Flow-dependent changes in topography of LVAD poly(urethane urea) blood sacs implanted in calves

Left ventricular assist devices (LVADs) were implanted in calves for 30 days. The surface topography of poly(urethane urea) blood sacs retrieved from the LVADs varied with blood pump flow rates and regions with different flow dynamics in the sac. Structures similar to those observed in a fibrin clot were observed in the inlets and outlets. The topography of the region between was distinctively different from that of the inlet and outlet.