The use of microvascular graft as an arterial substitute in the abdominal aorta of the rat.

The purpose of this study was to compare by means of microsurgical techniques a porous with an interiorly smooth siliconized vascular graft. Compatibility and patency of the graft were examined in a long term follow-up. A microvascular prosthesis with a particular fibrous texture was used. The fibres consisted of polyurethane (PUR), a new prosthetic material. The lumen of the prosthesis measured 1.6 mm; the outer diameter was 2.4 mm. In group A an in- and exteriorly microporous graft was applied; in group B the inner surface of the prosthesis was smoothed by a silicon layer. 30 SPF-Wistar rats were randomized in group A (n = 15) and B (n = 15), and both prosthetic materials were implanted as a substitute for an infrarenal part of the abdominal aorta. Monofile suture material (MirafilR--DR 5) size 10:0 was used for the anastomosis. The mean pressure of the aorta amounted to 108 +/- 30 mm Hg. After 4 +/- 2 months the total survival rate was 77% (n = 23): in group A, 80% (n = 12); in group B, 73% (n = 11). Cause of death was early thrombosis due to technical mistakes. The following results were obtained by angiography: highest patency--group A, 8; group B, 1; constriction--group A, 6; group B, 9; occlusion--group A, 1; group B, 4; total--group A, 15; group B, 14; 1 angiography technically failed. Arterial substitution in the abdominal aorta of the rat by PUR-grafts is possible and is a suitable model for further experiments.(ABSTRACT TRUNCATED AT 250 WORDS)