title: Improved healing of microvascular PTFE prostheses by induction of a clot layer: an experimental study in rats.
abstract: This study was undertaken to test the hypothesis that the induction of a clot layer on the graft surface of microvascular polytetrafluoroethylene (PTFE) prostheses might improve their healing. PTFE microvascular prostheses (n = 18), mechanically roughened PTFE microvascular prostheses (n = 18), and Chitosan-impregnated PTFE microvascular prostheses (n = 18) (all prostheses: length 1 cm, inside diameter 1.5 mm, fibril length 30 microns) were implanted into the abdominal aortas of rats and were evaluated at 3 days (n = 3), 10 days (n = 3), 3 weeks (n = 6), and 6 weeks (n = 6) with regard to the presence or absence of a clot layer and with regard to the amount of graft healing. All untreated PTFE prostheses were never found to be covered with a clot layer, only scarcely with some platelets, and showed poor neoendothelial healing; even at 6 weeks after implantation, there was only endothelial cell coverage near the anastomotic sides (coverage = 19 +/- 4 percent). The endothelial cells were present directly on the graft surface. In contrast, both the roughened and the Chitosan-impregnated PTFE prostheses were completely covered with a thin clot layer upon implantation and demonstrated significantly better neoendothelial healing (endothelial cell coverage at 6 weeks = 76 +/- 22 percent and 75 +/- 18 percent, respectively; p less than 0.001); moreover, in these prostheses, the endothelial cells were present on a matrix of smooth-muscle cells, which covered the graft surface completely. These results confirm our hypothesis that the induction of a clot layer on the graft surface of microvascular PTFE prostheses improves their healing.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of General Surgery, University Hospital of Groningen, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: van der Lei
authors.forename: C R
authors.initials: CR
authors.lastname: Wildevuur
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D001777:Blood Coagulation / Q000187:drug effects; D001807:Blood Vessel Prosthesis; D002686:Chitin / Q000494:pharmacology; D048271:Chitosan; D006490:Hemostatics / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D011138:Polytetrafluoroethylene; D051381:Rats; D013499:Surface Properties; D014945:Wound Healing
chemical_list: D006490:Hemostatics; D002686:Chitin; D011138:Polytetrafluoroethylene; D048271:Chitosan