Development of collagenous linings on impermeable prosthetic surfaces

In an effort to accelerate development of a biologic lining on the fibrillar surface of a left ventricular assist pump, the blood-contacting interface was covered with bovine fetal fibroblasts immediately prior to implantation into the animal. Selection of these syngeneic cells was based on their demonstrated prolificacy and abundant collagen production. Comparative studies, carried out in 17 Holstein calves, indicated that an adherent, thin, collagenous lining developed on the fibroblast-seeded polyurethane pump chamber in nine animals. Similar implantations of eight non-cell-seeded (control) devices resulted in formation of a predominantly acellular, fibrinous membrane, varying in thickness from 1 to 8 mm. Pump chamber compliance was significantly reduced when the histologic surface exceeded 3 mm in thickness, resulting in impaired filling and an inadequate stroke volume. The use of 14C-thymidine-labeled fibroblasts permitted later identification of the donor cells in the collagenous linings by radioautography. Serial immunologic studies undertaken to detect evidence of rejection in recipient Holstein calves were negative.