Prostacyclin (PGI2) and plasminogen activator (PA) activity in umbilical vein grafts. An experimental study.

Glutaraldehyde-tanned human umbilical cord vein grafts (Dardik Biograft, Meadox) (HUV) measuring 6 cm in length and 5-6 mm in diameter were placed in the carotid arteries (CA) or jugular veins (JV) of sheep and the anastomoses were made end-to-end. Sections from the anastomotic sites and mid-graft were submitted to prostacyclin (PGI2) (radioimmunoassay) and plasminogen activator, PA, (histochemical) assays. Anastomotic PGI2 production from 6 grafts placed in the CA and removed 10 days later was similar to that of control arteries. The midgraft PGI2 synthesis tended to be less but the difference was not statistically significant. Anastomotic PGI2 from 11 grafts placed in the CA and removed 90 days later was also similar but the midgraft production was significantly less (p less than 0.025). From the distal anastomoses and mid portion of grafts placed in the jugular veins and removed 10 days later PGI2 synthesis was significantly less than that of control veins (p less than 0.025 and p less than 0.005 respectively) but no difference between the proximal anastomosis and control veins was observed. In none of 11 HUV removed on the 10th postoperative day was there any PA in the neointima; however, in 6 out of the 9 HUV removed on the 90th postoperative day, PA was demonstrated in the neointima. In conclusion, PGI2 synthesis similar to that of control vessels but less from the mid-graft regions. Neointima gained the ability to produce plasminogen activator.