Experimental replacement of the thoracic inferior vena cava with a high-porosity expanded polytetrafluoroethylene graft wrapped in an omental pedicle flap.

We examined the patency and healing of a high-porosity expanded polytetrafluoroethylene (ePTFE) graft implanted as an interposition graft in the thoracic inferior vena cava (IVC) and wrapped in an omental pedicle flap. High-porosity ePTFE grafts of 60 microns fibril length, with an internal diameter of 10 mm and a length of 4 cm, were implanted in 12 mongrel dogs. In 6 dogs, the grafts were wrapped in omental pedicle flap, and in the remaining 6 the grafts were unwrapped. The animals were killed 4 weeks after the replacement and the grafts were removed for examination. Patency of the graft in both groups was 100%; however, the thrombus-free area in the omentum-wrapped group was significantly larger (P < 0.05) than that in the unwrapped group. Light microscopy revealed the marked infiltration of cells and capillaries within the graft interstices in the omentum-wrapped group. These findings suggest that encapsulation of the high-porosity ePTFE graft is promoted by an omental pedicle flap.