Background:
Cardiovascular surgery is confronted by thrombosis and intimal hyperplasia of prosthetic bypass grafts [1]. Seeding of endothelial cells can reduce thrombogenicity; however, current animal models have limited relevancy [2]. The aim was to establish a clinically relevant porcine model of seeded peripheral bypass.

Material and Methods:
Vascular prostheses (knitted Dacron, 6mm, VUP, Joint-Stock Comp., Brno, CZ) were modified with cell-adhesive protein assemblies - fibrin gel and fibronectin. Autologous endothelial cells were harvested from internal jugular vein and seeded in the lumen. Endothelialized and control grafts were implanted in the same animal. Surgical feasibility of hind-limb bypass was tested in 5 animals (iliac-femoral, aortic-external iliac, aortic-internal iliac) and 5 other seeding procedures were performed. The patency was assessed by clinical status, angiography or ultrasound. Explants were observed in confocal microscope.

Result:
Mean period of double-stage seeding procedure was 50±16 days. Mean seeding density was 60×10exp3 cells/cm2. Two seeded grafts spontaneously occluded together with control grafts during 22 and 38 days, one got thrombosed due to sepsis, one due to poor outflow tract and one remained patent 22 days while control graft got occluded.

Conclusion:
The most durable surgical setting is bilateral aortic-internal iliac bypass graft with ligature of the external iliacs. Minipig represents more suitable model than domestic pig. Pre-coating vascular prosthesis with fibrin/fibronectin provides substratum for colonization with autologous endothelium. This may subsequently inhance the graft patency.