OPTIMAL BOVINE PERICARDIAL TISSUE SELECTION SITES - I - FIBER ARCHITECTURE AND TISSUE THICKNESS MEASUREMENTS

Use of bovine pericardium as an engineered biomaterial in the fabricat ion of bioprosthetic heart valves is Limited, in part, by substantial intra-and intersac variations in its fibrous structure. To quantitativ ely assess this variability, we determined the fiber architecture of 2 0 whole BP sacs. Each sac was mounted on a prolate spheroidal mold, cl eared and preserved in 100% glycerol, then sectioned into four equisiz ed quadrants. This preparation method allowed for accurate intersac co mparisons and minimized tissue distortions. The fiber architecture was evaluated by small-angle Light scattering (SALS) using a 2.54-mm rect ilinear grid resulting in similar to 1200 SALS measurements per quadra nt, along with tissue thickness measured at 55 locations per quadrant. The fiber architecture was described in terms of fiber preferred dire ctions, degree of orientation, and asymmetry of the fiber angular dist ribution. The BP sac fiber architecture demonstrated substantial intra -and intersac variability, with local fiber preferred directions chang ing by as much as 90 degrees within similar to 5 mm. Overall, most sac s revealed potential selection areas in the apex region characterized by a high degree of orientation, high uniformity in fiber Preferred di rections, and uniform tissue thickness. However, the size, location, a nd fiber orientation of these potential selection areas varied suffici ently from sac-to-sac to question whether anatomic location alone is s ufficient for consistent localization of regions of high structural un iformity suitable for improved BHV design. (C) 1998 John Wiley & Sons, Inc.