Pulmonary Valve Growth After Valve-Sparing Right Ventricle Outflow Tract Stenting in Tetralogy of Fallot: A Single-Centre Retrospective Cohort Study.

Right ventricular outflow tract (RVOT) stenting is an established initial palliation for neonates and infants with Tetralogy of Fallot (ToF). However, data on valve-sparing RVOT stenting and its impact on pulmonary valve (PV) growth are limited. Our aim was to evaluate pulmonary valve annular growth following valve-sparing RVOT stenting and to examine how this growth related to the type of definitive surgical repair performed. This retrospective single-centre study included 96 consecutive patients with palliated ToF over a 16-year period. Valve-sparing RVOT stenting was achieved in 46 patients, while 50 underwent valve-crossing stenting. PV growth was assessed using Z-scores in the valve-sparing group, and surgical strategies were compared between groups. In the valve-sparing group, PV annular Z-scores improved significantly from - 4.3 ± 1.3 at stenting to - 2.8 ± 1.0 before surgical repair (P < 0.001). In the valve-crossed group, final stent diameter Z-scores (-3.9 ± 1.9) showed minimal change from baseline (-4.5 ± 1.4). Time to surgical repair did not differ between groups. Definitive repair was achieved in 100% of valve-crossed cases and 95.6% of valve-spared cases, with similar weight between groups. A transannular patch (TAP) was performed in 65.9% of repaired valve-sparing patients and 64% of valve-crossed patients, while RV-PA conduit placement was performed in 22.7% and 36%, respectively. Valve-sparing repair was achieved in 11.4% of repaired patients in the valve-sparing cohort. Valve-sparing RVOT stenting is associated with significant pulmonary valve annular growth prior to definitive repair. Although only a minority of patients ultimately underwent valve-sparing surgery, the observed annular growth suggests that this strategy may increase future suitability for pulmonary valve preservation, subject to anatomical and surgical considerations.