The traditional endovascular treatment of aneurysms is based on the utilization of stent-grafts that create a mechanical barrier between the aneurysmal sac and normal blood flow. Problems such as endoleak and occlusion of collateral arteries impede its application in complex aneurysms adjacent to or involving vital branches. Advanced branched/fenestrated endografts have been applied in many experienced centers, but the application of these techniques is limited in less-experienced centers due to the complicated and cumbersome nature of these procedures.~The concept of using bare metal stents to occlude aneurysms was firstly described about two decades ago. Geremia et al suggested that a metallic stent bridging a saccular aneurysm would alter the local flow pattern, promoting thrombus formation, thereby leading to aneurysm occlusion. Optimal flow modulation effect is reached with a mean stent porosity of 65%. To achieve such low mesh porosity while maintaining the flexibility of the stent, the investigators applied multiple stents in an overlapping fashion. Computational simulation in this study has demonstrated that with 3 or 4 bare metal stents deployed, the mesh porosity could be decreased to an effective value, slowing flow velocity within the sac. The use of overlapping stents has been reported in the treatment of peripheral aneurysms with satisfactory clinical outcome.~The primary purposes of this study is to evaluate the safety, feasibility, and efficacy of multiple overlapping uncovered stents in treating aortic aneurysm while preserving major visceral branches, including the celiac artery (CA), superior mesenteric artery (SMA) and renal artery (RA).
Complex aortic aneurysms involving major branches have been difficult endovascularly. The primary purposes of this study is to evaluate the safety, feasibility, and efficacy of multiple overlapping uncovered stents in treating aortic aneurysm while preserving major visceral branches, including the celiac artery (CA), superior mesenteric artery (SMA) and renal artery (RA).