Body cavities as bioreactors to grow arteries

Abstract ‘Artificial blood vessels’ were grown in the peritoneal or pleural cavities of the dog for autologous transplantation as arterial interposition grafts. Tubing up to 250 mm long, either bare or wrapped in biodegradable polyglycolic acid (Dexon) mesh, was inserted into the body cavities using minimally invasive techniques. After 3 weeks, the tubes and their tissue capsules were harvested then the inert tubing discarded. The wall of living tissue was uniformly 1–1.5 mm thick and consisted of multiple layers of myofibroblasts that stained for α-smooth muscle actin, and extracellular matrix overlaid by a single layer of mesothelium. The bursting strength of tissue tubes with no biodegradable mesh scaffolds was in excess of 2500 mm Hg and the suture holding strength was 11.5 N. Tissue tubes (5–7 cm) were transplanted as interposition grafts into the femoral artery of the same dog in which they were grown where they remained patent until harvest at 3 to 6.5 months. Endothelial-like cells lined the lumen and the cells of wall stained for α-actin, smooth muscle myosin and smoothelin; a thick ‘neo-adventitia’ contained vasa vasorum. These studies demonstrate that peritoneal and pleural cavities of large animals can function as a bioreactor to grow tissue tubes for use as autologous vascular grafts.