title: Patency and neo-intima development in 10 cm-long microvascular polyurethane prostheses implanted into the rat aorta.
abstract: Microvascular fibrous polyurethane prostheses (inner diameter 1.5 mm, length 10 cm) were implanted in the abdominal aorta of rats. The prostheses were fixed in a loop. All rats (n = 37) were reoperated 6 weeks after implantation to verify the patency of the prostheses. Eight prostheses were obliterated from various causes. The remaining 29 prostheses were found to be patent 3 months after implantation, which gives a patency rate of 79%. Six weeks and 3 months after implantation 7 and 4 rats, respectively, with patent prostheses were sacrificed. The remaining 18 rats of this study are still alive, more than 4 months after implantation, and will be included in long-term observation studies. The prostheses were examined using both light and scanning electron microscopy. The patent prostheses exhibited macroscopically a clear and transparent inner surface. No obliterative processes could be found either macroscopically or microscopically. Neo-intima ingrowth had advanced +/- 10 mm into the prostheses over the anastomotic line from both ends 3 months after implantation, and was continued by a single endothelium layer for several centimeters. An acellular, stable fibrin film was found inbetween the cellular lining. The neo-intima was anchored at the prosthesis by cellular protrusions extending between the polyurethane fibers. Though 10 cm long prostheses were implanted under unfavorable hemodynamic conditions, a patency rate of 79% was achieved, both 6 weeks and 3 months after implantation. This patency rate could have been higher if evident technical failures had been avoided.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D001807:Blood Vessel Prosthesis; D004727:Endothelium / Q000473:pathology; D005337:Fibrin / Q000378:metabolism; D006083:Graft Occlusion, Vascular / Q000473:pathology / Q000503:physiopathology*; D006439:Hemodynamics; D008297:Male; D008833:Microcirculation / Q000503:physiopathology; D008855:Microscopy, Electron, Scanning; D011140:Polyurethanes; D051381:Rats; D011919:Rats, Inbred Strains; D012212:Rheology
chemical_list: D011140:Polyurethanes; D005337:Fibrin