Patients should be heparinized during the implant procedure (recommended activated clotting time is 200-300 seconds). During implantation of the Valiant endoluminal stent-graft, the pre-implant angiogram and CT scan are used together with (on-the-table) intravascular ultrasound (IVUS), digital subtraction angiography (DAS), roadmapping, and angiography for proper implant positioning. The Valiant endoluminal stent-graft endoprosthesis is inserted by delivery catheter and introducer sheath via a surgical cutdown (e.g., external iliac artery, femoral artery, common iliac artery conduit, etc.) approach. The introducer sheath and delivery catheter containing the stent-graft is inserted over a guidewire and advanced into the aorta and above the aneurysm. With the delivery catheter in the correct position, the introducer sheath is then withdrawn further until the stent-graft is completely deployed. A separate stent-graft balloon catheter system is provided with the device and may be used along the full length of the implanted device to model the springs against the vessel wall and to unravel possible wrinkles in the graft fabric. After deployment of the stent-graft, angiography is performed to verify implant position and to check for the presence of endoleaks.