Right Ventricular Outflow Tract Stenting is a Safe and Effective Bridge to Definitive Repair in Symptomatic Infants With Tetralogy of Fallot1.

INTRODUCTION:Right ventricular outflow tract (RVOT) stent angioplasty is a palliative procedure for neonates and infants with symptomatic tetralogy of Fallot prior to surgical repair. We review our institutional outcomes of RVOT stenting. METHODS:Retrospective review of all infants with tetralogy of Fallot under 3 months of age who underwent primary native RVOT stent angioplasty at The Children's Hospital at Westmead, Sydney, Australia between January 2010 and December 2020. Demographics and echocardiographic pulmonary artery dimensions were collected pre-stent angioplasty and prior to surgical repair. RESULTS:Twenty (20) infants underwent primary RVOT stenting. Median age at stent was 14 days (interquartile range [IQR] 7-32) and median weight 2.7 kg (IQR 2.1-3.4). Three patients underwent hybrid per-ventricular procedures. Indication for RVOT stenting was recurrent hyper-cyanotic spells in 12 (60%) and duct-dependent pulmonary blood flow in 8 (40%). Saturations increased from a median of 80% (IQR 75-85) to 91% (IQR 90-95) post procedure (P<0.001). A single major complication occurred: transient complete atrioventricular dissociation requiring isoprenaline infusion for <24 hours. Twelve (12, 60%) required catheter re-intervention prior to definitive repair for further augmentation of pulmonary blood flow. There were two non-cardiac deaths distant from the stent procedure, but prior to surgical repair. Median right and left pulmonary artery Z-scores increased respectively from -2.06 (IQR -2.99 to -0.17) and -1.2 (IQR -2.59 to -0.14) prior to RVOT stent, to -0.74 (IQR [-1.21 to 0.26], P=0.01) and 0.06 (IQR [-1.87 to 1.15], P=0.006) by the time of definitive repair. Eighteen (18) patients achieved definitive repair at a median age of 6.1 months (IQR 4.7-7.3). Palliation with more than one RVOT stent was associated with an increased duration of cardiac bypass (P=0.035) and cross-clamp (P=0.044) time at definitive repair. CONCLUSIONS:In symptomatic neonates and infants with tetralogy of Fallot at high-risk of peri-operative complications, RVOT stent angioplasty can safely and effectively augment pulmonary blood flow prior to definitive repair.