Letter to the Editor

Reference values of the right ventricular outflow tract (RVOT) proximal diameter in 665 healthy children and calculation of z-score values

Conduit dilatation above 110% and TPVI in conduits <16 mm is not recommended. However, if we want to reach normal values for RVOT diameters and diminish reintervention rates, pushing these boundaries is essential.

Analysis of subsequent patients who underwent TPVI with Edwards Sapien valves in conduits ≤16 mm between 2010 and 2020.

In n = 33 cases median age was 13 years (5–20 y) and median weight 47 kg (15–91 kg). Preexisting RVOT grafts were n = 28 Contegra® conduits and n = 5 homografts (12 mm n = 15; 14 mm n = 11; 16 mm n = 7). Implanted were the Sapien (n = 8), Sapien XT (n = 10) and Sapien 3 valve (n = 15) with 20 mm (n = 4), 23 mm (n = 19), 26 mm (n = 9) and 29 mm (n = 1). Mean minimal RVOT diameter after TPVI was 22,7 ± 2,3 mm (18–30 mm) which is 150% of the mean minimal RVOT diameter before TPVI (15,1 ± 4,3 mm). Covered stents were used in n = 10 cases. Contained conduit rupture occurred in n = 7 cases (21%). Residual RVOT gradients of 5,7 ± 4,9 mmHg (0–18 mmHg) showed adequate RV unloading.

TPVI could be performed successfully in all patients. Dilatation above 150% and a valve/conduit diameter ratio up to 2,4 were well tolerated. There was a considerable amount of conduit rupture but all were confined without further need for intervention or surgery.