Gore-Tex grafts for replacement of the superior vena cava.

In an effort to evaluate polytetrafluoroethylene (Gore-Tex) as a replacement for large veins, tubular grafts of the material were substituted for the precava in 33 mongrel dogs weighing 15 to 30 kg. Thirteen dogs had grafts 10 cm long by 12 mm wide with a 15-to 30 micron pore size; 15 dogs had grafts of the same length and width from 90-micron pore size material; and 5 dogs had grafts 5 cm long by 12 mm wide, of 90-micron pore size Gore-Tex. The effect of Gore-Tex tubes with and without spiral support and the differences in anatomical positions of the grafts were evaluated in terms of patency. Dogs were killed if a venogram showed occlusion of the graft. Twelve dogs survived 90 days; the longest survivor was killed at eleven months. At postmortem examination, the graft was patent but extremely narrow at the atrial end. Modification in the fabrication of Gore-Tex may eliminate factors contributing to graft failure; experiments longer than 90 days are necessary to evaluate Gore-Tex as a large vein replacement material. The 90-micron pore size material used in this experiment was unsuitable as a canine venous substitute.