Endoluminal Placement of PTFE Graft-Stent Devices in a Canine Model

Abstract

Endovascular placement of stents lined with prosthetic vascular graft materials offers promise in the treatment of dissections, aneurysms, and atherosclerotic occlusive disease. This study reports the development of and initial experience with polytetraflu oroethylene (PTFE) graft-stent devices endoluminally deployed in canines. Each iliac artery in 6 heparinized dogs received a 6-mm-diameter tubular PTFE graft mounted on either an 8 mm Palmaz stent (PS) or a metallic-ringed graft attachment device (GAD). The graft-stent devices were introduced from the femoral artery through a 14 Fr delivery catheter. Positioning and balloon expansion of the graft-stent devices were aided by fluoroscopic and intravascular ultrasound (IVUS) assessment. Animals were studied acutely (n = 2) or at weeks 1, 2, 4, or 8 after placement. No interval anticoagulation 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 in an additional 2 PTFE-GAD devices (acute and at one week, respectively) 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 catheter. Endoluminal placement of PTFE graft-stent devices is feasible. Accurate assessment of deployment by IVUS, reduction of delivery catheter size, and improved graft-stent design are required.