A fibronectin substrate will significantly enhance the strength of endothelial cell attachment on grafts constructed of polyester elastomer (PE) and polytetrafluoroethylene (e-PTFE). This experiment was undertaken to determine the short-term in vivo stability of endothelium on these fibronectin coated surfaces. Eight mongrel dogs underwent bilateral carotid artery replacement with both graft materials. All grafts were Inoculated with 2,000 cells/mm2 using cultured autogenous venous endothelium labelled with Indium-111-oxine. The lndium-111 label in the grafts was measured immediately prior to implantation, after 1 hour of in vivo perfusion, and at explanation after 24 hours. The percentage of inoculated cells attached to the grafts before perfusion was similar for both materials, 93.3 ± 3.0% versus 92.2 ± 7.2%, for PE and e-PTFE respectively. All grafts were patent at one hour after implantation. PE grafts were found to have 93.8 ± 3.9% of the attached cells present at one hour while e-PTFE grafts had only 54.5 ± 10.8% remaining, p < .001. After 24 hours, 5/8 (62.5%) e-PTFE grafts and 2/8 (25.0%) PE grafts remained patent, p = .13. Of the patent grafts however, endothelial cell retention was still superior on the PE grafts with 78.0 ± 0.6% of the attached cells remaining compared to only 24.5 ± 6.1% on e-PTFE, p < .001. Occluded PE grafts had fewer cells remaining at 24 hours than patent ones, 78.0 ± 0.6% versus 31.1 ± 32.8%, respectively, p = .13. Histologically, patent PE grafts demonstrated nearly confluent endothelial monolayers while e-PTFE had patches of endothelial cells surrounded by a platelet-fibrin carpet. We conclude that short-term patency appears to be determined by the extent of endothelial retention on PE but not e-PTFE.
- Arterial grafts
- Endothelial cells
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine