Abstract 11316: Successful Replacement of Beagle Pulmonary Valves by In Vivo Tissue-Engineered Valved-Conduits with the Sinus of Valsalva: Completely Autologous Tissue “BIOVALVEs” with No Synthetic Support Materials
Objectives: We developed autologous valved-conduits with the sinus of Valsalva (BIOVALVEs) using simple, safe and economical in vivo tissue engineering, which is a practical concept of regenerative medicine. In this study, the BIOVALVEs were successfully replaced to the pulmonary valves in a beagle model.
Methods: A pair of the custom-designed silicone rods was assembled with a small aperture in a trileaflet shape, as a mold for BIOVALVE preparation. One of the rods had 3 projections that resembled the sinus of Vasalva. BIOVALVEs were obtained after placement of the molds in the dorsal subcutaneous spaces of beagle dogs for 4 weeks. They were subsequently auto-implanted to the main pulmonary arteries under cardiopulmonary bypass after technical establishment in pilot study using allogenic implantation.
Results: The BIOVALVEs with a diameter of 14–18 mm had 3 separated leaflets in the luminal surface of the conduit with the sinus of Valsalva. They were composed only of autologous connective tissues without any support of synthetic materials, and had adequate mechanical properties similar to those of native valves. Tight valvular coaptation and sufficient open orifice area were observed under the flow circuit in vitro. In implantation experiment, postoperative echocardiography demonstrated smooth movement of the leaflets with trivial regurgitation and low pressure-gradient. In the histological examination after 3-month implantation, the surface of the leaflet was covered with endothelial cells. Neointima, including an elastin fiber network and circumferentially oriented smooth muscle cells, was formed at the anastomosis sites of the conduit, indicating rapid tissue regeneration.
Conclusions: Completely autologous BIOVALVEs have excellent biological and mechanical compatibilities with a potentiality for clinical applications in the treatment of patients with valvular disease including children in growth.
- © 2010 by American Heart Association, Inc.