An experimental study of inferior vena caval stent in canine

To investigate the feasibility of our self made inferior vena cave (IVC) stent.

Self-expanding, stainless steel, Z-shaped stents were deployed in the IVC of 14 dogs. They were randomly divided into four groups, four dogs in the first three groups, and 2 in the fourth group. IVC specimens were taken at 2, 4, 8 and 16 weeks following stent deployment. No anticoagulant or antiplatelet therapy was given.

All stents were widely stretched out and so was the vessel lumen. No thrombus was present and the patency was 100% in all groups. The stents were completely covered by neointima 2 weeks after stent deployment. The neointimal thickness varied significantly: the thinnest at 2 weeks, the thickest at 4 weeks and becoming thinner at 8 weeks and stable until 16 weeks. The inflammatory reaction was gradually reduced. Under scanning electronic microscopy, the neointima was covered by a layer of endothelial cells 2 weeks following stenting, which were irregularly shaped and aligned. The cells became slender, spindle-shaped and aligned parallel to the direction of bolld flow 4 weeks afterwards.

Experimental study indicated that our self-expanding IVC stent was feasible for clinical application.