Expandable Valve for Pediatric Application Constructed From Human Venous Valved Conduit Within a Stent.

Abstract

Options for pediatric valve replacement are limited by inability to adapt to child growth. An expandable valve design is presented in which human cryopreserved venous valved conduits are constructed within a bare-metal stent scaffold. We demonstrate functionality in vitro and acute competence in vivo. A cryopreserved femoral venous valved conduit was compressed within a bare-metal stent scaffold and sutured at the proximal and distal ends. In vitro testing was performed at low and high pressure after sequential balloon expansion. Valve morphology was measured in the nondistended state. The construct was tested in 2 patients. In vitro testing confirmed competence of the 14-mm femoral valve construct at 10-mm to 14-mm diameters. The median leaflet commissural height-to-diameter ratio was 2.2 (range, 1.6 to 4.1) for femoral. The construct was implanted in 2 patients at internal diameters of 6 mm and 8 mm. Echocardiograms demonstrated competence at short-term follow-up. In 1 patient, competence was demonstrated after balloon expansion. This study demonstrates the feasibility of this expandable valve design using an allograft venous valved conduit compressed within a stent.