[Comparative study of 3 implanted micrografts placed in the abdominal aorta of the rat].

A comparative study was conducted on three micrografts of 2 mm diameter: a frozen umbilical artery, a bovine heterograft and an inert P.T.F.E. material graft. These were implanted in the infrarenal aorta of 158 Wistar rats. Each graft was examined on eight occasions: after 4, 24 and 48 hours, one and two weeks, and 1, 2 and 6 months. Excluding 46 animals that died within 24 hours, the overall permeability rate for all grafts was 87.7% (88.9% for umbilical arteries, 82.8% for bovine heterografts and 85.4% for P.T.F.E.). All grafts were examined by optical and electron microscopy. The inert material showed excellent parietal stability. In contrast, alteration and resorption of the primary matrix were moderate in extent for bovine heterografts, and major for frozen umbilical arteries which appear to be a very unstable grafts.