ENDOLUMINAL PLACEMENT OF PTFE GRAFT-STENT DEVICES IN A CANINE MODEL

Endovascular placement of stents lined with prosthetic vascular graft materials offers promise in the treatment of dissections, aneurysms, a nd atherosclerotic occlusive disease. This study reports the developme nt of and initial experience with polytetrafluoroethylene (PTFE) graft -stent devices endoluminally deployed in canines. Each iliac artery in 6 heparinized dogs received a 6-mm-diameter tubular PTFE graft mounte d on either an 8 mm Palmaz stent (PS) or a metallic-ringed graft attac hment device (GAD). The graft-stent devices were introduced from the f emoral artery through a 14 Fr delivery catheter. Positioning and ballo on expansion of the graft-stent devices were aided by fluoroscopic and intravascular ultrasound (IVUS) assessment. Animals were studied acut ely (n = 2) or at weeks 1, 2, 4, or 8 after placement. No interval ant icoagulation was used. All 6 PTFE-PS devices remained patent. Two of 6 PTFE-GAD devices occluded (at two and four weeks, respectively) owing to initial inadequate deployment. Nonoccluding thrombus was present i n an additional 2 PTFE-GAD devices (acute and at one week, respectivel y) and in 2 PTFE-PS devices (at one week and two weeks, respectively). Complications included groin hematomas in 2 animals (at one week and two weeks, respectively) caused by the large traumatic delivery cathet er. Endoluminal placement of PTFE graft-stent devices is feasible. Acc urate assessment of deployment by IVUS, reduction of delivery catheter size, and improved graft-stent design are required.