Endothelial cell--seeded four-millimeter Dacron vascular grafts: effects of blood flow manipulation through the grafts.

The objective of this study was to compare the surface thrombogenicities of endothelial cell-seeded small-diameter vascular grafts with those of nonseeded contralateral grafts under conditions of acute controlled low blood flows through the grafts in a canine carotid artery model. Autologous venous endothelial cells seeded in the preclots onto 6 cm sections of 4 mm (internal diameter) double-velour Dacron grafts covered 15% and 80% of graft luminal surfaces at 3 and 5 weeks postsurgically, respectively. Contralateral nonseeded control graft lumina had pannus ingrowth of endothelium across the anastomoses only. There were significant differences in initial carotid graft blood flow rates between seeded and control grafts at both 3 and 5 weeks postsurgically. When blood flow was reduced to 30% of the initial flow levels for 4 hours through these grafts, endothelial cell-seeded grafts maintained patencies and mean blood flow returned to 63.3% and 93% of initial flow levels at 3 and 5 weeks postsurgically, respectively. Few thrombi accumulated. In contrast, thrombi accumulated on nonseeded graft lumina during restricted blood flow. Some nonseeded grafts occluded during low flows, and the ratios of final flow to initial flow were only 28% at 3 weeks and 20% at 5 weeks in these nonseeded grafts. These data demonstrate the efficacy of seeding autologous endothelial cells on small-diameter grafts in this canine model. If technically successful, endothelial cell seeding may provide a protocol for enhancement of the long-term implantation success of small-diameter vascular grafts used for human vascular repair and replacements.