A Small-Diameter Tricuspid Valve Prosthesis for the Correction of Congenital Heart Defects Based on an Adult Donor Mitral Valve Homograft

BACKGROUND: Tricuspid valve replacement is the preferred method when valve repair is not feasible. Stented xenobioprostheses, which limit the growth of the fibrous ring due to their rigid titanium frame and often have a short service life, are particularly problematic in children. An alternative approach is the implantation of a mitral valve homograft in the tricuspid position, which is more resistant to calcification. However, the limited availability of small-diameter homografts from adult donors restricts their use. To address this, a new technique for downsizing an adult mitral homograft was developed and tested in a wet lab and in silico (using 3D printing technologies). METHODS: Two techniques for reducing the size of the mitral homograft were developed: one creating a single papillary muscle and the other creating two neo-papillary muscles. The hydrodynamics of the resulting prostheses were assessed using visual inspection and ultrasound evaluation. RESULTS: It was demonstrated that reducing the mitral homograft by resecting the commissures, a portion of the anterior leaflet, and the posterior leaflet along with their subvalvular structures is a reliable method. This technique does not violate the congruence of the anterior and posterior leaflets and ensures optimal hydrodynamic parameters. CONCLUSIONS: The proposed technique makes it possible to downsize an adult mitral homograft to a "pediatric" size. It can be used clinically as an intraoperative adaptation technique, performed on the "back table" in 30-40 minutes.