Skeletal Muscle Ventricles Seeded With Autogenous Endothelium

Skeletal muscle ventricles (SMVs) are muscular pumping chambers constructed from skeletal muscle. Previously, SMVs were connected to the systemic circulation with vascular conduits and used to assist the heart. In this study, SMVs were constructed from the latissimus dorsi muscle in eight dogs. The SMVs were seeded with autologous endothelial cells, but not connected to the circulation. Endothelial cells were harvested enzymatically from autogenous external jugular vein and grown in tissue culture. After 9 weeks, 6 electrically conditioned SMVs were seeded with endothelial cells by injecting 4-5 ml of culture medium containing 5-8 x 10(6) autogenous endothelial cells into each SMV lumen adjacent to the mandrel. Conditioning was stopped at the time of endothelial seeding. One week after seeding, electrical conditioning was resumed. Two weeks after seeding, the animals were killed and the SMVs excised. Histologic examination confirmed the presence of a confluent monolayer of cells covering 80-100% of the luminal surface in each seeded SMV. The endothelial nature of the cells lining the SMV lumen was established by fluorescent microscopy. Endothelial cells were pre labeled with the cellular marker PKH before seeding; the SMVs were also incubated with the endothelial marker dil-acetylated LDL. Endothelial cells also were identified by staining with fluorescently labeled antibodies to von Willebrand factor. Based upon these data, electrically conditioned SMVs can be seeded successfully with a near-complete, autologous endothelial monolayer. Additionally, this endothelial monolayer can be maintained on the luminal surface of a contracting SMV. In-circulation studies will determine whether endothelial cell seeding of SMVs can decrease or eliminate the incidence of thromboembolism.