Valves That Can Grow with a Child Pass 18-Month Test

Published November 7, 2017 | Journal of the American College of Cardiology

Long-term follow-up reveals that a novel replacement tricuspid valve designed to grow with a child continued to function normally in an ovine model throughout an 18-month study period, without signs of calcification.

This contrasts with significant calcific degeneration seen by three months post-surgery in all currently available bioprosthetic valves tested in this model, according to a study led by Scott Baker, Senior Research Associate, and David Morales, MD.

The study continued an ongoing evaluation of a valve made by Georgia-based CorMatrix Cardiovascular, Inc., from a material called small intestinal submucosa–derived extracellular matrix (SIS-ECM). Previous research demonstrated successful valve function for up to eight months.

Developing a valve that can grow without calcification has been an important goal for pediatric heart surgery. Currently, children who need replacement valves at a young age require repeated procedures to adjust to their changing body size and blood flow demands.

The research team demonstrated that the SIS-ECM valves allowed resident mesenchymal cells to migrate into the scaffold where they organized themselves to form chordae and a cell-matrix structure similar to mature native valve tissues. All animals grew normally, with investigators noting “stable trivial-to-mild regurgitation of the SIS-ECM valve.” On average, annular diameter increased from 17 ± 1 mm to 32 ± 2 mm.

The device has not yet received U.S. FDA approval, but a clinical trial is pending.

Worldwide, more than 200 of these valves have been implanted in adults and a small number in children, including two at Cincinnati Children’s. Meanwhile, ovine studies have begun to evaluate SIS-ECM material for mitral valve replacement.