Patency of biologic and prosthetic inferior vena cava grafts with distal limb fistula.

A 5-cm segment of the infrarenal inferior vena cava (IVC) in 27 dogs was excised and replaced with a prosthesis of bovine heterograft, venous allograft, or polytetrafluoroethylene (ePTFE). On completion of the IVC graft, a side-to-side femoral arteriovenous fistula was constructed in the thigh. At six weeks an IVC venogram was obtained to assess patency and the femoral arteriovenous fistula closed. After three months, the dogs were reexplored, the grafts were removed, and patency was determined. Patency of the venous allograft and bovine heterografts were maintained with the arteriovenous fistula in only two dogs and further deteriorated after closure of the fistula so that only one dog in each group had a patent IVC graft at the end of three months. Eight of the 13 e-PTFE prostheses were patent at six weeks and remained patent for three months after fistula closure. Light and electron microscopy of the patent e-PTFE specimens excised at three months showed regenerative endothelium. Expanded e-PTFE was the most suitable prostheses for replacement of the IVC, resulting in 61% patency three months after closure of a distal arteriovenous femoral fistula.