Performance of allogeneic bioengineered replacement pulmonary valves in rapidly growing young lambs

Biological valve conduits can enlarge via passive dilatation without matrix synthesis, but this would result in decreased cusp coaptational areas. Bioengineered valves demonstrated similar annulus enlargement as cryopreserved valves but usually retained larger areas of cuspal coaptation. Heat-shock protein 47-positive (collagen-synthesizing) cells were present in previously acellular bioengineered sinus walls and cusp bases, but rarely in more distal cusp matrices.