Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombuscontaining lesions, and lesions with plaque rupture or adjacent pseudoaneurysm. Substantial residual angiographic diameter stenoses were seen in seven CSGs (25% ؎ 10% vs. 8% ؎ 6%; P F 0.01), which were implanted with relatively small balloon catheters (balloon-to-artery ratio 1.00 ؎ 0.09 vs. 1.24 ؎ 0.18; P ϭ 0.01) and required postdilatation. Overall, the largest balloon catheter applied measured 4.0 ؎ 0.7 mm (balloon-to-artery ratio 1.21 ؎ 0.20) and the inflation pressure was 16 ؎ 3 atm. Final intravascular ultrasound imaging demonstrated adequate and symmetrical expansion of the CSG (H85% ؎ 15% of the reference lumen). Elective implantation was associated with two small non-Q-wave myocardial infarctions, resulting from unavoidable occlusions of side branches. Thus, implantation of CSG is feasible and safe. Adequate expansion can be achieved by the use of relatively large low-compliant balloon catheters inflated with high pressure. Cathet.