Lab Grown Bioengineered Tissue-based Valved Conduit with Somatic Growth Potential and Framed Valve for Congenital Pulmonary Valve Disease

Abstract

Background: Congenital valve disease requires multiple interventions throughout a patient's lifetime as conventional bioprosthetic valves degrade and calcify. Current replacement options lack growth potential and lifelong durability, necessitating repeated surgeries for patients with congenital valve defect.

Objective: Evaluate bioengineered lab-grown tissue heart valves utilizing two complementary approaches: (1) a fibroblast-derived collagenous matrix valved conduit with somatic growth potential for surgical implantation, and (2) a bioengineered tissue-leaflet transcatheter pulmonary valve (TPV) for minimally invasive intervention.

Methods: For the valved conduit approach, 19mm conduits were implanted in growing lambs (n=3) for 52 weeks. For the TPV approach, bioengineered tissue leaflets mounted on nitinol stents were delivered via an 18Fr system and implanted in juvenile sheep (n=5) for up to 18 months. Both approaches were evaluated through serial echocardiography and histological assessment at explant.

Results: The valved conduits demonstrated somatic growth with increased diameter (38%) and leaflet length (25%) while maintaining mild or less regurgitation. The TPV implants showed sustained effective orifice area (>2cm²) without increased pressure gradients (<10mmHg) or regurgitation. Both approaches exhibited favorable histology with minimal calcification and appropriate cellular infiltration. The valved conduits successfully integrated with myocardium and demonstrated feasibility of subsequent stent placement, creating a pathway for future intervention without reoperation.

Conclusion: This dual-approach platform addresses immediate clinical needs through the TPV option while providing long-term solutions via the growth-accommodating valved conduit. The combined strategy offers potential for significantly reducing surgical interventions for children with congenital heart defects.