Experimental replacement of vena cava with expanded polytetrafluoroethylene graft.

Expanded polytetrafluoroethylene (Gore Tex) grafts were used for the replacement of the superior or inferior vena cava in dogs. When examined 2 weeks to 18 months after the replacement, the overall patency rate was 82%. If neither deformation nor narrowing of the graft on examination by cavagram had occurred within 14 days after implantation, the patency of the grafts remained unchanged. Ninety days after implantation, the formation of pseudointima was almost complete. However, since the grafts were not firmly anchored, superficial desquamation in their mid-portion continued for long periods. A composite graft made up of Gore Tex and noncrimped Dacron was studied in order to know the reason why high patency of the Gore Tex graft was obtained. The pseudointima of the Gore Tex graft gradually increased in thickness for 60 min, after which no further increase was observed. The pseudointima in the Dacron graft thickened markedly as time progressed and additional layers of blood cells accumulated on it. Although the ultimate fate of Gore Tex graft has not yet been determined, experimental trials indicate its suitability for patients requiring replacement of the vena cava.