Minute vascular replacements
B. A. Christie, V. Ketharanathan and L. J. Perloff
Glutaraldehyde-tanned, mesh-reinforced, mandrel-grown ovine collagen
conduits were compared with tanned human umbilical arteries and
polytetrafluoroethylene (PTFE) grafts in the aorta of rat recipients. All
grafts had 100% patency and became lined by a cellular neointima. The mean
maximum thickness of the neointima of the tanned human umbilical artery,
ovine collagen graft, and the PTFE grafts was 68, 57, and 13 micrometer,
respectively. Neointimal proliferation was complete for the two
biosynthetic grafts, but none was seen in the center of the PTFE grafts as
late as ten weeks. The mean increase in lumen cross-sectional area was 49%
for the umbilical artery grafts, 23% for ovine collagen conduits, and 4%
for the PTFE grafts. Longer follow-up periods will be required before
unqualified support can be given to clinical trials of these small-diameter
prostheses; however, long-term patency for synthetic grafts of such a small
caliber is encouraging for future microvascular applications and for study
of host-prosthesis interactions.
