Aortic valve conduit implantation in the descending thoracic aorta in a sheep model: The outcomes of pre-seeded scaffold

Background: We evaluated the outcomes of implanting pre-seeded decellularized aortic valve conduit (AVC) with bone marrow-derived mesenchymal stem cells (MSCs) in a sheep model.

Methods: Eight sheep AVCs were obtained under sterile conditions and decellularized by using detergent-based methods. Decellularized AVCs were seeded with autologous bone marrow-derived MSCs in a dynamic bioreactor system. Pre-seeded AVCs were implanted in the descending thoracic aorta in a sheep model. In all sheep, a decellularized pericardial patch was also anastomosed to the proximal part in order to reduce the incidence of rupture. Pathological evaluations, echocardiography, multislice computed tomography (CT), and CT angiography were performed for the evaluation of implanted AVCs.

Results: The longest survival period was 19 months in pre-seeded animals with complete recellularization at the long-term follow-up. Immunohistochemical staining for desmin, smooth muscle actin, and cytokeratin was significantly positive in the pre-seeded samples and reached near normal ranges. CT angiography revealed no intimal tearing after 18 months of follow-up.

Conclusion: Pre-seeded AVCs with bone marrow-derived MSCs may have satisfactory results in postoperative cell seeding capabilities with promising functional potentiality. This modality may be beneficial and may provide a new era of biological grafts in cardiovascular surgery.