RECOVERY OF ENDOTHELIAL-CELLS AND PROSTANOID PRODUCTION IN ENDOTHELIAL CELL-SEEDED GRAFTS

Objective: To investigate the function and morphology of endothelial c ell (EC) seeded grafts. Design: Experimental, open study. Chief outcom e measures: Endoluminal release of prostacyclin (6-Keto-PGF(1 alpha)) and thromboxane B-2 (TxB(2)), patency, EC coverage and cell identity M aterial: In 12 sheep, segments of both carotid arteries were excised. On one side a seeded and on the other an unseeded dacron graft were in serted. After 3 months the grafts were excised. In grafts and arteries , the endoluminal release of 6-keto-PGF(1 alpha) and TxB(2) suns deter mined in a perfusion system. Scanning electron microscopy (SEM) and li ght microscopy were used to determine the EC coverage and cell identit y. Results: Eight animals survived. Three seeded and two unseeded graf ts were occluded. Prostacyclin release did not differ significantly be tween seeded and unseeded grafts and arteries, when the arteries were looked upon as one group. When the graft was compared with its corresp onding artery i.e. the artery it replaced a significantly lower releas e was found in the unseeded group. Thromboxane release zoas undetectab le in arteries but significantly higher in both graft groups. SEM reve aled a cellular coverage of 75% in the seeded grafts and 50% in the un seeded (not significant). Light microscopy showed a patchy staining fo r Factor VIII-related antigen in some grafts in both groups. Conclusio n: Prostacyclin release in unseeded and seeded dacron grafts did not d iffer 3 months after implantation in sheep, except when the graft was compared with its corresponding artery. The significance of this remai ns to be settled. Seeded grafts did not have a higher proportion of en dothelial coverage than unseeded grafts.