Endovascular repair of abdominal aortic aneurysms with reverse taper neck anatomy using the Endurant stent-graft: analysis of stent-graft oversizing.

PURPOSE To evaluate endovascular repair of infrarenal abdominal aortic aneurysms (AAA) using the Endurant stent-graft and compare the outcomes of patients with different neck anatomies, particularly as pertains to stent-graft oversizing. METHODS A retrospective review was conducted of 75 consecutive patients (69 men; mean age 75 years) undergoing endovascular AAA repair using the Endurant Stent Graft System from December 2008 to September 2011. The mean AAA size was 57±10 mm (range 51-92), with a mean proximal neck length of 33±10 mm (9-127) and a mean infrarenal neck angulation of 25°±15° (0°-91°). Patients were stratified according to neck anatomy [reverse taper (n=22) vs. inside (n=44) and outside (n=9) the Instructions for Use (IFU) criteria]. Standard safety and efficacy outcome measures were augmented by measurements of the percent oversizing at the proximal and distal neck and volumes of the proximal neck and stent-graft. RESULTS Technical success was 100% in all groups, with no early or late type Ia endoleak detected in any group. Procedure time, contrast volumes, and radiation dosages were comparable in all groups. The reverse taper neck group had stent-graft diameters and volumes that were significantly larger (p=0.007) than the other groups. The proximal neck oversizing of the endograft was significantly greater (p=0.008) in the reverse taper neck group (42.9%±17.5%) compared to the within the IFU group (30.1%±11.7%). Over a mean follow-up of 20 months (range 14-46), there were no aneurysm-related deaths and 9 type II endoleaks (5 in the reverse taper neck group; overall, 3 were treated and 6 resolved spontaneously). The outside the IFU group suffered no endoleak of any type and had no secondary interventions. CONCLUSION The Endurant stent-graft can be utilized with acceptable results in more challenging neck anatomies, such as those with a reverse taper, as long as there is adequate oversizing of the stent-graft.