Purpose : To present a preliminary experience using a multilayer flow-modulating stent for trans/infragenicular popliteal endovascular aneurysm repair. Methods : Five men (mean age 76 years, range 62-86) with 6 popliteal artery aneurysms (PAAs) measuring 22 to 39 mm in diameter (mean 30) underwent endovascular repair using the Cardiatis Multilayer Aneurysm Repair System (MARS) between June and August 2011. Radiological assessments post procedure using duplex ultrasonography and biplanar knee radiographs (additional contrast studies as necessary) sought evidence of aneurysm exclusion, graft patency, and preservation of branches and runoff vessels. Results : Technical success was achieved in each case. There was one symptomatic stent occlusion requiring thrombectomy at 4 days, with reocclusion, and one leak via the stent struts into the sac with no branch outflow identified. Two further symptomatic stent occlusions were identified within a 6-week follow-up period, totaling 3 occlusions among the 6 devices deployed. Conclusion : No firm conclusion can be reached on the efficacy of the MARS in PAAs due to the inherent limitations of this small series, although a 50% thrombosis rate is a poor outcome. The risk of early thrombosis in flow-modulating stents deployed in the popliteal artery exists, as it does with earlier generation stent-grafts. Larger prospective trials and the influence of more aggressive antithrombotic/anticoagulant therapy should be considered to enable accurate evaluation of this device in popliteal artery aneurysms.