Outcomes After Stenting of Right Ventricular Outflow Tract for Tetralogy of Fallot and Its Variants

We reviewed our institutional database to examine the effect of right ventricular outflow tract (RVOT) stenting on branch pulmonary artery (PA) sizes and their outcomes. RVOT stenting was performed following standard technique. Since 2021, a conscious effort was made to spare the pulmonary valve (PV) whenever feasible. PA annulus and branch PA sizes were serially monitored by echocardiography. Sixty patients, (4.5 [1.75-24] months, weight 6.4 [3.5-9 kg]), were included (Time period:2012-2025). Commonest indications included cyanotic spell (65%) and hypoplastic branch PAs (30%). Pulmonary valve annulus measured 5.1 mm (4.0-7.7); Z score - 3.8 (- 5.1 to - 2.6), and MPA 4.35 mm (3.34-5.7); Z score - 4.9 (- 7.0 to [- 3.1]). At follow-up of 8(25-102) months, branch PAs grew in all, albeit at different paces. RPA z-scores improved from a baseline of - 2.48 (- 5.05 to [- 0.85]) to - 1.55 (- 3.07 to 0.46) and LPA z-scores from - 2.5 (- 4.38 to [- 0.78]) to - 1.08 (- 2.41 to 0.63) in hypoplastic PA group over 1-year period (p value < 0.001). Pulmonary valve was spared in 57% of patients in the cyanotic spell group and 22% of hypoplastic PA group. 29 (48%) patients underwent corrective surgery at 9 (6-14) months from RVOTS. Requirement of transannular patch (TAP) was 38% (11/29) and conduit was 34% (10/29). Valve sparing ICR was feasible in 67% (8/12) when the stent was placed below the valve. In addition to effective palliation, RVOT stenting promotes growth of branch pulmonary arteries even in those with inherently hypoplastic branch PAs. It is possible to effectively palliate selected patients without stenting across the pulmonary valve thereby potentially enabling valve-sparing TOF correction in those with suitable anatomy.