Endothelial cell seeding of expanded polytetrafluoroethylene vena cava conduits: effects on luminal production of prostacyclin, platelet adherence, and fibrinogen accumulation.

The blood-surface interface of 12 mm ID x 5 cm ePTFE vena cava conduits, unseeded (n = 8) and seeded (n = 8) with enzymatically derived autologous endothelial cells, was studied in a canine model at 4 and 12 weeks after graft implantation. Acetylsalicylic acid (325 mg each day) and Coumadin (prothrombin time 1.4 to 1.7 times the control value) were administered preoperatively and continued 4 weeks postoperatively. Platelets labeled with 111In and 125I-labeled fibrinogen were administered 24 hours before graft removal. Luminal platelet adherence, expressed as 10(6) platelets/cm2 of graft surface, was 8.9 +/- 5.6 vs. 56.4 +/- 8.0 (p less than 0.008) and 4.0 +/- 0.9 vs. 12.4 +/- 2.3 (p less than 0.005) in seeded vs. unseeded grafts at 4 and 12 weeks, respectively. Luminal fibrinogen deposition, expressed in micrograms per square centimeter of graft surface, was 11.8 +/- 2.2 vs. 32.0 +/- 2.0 (p less than 0.06) and 6.1 +/- 2.4 vs. 12.4 +/- 6.3 (p less than 0.005) in seeded vs. unseeded grafts at 4 and 12 weeks, respectively. Cumulative 4- and 12-week luminal production of 6-keto-PGF1 alpha from seeded and unseeded grafts represented 11% and 5%, respectively, of that produced from the native iliac vein. Luminal endothelial cell coverage was 71% +/- 22% vs. 33% +/- 9% and 79% +/- 8% vs. 55% +/- 8% (p less than 0.05) in seeded and unseeded grafts at 4 and 12 weeks, respectively. Although endothelialization was not complete in seeded vena cava grafts, it is clear that seeded prostheses exhibited improved thromboresistance compared with unseeded conduits.