37 weeks gestation. Further, 25% of the infants exhibited an underlying genetic syndrome, including ALGS, DiGeorge syndrome, trisomy 21, Russell-Silver syndrome, or CHARGE syndrome.
Among a variety of primary cardiac diagnoses reported in the infants was TOF in 14, doublet-outlet right ventricle/TOF variant in 4, unbalanced atrioventricular septal defect/TOF in 1, and pulmonary atresia with ventricular septal defect in 1. In addition, 1 infant exhibited branch pulmonary artery stenosis in the setting of ALGS, 2 had a left superior vena cava, 2 had a right-sided aortic arch, and 1 exhibited major aortopulmonary collateral arteries.
Indications for RVOT stent angioplasty included recurrent hypercyanotic spells in 12 infants and duct-dependent pulmonary blood flow in 8. Of the procedures performed, 18 were considered urgent and 2 were elective. At the time of stenting, 12 of the patients had a major noncardiac comorbidity, genetic syndrome, or a weight of less than 2.5 kg.
All of the 20 infants had a successful placement of at least 1 RVOT stent; 2 stents were used in 4 infants. Infant oxygen saturation levels improved significantly from a median of 80% prior to stenting to 91% post-procedurally (P <.001).
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Only a single major complication was reported—that is, transient complete atrioventricular dissociation, which required the use of isoprenaline infusion for less than 24 hours. Twelve infants required catheter re-intervention before definitive surgical repair
No procedure-associated deaths were reported, with a 30-day survival following stent placement of 100%. Two noncardiac deaths were reported, which were distant from the stenting and prior to the surgical repair. Eighteen patients attained definitive repair at a median age of 6.1 months. Median right and left pulmonary artery diameters showed statistically significant increases following RVOT stent placement (P =.01 and P =.006, respectively).
The researchers concluded, “RVOT stenting is a safe and effective intervention to augment pulmonary blood flow for young infants with symptomatic TOF.”
Reference
Luxford JC, Adams PE, Roberts PA, Mervis J. Right ventricular outflow tract stenting is a safe and effective bridge to definitive repair in symptomatic infants with tetralogy of Fallot. Heart Lung Circ. Published online March 22, 2023. doi:10.1016/j.hlc.2023.02.010
