Rationale and feasibility of transcatheter pulmonary valve implantation in small conduits with the Edwards Sapien valves.

Background: 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.

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

Results: 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.

Conclusion: 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.